The UC1525A/1527A family of PWM integrated circuits are designed to provide improved performance and reduced external parts count when used in all types of switching power supply designs. 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 the need for external resistors. The sync input oscillator can be slaved to multiple units 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 adjustments. These devices also feature built-in soft-start circuitry, requiring only an external timing capacitor. A shutdown terminal controls the soft-start circuit and output stage, providing instantaneous turn-off pulse shutdown through the PWM latch, and soft-start recycling longer shutdown commands. These functions also keep the undervoltage lockout control output off, and the soft-start capacitor is discharged from the normal input voltage. This locking circuit includes about 500mV of hysteresis for jitter-free operation. Another feature of these PWM circuits is a latched following comparison. Once the PWM pulse has been terminated for any reason, the output will remain off for the duration of the off period. with each reset latch clock pulse. The totem pole design of the output stage is capable of sourcing or sinking at more than 200mA. The features of the UC1525A output stage also have no logic, giving a low output to the off state. The UC1527A utilizes the OR logic result at a high output level when OFF