REGULATING PWM IC DESCRIPTIONThe UTC U3525 is a pulse width modulator IC and designed forswitching power supplies application to improve performance andreduce external parts usage.A shutdown terminal controls both the soft-start circuitry and theoutput stages, providing instantaneous turn off through the PWMlatch with pulsed shutdown, as well as soft-start recycle with longershutdown commands. The output stage features NOR logic, givinga LOW output for an OFF state. An under-voltage lockout circuitry,which keeps the outputs off and the soft-start capacitor dischargedfor sub-normal input voltages, includes approximately 500 mV ofhysteresis for jitter free operation. The PWM circuits also feature alatch following the comparator. When a PWM pulses has beenterminated, the outputs will remain off for the duration of the period.The latch is reset with each clock pulse. The output stages aretotem-pole designs capable of sourcing or sinking in excess of200mA. 特征*输入电压：8?35V的*片上5.1 V参考电压的微调至± 1％*?500kHz的振荡器100Hz的范围*独立的振荡器同步终端*可调死区时间控制*内部软启动*脉冲的脉冲关闭*输入欠压滞后锁定*闭锁的PWM脉冲，以避免多重*双源/汇输出驱动器