SRK1000BTR

Power Supply Controllers, Monitors Overview

The SRK1000BTR is an adaptive synchronous rectification controller designed for the secondary side of flyback converters. It supports QR and mixed CCM/DCM fixed frequency operation with a switching frequency up to 300 kHz. The device features a wide Vcc operating voltage range from 3.75 V to 32 V and supports CC regulation down to 2 V output. It provides a high-current gate-drive output for N-channel MOSFETs, utilizing fast turn-on and adaptive turn-off logic to maximize conduction time. The component operates within a temperature range of -40°C to +150°C and is housed in a SOT-23-6 package.

Power Supply Controllers, Monitors Feature Summary

• Adaptive control scheme that turns on the SR MOSFET when body diode current flows and turns it off as current approaches zero.
• Innovative adaptive turn-off logic eliminates parasitic inductance effects and maximizes SR MOSFET conduction time.
• Automatic entry into low consumption mode upon detecting primary side burst-mode or insufficient SR MOSFET conduction.
• High-voltage sensing input capable of handling 100 V AMR for SR MOSFET drain-source voltage detection.

Power Supply Controllers, Monitors Applications

• Secondary side synchronous rectification in QR flyback converters
• Mixed CCM/DCM fixed frequency flyback converter designs
• Low output voltage applications requiring CC regulation down to 2 V

Power Supply Controllers, Monitors Procurement Notes

Verify the specific suffix BTR against the official STMicroelectronics datasheet to confirm the fixed minimum turn-off time configuration. Ensure the design accounts for the SOT-23-6 thermal characteristics given the high junction temperature rating. Confirm that the 300 kHz maximum switching frequency aligns with the transformer specifications. Validate that the 3.75 V to 32 V Vcc range covers the startup and running conditions of the target power supply circuit.

Power Supply Controllers, Monitors Selection Notes

Select this component for flyback topologies requiring adaptive synchronous rectification to improve light-load efficiency. The SRK1000BTR variant offers a fixed minimum turn-off time option distinct from other variants in the series. It is suitable for designs needing high-current gate drive for N-MOSFETs without external drivers. Consider the 160 μA quiescent current in low consumption mode for strict standby power requirements.

Power Supply Controllers, Monitors Part Context

The SRK1000BTR belongs to the SRK1000 family of synchronous rectification controllers from STMicroelectronics. This family includes variants like SRK1000 and SRK1000A, which differ primarily in their programmable minimum turn-on and fixed minimum turn-off time settings. These controllers are optimized for enhancing efficiency in flyback power supplies by replacing traditional diodes with actively controlled MOSFETs.

Power Supply Controllers, Monitors Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult STMicroelectronics for potential obsolescence management or direct replacements if the NRND status applies.