Fairchild Semiconductor KA7500C Datasheet

KA7500C

SMPS Controller

www.fairchildsemi.com

Features

• Internal Regulator Provides a Stable 5V Reference Supply

Trimmed to ±1% Accuracy.

• Uncommitted Output TR for 200mA Sink or Source
Current

• Output Control for Push-Pull or Single-Ended Operation

• Variable Duty Cycle by Dead Time Control (Pin 4)
Complete PWM Control Circuit

• On-Chip Oscillator With Master or Slave Operation

• Internal Circuit Prohibits Double Pulse at Either Output

Internal Block Diagram

R

T

6

OSCILLATOR

5

C

T

Description

The KA7500C is used for the control circuit of the pulse
width modulation switching regulator. The KA7500C
consists of 5V reference voltage circuit, two error amplifiers,
flip flop, an output control circuit, a PWM comparator, a
dead time comparator and an oscillator. This device can be
operated in the switching frequency of 1kHz to 300kHz. The
precision of voltage reference (Vref) is improved up to ±1%
with trimming. This provides a better output voltage
regulation. The operating temperature range is

-25°C ~ +85°C.

16-DIP

13

1

1

C1

8

9

E1

16-SOP

OUTPUT CONTROL

D

Q

DEAD
TIME

CONTROL

EA(+)

EA(-)

EA(+)

EA(-)

©2003 Fairchild Semiconductor Corporation

16

15

4

1.2V

1

+

1

_

2

+

2

_

COMP INPUT

3

PWM
COMP

0.7MA

CK

Q

REFERENCE

5V

BAND GAP

11

10

12

14

7

C2

E2

V

CC

V

REF

GND

Rev. 1.0.1

KA7500C

Absolute Maximum Ratings

Parameter Symbol Value Unit

Supply Voltage V
Collector Supply Voltage V
Output Current I
Amplifier Input Voltage V

Power Dissipation (T
Operating Temperature Range T

Storage Temperature Range T

= 25°C) P

A

OPR
STG

Junction Temperature T

CC

C
O
IN

D

j

42 V
42 V

250 mA

V

+0.3 V

CC

1 (KA7500C)

0.9 (KA7500CD)

-25 ~ +85 °C

-65 ~ +150 °C
125 °C

W

Recommended Operating Conditions

Parameter Symbol Min. Typ. Max. Unit

Power Supply Voltage V
Collector Output Voltage V
Collector Output Current (Each Transistor) I
Amplifier Input Voltage V
Current Into Feedback Terminal I
Reference Output Current I
Timing Resistor R
Timing Capacitor C
Oscillator Frequency f

CC
C1,VC2
C1,IC2

IN

fb

ref

T
T

osc

PWM Input Voltage (Pins3, 4, 13) - 0.3 - 5.3 V

7.0 15 40 V

-3040 V

- - 200 mA

0.3 - VCC-2.0 V

--0.3mA

--10mA

1.8 30 500 ΚΩ

0.0047 0.001 10 uF

1.0 40 200 kHz

2

KA7500C

Electrical Characteristics

(VCC = 20V, f = 10kHz, TA = -25°C to +85°C, unless otherwise specified)

Parameter Symbol Conditions Min. Typ. Max. Unit
REFERENCE SECTION

I

= 1mA, TA=25°C(Note1) 4.95 5.0 5.05

Reference Output Voltage V
Line Regulation R

Load Regulation R
Short Circuit Output Current I

REF

Line

LOADIREF

SC

OSCILLATOR SECTION

Oscillation Frequency f

Frequency Change with
Temperature

osc

∆f/∆TC

DEAD TIME CONTROL SECTION

Input Bias Current I
Maximum Duty Cycle D

Input Threshold Voltage V

BIAS
(MAX)

ITH

ERROR AMP SECTION

Input Offset Voltage V
Input Offset Current I
Input Bias Current I
Common Mode Input Voltage V
Open-Loop Voltage Gain G

IO

IO

BIAS

CM

VO

Unit-Gain Bandwidth BW - - 650 - kHz

PWM COMPARATOR SECTION

Input Threshold Voltage V
Input Sink Current I

ITH

SINK

OUTPUT SECTION

Output Saturation Voltage
Common Emitter

V

CE(SAT)VE

REF

= 1mA 4.9 5.0 5.1

I

REF

VCC = 7V to 40V - 2.0 25 mV

= 1mA to 10mA - 1.0 15 mV

V

= 0V 10 35 50 mA

REF

CT = 0.001µF, RT = 30KΩ -40-

= 0.001µF, RT = 12KΩ,TA=25°C 9.2 10 10.8

C

T

= 0.001µF, RT = 30KΩ,

C

T

T

to T

A=Tlow

= 0.01µF, RT = 12KΩ --2%

T

high

9.0 - 12

VCC = 15V, 0V ≤ V4 ≤ 5.25V - -2.0 -10 µA
VCC = 15V, V4 = 0V

O.C Pin = V

REF

45 - - %

Zero Duty Cycle - 3.0 3.3
Max. Duty Cycle 0 - -

V3 = 2.5V - 2.0 10 mV
V3 = 2.5V - 25 250 mA
V3 = 2.5V - 0.2 1.0 µA
7V ≤ V

≤ 40V -0.3 - V

CC

CC

0.5V ≤ V3 ≤ 3 .5V 70 95 - dB

Zero Duty Cycle - 4 4.5 V
V3 = 0.7V -0.3 -0.7 - mA

= 0V, IC = 200mA - 1.1 1.3 V

V

kHz

V

V

3