UC3525AN | Texas Instruments

Regulating Pulse Width Modulator, UC3525AN, Texas Instruments

The UC3525AN pulse width modulator integrated circuit is designed to offer improved performance and lowered external parts count when used in designing all types of switching power supply. The on-chip 5.1-V reference is trimmed to 1% and the input common-mode range of the error amplifier includes the reference voltage, eliminating external resistor. A sync input to the oscillator allows a multiple unit to be slaved or a single unit to be synchronized to an external system clock.

A single resistor between CT and the discharge terminal provides a wide range of dead-time adjustment. This device also features built-in soft-start circuitry with only an external timing capacitor required. A shutdown terminal controls both the soft-start circuitry and the output stage, providing instantaneous turn off through the PWM latch with pulsed shutdown, as well as soft-start recycle with longer shutdown commands.

Features

• Separate Oscillator Sync Terminal
• Adjustable Dead-Time Control
• Internal Soft Start
• Pulse-by-Pulse Shutdown
• Input Undervoltage Lockout With Hysteresis

Applications

• Converters Using Voltage Mode
• Solar Inverters
• Welding Inverters
• Motor Control
• Battery Chargers