NCP1337PG

Overview

The NCP1337PG is a PWM current-mode controller designed for free-running quasi-resonant operation in AC-DC offline switching applications. It utilizes a flyback topology with one output, operating at a switching frequency of 100 kHz. The device supports an input voltage range from 90 VAC to 265 VAC and provides an output voltage of 18 V with a maximum output current capability of 500 mA. It functions within a temperature range of -25°C to +125°C and is housed in a PDIP-7 through-hole package.

Feature Summary

• Implements soft skip cycle technology to control peak current and remove switching pulses during light-load or no-load conditions, significantly reducing switching losses and improving efficiency in standby modes.
• Utilizes coil-less demagnetization detection for quasi-resonant operation, eliminating the need for auxiliary winding components and independent pins to reduce external component count.
• Integrates synchronous rectification control to match the output rectifier, substantially decreasing secondary side conduction losses while maintaining high efficiency under load.

Applications

• High-efficiency power adapters for consumer electronics
• ATX power supplies requiring strict energy conservation standards
• Offline switching regulators with low standby power requirements

Procurement Notes

Verify the specific suffix PG against the official onsemi datasheet to confirm the PDIP-7 through-hole package configuration. Confirm that the part number corresponds to the correct revision level, as manufacturing updates may affect pin compatibility or internal circuitry. Ensure the procurement source provides valid traceability documentation for this discontinued or legacy component series.

Selection Notes

Select this controller for designs prioritizing high efficiency across both full-load and no-load conditions using a flyback topology. The integrated coil-less sensing simplifies transformer design by removing auxiliary winding constraints. Consider the PDIP-7 package for through-hole assembly processes where thermal dissipation and mechanical robustness are required over surface-mount alternatives.

Part Context

The NCP1337 belongs to onsemi's family of AC-DC offline switching controllers focused on power factor correction and quasi-resonant operation. This specific variant targets applications demanding superior performance in both active and standby modes compared to traditional fixed-frequency PWM controllers. It addresses modern energy regulations by minimizing power consumption during idle states through advanced pulse-skipping techniques.

Replacement Considerations

Consult the official onsemi replacement guide for direct cross-reference parts. Verify pinout compatibility and electrical parameter equivalence before substituting with other flyback controllers in the NCP13xx series or equivalent offerings from other manufacturers.