CS3524A Datasheet | Cherry Semiconductor Corporation

Description The CS3524A PWM control circuit retains the same versatile architecture of the industry standard CS3524 (SG3524) while adding substantial improvements. The CS3524 is pin-patible with “non-A” versions, and in most applications can be directly interchanged. The CS3524A, however, eliminates many of the design restrictions which had previously required additional external circuitry. The CS3524A includes a precision 5V reference trimmed to ±1% accuracy (eliminating the need for potentiometer adjustments), an error amplifier with an output voltage swing extending to 5V, and a current sense amplifier useful in either the ground or power supply output lines. The unmitted 60V, 200m A NPN output pair greatly enhances the output drive capability. The CS3524A features an undervoltage lockout circuit which disables all internal circuitry (except the reference) until the input voltage has risen to 8V. This holds standby current low until turnon, and greatly simplifies the design of low power, off-line supplies. The turnon circuit has approximately 600m V of hysteresis for jitter free activation. Other improvements include a PWM latch that insures freedom from multiple pulsing within a period, even in noisy environments; logic to eliminate double pulsing on a single output, a 200ns external shutdown capability, and automatic thermal protection from excessive chip temperature. The oscillator circuit is usable to 500k Hz and is easier to synchronize with an external clock pulse. Features s Precision Reference Internally Trimmed to ±1% s Current Limit s Undervoltage Lockout s Start-up Supply Current < 4m A s Output to 200m A s 60V Output Capability s Wide mon-mode Input Range for Error and Current Limit Amplifiers s PWM Latch Insures Single Pulse per Period s Double Pulse Suppression s 200ns Shutdown s Guaranteed Frequency s Thermal Shutdown Block Diagram V IN 5V Reference Regulator Power to Internal Circuitry T V REF Package Options 16 Lead PDIP & SO Wide EA- 1 EA+...