DESCRIPTION
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.

FEATUREs
■ High Voltage Buck Regulator:
   4V to 35V Operating Range
   1.3A Output Current
■ OVLO Protects Input to 55V
■ Low Voltage Synchronous Buck Regulator:
   2.5V to 5.5V Input Voltage Range
   1.1A Output Current
■ Synchronizable, Adjustable 350kHz to 2.5MHz
   Switching Frequency
■ Programmable Power-On Reset Timer
■ Programmable Window Mode Watchdog Timer
■ Typical Quiescent Current: 290µA
■ Short-Circuit Robust
■ Programmable Soft-Start
■ Low Shutdown Current: IQ < 1µA
■ Available in Thermally Enhanced 28-Lead
   (4mm × 5mm) QFN and 28-Lead TSSOP Packages

APPLICATIONS
■ Industrial Power Supplies
■ Automotive Electronic Control Units