NCP1377BD1R2G

AC DC Converters, Offline Switchers Overview

The NCP1377BD1R2G is an offline PWM current-mode controller designed for flyback topologies. It integrates a true current mode modulator and demagnetization detector to ensure boundary conduction with minimum drain voltage switching. The device features an internal timer limiting no-load frequency to 150 kHz, skip regulation for low-noise burst mode operation, and transformer core reset detection via auxiliary winding for fast overvoltage protection. It includes short-circuit protection with auto-recovery and a 1 ms soft-start function.

AC DC Converters, Offline Switchers Feature Summary

• Combines current mode modulation with demagnetization detection for quasi-resonant operation
• Internal timer limits no-load frequency to prevent EMI issues
• Skip regulation enables noise-free burst mode at light loads
• Auxiliary winding-based core reset detection provides fast overvoltage protection

AC DC Converters, Offline Switchers Applications

• Offline AC-DC power supplies
• Flyback converter designs
• Adapters and chargers
• Set-top box power sources

AC DC Converters, Offline Switchers Procurement Notes

Verify component authenticity through authorized channels due to end-of-life status. Confirm package integrity upon receipt. Check datasheet revisions for parameter updates. Ensure storage conditions meet manufacturer specifications. Validate pinout compatibility during integration.

AC DC Converters, Offline Switchers Selection Notes

Select this controller for flyback applications requiring quasi-resonant efficiency and low acoustic noise. Consider the SOIC-7 package for surface mount constraints. Evaluate thermal performance within the specified operating temperature range. Verify input voltage requirements against the UVLO thresholds. Assess EMI compliance needs regarding the internal frequency limit.

AC DC Converters, Offline Switchers Part Context

Part of the NCP1377 series from onsemi, focusing on offline controllers. Belongs to the PMIC - Power Management ICs subcategory. Designed for variable frequency current mode control in flyback converters. Manufactured by onsemi under the NCP1377 family.

AC DC Converters, Offline Switchers Replacement Considerations

NCP1377BPG is a PDIP-7 through-hole alternative within the same series.

AC DC Converters, Offline Switchers FAQ

How does the NCP1377BD1R2G handle overvoltage conditions?

It uses transformer core reset detection via an auxiliary winding to implement fast overvoltage protection, which permanently latches off the device upon detection.

What mechanism prevents audible noise in this controller?

The internal skip regulation feature allows the device to enter burst mode at low peak currents when power requirements drop, eliminating audible noise.