25
MINI PROJECT REPORT 2008 INFRARED HEADPHONE DONE BY GUIDED BY: RE MY A .M.MENON RE SI I MA. I NX IKRISI I NAN SAJINI SASIKUMAR ABSTRACT ! I | The circuit for INFRARED HEADPHONE is designed to i t | demonstrate the transmission and reception of audio signal through ! infrared radiations. The infrared rays generated by the transmitter circuit are received by the receiver circuit after transmission through air. This communication is much more effective than ordinary communication. It helps to receive audio signals from any audio device like T.V,radio etc. i without disturbing others. It provides minimum transmission loss. It is a low cost project ! o INTRODUCTION c BLOCK DIAGRAM o BLOCK DIAGRAM EXPLANATION o CIRCUIT DIAGRAM

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Page 1: Infrared Headphone

MINI PROJECT REPORT 2008

INFRARED HEADPHONE

DONE BY GUIDED BY:

RE MY A .M.MENON

RE SI I MA. I NX IKRISI I NAN

SAJINI SASIKUMAR

ABSTRACT

! I | The circuit for INFRARED HEADPHONE is designed to

i

t

| demonstrate the transmission and reception of audio signal through ! infrared radiations. The

infrared rays generated by the transmitter circuit are received by the receiver circuit after transmission

through air. This communication is much more effective than ordinary communication. It helps to

receive audio signals from any audio device like T.V,radio etc.

i

without disturbing others. It provides minimum transmission loss. It is a low cost project

! o INTRODUCTION

c BLOCK DIAGRAM

o BLOCK DIAGRAM EXPLANATION

o CIRCUIT DIAGRAM

Page 2: Infrared Headphone

o CIRCUIT DIAGRAM EXPLANATION

o PCB DESIGNING AND FABRICATION

o PCB LAYOUT

o PCB SCHEMATIC

o COMPONENTS LIST

o CONCLUSION

o REFERENCES

o DATASHEETS

Page 3: Infrared Headphone

INTRODUCTION

INFRARED HEADPHONES

Using this low-cost project one can reproduce audio from

TV without disturbing others. It does not use any wire connection between TV

and headphones. In place of a pair of wires, it uses invisible infrared light to

transmit audio signals from TV to headphones. Without using any lens, a range

of up to 6 metres is possible. Range can be extended by using lenses and

reflectors with IR sensors comprising transmitters and receivers.

IR transmitter uses two-stage transistor amplifier to drive

two series-connected IR LEDs. An audio output transfonner is used (in reverse)

to couple audio output from TV to the IR transmitter. Transistors Tl and T2

amplify the audio signals received from TV through the audio transformer.

Low-impedance output windings (lower gauge or thicker wires) are used for

connection to TV side while high-impedance windings are connected to IR

transmitter. This IR transmitter can be powered from a 9-volt mains adapter or

battery. Red LED1 in transmitter circuit functions as a zener diode (0.65V) as

well as supply-on indicator.

IR receiver uses 3-stage transistor amplifier. The first

two transistors (T4 and T5) form audio signal amplifier while the third

transistor T6 is used to drive a headphone. Adjust potmeter VR2 for

max. clarity.

i

Direct photo-transistor tow aids IR LEDs of transmitter for max. range. A 9-volt

battery can be used with receiver for portable operation

INFRARED RADIATIONS

These rays were discovered in 1800 by William Herschel, a

British musician and astronomer, when he observed that a thermometer placed just

outside the visible spectrum of sunlight shows a greater increase in temperature than

one placed in the red region.

The Infrared region of the spectrum lies beyond the red end of the visible range, with

wavelengths between 0.01 to 7.5x10 5 cm.

Instruments for detecting infrared radiation include heat-sensitive devices such as

thermocouple detectors, bolometers, photovoltaic cells, and photoconductors.

Page 4: Infrared Headphone

Infrared radiation is absorbed and emitted by the

movement (rotations and vibrations) of chemically bonded atoms or groups of atoms

of many materials. Some of the materials that absorb infrared radiation are window

glass, water and also our atmosphere. Although invisible to the eye, longer infrared

radiation can be detected as warmth by the skin. It forms nearly 50% of the Sun's

radiant energy, with major portion of the rest being in the visible region.

One of the major uses of infrared rays is Infrared

photography. Infrared rays are also reflected off objects, just as visible light. Special

films or sensors which have the property to 'see in the dark' are used to observe these

rays, which enhance different areas according to their heat emission. For e.g., in an

infrared photograph, blue sky and water appear nearly black, whereas unexposed skin

shows up brightly.

Infrared photography is used to detect pathological tissue growths' (thermography)

and defects in electronic systems and circuits (due to their increased emission of

heat). They can also be used to detect heat leaks in houses and forest fires. Shorter

infrared rays are used in remote controls.

Physiotherapists use infrared radiation to warm damaged muscles and so speed up

healing. Infrared light can also be sent down optical fibres for cable television and

phone links.

Atmospheric haze and certain pollutants that scatter visible light are nearly

transparent to parts of the infrared spectrum (scattering efficiency increases with the

fourth power of the frequency). Infrared photography of distant objects from the air

takes advantage of this phenomenon, to observe cosmic objects through large clouds

of interstellar dust. However, since water vapour, G3 and C02 in the atmosphere

absorb large parts of the infrared spectrum, most infrared astronomical observations

are carried out at high altitudes, with the help of balloons, rockets and space-crafts.

The infrared absorption and emission characteristics of materials yield important

information about the size, shape, and chemical bonding of molecules, atoms and ions

present in them. Infrared spectroscopy is a powerful tool for determining the internal

structure of molecules and for identifying the amounts of known species in a given

sample. Infrared rays emitted by a given substance indicate the difference of some of

the internal energy states, which depend on atomic weight and other atomic

properties.

Hence, besides for identification, infrared rays can also be used to determine the

amount of a known material in a given substance. Infrared spectroscopy is also used

to examine archaeological specimens and for detecting forgeries of art and other

objects, which, under visible light, resemble the original.

Infrared radiation plays an important role in heat transfer and is integral to the

greenhouse effect.

Page 5: Infrared Headphone

Powerful infrared radiations can be artificially prepared, by using gases like Carbon

dioxide and Carbon mono-oxide, and can be used in light radar systems and to

modify chemical reactions.

Virtually every object at the Earth's surface emits electromagnetic radiation primarily

in the infrared region of the spectrum. Man-made sources of infrared radiation

include, besides hot objects, infrared light-emitting diodes (LEDs) and lasers, which

are used in some fibre-optic communication systems and light radar systems

respectively.

Other applications of infrared light include its use in remote controls,

automatic self-focusing cameras, security alarm systems, and night-vision optical

instruments.

AUDIO TRANSFORMERS

There are many ways to package audio transformers.

Flat packs are integrated circuit (IC) packages with gull wings or flat leads on two or

four sides. Modidar jacks incorporate the RJ-45 form factor and ensure high common

mode noise immunity while maintaining signal integrity. Audio transformers improve

sound quality by removing interference from audio signals. This interference, or

ground noise, is caused by voltages from other devices and produces a humming or

buzzing sound. Typically, audio transformers are encased in a magnetic shielding

which is filled with an epoxy resin that provides insulation, protects the windings, and

prevents vibration of the core material. Some audio transformers do not have a center

tap, while other devices have a center tap in only the primary side, only the secondary

side, or in both the primary and secondary sides. For audio transformers, the

impedance ratio equals the square-of-the-turn ratio.

Audio transformers vary according to output power, operating frequency range, and

rated DC current. They also vary in terms of insertion loss, 3-decibel (dB) bandwidth,

and direct current resistance. Insertion loss, the measured loss through a device

excluding the power division factor, is the ratio of power output to power input. 3-dB

bandwidth is the frequency range over which the insertion loss is less than 3 dB for

mid-band insertion loss. Direct current resistance (DCR), the resistance of windings

as measured in DC current, is often minimized in the design of audio transformers

and specified as a maximum Waveguide assemblies, which may contain solid or

gaseous dielectric materials, have a hollow metallic conductor and are used in

microwave systems. With through-hole technology (TUT), components are mounted

on printed circuit boards (PCBs) by inserting component leads through holes in the

board and then soldering. In surface mount technology (SMI), components plug into

PCBs by soldering component leads or terminals to the top surface of the board.

Other ways to package audio transformers include chassis, dish, or disk mounts. H-

frame mounting is used in applications with high levels of shock or vibration.

Manufacturers use several methods to pack audio transformers for automatic

assembly, shipping, and handling. The tape reel method packs components into a tape

system and draws specified lengths or quantities into a reel. The stick magazine

method packs components into a tube. Audio transformers that are distributed as

individual parts are processed in bulk packs, while components that have leads in

four-sides use trays.

Audio transformers are used in car radios and broadcast equipment, and in sound

reinforcement applications. In terms of certifications, audio transformers are built and

Page 6: Infrared Headphone

tested according to a variety of standards. For example, both Underwriters

Laboratories (UL) and the Canadian Standards Association (CSA) provide marks.

The International Electrotechnical Commission (IEC) also publishes applicable

standards,

PHOTOTRANSISTOR

Phototransistors also consist of a photodiode with internal gain. A phototransistor is

in essence nothing more than a bipolar transistor that is encased in a transparent case

so that light can reach the base-collector junction. The electrons that are generated by

photons in the base-collector junction are injected into the base, and this current is

amplified by the transistor operation. Note that although phototransistors have a

higher responsivity for light they are unable to detect low levels of light any better

than photodiodes. Phototransistors also have slower response times.

PHOTODIODE

Light-emitting diode, usually called an LED , is a semiconductor diode that emits

incoherent narrow-spectrum light when electrically biased in the forward direction of

the p-n junction, as in the common LED circuit. This effect is a form of

electroluminescence. An LED is usually a small area light source, often with optics

added to the chip to shape its radiation pattern. LEDs are often used as small indicator

lights on electronic devices and increasingly in higher power applications such as

flashlights and area lighting. The color of the emitted light depends on the

composition and condition of the semiconducting material used, and can be infrared,

visible, or ultraviolet. LEDs can also be used as a regular household light source.

Besides lighting, interesting applications include sterilization of water and

disinfection of devices.

Page 7: Infrared Headphone

AUDIO

DEVICE

AUDIO AUDIO \

i

I

1 IR [

INTERFAC

E

AMPLIFIE R DRIVE

1 R 1

i t

1. TRANSMITTER

IR AUDIO AUDIO HEAD

INTERFA AMPLI —p. INTERF PHONE

CE FIER. ACE

2, RECEIVER

I BLOCK DIAGRAM EXPLANATION

" TRANSMITTER

I

Infrared headphone has a transmitter connected to audio output

■ from anv audio source like TV, radio etc. The transmitter has 5

| parts 1) Audio Device

I ' 1 2) Audio Interface

| 3) Audio Amplifier

4) IR Driver

5) IR LED

Audio device is as explained before. The audio output is given to an audio interface

circuit which is a transformer connected in stepupmode.The output is given to an audio

amplifier mainly RC coupled amplifier where it is amplified to drive the IR driver. The

IR driver has a Iiigh current transistor which is used to drive IR LED connected to

emitter. The IR LED generate the infrared radiation corresponding to audio Input.

Page 8: Infrared Headphone

RECEIVER

The receiver section is what the user carries with him. The receiver section has 4 points.

1) IR Interface

2) Audio Amplifier

3) Audio Interface

4) Headphone

The IR interface is photo diode or transistor. Then receives the IR radiations and

produce corresponding electrical signals. This is given to audio amplifier where it is

amplified and given to audio interface circuit. It give the input to the headphone where

the transmitted audio signal is received.

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Page 9: Infrared Headphone

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Page 10: Infrared Headphone

IR .CUIT D I A GR , EXPLANATIO

N

An IR headphone has two parts.

One is the transmitter and the other is the receiver

TRANSMITTER

The transmitter has an audio input from tv, radio etc., an audio transformer, an amplifier

and IR driver AND IR LED's. The transformer is connected in inverse so as to amplify

signals and offer impedence matching. The signal is then given to an audio amplifier.

When base voltage increases the transistor is ON and the collector voltage decreases

simultaneously.The red LED connected to its collector glows when collector voltage

decreases. The voltage is given to the base of transistor BD 140. It is a high current

transistor with collector current of up to I amphers. The low voltage makes the BD 140

transistor off and its collector voltage increases and the LED emits radiations.A 9v

battery or adapter provides voltage supply.

RECEIVER

The transmitted IR rays are received by a photo transmitter and converted to

corresponding electrical signals. This is amplified by audio amplifier comprising of T4

and T5. When base voltage of T4 increases making it ON and thus collector voltage

decreases. Tliis is given to base of IS and it becomes OFF and its collector voltage

increases. This amplified signal is given to audio interface where it is given to head set

and the audio signal is received

PCB FABRICATION

PCB

Artwork

(Dip Trace)

PCB Artwork on tracing

sheet

Screen

printing (Poly

blue)

HI i

Page 11: Infrared Headphone

PCB Artwork on Cu plate

using paint

Etching

(FerricChloride)

Removal of paint from

Copper plate by

scrubbing

T

Drying

Drilling (0.9mm Bit)

and Cleaning

Printed Circuit Board (PCB) is a piece of art. The performance of an electronic circuit

depends on the layout and desien of PCB. A PCB mechanically supports and

connects components by conductive pathways, etched from copper sheets laminated

on to insulated substrate. PCB's are used to route electrical currents and signals

tlirough copper tracks which are firmly bonded to an insulating base.

PCB Fabrication involves the following steps: -

1. Drawing the layout of the PCB in a paper. The track layout of the electronic

circuit should be made in such a manner that the paths are in easy routes. It is

then transferred to a Mylar sheet. The sheet is then touched with black ink.

2. The solder side of the Mylar sheet is placed on the shiny side of the five-

star sheet and is placed in a frame. Then it is exposed to sunlight with Mylar

sheet facing the sunlight.

3. The exposed five-star sheet is put in Hydrogen Peroxide solution. Then it

is put in hot water and shook till unexposed region becomes transparent.

4. This is put in cold water and then the rough side is stuck on to the silk

screen. This is then pressed and dried well.

5. The plastic sheet of the five-star sheet is removed leaving the pattern on the

screen.

6. A Copper clad sheet is cut to the size and cleaned. This is placed under the

screen.

7. Acid resistant ink is spread on the screen so that a pattern of tracks and a pad

is obtained on the Copper clad sheet. It is then dried.

8. The dried sheet is then etched using Ferric chloride solution(32Baume)

till all the unwanted copper is etched away. Swish the board to keep the etch

fluid moving. Lift up the PCB and check, whether all the unwanted copper is

removed. Etching is done by immersing the marked Copper clad in Ferric

Chloride solution. After that the etched sheet is dried.

Page 12: Infrared Headphone

9. The unwanted resist ink is removed using Sodium Hydroxide solution. Holes

are then drilled.

PCB PARAMETERS

Copper thickness - 72m.il (1mm ^ 39.37 mils)

Track width - 60m.il

Clearance - 60niil

Pad width - 86mil

Pad height - 86mil

Pad shape - Oval

Pad hole size - 25mil

On board - Through

Hole size - 0.9mm (36mil)

Base - Paper phenolic, hylam

PCB quality - FRC4

SOLDERING

Soldering is the process of joining metals by using lower melting point to weld

or alloy with joining surfaces.

SOLDER

Solder is the joining material that melts below 427 degree connections between

components. The popularly used solders are alloys of tin (Sn) and lead (Pb) that melts

below the melting point of tin.

Types:

1. Rosin core: - 60/40 Sn/Pb and 63/67 Sn/'Pb solders are the most common

types used for electronics assembly. These solders are available in various

diameters and are most appropriate for small electronics work (0.02"-0.05" dia.

is recommended)

2. Lead free: - Lead free solders are used as more environmental friendly

substitutes for leaded solder, but they are typically not as easy to use mainly

because of their higher melting point and poorer wetting properties.

3. Silver: - Silver solders are typically used for low resistance connections but

they have a higher melting point and are more expensive than Sn/Pb solders.

4. Acid-Core: - Acid-core solders should not be used for electronics. They are

intended for plumbing or non-electronics assembly work. The acid-core flux

will cause corrosion of circuitry and can damage components.

5. Other special solders: -

• Various melting point eutetics: These special solders are typically used for

non-electronics assembly of difficult to construct mechanical items that mist

be assembled in a particular sequence.

• Paste solders: These solders are used in field applications or in

specialized manufacturing applications.

Page 13: Infrared Headphone

Flux

In order to make the surface accept the solder readily, the components terminals

should be free oxides and other obstructing films. The lead should be cleaned

chemically or by abrasion using blades or knives.

Small amount of lead coating can be done on the portion of the leads using

soldering iron. This process is called tinning. Zinc chloride or Ammonium chloride

separately or in combination is mostly used as fluxes. These are available in

petroleum jelly as paste flux.

Flux is a medium used to remove the degree of wetting. The desirable properties

of flux are:-

• It should provide a liquid cover over the materials and exclude air gap up to

the soldering temperature.

• It should dissolve any oxide on the metal surface.

• It should be easily displaced from the metal by the molten soldering operation.

• Residues should be removable after completing soldering operation.

The most common flux used in hand soldering of electronic components is

rosin, a combination of mild organic acids extracted from pine trees.

Soldering Iron

It is Hie tool used to melt the solder and apply it at the joint in the circuit. It

operates in 230V supply. The iron bit at the tip gets heated while few minutes. The

50W and 25W soldering irons are commonly used for soldering of electronic circuits.

Soldering Steps

1. Make the layout of the components in the circuit. Plug in the chord of the

soldering iron into the mains to get heated.

2. Straighten and clean the components leads using a blade or a knife. Apply a

little flux on the leads. Care must be taken to avoid the components getting

heated up.

3. Mount the components on the PCB by bending the leads of the .

components. Use nose pliers..

4. Apply flux on the joints and solder the joints. Soldering must be done in

minimum time to avoid dry soldering and heating up of the components.

5. Wash the residue using water and brush.

6. Solder joints should be inspected when completed to determine if they have

been properly made.

o Qualities of a good solder joint:

A) Shim surface.

B) Good, smooth fillet.

Page 14: Infrared Headphone

o Qualities of a poor solder joint:

1. Dull or crystallized surfaces: - This is an indicator of a cold solder joint. Cold

solder joints result from moving the components after the

soldering has been removed but before the solder has hardened. Cold solder joints

may work at first but will eventually fail.

2. Air pockets: - Air pockets (voids) result from incomplete wetting of

surfaces, allowing air to be in contact with the connecting metals. This will cause

oxidation of the joint and eventual failure. Blowholes can occur due to

vaporization of the moisture on the surface of the board and exiting through the

molten solder. Boards should be clean and dry prior to soldering. Ethanol (100%)

can be used as a moisture chaser if boards are wet prior to soldering.

3. Dimples: - Dimples in the surface do not always indicate a serious

problem, but they should be avoided since they are precursors to voids.

4. Floaters: - Black spots "floating" in the soldering fillet should be

avoided because they indicate contamination and a potential for failure as in the

case of voids. These black spots usually result from overheated (burnt) Rosin or

other contaminants such as burnt wire insulation. Maintaining a clean tip will help

to avoid these problems.

5. Balls: - A solder ball, instead of a fillet can occur if the trace was heated but the

lead was not (vice-versa). This prevents proper wetting of both surfaces and results

in solder being attached to only one surface (Component or trace).

6. Excess solder: - Excess solder usage can cover up other potential

problems and should be avoided. It can also lead to solder bridges. In addition,

spherical solder joints can result from the application of too much solder.

Page 15: Infrared Headphone
Page 16: Infrared Headphone

PCB SCHEMATIC

TRANSMITTER

RECEIVE

R

in

<X>

<3> CO

01

C3

O

RU

o

DOOO cho go

«—» C3

This project INFRARED HEADPHONE was designed to reproduce

audio from TV without disturbing others . It does not use any wire

CVJ

tar

Page 17: Infrared Headphone

connection between TV and headphone. In place of a pair of wires it uses

invisible IR radiations . Range of upto 5 mtrs is possible. Range can be

extended using lenses and reflectors.

Page 18: Infrared Headphone

COMPONENTS LIST

S.NO COMPONENTS QTY

1 AUDIO TRANSFORMER 1

2 TRANSISTOR

BC548 3

BEL 187 1

BD140 1

3 IR PHOTO TRANSISTOR 1

4 LED 1

5 IR LED 2

6 RESISTER

4.7K 3

22K 1

2.2K 2

470K 1

12 OHM 1

100 OHM 1

10 K 1

7 POTENTIOMETER

100K 1

8 CAPACITOR

.01 UF 2

.1 UF 2

100 UF 1

47 P 1

9 BATTERY 9 V 2

10 HEAD PHONE 1

ESTIMATE

Page 19: Infrared Headphone

COST OF COMPONENTS =Rs.244

PCB FABRICATION = Rs.700

TOTAL COST =Rs.944

Page 20: Infrared Headphone

REFERENCE

Basic Radio & Television by SP S harm

a Electronics maker

Audio and Video System s,by RG

Guptha Electronics Zone

Page 21: Infrared Headphone

MOTOROLA SEMICONDUCTOR TECHNICAL DATA

Order this document

by BC54G/D

Amplifier Transistors NPN Silicon

EMIT

TER

MAXIMUM RATINGS

Rating Symbol BC

546

BC

547

BC

548

Unit

Collector-Emitter Voltage vCEO 65 45 30 Vdc

Collector-Base Voltage VCBO 80 50 30 Vdc

Emitter-Base Voltage vEBO 6.0 Vdc

Collector Current — Continuous <C 100 mAdc

Total Device Dissipation @ T/\ = 25°C

Derate above 25°C

PD 625 5.0 mW

rnWrC

Total Device Dissipation @ 1q = 250C

Derate above 25°C

Pd 1.5 12 Watt

mW/"C

Operating and Storage Junction Temperature

Range

TJ.

Tstg -55 to+150 °C

THERMAL CHARACTERISTICS

Characteristic Symbol Max Unit

Thermal Resistance, Junction to Ambient R0JA 200 °C/W

°c/w Thermal Resistance, Junction to Case R0JC 83.3

BC546, B

BC547, A, B, C

BC548, A, B , C

CASE 29-04, STYLE 17 TO-92

(TO-226AA)

REV 1

------------------------------------------------------------- — f^) MOTOFiOLA © Motorola, Inc 1996

BASE

Characteristic Symbol Min Typ Max Unit

OFF CHARACTERISTICS

Collector-Emitter Breakdown Voltage BC546 v(BR)CEO 65

- V

0c = 1.0 mA.IB = 0) BC547 45 —

BC548 30 — Collector-Base Breakdown Voltage BC546

v(BR)CBO 80 — — V

(lc = 100|iAdc) BC547 50 —■

BC548 30 — Emitter-Base Breakdown Voltage BC546

v(BR)EBO 6.0 - - V

(lE = 10r.A, IC = 0) BC547 6.0 —-

BC548. 6.0 — —

Collector Cutoff Current 'CES (VCE = 70V,VBE = 0) BC546 — 0.2 15 nA

(VCE = 50V,VBE = 0) BC547 — 0.2 15 (VCE = 35V,VBE = 0) BC548 — 0.2 15 (VCE = 30V,TA= 125X) BC546/547/548 — 4.0 MA

ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted)

Page 22: Infrared Headphone

BC546, B BC547, A, B, C BC540, A, B, C

Motorola Small-Signal Transistors, FETs and Diodes Device Data 22

Characteristic Symbol Min Typ Max Unit

ON CHARACTERISTICS

DC Current Gain hFE _ (!c = 10mA,V ce = 5.0V )

BC547A/548A — 90 —

BC546B/547B/548B — 150

BC548C 270 —

(lc = 2.0 mA,VCE = 5.0V) BC546 110 — 450

BC547 110 — 800

BC548 110 — 800

BC547A/548A 110 180 220

BC546B/547B/548B 200 290 450

BC547C/BC548C . 420 520 800 (lc = 100 mA, VCE = 5.0V) BC547A/548A ___ 120 —

BC546B/547B/548B — 180 —

BC548C — 300 — Collector-Emitter Saturation Voltage

vCE(sat) V

(lc = 10 mA, lB = 0.5 mA) — 0.09 0.25

(lc= 100 mA, lB = 5.0 mA) — 0.2 0.6

(lc = 10 mA, Ib = See Note 1) — 0.3 0.6 Base-Emitter Saturation Voltage

vBE(sat) — 0.7 — V

(lc = 10 mA, lB = 0.5 mA) Base-Emitter On Voltage

vBE(on) V

(lc = 2.0 mA, VCE = 5.0V) 0.55 0.7

(IC = 10mA, Vce = 5.0 V) — 0.77

ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted) (Continued)

SMALL-SIGNAL CHARACTERISTICS

Current-Gain — Bandwidth Product H MHz

(IC = 10 mA, VCE = 5.0 V, f = 100 MHz) BC546 150 300 - -

BC547 150 300

BC548 150 300 -

Output Capacitance

cobo — 1.7 4.5 pF

(VCB = 10 V, lc = 0, f = 1.0 MHz) Input Capacitance

cibo — 10 — I'F

(VEB = 0.5 V, lc = 0, f = 1.0 MHz) Small-Signal Current Gain hfe —

(IC = 2.0 mA. VCE = 5.0 V, f = 1.0 kHz) BC546 125 — 500

BC547/548 125 — 900

BC547A/548A 125 220 260

BC546B/547B/548B 240 330 500

BC547C/548C 450 600 900 Noise Figure NF dB

(lc = 0.2 mA, VCE = 5.0 V, Rs = 2 kQ, BC546 — 2.0 10

f = 1.0 kHz, Af= 200 Hz) BC547 — 2.0 10

BC548 — 2.0 10

Note 1: lB is value for which Iq = 11 mA at VcE = 1.0

V.

Page 23: Infrared Headphone

BC546, B BC547, A, B, C BC548, A, B, C

Motorola Small-Signal Transistors, FETs and Diodes Device Data 4

BC547/BC548

o

- -

[j

I T

VCE = 5 V

1

I

I

"ft

- - 4-

I

"1

t

t

V

0.1 0.2 1.0 10 100

IC, COLLECTOR CURRENT (mA)

1.0

0 8

o 0.6

0.4

0.2

0

TA = 25'C "

VBE(sat) § Ic'lB =

10

VBE@VCE = 5.0V

VcE(sal) @ 'C/'B =

10 I I i I HI i ' rz±:

0.2 0.5 1.0 2.0 5.0 10 20 50 100 200 lrj,

COLLECTOR CURRENT (mA)

Figure 8. "On" Voltage

a-

-10

-3.0

1

J 5 for F

j 5"C

;to

125

C

C

0.2 0.5 1.0 2.0 5.0 10 20 50 100 200 lc, COLLECTOR

CURRENT (mA)

Figure 9. Collector Saturation Region Figure 10. Base-Emitter Temperature Coefficient

BC546

2.0

< w 1.0

UJ

£ 0.5

O O O

ILJ

0.2

-1.4

-2.2

Figure 7. DC Current Gain

0.02 0.05 0.1 0.2 0.5 1.0 2.0 50 10 20 lB. BASE

CURRENT (mA)

£ -1.1

S -2.6

VR, REVERSE VOLTAGE (VOLTS) lc, COLLECTOR CURRENT (mA)

Figure 11. Capacitance Figure 12. Current-Gain - Bandwidth Product

Page 24: Infrared Headphone

BC546, B BC547, A, B, C BC548, A, B, C

Motorola Small-Signal Transistors, FETs and Diodes Device Data 3

1.0 2.0 5.0 10 20 50 100 lc, COLLECTOR CURRENT (mAdc)

Figure 1. Normalized DC Current Gain

Figure 2. "Saturation" and "On" Voltages

o >

2.0

I \ II I I I Tft

= 25°0 \ 1

\ | \

\ \

I I 1 1

'c = ic = IC = 50 mA V lc = 100 mA

1 3rr

A 2 On

lA

\

\ \ S

M.-

-

I 0.02 0.1 1.0 10 20

lB, BASE

CURRENT

(mA)

1.0

o

I 1 2

LU

y 1.6 LL LL. LL)

8 2.0

UJ

1 2A

UJ Q_

£ 2.8

100

Figure 3. Collector Saturation Region Figure 4. Base-Emitter Temperature Coefficient

BC547/BC548

10 7.0

% 5.0

UJ

o < t 3.0

<

o r , 2.0

400 300

200

100 80

60

40 30

20

1 2

0.8

o o UJ

o

1.6

1.0

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

BE(<

at) <2

V /lB = 10 _

Votr/n«\

@

\

'CE

= 1 o

v

VCE (sat) @ 'C"B =

10

| | It 0.1 0.2 0.3 0.5 0.7 1.0 2.0 3.0 5.0 7.0 10 20 30 50 70 100 IC,

COLLECTOR CURRENT (mAdc)

200

I I 1 1 1 1 I I _ scop in inwr

02

1.0 10

lc. COLLECTOR CURRENT

(mA)

ta =

25°C

c o

t

0.4 0.6 0 8 1.0 2.0 4.0 6.0 8.0 10 20 VR,

REVERSE VOLTAGE (VOLTS)

\ 'CE =

10 V

0.5 0.7 1.0 2.0 3.0 5.0 7.0 10 • 20 30 50 IC.

COLLECTOR CURRENT (mAdc)

Page 25: Infrared Headphone

BC546, B BC547, A, B, C BC548, A, B, C

Motorola Small-Signal Transistors, FETs and Diodes Device Data 3

Figure 5. Capacitances Figure 6. Current-Gain - Bandwidth Product

PACKAGE DIMENSIONS

SECTION X-X

MOTES:

1. DIMENSIONING AND TOLERANCING PER

ANSI Y14.5M, 1982.

2. CONTROLLING DIMENSION: INCH.

3. CONTOUR OF PACKAGE BEYOND

DIMENSION R IS UNCONTROLLED.

4. DIMENSION F APPLIES BETWEEN P AND L.

DIMENSION D AND J APPLY BETWEEN L AND

K MINIMUM. LEAD DIMENSION IS

UNCONTROLLED IN P AND BEYOND

DIMENSION K MINIMUM

DIM INCHES MILLIMETERS

MIN MAX MIN MAX

A 0.175 0.205 4.45 5.20

B 0.170 0210 4.32 5.33

C 0.125 0.165 3.18 4.19

D 0.016 0.022 0.41 0.55

F . 0.0)6 0.019 0.41 0.48

G 0.045 0.055 1.15 1.39

H 0.095 0.105 2.42 2.66

J 0.015 0.020 0.39 0,50

K 0.500 — 12.70 — L 0.250 — 6.35 — N 0.060 0.105 2.04 2.66

P — 0.100 — 2.54

R 0.115 — 2.93 — V 0.135 — 3.43 —

CASE 029-04 (TO-226AA) ISSUE AD

STYLE 17:

PIN 1. COLLECTOR 2.

BASE 3 EMITTER