SG3525ADTR(XBLW)

The SG3525 pulse width modulator control circuit offers improved performance and lower external parts count when Implemented for controlling all types of switching power supplies. The on-chip +5.1V reference is trimmed to ±1%, and the error amplifier has an input common-mode voltage range that includes the reference voltage, thus eliminating the need for external divider resistors. A sync input to the oscillator enables multiple units to be slaved or a single unit to be synchronized to an external system clock. A wide range of deadtime can be programmed by a single resistor connected between the CT and Discharge pins. This device also features builtin soft-start circuitry, requiring only an external timing capacitor. A shutdown pin controls both the soft-start circuitry and the output stages, providing instantaneous turn off through the PWM latch with pulsed shutdown, as well as soft-start recycle with longer shutdown commands. The under voltage lockout inhibits the outputs and the changing of the soft-start capacitor when VCC is below nominal. The output stages are totem-pole design capable of sinking and sourcing in excess of 150mA. The output stage of the SG3525 features NOR logic resulting in a low output for an off-state.

Applications

• Welding Inverters
• Solar Inverters
• Motor Control
• Battery Chargers
• Converters Using Voltage Mode
• Off-Line and DC/DC Power Supplies
• Single-Ended or Two-Switch Topology Designs

Key features

• 8.0 V to 35 V Operation
• 5.1 V Reference Trimmed to ±1%
• 100 Hz to 500 kHz Oscillator Range
• Separate Oscillator Sync Terminal
• Adjustable Deadtime Control
• Input Undervoltage Lockout With Hysteresis
• Latching PWM to Prevent Multiple Pulses
• Pulse-by-Pulse Shutdown
• Dual Source/Sink Output Drivers
• Internal Soft-Start