HEI GL494 Datasheet

1

Q

+ + −

−

Description

The GL494 incorporates on a single monolithic chip all the
functions required in the construction of a pulse-width­modulation control circuit. Designed primarily for power
supply control, the GL494 contains an on-chip 5-volt
regulator, two error amplifiers, adjustable oscillator, dead­time control comparator, pulse-steering flip-flop, and
output-control circuitry. The uncommitted output
transistors pro-vide either common-emitter or emitter­follower output capability. Push-pull or single-ended
output operation may be selected through the output­control function. The ar-chitecture of the GL494 prohibits
the possibility of either output being pulsed twice during
push-pull operation.

Features

— Complete PWM Power Control Circuitry
— Uncommitted Outputs for 200mA Sink or Source
— Output Control Selects Single-Ended or Push-Pull

Operation

— Internal Circuitry Prohibits Double Pulse at Either

Output

— Internal Regulator Provides a Stable 5V Reference

Supply

— Variable Dead-Time Provides Control Over Total

Range

GL494

GL494

PWM CONTROL CIRCUIT

Pin Configuration

NONINV INPUT

INV. INPUT

FEEDBACK

DEAD TIME CONTROL

Cr

Rr

GND

C1

1
2
3
4
5
6
7
8

Function Table

Output Control Output Function
Grounded Single-ended or Parallel Output
At

V Normal Push-Pull Operation

ref

16

NON INV INPUT

15

INV. INPUT

14

REF. OUT

13

OUTPUT CONTROL

12

Vcc

11

C2

10

E2

9

E1

Block Diagram

DEAD

TIME

CONTROL

NONINVERTING(1)

INPUT

INVERTING (2)

INPUT

NONINVERTING(16)

INPUT

INVERTING (15)

INPUT

FEEDBACK

RT

CT

OSCILLATOR

0.1V

(4)

ERROR AMPLIFIERS

ERROR AMP1

ERROR AMP2

(3)

PWM

COMPARATOR

REFERENCE
REGULATOR

PULSE STEERING

(See Function Table)

FLIP FLOP

T

OUTPUT

CONTROL

(13)

Q

VCC
(12)

REF OUT
(14)

GND

(7)

E1(9) C1(8)

E1(10) C2(11)

2

Absolute Maximum Ratings

°

°

K

°

°

−

=

=

°

=

=

°

=

°−=

°

=

µ

=,Ω

=

=

°

=

µ

=,Ω

=

°−=

Supply Voltage,
Amplifier Input Voltage ………………………………………………………………..
Collector Output Voltage ……………………………………………………………………… 41 V
Continuous Total dissipation at (or below) 25C° ………………………………………. 1000 mW
Operating Free-Air Temperature Range ……………………………………………… -20 to 85
Storage Temperature Range ……………………………………………………….….. -65 to 150
Collector Output Current ………………………………………………………………….. 250 mA

V ……………………………………………………………………….. 41 V

CC

V +0.3 V

CC

Recommended Operation Conditions

PARAMETER MIN MAX UNIT

Supply Voltage,
Amplifier Input Voltage,

V 7 40 V

CC

V -0.3

1

V -2 V

CC

Collector Output Voltage, Vo 40 V
Collector Output Current

200 mA

(Each Transistor)
Current Into Feed back Terminal 0.3 mA
Timing Capacitor,
Timing Resistor,

C 0.47 10,000 nF

T

R 1.8 500 Ω

T

Oscillator Frequency 1 300 KHz
Operating Free-Air Temperature -20 85

Electrical Characteristics (Temperature

,

V =15V, f=10KHz)

C85~20

CC

Reference Section

PARAMETER TEST CONDITIONS MIN TYP(1) MAX UNIT

Output voltage (
Input regulation V7V
Output regulation 1I
Output Voltage change

with temperature
Short-circuit

Output current(2)

V ) mA1I

ref

O

CC

O

A

ref

4.75 5 5.25 V
to 40V, C25T

to 10mA, C25T

C20T

to

0V

35 mA

A

A

0.2 1 %

C85

2 25 mV

1 15 mV

GL494

C

C
C

Oscillator Section

PARAMETER TEST CONDITIONS MIN TYP(1) MAX UNIT

Frequency F01.0C
Standard deviation

of frequency (3)
Frequency change with

Voltage
Frequency change with

temperature

T

All values of

T,R,C Constant

ATT

V7V

CC

T

A

to 40V, C25T

F01.0C

C20T

to

T

V ,

CC

T

C85°

k12R

10 KHz

10 %

A

k12R

0.1 %

2 %

3

Dead Time Control Section

°

=

GL494

PARAMETER TEST CONDITIONS MIN TYP(1) MAX UNIT

Input bias current (pin 4) VI=0 to 5.25V -2 -10 Aµ
Maximum duty cycle,

Each output
Input threshold voltage

(pin 4)

V =0V 45 %

)4pin(I

Zero duty cycle 3 3.3 V
Maximum duty cycle 0 V

Error Amp Sections

Input offset voltage V5.2V
Input offset current V5.2V
Input bias current V5.2V
Common-mode input

voltage range
Open-loop voltage

Amplification
Unity-gain bandwidth 800 KHz
Common-mode rejection ratio

Output sink current (pin 3)

Output source current (pin 3)

PARAMETER TEST CONDITIONS MIN TYP(1) MAX UNIT

= 2 10 mV

)3PIN(O

= 25 250 nA

)3PIN(O

= 0.2 1 Aµ

)3PIN(O

5V

−= to –5V,

ID

V7VCC=

to 40V

==∆ to3.

OO

V40VCC= , C25T

A

mV15V

V7.0V

=

)3pin(O

mV15VID= to 5V,

V5.3V

=

)3pin(O

LOW

HIGH

5.0V,V3V

-0.3

2VCC−

70 95 dB

65 80 dB

0.3 0.7 mA

-2 mA

V

PWM Comparaor Section

Input threshold voltage (pin 3) Zero duty cycle 4 4.5 V
Input sink current (pin 3) V7.0V

PARAMETER TEST CONDITIONS MIN TYP(1) MAX UNIT

= 0.3 0.7 mA

)3pin(O

Switching Characteristics

PARAMETER TEST CONDITIONS MIN TYP(1) MAX UNIT

Output Voltage rise time 100 200 ns
Output Voltage fall time
Output Voltage rise time 100 200 ns
Output Voltage fall time

Common-emitter configuration,
See Test Circuit 3

Emitter-follower configuration,
See Test Circuit 4

25 100 ns

40 100 ns