The LTC1735 is a synchronous step-down switching regulator controller that drives external N-channel power MOSFETs using a fixed frequency architecture. Burst Mode operation provides high efficiency at low load currents. The precision 0.8V reference is compatible with future generation microprocessors. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The operating frequency (synchronizable up to 500kHz) is set by an external capacitor allowing maximum flexibility in optimizing efficiency. A forced continuous control pin reduces noise and RF interference and can assist secondary winding regulation by disabling Burst Mode operation when the main output is lightly loaded. Protection features include internal foldback current limiting, output overvoltage crowbar and optional short-circuit shutdown. Soft-start is provided by an external capacitor that can be used to properly sequence supplies. The operating current level is user-programmable via an external current sense resistor. Wide input supply range allows operation from 4V to 30V (36V maximum).
The LTC1735 is a synchronous step‑down switching regulator controller that drives external N‑channel MOSFETs. It offers a wide input range, programmable output voltage, and high efficiency with Burst Mode operation. Key features include +1% output voltage accuracy, internal current foldback protection, and optional short‑circuit shutdown.
The document provides electrical characteristics, absolute maximum ratings, pin descriptions, typical performance graphs, package dimensions, and a reference application circuit. It also lists part numbers for related controllers and includes mechanical drawings for the SSOP and TSSOP packages.
| Input Voltage Range | 4 V to 36 V |
|---|---|
| Output Voltage Range | 0.8 V to 6 V |
| Output Voltage Accuracy | +1 % |
| Package Options | 16‑Lead Narrow SSOP, 20‑Lead TSSOP |
| Synchronizable Frequency | up to 500 kHz |
The device operates from 4 V up to 36 V input.
The output voltage is set by an external resistive divider connected to the Vosense pin, using the internal 0.8 V reference.
It provides internal current foldback, an output overvoltage crowbar, and an optional latched short‑circuit shutdown timer.