©2002 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev. 1.0.0
Features
• Inter nal Regulat or Provides a Stable 5V Re ference Sup ply
Trimmed to 5%
• Uncommitted Ou tput T R for 200mA Sink or So urce
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 KA7500B is used for the control circu it of the PWM
switching regulator. The KA7500B consists of 5V reference
voltage circuit, two error amplifiers, a 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.
16-DIP
16-SOP
1
1
Internal Block Diagram
KA7500B
SMPS Controller
KA7500B
2
Absolute Maximum Ratings
Parameter Symbol Value Unit
Supply Voltage VCC 42 V
Collector Supply Voltage VC42 V
Output Current IO250 mA
Amplifier Input Voltage VIN VCC +0.3 V
Power Dissipation (TA = 25°C) PD1 (KA7500B)
0.9 (KA7500BD) W
Operating Temperature Range TOPR 0 ~ +70 °C
Storage Temperature Range TSTG -65 ~ +150 °C
KA7500B
3
Electrical Characteristics
(VCC = 20V, f = 10kHz, TA = 0°C to +70°C, unless otherwise specified)
Note:
1. This parameter, although guaranteed, is not 100% tested in production.
Parameter Symbol Conditions Min. Typ. Max. Unit
REFERENCE SECTION
Reference Output Voltage VREF IREF = 1mA 4.75 5.0 5.25 V
Line Regulation ∆VREF VCC = 7V to 40V - 2.0 25 mV
Temperature Coef ficient of VREF ∆VREF/∆TT
A = 0°C to 70°C - 0.01 0.03 %/°C
Load Regul ation ∆VREF IREF = 1mA to 10mA - 1.0 15 mV
Short-Circuit Output Current ISC VREF = 0V 10 35 50 mA
OSCILLATOR SECTION
Oscillation Frequency f CT = 0.01µF, RT = 12kΩ-10-kHz
Frequency Change with Temperature ∆f/∆TC
T = 0.01µF, RT = 12kΩ--2%
DEAD TIME CONTROL SE CTION
Input Bias Current IBIAS VCC = 15V, 0V≤V4≤5.25V - -2.0 -10 µA
Maximum Duty Cyc le D(MAX) VCC = 15V, V4 = 0V
O.C Pin = VREF 45 - - %
Input Threshold Volt age VITH Zero Duty Cycle - 3.0 3.3 V
Max. Du t y Cycle 0 - -
ERROR AMP SECTIO N
Input Offset Voltage VIO V3 = 2.5V - 2.0 10 mV
Input Offset Current IIO V3 = 2.5V - 25 250 mA
Input Bias Current IBIAS V3 = 2.5V - 0.2 1.0 µA
Common Mode Input Voltage VCM 7V ≤ VCC ≤ 40V -0.3 - VCC V
Open-Loop Voltage Gain GVO 0.5V ≤ V3 ≤3 .5V 70 95 - dB
Unit-Gain Bandwidth (Note1) BW --650-kHz
PWM COM PARATOR SECTION
Input Threshold Voltage VITH Zero Du ty Cy cl e - 4 4.5 V
Input Sink Current ISINK V3=0.7V -0.3 -0.7 - mV
OUTPUT SECTI ON
Output Saturation Voltage
Common Emitter VCE(SAT) VE = 0, IC = 200mA - 1.1 1.3 V
Common Collec tor VCC(SAT) VC = 15V , IE = -200mA - 1.5 2.5
Collector Off-S tate Curren t IC(OFF) VCC = 40V, VCE = 40V - 2 100 µA
Emitter Off-State Current IE(OFF) VCC = VC = 40V, VE = 0 - - -100
TOTAL DEVICE
Supply Current ICC Pin 6 = VREF, VCC = 15V - 6 10 mA
OUTPUT SWITCHING CH ARACTERISTICS
Rise Time tR-----
Common Emitter - --100200
ns
Common Collec tor - --100200
Fall Ti me tF-----
Common Emitter - --25100
ns
Common Collec tor - --40100
KA7500B
4
Typical Application
Pulse Width Modulated Step-down Converter
KA7500B
12
Vcc 11
C2 8
C1 3
COMP INPUT - 2
VREF 14
- 15
+ 1
+16
D.T
4GND
7E1
9E2
10 O.C
13 RT
6CT
5
KSA1010 1mH,2A Vo=5V
Io=1A
VI=10V to 40V
47Ω
150Ω1MΩ
0.1uF 50uF
10V
5.1kΩ
50uF
10V
GND
0.1
0.001uF
50uF
50V
5.1kΩ
150Ω
47kΩ
5.1kΩ
+
+
+
KA7500B
5
Mechanical Dimensions
Package
#1
#8 #9
#16
6.40
±0.20
7.62
0.300
2.54
0.100
0.252
±0.008
0~15°
0.25
+0.10
–0.05
0.010
+0.004
–0.002
3.30
±0.30
0.130
±0.012
3.25
±0.20
0.128
±0.008
19.40
±0.20
0.764
±0.008
19.80
0.780 MAX
5.08
0.200
0.38
0.014
MAX
MIN
0.81
0.032
()
0.46
±0.10
0.018
±0.004
0.059
±0.004
1.50
±0.10
16-DIP
KA7500B
6
Mechanical Dimensions (Continued)
Package
0.70 ±0.20
0.0275 ±0.008
#1
#8 #9
#16
9.90 ±0.20
0.39 ±0.008
1.27
0.050
5.72
0.225
1.55 ±0.10
0.061 ±0.004
0.05
0.002
6.00 ±0.30
0.236 ±0.012
3.95 ±0.20
0.156 ±0.008
10.30
0.405 MAX
0~8°
0.51
0.020
()
1.80
0.071
MAX0.10
MAX0.004
MAX
MIN
+0.10
-0.05
0.20+0.004
-0.002
0.008
+0.10
-0.05
0.406+0.004
-0.002
0.016
16-SOP
KA7500B
7
Ordering Information
Product Number Package Operating Temperature
KA7500B 16-DIP 0 ~ +70°C
KA7500BD 16-SOP
KA7500B
9/10/02 0.0m 001
Stock#DSxxxxxxxx
2002 Fairchild Semicond uctor Corporation
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FAIRCHILD’S PRODUCTS AR E NOT AUTHORIZED FOR USE AS C RITICAL COMPONENTS I N LIFE S UPPORT DEVICE S
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
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or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or syst em who se failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effec tiv ene ss.
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