1 q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e fuji power supply control ic FA7700V/01v application note dec -2000 fuji electric co., ltd. matsumoto factory
2 q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e 1.this data book contains the product specifications, characteristics, data, materials, and structures as of dec 2000. the contents are subject to change without notice for specification changes or other reasons. when using a product listed in this data book, be sure to obtain the latest specifications. 2. all applications described in this data book exemplify the use of fuji's products for your reference only. no right or license, either express or implied, under any patent, copyright, trade secret or other intellectual property right owned by fuji electric co., ltd. is (or shall be deemed) granted. fuji makes no representation or warranty, whether express or implied, relating to the infringement or alleged infringement of other's intellectual property rights which may arise from the use of the applications described herein. 3. although fuji electric is enhancing product quality and reliability, a small percentage of semiconductor products may become faulty. when using fuji electric semiconductor products in your equipment, you are requested to take adequate safety measures to prevent the equipment from causing a physical injury, fire, or other problem if any of the products become faulty. it is recommended to make your design fail-safe, flame retardant, and free of malfunction. 4.the products introduced in this data book are intended for use in the following electronic and electrical equipment which has normal reliability requirements. ? computers ? oa equipment ? communications equipment (terminal devices) ? measurement equipment ? machine tools ? audiovisual equipment ? electrical home appliances ? personal equipment ? industrial robots etc. 5.if you need to use a product in this data book for equipment requiring higher reliability than normal, such as for the equipment listed below, it is imperative to contact fuji electric to obtain prior approval. when using these products for such equipment, take adequate measures such as a backup system to prevent the equipment from malfunctioning even if a fuji's product incorporated in the equipment becomes faulty. ? transportation equipment (mounted on cars and ships) ? trunk communications equipment ? traffic-signal control equipment ? gas leakage detectors with an auto-shut-off feature ? emergency equipment for responding to disasters and anti-burglary devices ? safety devices 6. do not use products in this data book for the equipment requiring strict reliability such as (without limitation) ? space equipment ? aeronautic equipment ? atomic control equipment ? submarine repeater equipment ? medical equipment 7. copyright ? 1995 by fuji electric co., ltd. all rights reserved. no part of this data book may be reproduced in any form or by any means without the express permission of fuji electric. 8. if you have any question about any portion in this data book, ask fuji electric or its sales agents before using the product. neither fuji nor its agents shall be liable for any injury caused by any use of the products not in accordance with instructions set forth herein. warning
3 q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e contents page 1. description ??????????????????? 4 2. features ??????????????????? 4 3. outline ??????????????????? 4 4. block diagram ??????????????????? 5 5. pin assignment ??????????????????? 5 6. ratings and characteristics ??????????????????? 6 7. characteristics curves ??????????????????? 9 8. description of each circuit ??????????????????? 13 9. design advice ??????????????????? 17 10. application circuit ??????????????????? 18 note ? parts tolerance and characteristics are not defined in all application described in this data book. when design an actual circuit for a product, you must determine parts tolerances and characteristics for safe and stable operation.
4 q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e 1 ? ? ? ? description FA7700V/fa7701v are the pwm type dc to dc converter control ics with 1ch output that can directly drive power mosfets. cmos devices with high breakdown voltage are used in these ics and low power consumption is achieved. these ics have the many functions equivalent to those which our conventional version bipolar ics ? fa76xx series- have,and have merits of output on/off control function,directly driving nch/pch mosfets,low power consumption , higher frequency operation, and less external discrete components. 2 ? ? ? ? features ? ? wide range of supply voltage.: vcc=2.5 to 20v ? ? FA7700V?for boost, flyback converter (maximum output duty cycle is 80%) fa7701v?for buck converter (maximum output duty cycle is 100%) ? ? output stage consist of cmos push-pull circuit, and achieves a high speed switching of external mosfets. (FA7700V: for nch-mosfet driving, fa7701v: for pch-mosfet driving) ? ? high accuracy reference voltage (error amplifier): 0.88v 2% ? ? soft start function. ? ? adjustable built-in timer latch for short-circuit protection. ? ? output on/off control function ? ? less external discrete components needed (2 components less than conventional version of the equivalent products) ? ? low power consumption stand-by current: 40 a(typ.) operating current: 1.2ma(typ.) (including error amplifier output current and oscillator current) ? ? high frequency operation: 50khz to 1mhz ? ? package: tssop-8(thin and small) 3 ? ? ? ? outline units:mm
5 q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e q ualit y is our messa g e 4 ? ? ? ? block diagram 5 ? ? ? ? pin assignment pin no. pin name function 1 rt oscillator timing resistor 2 ref internal bias voltage 3 in(-) error amplifier inverting input 4 fb error amplifier output 5 gnd ground 6 out output for driving switching device 7vccpower supply 8 cs on/off, soft start, timer latched short circuit protection ') ' +' $( *+!$ ? - +
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