KA3842ACS

AC DC Converters, Offline Switchers Overview

The KA3842ACS is an offline switcher IC from Fairchild Semiconductor, packaged in an 8-DIP (0.300 inch) housing. It operates as a fixed PWM controller for off-line and DC-to-DC converter applications. The device features a maximum switching frequency of 500kHz and supports up to 97% duty cycle operation. Electrical parameters include a supply voltage range of 12V to 25V, a start-up voltage of 16V, and an operating temperature range of 0°C to 70°C.

AC DC Converters, Offline Switchers Feature Summary

• Integrated UVLO with hysteresis for stable startup
• High current totem-pole output for MOSFET driving
• Cycle-by-cycle current limiting protection

AC DC Converters, Offline Switchers Applications

• Off-line power supplies
• DC-to-DC converters
• General purpose SMPS controllers

AC DC Converters, Offline Switchers Procurement Notes

Verify the specific suffix 'CS' against official datasheets, as standard documentation typically lists 'AC' or 'AE'. Confirm RoHS compliance status and package dimensions. Check for obsolescence notices from Fairchild or ON Semiconductor. Ensure the supplier provides valid traceability documents for this specific variant.

AC DC Converters, Offline Switchers Selection Notes

Select this component for designs requiring a robust, low-cost PWM controller with integrated protection features. The 8-DIP package suits through-hole assembly processes. Consider the 16V start-up threshold and 25V maximum Vcc when designing the bias circuit. Verify thermal requirements for the 0°C to 70°C operating range.

AC DC Converters, Offline Switchers Part Context

This part belongs to the KA3842 family of fixed PWM controllers. It shares functional similarities with the KA3842A and KA3842E variants, differing primarily in temperature ratings and manufacturing revisions. The series is widely used in legacy and cost-sensitive power supply designs.

AC DC Converters, Offline Switchers Replacement Considerations

Direct substitutes include KA3842A and KA3842E from Fairchild/ON Semiconductor. Cross-brand equivalents like UC3842B may require pinout and parameter verification.