Document
KA7500C — SMPS Controller
April 2009
KA7500C SMPS Controller
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
Description
The KA7500C is used for the control circuit of the pulsewidth 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-Lead DIP 16-Lead SOP
Ordering Information
Part Number
Operating Temperature Range
KA7500C KA7500CD KA7500CDTF
-25 to +85°C
Eco Status
RoHS
Package
Packing Method
16-Lead Dual Inline Package (DIP) 16-Lead Small Outline Package (SOP)
Tube Tube Tape and Reel
For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2003 Fairchild Semiconductor Corporation KA7500C • Rev. 1.0.2
www.fairchildsemi.com
KA7500C — SMPS Controller
Block Diagram
Figure 1. Block Diagram
© 2003 Fairchild Semiconductor Corporation
KA7500C • Rev. 1.0.2
2
www.fairchildsemi.com
KA7500C — SMPS Controller
Typical Application
VI =10V to 40V
KSA1010
1mH, 2A
V O =5V IO =1A
47 Ω
150 Ω
1MΩ 0.1µF
50µF 10V +
12 VC C
11 C2
8
3
-2
C1
COMP INPUT
5.1KΩ
VR EF 14
KA7500C
5.1KΩ - 15
D.T GND E1
4
7
9
E2
O.C
10
13
+1
150 Ω
+ 16
RT
CT
6
5
5.1KΩ
+ 50µF 50V
+ 47KΩ 0.001µF
+ 500µF
10V
GND
0.1 Figure 2. Pulse-Width Modulated Step-Down Converter
© 2003 Fairchild Semiconductor Corporation
KA7500C • Rev. 1.0.2
3
www.fairchildsemi.com
KA7500C — SMPS Controller
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only.
Symbol VCC VC IO VIN
PD
TOPR TSTG
TJ
Parameter
Supply Voltage
Collector Supply Voltage
Output Current
Amplifier Input Voltage
Power Dissipation
KA7500C KA7500CD
Operation Temperature Range
Storage Temperature Rang
Junction Temperature
Min.
-25 -65
Max. 42 42 250
VCC + 0.3 1 0.9
+85 +150 +125
Unit V V mA V
W
°C °C °C
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual dev.