REGULATING PWM IC
D*CRIPTION
The UTC U3525 is a pulse width modulator IC and designed for
switching power supplies application to improve performance and
reduce external parts usage.
A shutdown terminal 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 output stage features *R logic, giving
a LOW output for an OFF state. An under-voltage lockout circuitry,
which keeps the outputs off and the soft-start capacitor discharged
for sub-normal input voltages, includes approximately 500 mV of
hysteresis for jitter free operation. The PWM circuits also feature a
latch following the comparator. When a PWM pulses has been
terminated, the outputs will remain off for the duration of the period.
The latch is reset with each clock pulse. The output stages are
totem-pole designs capable of sourcing or sinking in excess of
200mA.
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
**的振荡器同步终端
*可调*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