SG2525AN

Overview

The SG2525AN is a regulating pulse width modulator integrated circuit designed for switching power supply applications. It operates within an 8V to 35V supply range and features a 5.1V reference trimmed to ±1% accuracy. The device supports oscillator frequencies from 100Hz to 500kHz with a maximum duty cycle of 49%. It includes built-in soft-start, undervoltage lockout with hysteresis, and a shutdown pin. The output stages are totem-pole designs capable of sourcing or sinking over 200mA, housed in a 16-pin DIP package.

Feature Summary

• Built-in soft-start circuitry requiring only an external timing capacitor
• Undervoltage lockout with approximately 500mV hysteresis for jitter-free operation
• Totem-pole output drivers capable of sourcing or sinking in excess of 200mA
• Pulse-by-pulse shutdown via PWM latch preventing multiple pulses

Applications

• All types of switching power supplies
• AC/DC converters
• DC/DC converters

Procurement Notes

Verify the manufacturer designation carefully, as the SG2525A series was originally developed by SGS-Thomson (now STMicroelectronics) and Microsemi (now Microchip). Ensure the specific part number matches the required logic family and performance specifications from the official datasheet before procurement to avoid functional mismatches in critical power management designs.

Selection Notes

Select this component when designing systems requiring a dual-channel push-pull PWM controller with integrated soft-start and precise voltage regulation. The wide operating frequency range and adjustable dead-time control make it suitable for various transformer-coupled topologies. Consider the 49% maximum duty cycle limitation when selecting transformer turns ratios.

Part Context

The SG2525AN belongs to the SG1525A/1527A series of pulse width modulators. This series is engineered to improve performance while lowering external parts count compared to earlier generations. The SG2525 variant specifically utilizes NOR logic for its output stage, resulting in a LOW output level during the OFF state, distinguishing it from the OR-logic based SG2527A.

Replacement Considerations

The SG2525AP serves as a direct pin-compatible replacement offering the same functionality in an NSOIC-16 surface-mount package instead of the through-hole DIP-16 format.