Features

• Wide Operating Input Voltage Range: 4V to 140V
• Internal Low Resistance Power MOSFET
• No Compensation Required
• Adjustable 20mA to 250mA Maximum Output Current
• Low Dropout Operation: 100% Duty Cycle
• Low Quiescent Current: 12μA
• Wide Output Range: 0.8V to V_IN
• 0.8V ±1% Feedback Voltage Reference
• Precise RUN Pin Threshold
• Internal or External Soft-Start
• Programmable 1.8V, 3.3V, 5V or Adjustable Output
• Few External Components Required
• Programmable Input Overvoltage Lockout
• Thermally Enhanced High Voltage MSOP Package

Typical Application

Description

The LTC®3638 is a high efficiency step-down DC/DC regulator with internal power switch that draws only 12μA typical DC supply current while maintaining a regulated output voltage at no load.

The LTC3638 can supply up to 250mA load current and features a programmable peak current limit that provides a simple method for optimizing efficiency and for reducing output ripple and component size. The LTC3638’s combination of Burst Mode® operation, integrated power switch, low quiescent current, and programmable peak current limit provides high efficiency over a broad range of load currents.

With its wide input range of 4V to 140V and programmable overvoltage lockout, the LTC3638 is a robust regulator suited for regulating from a wide variety of power sources. Additionally, the LTC3638 includes a precise run threshold and soft-start feature to guarantee that the power system start-up is well-controlled in any environment. A feedback comparator output enables multiple LTC3638s to be connected in parallel for higher current applications.

The LTC3638 is available in a thermally enhanced high voltage-capable 16-lead MSE package with four missing pins.