SC1409 Datasheet | SEMTECH

1 A Synchronous Switching Regulator June 28, 2000 TEL:805-498-2111 FAX:805-498-3804 WEB:http://.semtech. DESCRIPTION The SC1409 is a versatile, voltage-mode switching regulator designed for use in battery operated power supply applications. A simple, fixed-voltage buck regulator can be implemented using the SC1409 with a minimum of external ponents. Internal MOSFETs and control circuitry minimize board space and design time. The small device footprint allows for pact circuit design. SC1409 Features include a temperature pensated voltage reference, triangle wave oscillator, hiccup mode current limit, an internally pensated error amplifier, overcurrent temperature protection, soft start, and under voltage lock out. The SC1409 operates at a selectable, fixed frequency of 300k Hz or 500k Hz, or can be synchronized to an external clock within this range, providing an optimum promise between efficiency, external ponent size, and cost. Features - = Internal MOSFETs - = Excellent efficiency >88% - = 1% Voltage accuracy - = Built-in over current protection - = 1A Output current - = 5µA Standby current - = Industrial temperature range - = 300k Hz/500k Hz selectable frequency APPLICATIONS - = Handheld equipment - = PDA power supplies - = Notebook I/O power supplies - = Peripheral card supplies - = High density DC/DC conversion ORDERING INFORMATION DEVICE (1) PACKAGE SO-8 SC1409ISTR Note: (1) Only available in tape and reel packaging. A reel contains 2500 devices. APPLICATION CIRCUIT Vin=5V R1 OPEN U1 1 2 Vout 3.45V 3.30V 3.10V 2.90V 2.80V 2.50V 1.50V R3 1.87k 1.74k 1.58k 1.40k 1.33k 1.07k 249 R4 1.00k 1.00k 1.00k 1.00k 1.00k 1.00k 1.00k C6 0.1u F SYNC/FSET EN/SS AGND FB...