KSR1004BU

Overview

The SRK1004BU is a synchronous rectifier controller designed for secondary-side implementation in non-complementary active clamp flyback, resonant flyback, and quasi-resonant flyback converters. It provides gate drive for N-channel MOSFETs, switching on during body diode conduction and off near zero current. The device supports low-side and high-side configurations with a supply voltage range of 4 V to 36 V. Key specifications include a maximum operating frequency of 500 kHz, a quiescent current of 230 µA, and an operating current of 580 µA. It features a high-voltage sensing input rated at 190 V AMR and fast short-circuit protection. The component is housed in a compact DFN 6L 2x2 mm package.

Feature Summary

• Optimized control scheme for secondary-side synchronous rectification in NC-ACF and QR topologies
• Supports both low-side and high-side MOSFET configurations with dedicated power options
• Integrated fast short-circuit detection mechanism for enhanced reliability
• Compatible with logic-level and standard-level N-channel power MOSFETs

Applications

• Secondary-side synchronous rectification in non-complementary actively clamped flyback converters
• Resonant flyback converter designs requiring efficient rectification
• Quasi-resonant flyback power supplies

Procurement Notes

Verify the exact manufacturer designation, as the model prefix 'SRK' typically corresponds to STMicroelectronics products rather than Fairchild Semiconductor. Confirm the datasheet source and part authenticity through official manufacturer channels or authorized distributors to ensure compatibility with the specified electrical parameters and package dimensions.

Selection Notes

Select this controller for applications requiring flexible configuration in either low-side or high-side synchronous rectification modes. Ensure the chosen N-channel MOSFET matches the supported logic or standard level requirements. Verify that the converter topology aligns with the device's optimization for non-complementary active clamp or quasi-resonant schemes to achieve optimal efficiency and performance.

Part Context

This component belongs to the family of synchronous rectifier controllers intended for high-efficiency power conversion. It serves as a replacement for traditional rectifier diodes in flyback architectures, utilizing active MOSFET control to reduce conduction losses. The specific variant includes features tailored for robust operation across varying load conditions and supply voltages within the specified range.