The LTC3703 is a synchronous step-down switching regulator controller that can directly step down voltages from up to 100V, making it ideal for telecom and automotive applications. It drives external N-channel MOSFETs using a constant frequency (up to 600kHz), voltage mode architecture. A precise internal reference provides 1% DC accuracy. It has a high bandwidth error amplifier and patented line feed-forward compensation for fast line and load transient response. The LTC3703 has strong 1Ω gate drivers for higher current applications. The operating frequency is user programmable from 100kHz to 600kHz and can be synchronized to an external clock for noise-sensitive applications. Current limit is programmable with an external resistor and utilizes the voltage drop across the synchronous MOSFET to eliminate the need for a current sense resistor. For applications requiring up to 60V operation with logic-level MOSFETs, refer to the LTC3703-5 data sheet.
The LTC3703 is a synchronous step‑down switching regulator controller designed for high‑voltage applications up to 100 V. It features large 1Q gate drivers, no current‑sense resistor, programmable constant‑frequency operation (100 kHz‑600 kHz), +1% reference accuracy, and a selectable pulse‑skip mode. The device supports both step‑up (boost) and step‑down (buck) configurations and includes programmable current limit and soft‑start functions.
Electrical characteristics include a supply voltage range of –0.3 V to 100 V, shutdown current of 50 µA typ, and operating temperature ranges from –40 °C to 150 °C depending on package. Pin functions cover mode/sync, frequency set, compensation, feedback, current limit, gate drives, and power supplies. The part is offered in 16‑lead narrow SSOP and 28‑lead SSOP packages, with detailed package dimensions and recommended solder pad layouts. Typical applications include telecom, networking equipment, and automotive power supplies.
| Maximum Input Voltage | 100 V |
|---|---|
| Programmable Frequency Range | 100 kHz to 600 kHz |
| Reference Accuracy | +1 % (typ) |
| Shutdown Current | 50 µA typ |
The LTC3703 can handle input voltages up to 100 V.
The device’s constant‑frequency operation can be programmed from 100 kHz to 600 kHz.
The shutdown current is typically 50 µA.