SC4431CSK-1 TRT

Overview

The SC4431CSK-1 TRT is a four-terminal shunt regulator with an open collector output, designed for regulating isolated power supplies with output voltages as low as 1.5V. It features a trimmed bandgap reference with initial accuracies of ±0.5% and a typical supply current of 110µA. The device supports a wide supply voltage range from 1.5V to 15V and can regulate output down to 50mV. It operates within the full industrial temperature range and is housed in a SOT-23 five-lead package.

Feature Summary

• Four-terminal architecture separates supply and output pins to enable regulation at very low output voltages
• Open collector output drives optoisolators with minimal input voltage requirements
• Trimmed bandgap design ensures high initial accuracy without external trimming components

Applications

• Opto driver for very low output voltage (1.5V) isolated power supplies
• Telecom power supplies
• Battery operated applications
• Point of use power supplies

Procurement Notes

Verify the specific suffix 'TRT' against official Semtech documentation to confirm reel packaging specifications and tape-and-reel dimensions. Ensure the component matches the exact pinout and electrical characteristics defined in the datasheet for the CSK variant. Cross-reference the manufacturer part number with authorized distributors to confirm availability and authenticity before procurement.

Selection Notes

Select this component when standard three-terminal shunt regulators cannot function due to insufficient voltage headroom across an optocoupler. The separate supply and cathode pins allow the device to maintain regulation even when the output voltage drops below the internal reference level. This makes it suitable for low-voltage isolated DC-DC converters where traditional references fail.

Part Context

This device belongs to the SC4431 family of low-voltage shunt regulators. It serves as a specialized replacement for standard three-terminal devices like the SC431L in applications requiring regulation below 2V. The four-terminal design distinguishes it from conventional references by decoupling the operating supply voltage from the regulated output sink capability.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material.