VOLTAGE-MODE PWM CONTROLLER FEATURES ORDERING INFORMATION BLOCK DIAGRAM 16-DIP

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1 VOLTAGE-MODE PWM CONTROLLER The KA7500B is used for the control circuit of the pulse width modulation switching regulator. The KA7500B 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 1 KHz to 300 KHz. FEATURES Internal regulator provides a stable 5V reference supply trimmed to 1 % 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 16-DIP 16-SOP ORDERING INFORMATION Device Package Operating Temperature KA7500B 16 DIP 0 ~ + 70Î KA7500BD 16 SOP 0 ~ + 70Î BLOCK DIAGRAM Rev. B 1999 Fairchild Semiconductor Corporation

2 ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Value Unit Supply Voltage V CC 42 V Collector Supply Voltage V C 42 V Output Current I O 250 ma Amplifier Input Voltage V IN V CC V Power Dissipation (T A = 25Î) P D 1 (KA7500B) 0.9 (KA7500BD) Operating Temperature Range T OPR 0 ~ +70 Î Storage Temperature Range T STG -65 ~ Î W ELECTRICAL CHARACTERISTICS (V CC = 20V, f = 10KHz, T A = 0Î to + 70Î, unless otherwise specified) Characteristic Symbol Test Conditions Min Typ Max Unit REFERENCE SECTION Reference Output Voltage V REF I REF = 1mA V Line Regulation LV REF V CC = 7V to 40V mv Temperature Coefficient of V REF LV REF/LT T A = 0Î to 70Î %/Î Load Regulation LV REF I REF = 1mA to 10mA mv Short-Circuit Output Currnet I SC V REF = ma OSCILLATOR SECTION Oscillation Frequency f C T = 0.01sF, R T = 12K` 10 KHz Frequency Change with Temperature Lf/LT C T = 0.01sF, R T = 12K` 2 % DEAD TIME CONTROL SECTION Input Bias Currnet I BIAS V CC = 15V, 0VV 45.25V sa Maximum Duty Cycle D (MAX) V CC = 15V, V 4 = 0V O.C Pin = V REF 45 % Zero Duty Cycle Input Threshold Voltage V ITH V Max. Duty Cycle 0 ERROR AMP SECTION Input Offset Voltage V IO V 3 = 2.5V mv Input Offset Current I IO V 3 = 2.5V ma Input Bias Current I BIAS V 3 = 2.5V sa Common Mode Input Voltage V CM 7VV CC40V -0.3 V CC V Open-Loop Voltage Gain G VO 0.5VV 33.5V db Unit-Gain Bandwidth BW 650 KHz

3 ELECTRICAL CHARACTERISTICS (V CC = 20V, f = 10KHz, T A = 0Î to + 70Î, unless otherwise specified) Characteristic Symbol Test Conditions Min Typ Max Unit PWM COMPARATOR SECTION Input Threshold Voltage V ITH Zero Duty Cycle V Input Sink Currnet I SINK V 3=0.7V mv OUTPUT SECTION Output Saturation Voltage Common Emitter V CE(SAT) V E = 0, I C = 200mA Common Collector V CC(SAT) V C = 15V, I E = -200mA Collector Off-State Currnet I C(OFF) V CC = 40V, V CE = 40V Emitter Off-State Current I E(OFF) V CC = V C = 40V, V E = TOTAL DEVICE Supply Current I CC Pin 6 = V REF, V CC = 15V 6 10 ma OUTPUT SWITCHING CHARACTERISTIC Rise Time t R Common Emitter Common Collector Fall Time t F Common Emitter Common Collector V sa ns ns

4 TYPICAL APPLICATION PLUSE WIDTH MODULATED STEP-DOWN CONVERTER

5 TRADEMARKS The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. DISCLAIMER ACEx CoolFET CROSSVOLT E 2 CMOS TM FACT FACT Quiet Series FAST FASTr GTO HiSeC ISOPLANAR MICROWIRE POP PowerTrench QS Quiet Series SuperSOT -3 SuperSOT -6 SuperSOT -8 TinyLogic UHC VCX FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, or (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 significant injury to the user. PRODUCT STATUS DEFINITIONS Definition of Terms 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. Datasheet Identification Product Status Definition Advance Information Preliminary No Identification Needed Formative or In Design First Production Full Production This datasheet contains the design specifications for product development. Specifications may change in any manner without notice. This datasheet contains preliminary data, and supplementary data will be published at a later date. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. This datasheet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. Obsolete Not In Production This datasheet contains specifications on a product that has been discontinued by Fairchild semiconductor. The datasheet is printed for reference information only.

CURRENT-MODE PWM CONTROLLERS FEATURES ORDERING INFORMATION BLOCK DIAGRAM

CURRENT-MODE PWM CONTROLLERS FEATURES ORDERING INFORMATION BLOCK DIAGRAM CURRENT-MODE PWM CONTROLLERS The KA3842B/3B/4B/5B are fixed frequency current-mode PWM controller. They are specially designed for Off - Line and DC-to-DC converter applications with minimal external components.