The LTC3775IUD#PBF is a high efficiency synchronous step-down switching DC/DC controller that drives an all N-channel power MOSFET stage from a 4.5V to 38V input supply voltage. A patented line feedforward compensation circuit and a high bandwidth error amplifier provide very fast line and load transient response.
High step-down ratios are made possible by a low 30ns minimum on-time, allowing extremely low duty cycles. MOSFET RDS(ON) current sensing maximizes efficiency. Alternatively, a sense resistor can be used for higher current limit accuracy. Continuous monitoring of the voltages across the top and bottom MOSFETs allows cycle-by-cycle control of the inductor current, configurable by external resistors.
The soft-start function controls the duty cycle during start-up, providing a smooth output voltage ramp up. The operating frequency is user programmable from 250kHz to 1MHz and can be synchronized to an external clock.
Feature
- Wide VIN Range: 4.5V to 38V
- Line Feedforward Compensation
- Low Minimum On-Time: tON(MIN) < 30ns
- Powerful On-board MOSFET Drivers
- Leading Edge Modulation Voltage Mode Control
- ±0.75%, 0.6V Reference Voltage Accuracy Over Temperature
- VOUT Range: 0.6V to 0.8VIN
- Programmable, Cycle-by-Cycle Peak Current Limit
- Sense Resistor or RDS(ON) Current Sensing
- Programmable Soft-Start
- Synchronizable Fixed Frequency from 250kHz to 1MHz
- Selectable Pulse-Skipping or Forced Continuous Modes of Operation
- Low Shutdown Current: 14μA Typical
- Thermally Enhanced 16-Lead MSOP and 3mm × 3mm QFN Packages
Applications
- Automotive Systems
- Telecom and Industrial Power Supplies
- Point of Load Applications
(Picture: Pinout)
