The LTC3631 is a high-voltage, high-efficiency step-down DC/DC converter in heat-enhanced 3mm x 3mm DFN and MS8E packages with built-in high-side and synchronous power switches that absorb only 12μA of typical DC supply current when unloaded while maintaining output voltage regulation.
Typical Application
The LTC3631 delivers load current up to 100mA and features programmable peak current limits, providing an easy way to optimize efficiency for low-current applications. The LTC3631's burst mode operation, integrated power switch, and combination of low static current and programmable peak current limits provide high efficiency over a wide range of load currents.
Pin Configuration
With an extensive 4.5V to 45V input range and an internal overvoltage monitor capable of protecting components from 60V surges, the LTC3631 is a powerful converter suitable for regulating a wide range of power supplies. In addition, the LTC3631 includes precise operating thresholds and soft start capabilities to ensure that power system startup is well controlled in any environment.
The LTC3631 is a step-down DC/DC converter with a built-in power switch and burst mode control that combines low static current with high switching frequency to achieve high efficiency over a wide load current range. Burst mode tilts inductive current through the internal power switch by using a short "burst" period, followed by a sleep period in which the power switch is off and the load current is supplied by the output capacitor. During the sleep cycle, LTC3631 attracts only 12 μA of supply current. At light loads, burst cycles account for a small portion of the total cycle time, thus minimizing the average supply current and greatly improving efficiency.
Block Diagram
Features
● Wide Input Voltage Range: Operation from 4.5V to 45V
● Overvoltage Lockout Provides Protection Up to 60V
● Internal High Side and Low Side Power Switches
● No Compensation Required
● 100mA Output Current
● Low Dropout Operation: 100% Duty Cycle
● Low Quiescent Current: 12µA
● 0.8V ±1% Feedback Voltage Reference
● Adjustable Peak Current Limit
● Internal and External Soft-Start
● Precise RUN Pin Threshold with Adjustable Hysteresis
● 3.3V, 5V and Adjustable Output Versions
● Only Three External Components Required for Fixed Output Versions
● Low Profile (0.75mm) 3mm x 3mm DFN and Thermally-Enhanced MS8E Packages
Applications
● 4mA to 20mA Current Loops
● Industrial Control Supplies
● Distributed Power Systems
● Portable Instruments
● Battery-Operated Devices
● Automotive Power Systems
