The LTC3708EUH is a dual, 2-phase synchronous step-down switching regulator with output voltage up/down tracking capability. The IC allows either coincident or ratiometric tracking. Multiple LTC3708s can be daisy-chained in applications requiring more than two voltages to be tracked. Power supply sequencing is accomplished using an external soft-start timing capacitor.
The LTC3708EUH uses a constant on-time, valley current mode control architecture to deliver very low duty factors without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in input supply voltage. An internal phase-locked loop allows the IC to be synchronized to an external clock.
Fault protection is provided by an output overvoltage comparator and an optional short-circuit shutdown timer. The regulator current limit level is user programmable. A wide supply range allows voltages as high as 36V to be stepped down to 0.6V output.
Feature
- Very Low Duty Factor Operation (tON(MIN) < 85ns)
- No RSENSE™ Option for Maximum Efficiency
- Very Fast Transient Response
- Programmable Output Voltage Up/Down Tracking
- 2-Phase Operation Reduces Input Capacitance
- 0.6V ±1% Output Voltage Reference
- External Frequency Synchronization
- Monotonic Soft-Start
- On-board High Current MOSFET Drivers
- Wide VIN Range: Up to 36V
- Adjustable Cycle-by-Cycle Current Limit
- Instant Output Overvoltage Protection
- Optional Short-Circuit Shutdown Timer
- Power Good Output with 100µs Masking
- Available in 5mm × 5mm QFN Package
Applications
- Notebook and Palmtop Computers, PDAs
- Digital Signal Processors
- Network Servers
(Picture: Pinout)
