AP1539 Datasheet | Diodes Incorporated

18V 4A 300KHz BUCK CONVERTER Features General Description - Input voltage: 3.6V to 18V - Output voltage: 0.8V to VCC - Output current: up to 4A - Duty ratio: 0% to 99% PWM control - Oscillation frequency: 300KHz typ. - Soft-start like, Current limit and Enable function - Thermal Shutdown function - Built-in internal SW P-channel MOS - SOP-8L-DEP: Available in “Green” Molding pound (No Br, Sb) - Lead Free Finish / Ro HS pliant (Note 1) AP1539 consists of step-down switching regulator with PWM control. These devices include a reference voltage source, oscillation circuit, error amplifier, internal PMOS. AP1539 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to vary the duty ratio linearly from 0 up to 99%. This converter also contains an error amplifier circuit as well as a soft-start circuit that prevents overshoot at startup. An enable function, an over current protect function and a short circuit protect function are built inside, and when OCP or SCP happens, the operation frequency will be reduced from 300KHz to 50KHz. Also, an internal pensation block is built in to minimum external ponent count. With the addition of an internal P-channel Power MOS, a coil, capacitors, and a diode connected externally, these ICs can function as step-down switching regulators. They serve as ideal power supply units for portable devices when coupled with the SOP-8L-DEP mini-package, providing such outstanding Features as low current consumption. Since this converter can acmodate an input voltage up to 18V, it is also suitable for the operation via an AC adapter. Applications - PC Motherboard - LCD Monitor - Graphic Card - DVD-Video Player - Tele Equipment - ADSL Modem - Printer and other Peripheral Equipment - Microprocessor core supply Typical Application Circuit Vcc Output ROCSET COCSET 3.9K Option AP 1539 C...