Datasheet MC34063ABN, MC34063ACD, MC34063ACD-TR, MC34063ACN, MC34063ABD Datasheet (SGS Thomson Microelectronics)



DC-DC CONVERTER CONTROL CIRCUITS

■ OUTPUT SWITCHCURRENT IN EXCESSOF

1.5A

■ 2%REFERENCEACCURACY

■

LOWQUIESCENTCURRENT: 2.5mA(TYP.)

■ OPERATINGFROM3VTO 40V

■ FREQUENCYOPERATIONTO100KHz

■

ACTIVECURRENT LIMITING

DESCRIPTION

The MC34063A series is a monolithic control
circuit delivering the main functions for DC-DC
voltageconverting.

The device contains an internal temperature
compensated reference, comparator, duty cycle
controlled oscillator with an active current limit
circuit,driver and high current outputswitch.

Output voltage is adjustable through two external
resistorswitha 2% referenceaccuracy.

Employing a minimum number of external
components the MC34063A devices series is
designed for Step-Down, Step-Up and
Voltage-Invertingapplications.

MC34063A

DIP-8

SO-8

BLOCKDIAGRAM

April 2000

1/15

MC34063A

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

V
V

V

Absolute Maximum Rating are those values beyond which damage to the device may occur.
Functionaloperation under these condition is not implied.

THERMALDATA

PowerSupplyVoltage 50 V

CC

Comparator InputVoltage Range -0.3 to 40 V

V

ir

SwitchCollectorVoltage 40 V

SWC

SwitchEmitterVoltage(VSWC =40V) 40 V

SWE

SwitchEmitterto Collector Voltage 40 V

CE

DriverCollectorVoltage 40 V

V

dc

DriverCollectorCurrent 100 mA

I

dc

SwitchCurrent 1.5 A

I

SW

P

PowerDissipation at T

tot

OperatingAmbientTemperature Range (forAC SERIES)

T

op

StorageTemperature Range - 40 to 150

T

stg

=25oC (for

amb

PlasticPackage

(for SOICPackage)

(for ABSERIES)

)

1.25

0.625

0to70

-40to85

W

o

C

o

C

o

C

Symbol Parameter DIP-8 SO-8 Unit

R

thj-amb

(*) This value depends from thermal design ofPCB on which the device is mounted.

CONNECTION DIAGRAM

Thermal Resistance Junction-ambient (*) Max 100 160

(top view)

PIN CONNECTIONS

o

Pin No Symbol Name and Function

1 SWC SwitchCollector
2 SWE SwitchEmitter
3 TC TimingCapacitor
4 GND Ground
5 CII Comparator InvertingInput
6V
7I

CC
pk

Voltage Supply
IpkSense

8 DRC Voltage DriverCollector

ORDERING NUMBERS

Type DIP-8 SO-8 SO-8 (tape & reel)

MC34063AB MC34063ABN MC34063ABD MC34063ABD-TR
MC34063AC MC34063ACN MC34063ACD MC34063ACD-TR

C/W

2/15

MC34063A

ELECTRICALCHARACTERISTICS

(Refer to the testcircuits,V

= 5V,Ta=T

CC

LOW

toT

HIGH

, unless

otherwisespecified,see note 2)
OSCILLATOR

Symbol Parameter Test Conditions Min. Typ. Max. Unit

f

OSC

I

I

dischg

I

dischg/Ichg

Frequency V
Charge Currernt VCC= 5 to 40V Ta=25oC 243342

chg

=0V CT= 1 nF Ta=25oC243342KHz

pin5

Discharge Current VCC= 5 to 40V Ta=25oC 140 200 260
Discharge toCharge

Pin 7 = V

CCTa

=25oC 5.2 6.2 7.5

CurrentRatio

V

ipk(sense)

CurrentLimit SenseVoltage I

chg=IdischgTa

=25oC 250 300 350 mV

OUTPUTSWITCH

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

CE(sat)

SaturationVoltage,

ISW= 1 A Pins1, 8 connected 1 1.3 V

Darlington Connection

V

CE(sat)

SaturationVoltage ISW=1A R

=82ΩtoVCC,

pin8

0.45 0.7 V

Forcedβ~20

h

I

C(off)

DC Current Gain ISW=1A VCE=5V Ta=25oC50120

FE

CollectorOff-StateCurrent VCE=40 V 0.01 100 µA

COMPARATOR

A

µ

A

µ

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

Reg

ThresholdVoltage Ta=25oC

th

ThresholdVoltageLine

line

T

a=TLOW

to T

HIGH

1.225

1.21

1.25 1.275

1.29

V
V

VCC= 3 to 40V 1 5 mV

Regulation
InputBias Current VIN=0 V -5 -400 nA

I

IB

TOTALDEVICE

Symbol Parameter Test Conditions Min. Typ. Max. Unit

I

Supply Current VCC= 5 to 40V CT=1nF

CC

Pin 7 = V

CCVpin5>Vth

Pin2 =GND

Remaining pinsopen

NOTES:

1) Maximum package power dissipation limit must be observed.
=0oC, T

2) T

LOW

3) If Darlington configuration is not used, care must be taken to avoiddeep saturation of output switch. The resulting switch-off time may be

adversely affected.In a Darlington configuration the following output driver condition is suggested:

β

Forced
* Current less due to a built in 1KΩantileakageresistor.

of output current switch = I

=70oC (AC series); T

HIGH

COUTPUT

= -40oC, T

LOW

/(I

CDRIVER

HIGH

-1mA*) ≥ 10

=85oC (ABseries).

2.5 4 mA

3/15

MC34063A

TYPICALELECTRICAL CHARACTERISTICS

EmitterFollowerConfigurationOutput Saturation
Voltagevs EmitterCurrent

CommonEmitterConfiguration Output Switch
SaturationVoltage vs CollectorCurrent

OutputSwitchON-OFF Timevs Oscillator
TimingCapacitor

DarlingtonConfiguration CollectorEmitter
SaturationVoltage (V

) vsTemperature

CE(sat)

PowerCollectorEmitter Saturation Voltage
(V

4/15

) vsTemperature

CE(sat)

CurrentLimit Sense VoltageVoltage(V
Temperature

ipk

)vs

MC34063A

TYPICALELECTRICAL CHARACTERISTICS

(Continued)

ReferenceVoltagevs Temperature BiasCurrent vsTemperature

SupplyCurrent vs Temperature SupplyCurrent vs Input Voltage

5/15

MC34063A

TYPICALAPPLICATION CIRCUIT

Step-UpConverter

PrintedDemoboard

TestCondition (V

Test Conditions Value (Typ.) Unit

LineRegulation V
LoadRegulation V
OutputRipple V
Efficency V

OUT

= 28V)

Symbol Pin

Vout 1
GND 2
GND 3

Vin 4

=8 to 16V, IO=175mA 30 mV

IN

=12V, IO=75 to 175mA 10 mV

IN

=12V, IO=175mA 300 mV

IN

=12V, IO=175mA 89 %

IN

6/15

Step-DownConverter

MC34063A

PrintedDemoboard

TestCondition (V

Test Conditions Value (Typ.) Unit

LineRegulation V
LoadRegulation V
OutputRipple V
Efficency V
I

SC

OUT

= 5V)

Symbol Pin

Vout 1
GND 2
GND 3

Vin 4

=15 to 25V, IO= 500mA 5 mV

IN

=25V, IO=50 to 500mA 30 mV

IN

=25V, IO=500mA 100 mV

IN

=25V, IO=500mA 80 %

IN

VIN=25V, R

LOAD

= 0.1

Ω

1.2 A

7/15

MC34063A

VoltageInvertingConverter

PrintedDemoboard

TestCondition (V

Test Conditions Value (Typ.) Unit

LineRegulation V
LoadRegulation V
OutputRipple V
Efficency V
I

SC

OUT

=-12V)

Symbol Pin

Vout 1
GND 2
GND 3

Vin 4

=4.5 to 6V, IO=100mA 15 mV

IN

=5V, IO=10to 100mA 20 mV

IN

=5V, IO=100mA 230 mV

IN

=5V, IO=100mA 58 %

IN

VIN=5V, R

lLOAD

= 0.1

Ω

0.9 A

8/15

Calculation

MC34063A

Parameter Step-Up

(Discontinuos mode)

t

on/toff

(ton+t

)max 1/f

off

C

T

I

PK(switch)

R

SC

C

O

L(min) V

NOTES:

V

= Saturation voltage of the output switch

sat

V

= Foward voltage drop ofthe output rectifier

F

THE FOLLOWING POWER SUPPLY CHARACTERISTICS MUST BECHOSEN:
V

= Nominal input voltage

in

= Desired output voltage,|V

V

out

= Desired output current

I

out

= Minimum desired output switching frequency at the selected values ofVin and Io

f

min

V

= Desired peak to peak output ripple voltage. In practice, the calculaed capacitor value will and to be increased due to its equivalent

ripple

series resistance and board layout. The ripplevoltage should be kept to a low value since it will directly affect the line and load regulation.

out

V

out+VF−Vin(min)

V

in(min)

4.5x 10-5t

2I

out(max)

0.3/ I

≅

V

in(mi n)−Vsat

I

PK (switch)

| = 1.25(1+R2/R1)

− V

min

[(ton/t

PK(switch)

I

outton

ripple(p−p

t

on(max)

sat

on

)+1] 2I

off

)

Step-Down

(Continuos mode)

V

out+VF

V

− V

in(min)

1/f

min

4.5x 10-5t

out(max)

0.3/I

PK(switch)

I

PK(switch)(ton+toff

8V

ripple

V

− V

in(min)

sat−Vout

I

PK (switch)

sat

p−p)

(

− V

on

out

)

t

on (max)

Voltage Inverting

(Discontinuos mode)

|V

| + V

out

F

Vin− V

sat

1/f

min

2I

out(max)

V

in(min)

I

PK (switch)

4.5x1 0-5t

0.3/I

≅

[(ton/t

PK(switch )

I

outton

V

ripple(p−p

− V

sat

on

)+1]

off

)

t

on (max)

Step-upWith External NPN Switch

9/15

MC34063A

Step-downWithExternal NPN Switch

Step-downWithExternal PNP Switch

10/15

VoltageInvertingWith ExternalNPN Switch

MC34063A

VoltageInvertingWith ExternalPNP SaturatedSwitch

11/15

MC34063A

DualOutput Voltage

HigherOutputPower, HigherInput Voltage

12/15

Plastic DIP-8 MECHANICALDATA

MC34063A

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 3.3 0.130

a1 0.7 0.028

B 1.39 1.65 0.055 0.065

B1 0.91 1.04 0.036 0.041

b 0.5 0.020

b1 0.38 0.5 0.015 0.020

D 9.8 0.386
E 8.8 0.346

e 2.54 0.100
e3 7.62 0.300
e4 7.62 0.300

F 7.1 0.280

I 4.8 0.189

L 3.3 0.130

Z 0.44 1.6 0.017 0.063

mm inch

P001F

13/15

MC34063A

SO-8 MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 1.75 0.068
a1 0.1 0.25 0.003 0.009
a2 1.65 0.064
a3 0.65 0.85 0.025 0.033

b 0.35 0.48 0.013 0.018

b1 0.19 0.25 0.007 0.010

C 0.25 0.5 0.010 0.019
c1 45 (typ.)

D 4.8 5.0 0.188 0.196

E 5.8 6.2 0.228 0.244

e 1.27 0.050

e3 3.81 0.150

F 3.8 4.0 0.14 0.157

L 0.4 1.27 0.015 0.050
M 0.6 0.023
S 8 (max.)

mm inch

14/15

0016023

MC34063A

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