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TPS92682-Q1
2 Phase Boost
Controller
Transient
ProtectionEMI Filter
TPS92520-Q1
Dual Synchronous
Buck Current
Regulator
TPS92520-Q1
Dual Synchronous
Buck Current
Regulator
GND
MSP432E401Y
Micro Controller
TPS57060 + LM26420
5V and 3V3 Supplies
VBOOST
SP
I
UARTCAN
Battery
TPS9266EVM6-900
TCAN1042
CAN Transciever
TCAN1042
CAN Transciever
TPS92662-Q1
TPS92662-Q1
TPS92662-Q1
TPS92662-Q1
GNDTCAN1042
CAN Transciever
MASTER
CAN
TIDA-050030
GND
1TIDUEU1A–October 2019–Revised November 2019Submit Documentation Feedback
Copyright © 2019, Texas Instruments Incorporated
120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
Design Guide: TIDA-050030120W Dual-Stage Matrix Compatible Automotive HeadlightECU Reference Design
DescriptionThis reference design details a headlight ECU usingan interleaved boost in voltage regulation modefeeding four synchronous buck channels. This designis also capable of matrix headlight control and ismounted to a heatsink and enclosed to emulate anautomotive headlight ECU.
The TPS92682-Q1 is setup as a two phase interleavedboost controller set in voltage regulation mode capableof 130W output power. The boost output drives twoTPS92520-Q1 dual channel synchronous buck driversfor a total of four buck channels at 120W total output.The design is mounted to a heatsink and enclosed toemulate an automotive headlight ECU. A MSP432processor controls the TPS92682-Q1 and the twoTPS92520-Q1 devices by the SPI interface. TheMSP432 communicates to the master via CAN andalso communicates to the lighting matrix module usingUART communications via a CAN transceiver.
Several bench-test results are available for the designincluding an efficiency data, thermal measurements,pixel-controlled load data, and EMC measurementsaccording to the CISPR 25 Class 5 conductedspecification.
Resources
TIDA-050030 Design FolderTSP92682-Q1 Product FolderTPS92520-Q1 Product Folder
Search Our E2E™ support forums
Features• Interleaved voltage output boost using one
TPS92682• Four synchronous-buck channels capable of pixel
controlled loads using two TPS92520s• Supports dynamic loads, matrix controllers for LED
pixel control• Buck channels capable for 1.5A maximum, 55W
limited to a total of 120W• 9 V to 24 V full power operating range, power de-
rate down to 6V inputs• Fully enclosed headlight ECU example CISPR 25
Class 5 conducted test data from 0.15 to 108 MHz.• Reverse battery protection circuit included in this
reference design
Applications• Automotive Lighting:
– Dynamic and static headlights– Rear light
System Description www.ti.com
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
An IMPORTANT NOTICE at the end of this TI reference design addresses authorized use, intellectual property matters and otherimportant disclaimers and information.
1 System DescriptionThis reference design demonstrates a self-contained headlight ECU with four output channels that can bepixel controlled for a complete headlight solution including low beam, high beam, turn, and DRL (daytimerunning lights). The design is a two stage boost into multiple buck configuration. The boost, using oneTPS92682 in voltage regulation mode, is an interleaved 130W output with adjustable voltage output. Thefour-buck outputs are delivered by two dual-channel TPS92520 synchronous buck converters. The systemcan operate during cold crank and load dump conditions when the battery voltage varies. A two-stageECU is needed due to the dynamic nature of a matrix load where the LED current regulation is done by alow output capacitor topology such as a buck at the second stage, and the wide input voltage variability ofan automotive battery system requires a boost first stage to ensure a consistent input voltage for the bucksecond stage. The buck converter outputs are capable of pixel control using TPS9266x lighting matrixmanager devices.
The reference design also includes reverse battery protection, bias supplies, a heat sinking enclosure, anda MSP432 micro controller with self-contained software enabling a headlight ECU with CAN interface.
This reference design considers the following as part of the design requirements:• Each channel capable of 55W max, total for all channels is 120W• Each channel capable of 1.5-A LED current maximum• Operation during cold cranking, warm crank, power is derated• Tested via SPI communications, self-contained ECU via CAN communications• Enclosure and heatsink to provide EMC and thermal test data• Reverse battery connection protection
1.1 Key System Specifications
Table 1. Key System Specifications
PARAMETER TEST CONDITIONS MIN TYP MAX UNITINPUT CHARACTERISTICSInput voltage range of operating
DC (continuous) Full output power 9 13 24 V
Input voltage range of operatingDC (power derated) Power de-rated which covers cold and warm crank conditions 6 - 44 V
OUTPUT CHARACTERISTICSInterleaved Boost output Output power at Vout = 50V 130 W
Maximum string length perchannel LEDs at forward voltage of 3V 14
VLED output voltage 4 42 VILED output current 1.5 ABucks Output power 120 W
SYSTEM CHARACTERISTICSfSW switching frequency -
Boost400 kHz
fSW switching frequency - Buck 400 kHz
Total System Efficiency@ 5 LEDs 86 %@10 LEDs 89 %
EMI (conducted)BASE BOARD CHARACTERISTICS
PCB Form Factor 3.610" (W) x 4.280" (L) x 0.062" (T) - - in.ECU Fort Factor 4.5" (W) x 5.0" (L) x 1.425" (T) in.
Output Power (W)
Eff
icie
ncy (
%)
10 20 30 40 50 60 70 80 90 100 110 12074%
76%
78%
80%
82%
84%
86%
88%
90%
92%
94%
10 LED5 LED
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
Table 1. Key System Specifications (continued)PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Number of layers and Stackup Layer 1:1 oz. cu., Layer 2:2 oz. cu., Layer 3:2 oz. cu., Layer 4:2 oz.cu., Layer 5:2 oz. cu., Layer 5:and 1 oz. cu.
- 6 - Layers
Figure 1. Output Power vs. Efficiency at VIN = 13 V
TPS92682-Q1
2 Phase Boost
Controller
Transient
ProtectionEMI Filter
TPS92520-Q1
Dual Synchronous
Buck Current
Regulator
TPS92520-Q1
Dual Synchronous
Buck Current
Regulator
GND
MSP432E401Y
Micro Controller
TPS57060 + LM26420
5V and 3V3 Supplies
VBOOST
SP
I
UARTCAN
Battery
TPS9266EVM6-900
TCAN1042
CAN Transciever
TCAN1042
CAN Transciever
TPS92662-Q1
TPS92662-Q1
TPS92662-Q1
TPS92662-Q1
GNDTCAN1042
CAN Transciever
MASTER
CAN
TIDA-050030
GND
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
2 System Overview
2.1 Block Diagram
Figure 2. Block Diagram of TIDA-01520
2.2 Design ConsiderationsThis reference design implements a high density, high efficiency, two stage boost into multiple buck LEDdrivers that supports four channels into a LED matrix manager with a total of 120 watts of output power.The design was implemented considering the following automotive requirements and design goals:• Small form factor that is approximately a 100 cm2 with high power density• Enclosure to provide EMC shielding and heat sinking for thermal dissipation• Reverse battery connection protection• Operation during cold cranking, warm crank, power is derated• Each channel capable of 55W max, total for all channels is 120W• Each channel capable of 1.5-A LED current maximum• CISPER25 Class 5 compliant
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
2.3 Highlighted Products
2.3.1 TPS92682-Q1The TPS92682-Q1 is a dual-channel, peak current-mode controller with SPI communication interface. Thedevice is programmable to operate in constant-voltage (CV) or constant-current (CC) modes. In CV mode,TPS92682-Q1 can be programmed to operate as two independent or dual-phase Boost voltage regulators.The output voltage can be programmed using an external resistor voltage divider, and a SPI-programmable 8-bit DAC.
In CC mode, the device is designed to support dual channel step-up or step-down LED driver topologies.LED current can be independently modulated using analog or PWM dimming techniques. Analog dimmingwith over 28:1 range is obtained using a programmable 8-bit DAC. PWM dimming of LED current isachieved either by directly modulating the PWM input pins with the desired duty cycle, or using a SPI-programmable 10-bit PWM counter. The optional PDRV gate driver output can be used to drive anexternal P-Channel series MOSFET.
The TPS92682-Q1 incorporates an advanced SPI-programmable diagnostic and fault protectionmechanism including: cycle-by-cycle current limit, output overvoltage and undervoltage protection, LEDovercurrent protection, and thermal warning. The device also includes an open-drain fault indicator outputper channel.
The TPS92682-Q1 includes an LH pin, when pulled high, initiates the limp home (LH) condition. In LHmode, the device uses a separate set of SPI-programmed registers.
Figure 3 shows the functional block diagram of the TPS92682-Q1 boost controller. The TPS92682-Q1 isused in constant-voltage (CV) mode for the design of this headlight ECU reference design.
S
R
Q GATE1
PGND
OSCILLATOR Clk_M
Slope Gen. &
MAX Duty
CHx_Islope
PWM1
+±CH1_UV FB1/OV1
+
±
CH1_VFB
CH1_Isense
CH1_CV
CSP1
CSN1
COMP1
CH2_comp
2PH
DAC
SS1
x14 0
1
OC/UC
SENSE
(150%/50%)
CH1_OC
CH1_UC
PDRV1
CSP1
PWM1
RT
DAC
Dither
FMDAC
RT_Open
CH1_PD_comp
R
Dominant
CH1_EN
7.5V LDO
5V LDO
VIN
EN
VCC
VDD
EN
+
±
CH1_complow100mV
CH
1_
FB
O_
EN
10Ps
Filter
DAC1
IADJ
PWM1
0
1
0
1
CH1_MAXD_EN
CH1_Clk100p
CH1_Clk100p
CH1_Clk10p
CH1_MAXD
CH1_s
CH1_s
CH1&2_Clk100p
CH1&2_Clk10p
SYNC
CH1_HG
POR
+
±
50mV
CH1_OV
DAC
OV0
1
0
1
1.23V
ref
CH1_CV
VDD
CH1_OV_EN
VDD
CH1_EAref
+
±
ISP1
ISN1
CH1_ILIMIT
CH1_Islope
CH1_LBSEL
CH1_Gate
VDD
CH1ILIM20PA
CH1_FILT1
VDD
+
±
CH1_comp
CH1_Gate
CH1_IS_OPEN
CH1_Duty
INT_PWM
0
1
S
R QR
DominantCH1_Duty
CH1_PWM_O
PWM1PWM1
CH1_EAref
CH1_VFB
SYNC_EN
1
0
FLT1
SYNC/FLT2 SYNC
CH1_EA_FB
CH1&2_ISLP
CH1_OVDAC
CH1_SSDAC
CH1&2_DIV
CH1&2_CLK
CH1_nPDRV
CH1_FAULT
CH2_FAULT
UVLOUVLO
Thermal
Limit
TSDPOR
POR
TW
100%
10%
Clk10p
Clk100p
Power_FLT
Power_FLT
Power_FLT
CH1_close_comp
TSD
BG_NOK
UVLO
POR
Power_FLT
CH1_comp
5Ps
Delay
CH1_PD_O
CH1_PD_O
Dither_EN
RT OPEN
CH1_MAXD
LEB
CH1_close_comp_n
CH1_close_comp_n
CH1_close_comp
CH1_close_comp
CH1_close_comp
CH1_close_comp
CH1_IADJ
+
±
gM
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
Figure 3. Functional Block Diagram of TPS92682-Q1 Boost Controller
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
2.3.2 TPS92520-Q1The high-performance LED driver can independently modulate LED current using both analog or PWMdimming techniques. The TPS92520-Q1 is a dual synchronous monolithic device that incorporates fourMOSFETs into a high density package that provides superior thermal performance. Linear analogdimming response with over 20:1 range is obtained by programming the 10-bit IADJ value via SPI. PWMdimming of LED current is achieved by directly modulating the corresponding UDIM input pin with thedesired duty cycle or by enabling the internal PWM generator circuit. The PWM generator translates the10-bit PWM register value to a corresponding duty cycle by comparing it to an internal digital counter.
The TPS92520-Q1 incorporates an advanced SPI programmable diagnostic and fault protection featuring:cycle-by-cycle switch current limit, BOOT undervoltage, LED open, LED short, thermal warning andthermal shutdown. An on-board 10-bit ADC samples critical input parameters required for system healthmonitoring and diagnostics.
The TPS92520-Q1 is available in 6.2 mm x 11 mm thermally enhanced 32-pin HTSSOP package with a3.86mm x 3.9 mm top exposed pad.
Figure 4 shows a block diagram of the TPS92520-Q1 buck LED driver.
V5D
UVLO
Rising: 4.1 V
Falling: 4.0 V
Hys: 100 mV
BandgapVBG
BST1
LEB
Control
and
Switch
Fault
Logic
VIN1
SW1
PGND
DAC
IADJ1
UDIM1
V5A
+
VBG pwm1
+
+±
3 V
CSP1
CSN1
COMP1
VIN1
ADC
iadj1
ton1
MISO
MOSI
SCK
SSN
10MHz
Oscillator
clk_m
V5A
GND
2VBG
Digital Supply
V5A
LHIVLHI
+
Thermal
Sensor
adc_sel
adcout
Current
Limit
Circuit
LEB
Current
Limit
Circuit
ch1_en
Analog Supply
2VBG
VIADJ1
VCSN1
Valley Current
Control
udim1
Digital Logic
5 V
Logic
IO
bstuv1
lsilim1
hsilim1
Channel 1
V5D
On Time
Control
BST2
VIN2
SW2
PGND
CSP2
CSN2
COMP2DAC
IADJ2
iadj2
ch2_en
udim2
bstuv2
lsilim2
hsilim2
VIN1
Sleep Enable
ton1
Channel 2
ton2
toffmin1
toffmin1
toffmin2
ch1_en
bstuv1
lsilim1
hsilim1
VIADJ2
por
uvlo
open1
short1VIN1
VIN2
VCSN1
VCSN2
V5D
VLHI
VTMP
LED Fault
Detection
open2
short2open1
short1
open2
short2
uvlo
por
slp
ts1
ts2
UDIM2
FLT
fpin
UVLO &
PWM
INPUT
pwm1
Rail-to-Rail
Error Amplifer
Current
Reference
slp_o
slp_o
slp_o
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
Figure 4. Functional Block Diagram of TPS92520-Q1 Buck LED Driver
ArmCortex-M4F
(120 MHz)
NVIC MPU
FPUETM Flash
(1024KB)
Bootloader
DriverLib
AES and CRC
Ethernet Bootloater
ROM
DCode bus
ICode bus
JTAG, SWD
SystemControl and
Clocks(with Precision
Oscillator)
Bus Matrix
System Bus
SRAM(256KB)
SYSTEM PERIPHERALS
WatchdogTimer
(2 Units)DMA
HibernationModule
Tamper
EEPROM(6K)
General-Purpose
Timer (8 Units)
GPIOs(90)
ExternalPeripheralInterface
CRCModule
AESModule
DESModule
SHA/MD5Module
SERIAL PERIPHERALS
UART(8 Units)
USB OTG(FS PHYor ULPI)
I2C(10 Units)
SSI(4 Units)
CANController(2 Units)
EthernetMAC, PHY, MII
ANALOG PERIPHERALS
12-Bit ADC(2 Units,
20 Channels)
AnalogComparator
(3 Units)
MOTION CONTROL PERIPHERALS
QEI(1 Unit)
PWM(1 Unit,
8 Signals)
Advanced
Periphera
lB
us
(AP
B)
Advanced
Hig
h-P
erf
orm
ance
Bus
(AH
B)
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
2.3.3 MSP432E401YThe SimpleLink MSP432E401Y Arm® Cortex® -M4F microcontrollers provide top performance andadvanced integration. The product family is positioned for cost-effective applications requiring significantcontrol processing and connectivity capabilities. The MSP432E401Y microcontrollers integrate a largevariety of rich communication features to enable a new class of highly connected designs with the ability toallow critical real-time control between performance and power. The microcontrollers feature integratedcommunication peripherals along with other high-performance analog and digital functions to offer a strongfoundation for many different target uses, spanning from human-machine interface (HMI) to networkedsystem management controllers
Figure 5 shows a block diagram of the MSP432E401Y microcontroller.
Figure 5. Functional Block Diagram of MSP432E401Y Microcontroller
TPS92682-Q1
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
2.4 System Design Theory
2.4.1 PCB and Form FactorThis reference design uses a six-layer printed circuit board (PCB) where components are placed on bothsides and a machined enclosure interfaces to the bottom of the board to provide heat sinking. Thermalvias are used to conduct heat from the top side of the PCB to the bottom for thermal management. Theenclosure is machined to allow for direct thermal connection to the TPS92520s on the bottom of the boardalong with other components that need heasinking directly to the enclosure. Placing components on bothsides of the board ensures a high density design. The PCB has a dimension of 109 mm × 92 mm. Theprimary objective of the design with regards to the PCB is to make a solution that is compact while stilladequate heat sinking. The enclosure was also designed to provide shielding for EMI/EMC compliancerequired by each automotive company. In a final-production version of this reference design, the size ofthe solution can be further reduced. Figure 6 shows a 3D rendering of the PCB.
Figure 6. 3D Render of TIDA-050030 PCB–Top Side
TPS92520-Q1
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
Figure 7. 3D Render of TIDA-050030 PCB–Bottom Side
VIN+
VIN+VBAT+
VBAT-
3
1
2
60 V
Q2
60V
D3
60V
D4
60V
D5
GND
VBOOST
4.7uF
C5
VIN 6-44VDC
150W MAX
100k
R3
100k
R2
100k
R4
50V
0.01uF
C1
50V
0.1uF
C4
50V
0.1uF
C6
50V
0.1uF
C11
5
4
1
2
3
Q1
two holes each, 0.1"
VBAT+
VBAT-
100k
R1
Vin
GND
50V
0.01uF
C2
8.2V
D2
1µH
L1
10uF
C7
GND
10uF
C8 50V
220µF
C3
10uF
C9
10uF
C10
10uF
C1226V
D1
GND
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
2.4.2 Input ProtectionIn this reference design, reverse polarity protection is implemented by using the body diode of an N-channel MOSFET, Q1, in conjunction with the VBOOST to turn on the MOSFET when the system is activeand thus reducing the power dissipation that would otherwise be dissipated using a schottky. Q2, D3, andD4 work together to ensure fast turn off of the Q1 FET during fault conditions, D2 is a zener that protectthe gate of the Q1 by clamping it to less than 10 V, and D5 ensures that Q1 doesn't turn on until thesystem is fully up and running and VBOOST has been raised to greater than +VBAT, see Figure 8. D1 isa transient voltage suppressor (TVS) that protections against over voltage conditions during faults andprovides reverse battery protection.
Figure 8. Schematic of Input Protection + EMI Filter
2.4.3 EMI FilterA LC low-pass filter is placed on the input of the boost controller to attenuate conducted differential modenoise generated by the system. The filter consists of C3, C7, C8, C9, C10, C11, and L1 as shown inFigure 8. Additional localized filtering, which includes C1, C2, C4, C5 and C12, is added close to theconnector J2 to further help reduce conducted EMI. For more details, see Simple Success WithConducted EMI From DC-DC Converters.
2.4.4 TPS92682-Q1 Boost ControllerTable 2 shows the default design parameters for the boost controller.
Table 2. Design Parameters of Default Boost Controller
DESIGN PARAMETERS VALUEOutput voltage range 18 V to 55 V
Output power 130 WMinimum input voltage (DC) 6 VTypical input voltage (DC) 13.5 V
Maximum input voltage (DC) 24 VSwitching frequency 260 kHz
For the maximum boost ratio (6 V to 45 V), the switching frequency of the TPS92682-Q1 is limited by aforced off-time. Based on Equation 1, the internal clock frequency, FCLKM, is set by R23. In conjunction withthe SWDIV register (address 0x03h) setting (in this case set to divide by four (0x01h), the switchingfrequency, FSW, is set following to CHxCLK = fCLKM/4, where CHxCLK is the channel clocks (switchingfrequency).
NOTE: The TPS92682 is setup as a two phase constant voltage controller and the effective FSW istwice the channel frequency.
GND
GND
GND
BS
TC
OM
P
GNDGND
GND
100k
R9
GND
GND
VBOOST
GND
GND
1uF
50V
C24
2.2uF
C37
2.2uF
C39 GND
470pF
100V
C36
7.5
R21
GND
GND
GND
MAX POWER = 140W (2-PHASE)BOOST LED VOLTAGE REGULATOR
VBST_FB
SCK
MOSI
TP1
GND
GND
GND
50V
100pF
C27
VIN1
EN2
PWM13
PWM24
SSN5
SCK6
MISO7
MOSI8
ISN124
ISP123
GATE122
VCC21
PGND20
GATE219
ISP218
ISN217
LH9
FLT110
FLT2/SYNC11
COMP212
PDRV213
CSN214
CSP215
FB2/OV216
RT32
VDD31
AGND30
COMP129
PDRV128
CSN127
CSP126
FB1/OV125
PAD33
TPS92682QRHMQ1
U1
GND
GND
GND
50V
0.033uF
C18
50V
10pF
C23
20.0k
R10
4.12k
R15
50V
10pF
C40
80V
33uF
C14
VIN+
MOSI
MISO
SCK
SSN_BOOSTSSN0
BnFLT2
BnFLT1
MISO
80V
33uF
C28
GND
2X PCE4126TR-ND
2X PCE4126TR-ND
4.7uF
C16
4.7uF
C17
4.7uF
C30
4.7uF
C31
L6 multiple footprint
50V
1000pF
C38
50V
1000pF
C26
10.0
R24
1
3
2
D6
PDS5100HQ-13
1
3
2
D7
PDS5100HQ-13
5
4
1 2 3
Q4
SQJA90EP-T1_GE3
5
4
1 2 3
Q3
SQJA90EP-T1_GE3
10.0
R14
BSTnFLT1
V_BOOST
Vin
GND
7.5
R6
GND
470pF
100V
C25VBST_FB
VDD
BS
TC
OM
P
Vin
BSTnFLT2
10.0k
R16
10.0k
R17
MCU_3V3D
10.0k
R7
GND
10.0k
R13
GND
10.0k
R20
100k
t° RT1
NCP18WF104J03RB
MCU_3V3D
GND
0.02
R26DNP
0.02
R19DNP
A_BST
A_VIN
A_NTC1
1.00
R11
221k
R5
221k
R8
15µH
L3
15µH
L2
4.99
R22
4.99
R12
0.01
R18
0.01
R25
100V
4.7uF
C19
100V
4.7uF
C20
100V
4.7uF
C21
100V
4.7uF
C22
100V
4.7uF
C32
100V
4.7uF
C33
100V
4.7uF
C34
100V
4.7uF
C35
143k
R23
u
12
CLKM
T
10f
12.5 R
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
(1)
Figure 9 shows the default TPS92682-Q1 boost controller schematic of this reference design.
Figure 9. Schematic of TPS92682-Q1 Boost Controller
The main components of the boost stage are selected by following the Detailed Design Procedure sectionin the data sheet TPS92682-Q1 Dual -Channel Constatnt-Voltage and Constant-Current Controller withSPI Interface.
R23, same as RT, sets the switching frequency. The inductor L2 and L3 has a value of 15 µH with asaturation current rating above the maximum expected inductor current of 10.6 A at a minimum inputvoltage of 9 V. Based on this input current capability, a value of 10 mΩ is selected for the current senseresistor R18 and R25. R14, R26, C26, and C38 form a filter for the current sensing for each phase.
The output capacitors smooth the output voltage ripple and provide a source of charge during transientloading conditions. Also the output capacitors reduce the output voltage overshoot when the load isdisconnected suddenly. Ripple current rating of output capacitor must be carefully selected. In a boostregulator, the output is supplied by discontinuous current and the ripple current requirement is usuallyhigh, which makes ceramic capacitors a perfect fit. The output voltage ripple is dominated by ESR of theoutput capacitors. Paralleling the output capacitor is a good choice to minimize effective ESR and split theoutput ripple current into capacitors. This example uses four 4.7-µF ceramic capacitors and one 0.1-µFceramic capacitor with a voltage rating of 100 V per phase. Additional bulk capacitance was added via two33-µF electrolytic capacitors for added ripple reduction and greater energy storage. A higher outputvoltage ripple in this reference design is not a concern for the buck LED drivers, which are connected tothe boost output voltage. Input capacitors C16, C17, C30, and C31 smooth the input voltage ripple. Thisreference design uses small-sized 4.7-µF ceramic capacitors with a voltage rating of 50 V.
The low-side power switches Q3 and Q4 are 80-V rated N-channel MOSFETs in a PowerPAK® package.100-V Schottky diodes D6 and D7 are used as the catch diode to improve efficiency. R12 and R22 aregate resistors that can limit the rise and fall times of the switch node voltage. A resistor-capacitor snubbernetwork (R6, R21, C25, and C36) across the N-channel MOSFETs, Q3 and Q4, reduces ringing andspikes at the switching node. For how to calculate these values, see Power Tips: Calculate an R-Csnubber in seven steps.
R10, C18, C23 and C40 configure the error amplifier gain and phase characteristics to produce a stablevoltage loop. For more details, see How to Measure the Loop Transfer Function of Power Supplies.
See Section 4.3 for layout guidelines for the boost controller in this reference design.
100V
0.1uF
C55
GND
100V
0.1uF
C41
GND
CSN1
CSP1
CSN2
CSP2
BST2
SCK
BUCK2
BUCK1
SSN_1-2
GND
100k
R36
MISO
MOSI
SCK
SSN_BUCK_1-2
BUCK1-2_nFLT
SSN_1-2a
BUCK_nFLT_1-2
GND
GND
GND
GND
0R32
0R34
BKPWM_11
BUCK1-2_V5D
BUCK1-2_V5A
COMP1
5V
BKPWM_12
V_BUCK2
V_BUCK1
25V
0.1uF
C43
25V
0.1uF
C52
1.5uF
C45
100V
1.5uF
C51
16V
1uF
C46
16V
1uF
C48
COMP2
16V
2200pF
C42
16V
2200pF
C54
0.1µF
16V
C47
0.1µF
16V
C500.1µF
16V
C49
1000pF
C44
100V
1000pF
C53
V_BUCK_2
V_BUCK_1
BCKPWM_11
BCKPWM_12
SW2
SW1
BST1
3
1
2
Q5
SI2323DS
3
1
2
Q6
MMBT3904LT1G
10.0k
R35
10.0k
R40
GND
5V_EN
5V
5V
COMP216
UDIM215
PGND14
PGND13
VIN212
VIN211
GND10
V5A9
V5D8
GND7
VIN16
VIN15
PGND4
PGND3
UDIM12
COMP11
CSN132
CSP131
BST130
SW129
SW128
FLT27
LHI26
SSN25
SCK24
MISO23
MOSI22
SW221
SW220
BST219
CSP218
CSN217
TPS92520QDADQ1
U2
LHI_1-2
15.8k
R27
15.8k
R39
30.1k
R43
30.1k
R31
V_BOOST
V_BOOST
1.00kR33
1.00k
R29
1.00k
R41
10.0k
R37
0R30
0R38
47µH
L4
47µH
L5
D9
PD3S160Q-7
GND
D8
PD3S160Q-7
GND
0.22uF
C74
0.22uF
C75
0.22uF
C76
0.22uF
C77
0.1
R28
0.1
R42
GND
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2.4.5 TPS92520-Q1 Buck LED DriverTable 3 shows the default design parameters for the buck LED drivers.
Table 3. Design Parameters of Default Buck LED Driver
DESIGN PARAMETER RANGE DEFAULT VALUEInput voltage 18 V to 55 V 50 V
LED forward voltage 3 VNumber of LEDs in series 1 to 14 8
Output current range 0.2 A to 1.5 A 1 AOutput voltage 3 V to 42 V 24 V
Output power per channel 30 W max 24 WSwitching frequency 440 kHz
Figure 10 and Figure 11 shows the default TPS92520-Q1 LED driver schematic of this reference design.
Figure 10. Schematic of TPS92520-Q1 Buck LED Driver–Channels 1 and 2
OUT
IN
VD
V
GND
GND
GND
COMP3
GND
PGND
COMP4
0R49
0R51
UDIM-3
GND
BUCK3-4_V5D
BUCK3-4_V5A
100V
0.1uF
C70
GND
100V
0.1uF
C56
GND
CSN3
CSP3
CSN4
CSP4
BST4
SCK
BUCK4
BUCK3
SSN_3-4
GND
100k
R53
MISO
MOSI
SCK
SSN_BUCK_3-4
BUCK3-4_nFLT
SSN_3-4a
BUCK_nFLT_3-4
UDIM-4
V_BUCK4
V_BUCK3
25V
0.1uF
C59
25V
0.1uF
C67
1.5uF
C60
100V
1.5uF
C66
16V
1uF
C61
16V
1uF
C63
BKPWM_22
BKPWM_21
16V
2200pF
C69
16V
2200pF
C57
0.1µF
16V
C64
0.1µF
16V
C62
0.1µF
16V
C65
1000pF
C58
100V
1000pF
C68
V_BUCK_3
V_BUCK_4
BCKPWM_22
BCKPWM_21
SW3
BST3
SW4
5V
3
1
2
Q7
SI2323DS
3
1
2
Q8
MMBT3904LT1G
10.0k
R52
10.0k
R56
GND
5V
5V
COMP216
UDIM215
PGND14
PGND13
VIN212
VIN211
GND10
V5A9
V5D8
GND7
VIN16
VIN15
PGND4
PGND3
UDIM12
COMP11
CSN132
CSP131
BST130
SW129
SW128
FLT27
LHI26
SSN25
SCK24
MISO23
MOSI22
SW221
SW220
BST219
CSP218
CSN217
TPS92520QDADQ1
U3
LHI_3-4
15.8k
R44
15.8k
R57
30.1k
R47
30.1k
R60
V_BOOST
V_BOOST
1.00kR50
1.00k
R46
1.00k
R58
10.0k
R54
47µH
L6
47µH
L7
0R48
0R55
5V_EN
D11
PD3S160Q-7
D10
PD3S160Q-7
GND
GND
0.22uF
C80
0.22uF
C81
0.22uF
C82
0.22uF
C83
GND
0.1
R45
0.1
R59
GND
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Figure 11. Schematic of TPS92520-Q1 Buck LED Driver–Channels 3 and 4.
The main components of the buck LED drivers are selected by following the Detailed Design Proceduresection in TPS92520-Q1 4.5V to 65V Input Dual 1.6-A Synchronous Buck LED Driver with SPI Control.
Components R22, R35, C26, and C39 are used to program the off-time of the hysteretic LED drivers to0.2 µs. With the default configuration, the LED current is set to 1 A with a inductor ripple current of 0.1 A.When selecting an inductor, ensure the ratings for both peak and average current are adequate. For theinductors L3 and L4, a value of 47 µH is selected. Based on the output current capability, a value of 220mΩ is selected for the current sense resistors R21 and R34. R23, R24, R36, and R37 program the startupand UVLO level. C28 and C40 at the UVLO pin are placed for noise immunity. Capacitors C20 and C33tied to the switch node (SW pin) and the diodes D6 and D10 connected to the VCC supply power theBOOT pin to ensure proper operation of the internal MOSFET. The 10-µF VCC capacitors C19 and C31supply current for the device operation as well as additional power for external circuitry. The low-siderectifier diodes D7 and D12 are 3-A rated, low-leakage, Schottky diodes in a PowerDI5 package. DiodesD8 and D13 provide reverse polarity protection to the PWM pin because the signal is coming from theinput voltage. With a voltage higher than 1 V on the PWM, the device starts operation.
The input capacitors C21, C22, C23, C34, C35, and C36 provide a low impedance source for thediscontinuous input current of the buck LED drivers. The output capacitors C24, C25, C37, and C38 inparallel with the LED load reduce the ripple current on the LEDs. The TPS9250-Q1 has a rail to rail, fastoutput current sense that allows true average current regulation all the way down to fully shunted output toallow for current regulation accuracy as well as dynamic load operation.
2.4.6 Duty Cycle ConsiderationThe switch duty cycle, D, defines the converter operation and is a function of the input and outputvoltages. In steady state, the duty cycle is derived using Equation 2:
(2)
There is no limitation for small duty cycles, since at low duty cycles, the switching frequency is reduced asneeded to always ensure current regulation. The maximum duty cycle attainable is limited by the minimumoff-time duration and is a function of switching frequency.
L(MAX)OUT
SW D LED
iC
8 f r i
'
u u u '
L(MAX)L(PK) LED(MAX)
ii I
2
'
2L(MAX)2
L(RMS) LED(MAX)
ii I
12
§ ·'¨ ¸ ¨ ¸© ¹
IN(TYP)
L SW
VL
4 i f
u ' u
DAC(FS)CS
LED(MAX)
0.9 VR
14 I
u
u
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2.4.7 Switching Frequency SelectionNominal switching frequency (tON > tON(MIN)) is set by programming the CHxTON register. The switchingvaries slightly over operating range and temperature based on converter efficiency. Table 4 showscommon switching frequencies and corresponding CHxTON register values.
Table 4. Frequency Setting
FREQUENCY CHxTON REGISTER VALUE (DECIMAL) CHxTON REGISTER VALUE (BINARY)200 kHz 3 000011400 kHz 7 0001111 MHz 19 010011
1.6 MHz 31 0111112.2 MHz 43 101011
2.4.8 LED Current Set PointThe LED current is set by the external resistor, RCS, and the CHxIADJ register value. The current senseresistor, RCS, is selected to meet the maximum LED current specification and 90% of the full-scale rangeof CHxIADJ-DAC.
(3)
The LED current can be varied between minimum and maximum specified limits by writing to the CHxIADJregister.
2.4.9 Inductor SelectionThe inductor is sized to meet the ripple specification at 50% duty cycle. TI recommends a minimum of30% peak-to-peak inductor ripple to ensure periodic switching operation. Use Equation 4 to calculate theinductor value.
(4)
Use Equation 5 and Equation 6 to calculate the RMS and peak currents through the inductor. It isimportant that the inductor is rated to handle these currents.
(5)
(6)
2.4.10 Output Capacitor SelectionThe output capacitor value depends on the total series resistance of the LED string, rD, and the switchingfrequency, fSW. The capacitance required for the target LED ripple current is calculated using the .
(7)
For applications where the converter supports pixel beam or matrix LED loads, additional designconsiderations influence the selection of output capacitor. The size of the output capacitor depends on theslew-rate setting of the LED bypass switches and must be selected after consulting the lighting matrixmanager.
When choosing the output capacitors, it is important to consider the ESR and the ESL characteristicssince they directly impact the LED current ripple. Ceramic capacitors are the best choice due to thefollowing:
BWCOMP
SW
0.0055C
f
uV
Q(BST)
BST
5D BST(HYS) BST(UV) FREQ
IC
V V V PWM
u
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• Low ESR• High ripple current rating• Long lifetime• Good temperature performance
With ceramic capacitor technoloy, it is important to consider the derating factors associated with highertemperature and DC bias operating conditions. TI recommends an X7R dielectric with a voltage ratinggreater than maximum LED stack voltage.
2.4.11 Input Capacitor SelectionThe input capacitor buffers the input voltage for transient events and decouples the converter from thesupply. TI recommends a 2.2 µF input capacitor across the VIN pin and PGND placed close to the device,and connected using wide traces. X7R-rated ceramic capacitors are the best choice due to the low ESR,high ripple current rating, and good temperature performance. Additional capacitance can be required tofurther limit the input voltage deviation during PWM dimming operation.
2.4.12 Bootstrap Capacitor SelectionThe bootstrap capacitor biases the high-side gate driver during the high-side FET on-time. The requiredcapacitance depends on the PWM dimming frequency, PWMFREQ, and is sized to avoid boot undervoltageand fault during PWM dimming operation. The bootstrap capacitance, CBST, is calculated using .
(8)
Table 5 summarizes the TI recommended bootstrap capacitor value for different PWM dimmingfrequencies.
Table 5. Bootstrap Capacitor Value
PWM DIMMING FREQUENCY (Hz) BOOTSTRAP CAPACITOR (µF)1395 0.11221 0.1977 0.15814 0.15610 0.22407 0.33199 0.56100 1
2.4.13 Compensation Capacitor SelectionA simple integral compensator is recommended to achieve stable operation across the wide operatingrange. Use to calculate the compensation capacitor needed to achieve stable response.
(9)
The factor, σBW, determines the bandwidth of the loop and is usually set between 50 and 100 isrecommended. A larger σBW value results in lower loop bandwidth and over-damped response.
2.4.14 Input Undervoltage ProtectionFigure 10 and Figure 11 shows that the undervoltage protection threshold is programmed using a resistordivider, RUV1 and RUV2, from the input voltage, VIN, to ground. Use Equation 10 and Equation 11 tocalculate the resistor values.
UDIM(RISE)UVx1 UVx2
INx(RISE) UDIM(RISE)
VR R
V V u
HYSUVx2
UDIM(UVLO)
VR
I
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(10)
(11)
See Section 4.3 for layout guidelines for the TPS92520-Q1 in this reference design.
0.10
-
VIN
+
0+ -VI_IN
DC Power Supply
0-50V / 20A
0.10
0+ -VI_1LED load - 1
1-16 LEDs
0.10
0+ -VI_2LED load - 2
1-16 LEDs
0.10
0+ -VI_3LED load - 3
1-16 LEDs
0.10
0+ -VI_4LED load - 4
1-16 LEDs
+
VLED1
-
+
VLED2
-
+
VLED3
-
+
VLED4
-
-
VBOOST
+
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3 Hardware, Testing Requirements, and Test Results
3.1 Required HardwareFigure 12 shows the default test setup for taking efficiency measurements, startup/shutdown, and steadystate waveforms of this reference design. Voltage measurements were taken using kelvin connections.The currents were measured using a one percent, 0.1 Ω shunt resistor in conjunction with a precisionmulti meter for all current measurements. Voltage and current waveforms were taken using voltage andcurrent probes with an oscilloscope. Inductor currents were measured by putting a loop in series with theinductor and using the current probe attached to the oscilloscope.
Figure 12. Efficiency, Startup/Shutdown, and Steady State Test Setup
Connect a DC power supply to each input terminal (J2, pin 11 (+BAT) and 12 (-BAT)) and the LED stringsto the output terminals (J2, pin 1-4, 13, and 1 4).
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3.2 Testing and ResultsAll tests in this section are performed in the default configuration where the input voltage is 13.5 V and theLED current is adjusted to generate 30W per channel up to 1.5A. Testing was done with 10 and 5 LEDs.
3.2.1 Startup/ShutdownFigure 13 through Figure 16 show the startup and shutdown behavior of the reference design. Duringstartup, the adaptive pre-boost control starts acting and regulates the boost output voltage to the set level.
Figure 13. Startup, 12 LEDs at 0.75A Figure 14. Startup, 6 LEDs at 1.5A
CH1: VIN, CH2: VOUT LED driver, CH3: LED current, CH4:VBOOST
CH1: VIN, CH2: VOUT LED driver, CH3: LED current, CH4:VBOOST
Figure 15. Shutdown, 12 LEDs at 1.5A Figure 16. Shutdown, 12 LEDs at 0.75A
CH1: VIN, CH2: VOUT LED driver, CH3: LED current, CH4:VBOOST
CH1: VIN, CH2: VOUT LED driver, CH3: LED current, CH4:VBOOST
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3.2.2 Steady State OperationFigure 17 through Figure 20 show the steady state operation of the TPS92682-Q1 boost controller. With10 LEDs connected, the boost controller operates with nearly a 50 percent duty cycle.
Figure 17. Boost Operation at 120W output Figure 18. Boost Operation at 60W output
CH1: SW boost, CH2: VIN, CH3: IL boost, CH4: VBOOST(NOTE: only one of two phases)
CH1: SW boost, CH2: VIN, CH3: IL boost, CH4: VBOOST(NOTE: only one of two phases)
Figure 19 and Figure 20 show the steady state operation of the TPS92520-Q1 buck LED driver.
Figure 19. LED Driver Operation at 12 LEDs and 1A Figure 20. LED Driver Operation at 6LEDs at 1A
CH1: SW LED driver, CH2: VOUT LED driver, CH3: IL LED,CH4: VBOOST
CH1: SW LED driver, CH2: VOUT LED driver, CH3: IL LED,CH4: VBOOST
Output Power (W)
Eff
icie
ncy (
%)
10 20 30 40 50 60 70 80 90 100 110 12074%
76%
78%
80%
82%
84%
86%
88%
90%
92%
94%
10 LED5 LED
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3.2.3 EfficiencyFigure 21 shows the efficiency of the design in different conditions. To achieve a total efficiency of 89percent, each stage (boost and buck) operates with an efficiency of ≈ 94 percent.
Figure 21. Output Power vs. Efficiency at VIN = 13 V
3.2.4 Thermal PerformanceFigure 22 through Figure 25 show the thermal behavior for different conditions. To improve the thermalperformance of the whole board, consider implementing the following items:• Add more layers on the PCB• Increase the PCB size• Increase the copper thickness to 2 oz• Add a heat sink• Select larger and more expensive components
The design was run at 120 watts of output power at input voltage of 13.5 V and allowed to thermallystabilize. The TPS92520-Q1 has an internal temp sense to allow for the measurement of the junctiontemperature of the device via register TEMPL/H (0x1B/1C). The internal junction temperatures of U2 andU3 where read via the SPI bus to confirm the rise in junction temperature (TJ) of the two TPS92520'scompared to the ambient air temp of 25°C. The junction temperatures, TJ, are listed in each figure asTPS92520_1-2 and TPS92520_3-4.
TPS92520_1-2: TJ = 34°C
TPS92520_3-4: TJ = 33°C
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Figure 22. Thermal Image with respect to TIDA-050030 PCB.
Figure 23 shows temperatures at various sample points (Sp). Figure A shows that most of the powerdissipation is contained within the boost converter section of the design. Sp1 is the case temperature ofthe TPS92682-Q1. Sp2 and Sp3 are temperatures at the current sense resistors (R25 and R18). Sp5 isthe temperature for the current sense resistor of for VBUCK1 (R42). Sp4 and Sp6 are the temperaturesnext to Q3, D6, Q4, and D7.
Figure 23. Thermal Image of Top Side PCB at ≈120W Output and at 13.5 V Input. Sample Points 1-6Shown
TPS92520_1-2: TJ = 34°C
TPS92520_3-4: TJ = 33°C
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Figure 24 shows a close up of the boost converters surface temperatures. Sp1 shows the temperature atU1 (TPS92682-Q1). Sp2 and Sp3 show the temperatures of the current sense resistors R18 and R23.Sp4 shows the temp at schottky diode D7 and Sp5 shows the temperature at Q4. We are seeing no morethan a 30°C rise worst case at the sense resistors. The other parts that are seeing significant powerdissipation are seeing less than 20°C rise.
Figure 24. Thermal Image: Closeup of Boost Converter Circuitry at ≈ 120 W Output
Figure 25 shows a close up of the two buck LED driver's (TPS92520-Q1) surface temperatures. Sp1, Sp2,Sp3, and Sp4 shows the temperature at all four current sense resistors (R28, R42, R45, and R59) for thefour channels (VBUCK1/2/3/4). Sp5 shows the temperatures at the PCB above the TPS92520. We areseeing no more than a 12°C rise worst case at the sense resistors. The TPS92520's are seeing less than10°C rise given 120W of output power. The enhanced 32-pin HTSSOP package with the 3.86mm x 3.9mm top exposed pad when mated with heat sink enclosure in conjunction with thermal potting compoundperforms very well.
TPS92520_1-2: TJ = 34°C
TPS92520_3-4: TJ = 33°C
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Figure 25. Thermal Image: Closeup of Buck Converter Circuitry at ≈ 120 W Output
CANO ± Master
CAN
DC Power Supply
0-50V / 20A
(BATTERY)
TPS92663-Q1 Six Channel Matrix Evaluation Module
TIDA-050030
Matrix Module Harness
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3.2.5 LED Matrix ManagerFigure 26 shows the setup of the design operating with a full light matrix manager solution, specifically theTPS92662/3-Q1 EVM. The matrix evaluation module was controlled via CAN and registers were modifiedto adjust phase, pulse width, and slew rate, see TPS92662/3-Q1 datasheet for specific register details.
Figure 26. TIDA 050030 Setup for Lighting Matrix Module Testing
Figure 27 shows the connection points for the TIDA-050030 connector to the TPS92663-Q1 six channelmatrix evaluation module.
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Figure 27. Schematic of TIDA-050030 Connector Connections
Channel 2 of the oscilloscope was setup on V_BUCK2 (teal) to measure the LED voltage of the TIDA-050030 board, while channel 3 of the oscilloscope (magenta) was a current probe measuring the outputcurrent of V_BUCK2. The worst case phase and pulse width settings were selected to demonstrateperformance. Figure 27 shows the connection points for the TIDA-050030 connector to the TPS92663-Q1six channel matrix evaluation module. TheTPS92662-Q1's registers were setup for phase, pulse width,and slew rate. It is important to note that Figure 28, Figure 29, and Figure 30 show how the TPS92520-Q1's maintains current regulation with minimal over/undershoot with fast settling to the regulation setpoint. See the TPS92662-Q1 data sheet for details about registers and settings.
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Figure 28. Waveforms of 0 Phase Shift, 20/1024 Pulse Width, SLEWRATE=01, at 350mA Using LightingMatrix Module EVM
Figure 29. Waveforms of 0 Phase Shift, 1000/1024 Pulse Width, SLEWRATE=01, at 350mA Using LightingMatrix Module EVM
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Figure 30. Waveforms of 85 Phase Shift, 70/1024 Pulse Width, SLEWRATE=01, at 350mA Using LightingMatrix Module EVM
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
3.2.6 Electromagnetic Compatibility (EMC)All tests in this section are performed according to the CISPR 25 standard. Figure 31 shows the setup.Note that the test setup for conducted emissions is a worst case scenario where the LED driver PCB isplaced 5 cm above the reference ground plane. In a real application housing, the distance from the LEDdriver PCB to the reference ground plane will be higher; thus, the common-mode noise coupling will belower.
Figure 31. CISPR 25 Conducted Emissions Setup
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
Figure 32. CISPR 25 Conducted Emissions Connections
CISPER 25 Class 5
PK detector
AVG detector
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3.2.6.1 Conducted EmissionsFigure 33 shows the conducted emissions at a power level of approximately 68 W with all four channelswith 10 LEDs per channel. From 150 kHz to 30 MHz, the design is passing class 5.
Figure 33. Conducted Emissions: 0.15 MHz to 30 MHz, BUCK1, BUCK2, BUCK3, and BUCK4 on Ten LEDs(≈ 86 W)
D7
Q4
C32C33C35C34
R25R26
Q3
D6
R19R18
C19C20C21C22
L2
BOTTOM
L3
BOTTOM
U1
C3
0
C3
1
C1
6
C1
7
SW
SW
VBOOST
VBOOST
VIN+
VIN+
GND
GND
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4 Design Files
4.1 SchematicsTo download the schematics, see the design files at TIDA-050030.
4.2 Bill of MaterialsTo download the bill of materials (BOM), see the design files at TIDA-050030.
4.3 PCB Layout RecommendationsThe layout of the boost controller as shown in Figure 34 is created by following the layout example andguidelines in the Layout section of TPS92682-Q1 Dual Channel Constant-Voltage and Constant-CurrentController with SPI Interface.
Figure 34. TPS92682-Q1 Boost Controller Layout (Top Layer)
L4
C8
0
L5
L6
L7
U2
U3
C8
1
C8
3
C8
2
C7
7
C7
6
C7
5
C7
4
C28
C14
VBOOST
VBOOST
VBOOST
VBOOST
SW
SW
SW
SW
GND
GND
CSP1
CSP2
CSP3
CSP4
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120W Dual-Stage Matrix Compatible Automotive Headlight ECU ReferenceDesign
The layout of the buck converters as shown in Figure 35 is created by following the layout examples andguidelines in the application note: TPS92520-Q1 4.5V to 65V Input Dual 1.6-A Synchronous Buck LEDDriver with SPI Control or AN-1229 SIMPLE SWITCHER PCB Layout Guidelines.
Figure 35. TPS92520-Q1 Buck LED Drivers Layout (Bottom Layer)
4.3.1 Layout PrintsTo download the layer plots, see the design files at TIDA-050030.
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4.4 Altium ProjectTo download the Altium project files, see the design files at TIDA-050030.
4.5 Gerber FilesTo download the Gerber files, see the design files at TIDA-050030.
4.6 Assembly DrawingsTo download the assembly drawings, see the design files at TIDA-050030.
5 Related Documentation1. Texas Instruments, AN-2162 Simple Success With Conducted EMI From DC-DC Converters
Application Report2. Texas Instruments, LM5122 Wide-Input Synchronous Boost Controller With Multiple Phase Capability
Data Sheet3. TI E2E Community, Power Tips: Calculate an R-C snubber in seven steps4. Texas Instruments, AN-1889 How to Measure the Loop Transfer Function of Power Supplies
Application Report5. Texas Instruments, TPS92520-Q1 4.5V to 65V Input Dual 1.6-A Synchronous Buck LED Driver with
SPI Control6. Texas Instruments, PMP9796 - 5V Low-Power TEC Driver Reference Design
5.1 TrademarksE2E is a trademark of Texas Instruments.
Revision History www.ti.com
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Revision History
Revision HistoryNOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Original (October 2019) to A Revision .................................................................................................... Page
• Changed figure 28 title "Phase Margin" to "Phase Shift" ........................................................................... 28• Changed figure 29 title "Phase Margin" to "Phase Shift" ........................................................................... 28• Changed figure 30 title "Phase Margin" to "Phase Shift" ........................................................................... 29
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