LT3640

LT3640 Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer Features Description n High Voltage Buck Regulator: 4V to 35V Operating Range 1.3A Output Current n OVLO Protects Input to 55V n Low Voltage Synchronous Buck Regulator: 2.5V to 5.5V Input Voltage Range 1.1A Output Current n Synchronizable, Adjustable 350kHz to 2.5MHz Switching Frequency n Programmable Power-On Reset Timer n Programmable Window Mode Watchdog Timer n Typical Quiescent Current: 290µA n Short-Circuit Robust n Programmable Soft-Start n Low Shutdown Current: IQ < 1µA n Available in Thermally Enhanced 28-Lead (4mm × 5mm) QFN and 28-Lead TSSOP Packages Applications n Industrial Power Supplies n Automotive Electronic Control Units L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. The LT®3640 is a dual channel, current mode monolithic buck switching regulator with a power-on reset and a watchdog timer. Both regulators are synchronized to a single oscillator with an adjustable frequency (350kHz to 2.5MHz). At light loads, both regulators operate in low ripple Burst Mode® to maintain high efficiency and low output ripple. The high voltage channel is a nonsynchronous buck with an internal 2.4A top switch that operates from an input of 4V to 35V; a 36.5V OVLO protects the device to 55V. The low voltage ch...