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Project 1 - ECE4430, Fall 2011Group 10

Todd Biesiadecki

Eswar Paladugu

Kowshik Murali

Beta Multiplier Reference Circuit

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Differential Amplifier Schematic

To Save power let the actual current that flows be 0.5uA

For M1,0.5u= (1/2)Kn*(W1/L1)*(0.6-0.45)^2from which (W/L)= 0.238

Also Iref= 2/(B*R^2) *(1-1/sqrt(K))from which we can get the value of R=205K for K=4.

W1 after fine tuning 645n (W/L) after tuning= 0.43L1 after fine tuning 1.465u

Resistor value= 216KW3= 600nL3= 400n

Hand Calculations

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Reference Voltage Vs Supply voltage

Reference Current Vs Supply Voltage

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Reference Voltage and Current vs Temperature

Vref Sensitivity Vs Supply Voltage

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Reference Current Senstivity vs Supply Voltage

Reference Voltage Sensitivity Vs Temperature

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Reference Current Sensitivity Vs Temp

Variation of Vref and Iref with Resistor value

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Vref and Iref Vs Vthn

Vref and Iref Vs Vthpo

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PSRR Vref Vs Frequency

PSRR of Iref vs Frequency

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Transient Response and Startup Delay

ResultsSupply Voltage 2.4 V

Vref .5999 V

Iref 2.499uA

Supply Sensitivity 39.7 ppm for Vref; 373.1ppm Iref

Temperature Sensitivity 455.9 ppm for Vref; 700.5ppm Iref

Power Consumption 9.602 uW

Vref and Iref with Vthn = 10% Vref=47mV Iref=0.005uA

Vref and Iref with Vthp = 10% Vref=0.0003m Iref=0.0021uA

Vref and Iref with R = 10% Vref=14mv Iref=0.163uA

Minimum Vdd 0.8011mV

Maximum Vdd 4.85V

TCIref 26ppm

TCVref 16.85ppm

PSRR for Vref 210dB

PSRR for Iref 104dB

Start up Delay 11ns

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Bandgap Reference Circuit

Differential Amplifier and Startup Circuit

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Hand Calculations

Choose K = 8, R =185k L = 1.6/(.085*ln(K)) = 9.41 N = Vref/(Iref*R) = 1.297 Actual Values

o R =164.15ko L = 10.77o N = 1.462

ResultsSupply Voltage 2.4 V

Vref .5997 V

Iref 2.505 uA

Supply Sensitivity 73.05 ppm

Temperature Sensitivity 77.298 ppm

Power Consumption 9.276 uW

Iref with Vthn = 10% 13 nA

Iref with Vthp = 10% 14 nA

Iref with R = 10% 247.5 nA

Minimum Vdd 2.00 V

Maximum Vdd 3.04 V

TCIref -2403 ppm/C

TCVref -.9207 ppm/C

PSRR for Vref 215.51 dB

PSRR for Iref 463.23 dB

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Iref vs. Supply Voltage

Vref vs. Supply Voltage

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Supply Sensitivity of Vref

Iref vs. Temperature

Variation of reference current with temperature

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Vref vs. Temperature

Variation of reference current with temperature

TCIref

TCIref vs. Temperature

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TCVref

TCVref vs. Temperature

Iref vs. Vthn

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Iref vs. Vthp

Iref vs. R

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PSRR of Vref

PSRR of Iref

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Conclusions

BMR has a very low supply sensitivity, but a relatively high temperature sensitivity compared to the BGR.

The Supply Sensitivity of the BGR is a little higher than that of the BMR but its temperature sensitivity is a lot better.

In BGR, there is a trade-off between power consumption and chip area

In both references we had to let the actual currents flowing through the reference branches to be much lower than the reference current needed and later mirror these currents to produce the reference current. This lowers the power dissipation of the circuit.

Thank You

Questions?