
Linear Technology
DESCRIPTION
The LT®3685 is an adjustable frequency (200kHz to 2.4MHz) monolithic step-down switching regulator that accepts input voltages up to 38V operating and 60V maximum. An internal overvoltage protection circuit turns off the power switch when VINis above 38V typical (36V minimum) which then allows the part to safely withstand 60V transients. A high efficiency 0.25 switch is included on the die along with a boost Schottky diode and the necessary oscillator, control, and logic circuitry. Current mode topology is used for fast transient response and good loop stability.
FEATURES
■ Wide Input Range:
Operation From 3.6V to 36V
Overvoltage Lockout Protects Circuit through
60V Transients
■ 2A Maximum Output Current
■ Adjustable Switching Frequency: 200kHz to 2.4MHz
■ Low Shutdown Current: IQ < 1μA
■ Integrated Boost Diode
■ Synchronizable Between 250kHz to 2MHz
■ Power Good Flag
■ Saturating Switch Design: 0.25 On-Resistance
■ 0.790V Feedback Reference Voltage
■ Output Voltage: 0.79V to 20V
■ Soft-Start Capability
■ Small 10-Pin Thermally Enhanced MSOP and
(3mm × 3mm) DFN Packages
APPLICATIONS
■ Automotive Battery Regulation
■ Set Top Box
■ Distributed Supply Regulation
■ Industrial Supplies
■ Wall Transformer Regulation