Chip Features Wide operating voltage range: +8V～+35V Built-in 5.1V reference voltage, accuracy ±2% Wide oscillation frequency range: 100Hz～500KHz With oscillator external synchronization function Adjustable dead time Built-in soft start circuit With input undervoltage lockout function With PWM latch function, prohibiting multiple pulses Dual-channel sink current, source current drive capability Package: SOP-16 and DIP-16

Chip Description

The EG3525S chip integrates a 5.1V reference voltage source, a 100Hz～500KHz wide-frequency oscillator, a soft-start circuit, an error amplifier, a PWM comparator, an undervoltage lockout circuit, and a power tube output drive circuit, etc. The EG3525S has a synchronous clock function and can operate in master-slave mode or synchronize with external system clock signals, providing great flexibility in design. Adding a resistor between the CT pin and the Discharge pin allows adjustment of the dead time.

The EG3525S integrates a soft-start circuit. A timing capacitor connected to pin 8 is all that's needed to implement the PWM soft-start function. During power-up, the voltage of the soft-start timing capacitor is charged by an internal 50uA constant current source. The voltage across the capacitor slowly rises from zero to Vref, and the PWM output also slowly increases from zero to the maximum duty cycle required for voltage regulation. When the voltage across the timing capacitor reaches Vref, the soft-start process is complete.

When the fault circuit controls the Shutdown signal, this shutdown signal affects both the output stage and the soft-start circuit. When the signal on Shutdown (pin 10) is high, the EG3525S output is disabled, and the soft-start capacitor begins to discharge. If this high level persists, the soft-start capacitor will fully discharge until the shutdown signal ends, at which point the soft-start process restarts. The Shutdown pin should not be left floating; it should be reliably grounded through a ground resistor to prevent external interference signals from coupling and affecting the normal operation of the EG3525S.