The LTC1649 is a high power, high efficiency switching regulator controller optimized for use with very low supply voltages. It operates from 2.7V to 5V input, and provides a regulated output voltage from 1.26V to 2.5V at up to 20A load current. A typical 3.3V to 2.5V application features efficiency above 90% from 1A to 10A load. The LTC1649 uses a pair of standard 5V logic-level N-channel external MOSFETs, eliminating the need for expensive P-channel or super-low-threshold devices. The LTC1649 shares its internal switching architecture with the LTC1430, and features the same ±1% line, load and temperature regulation characteristics. Current limit is user-adjustable without requiring an external low-value sense resistor.
The LTC1649 switching regulator controller operates from 2.7 V to 5 V input and provides a regulated output of 1.26 V to 2.5 V at up to 20 A. It features a 200 kHz internal PWM oscillator, a charge‑pump that supplies 5 V gate drive, and a synchronous architecture for high efficiency.
The device is supplied in a 16‑lead plastic small‑outline (narrow) package and includes pins for driver outputs, feedback, shutdown, soft‑start, and external compensation. Detailed electrical characteristics, pin functions, and external component selection guidelines are provided for designing high‑efficiency buck converters.
| Input Voltage Range | 2.7 V to 5 V |
|---|---|
| Output Voltage Range | 1.26 V to 2.5 V |
| Maximum Output Current | 20 A |
| Switching Frequency | 200 kHz |
| Efficiency | >90 % |
| Maximum Duty Cycle | ≈93 % |
| Package | 16‑lead plastic small‑outline (narrow) |
The LTC1649 operates from 2.7 V to 5 V input.
It can deliver up to 20 A of load current.
The internal PWM oscillator runs at 200 kHz.
The device is supplied in a 16‑lead plastic small‑outline (narrow) package.