The LTC3850IUF is a high performance dual synchronous step-down switching regulator controller that drives all N-channel power MOSFET stages. A constant-frequency current mode architecture allows a phase-lockable frequency of up to 780kHz. Power loss and supply noise are minimized by operating the two controller output stages out of phase.
OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3850IUF features a precision 0.8V reference and a power good output indicator. A wide 4V to 24V (28V maximum/30V for LTC3850I) input supply range encompasses most battery chemistries and intermediate bus voltages.
Independent TK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping mode, or continuous inductor current mode and allows the IC to be synchronized to an external clock.
The LTC3850IUF is available in low profile 28-pin 4mm x 4mm, 4mm x 5mm QFN and narrow SSOP packages.
Features LTC3850SSOP-28 and QFN-28 PackagesLTC3850-1 ILIM function replaced with an EXTVCC function, SSOP-28 package onlyLTC3850-2 The LTC3850-2 is identical to the LTC3850-1 SSOP-28, except they have different pin-outsFeature
- Dual, 180° Phased Controllers Reduce Required
- Input Capacitance and Power Supply Induced Noise
- High Efficiency: Up to 95%
- RSENSE or DCR Current Sensing
- ±1% 0.8V Output Voltage Accuracy
- Phase-Lockable Fixed Frequency 250kHz to 780kHz
- Supports Pre-Biased Output
- Dual N-Channel MOSFET Synchronous Drive
- Wide VIN Range: 4V to 24V (30V for LTC3850I) Operation
- Adjustable Soft-Start Current Ramping or Tracking
- Foldback Output Current Limiting
- Output Overvoltage Protection
- Power Good Output Voltage Monitor
- 28-Pin 4mm × 4mm, 4mm × 5mm QFN and Narrow SSOP Packages
Applications
- Notebook and Palmtop Computers
- Portable Instruments
- Battery-Operated Digital Devices
- DC Power Distribution Systems
(Picture: Pinout)
