AP1533

• Product Introduction

AP1533The buck switch regulates PWM control

description The AP1533 includes a buck switch to regulate PWM control. The devices include a reference voltage source, oscillation circuitry, error amplifier, internal PMOS. The AP1533 provides a low-ripple power supply, high efficiency, and excellent transient characteristics. The PWM control circuit is capable of changing the duty cycle linearity from 0 to 99%. The converter also contains an error amplifier circuit as well as a soft-start circuit to prevent overshoot during start-up. Built-in enable function, overcurrent protection function and short circuit protection function will reduce the operating frequency from 300kHz to 50kHz when OCP or SCP occurs. In addition, the internal compensation block is built with a minimum number of external components. With internal P-channel power MOS, coils, capacitors and external diodes, these chips can also be used as buck switching regulators. They serve as an ideal power supply unit for portable devices in SO-8 small packages, offering outstanding features such as low current consumption. Since this converter can accommodate input voltages up to 23V, it is also suitable for operation through an AC adapter. Features and Benefits: • Input Voltage: 4V to 23V • Output Voltage: 0.8V to V CC • Output Current: 1.8A Peak 2A • Duty Cycle: 0% to 99% PWM Control • Oscillation Frequency: Typical at 300KHz. • Soft start as well, current limit and enable function • Thermal shutdown function • Built-in internal switch for P-channel MOS • SO-8: in "green" molded compound (bromine-free, antimony) • Lead-free finish/RoHS compliant apply • Computer motherboards • LCD displays • Graphics cards • DVD video players • Telecommunications equipment • ADSL modems • Printers and other peripherals • Microprocessor cores for power supply