LTC3851-1: Synchronous Step-Down Switching Regulator Controller Data Sheet4/15/2009357K
Features and Benefits
- Wide VIN Range: 4V to 38V Operation
- RSENSE or DCR Current Sensing
- ±1% Output Voltage Accuracy
- Power Good Output Voltage Monitor
- Phase-Lockable Fixed Frequency: 250kHz to 750kHz
- Dual N-Channel MOSFET Synchronous Drive
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Output Voltage Soft-Start or Tracking
- Output Current Foldback Limiting
- Output Overvoltage Protection
- OPTI-LOOP® Compensation Minimizes COUT
- Selectable Continuous, Pulse-Skipping or Burst Mode® Operation at Light Loads
- Low Shutdown IQ: 20μA
- VOUT Range: 0.8V to 5.5V
- Thermally Enhanced 16-Lead MSOP or 3mm × 3mm QFN Package
The LTC3851-1 is a high performance synchronous step-down switching regulator controller that drives an all N-channel synchronous power MOSFET stage. A constant frequency current mode architecture allows a phase-lockable frequency of up to 750kHz.
OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3851-1 features a precision 0.8V reference and a power good indicator. A wide 4V to 38V (40V absolute maximum) input supply range encompasses most battery configurations and intermediate bus voltages.
The TK/SS pin ramps the output voltage during start-up and shutdown with coincident or ratiometric tracking. 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 at light loads and allows the IC to be synchronized to an external clock.
The LTC3851-1 is identical to the LTC3851 except that the ILIM pin is replaced by PGOOD.
|LTC3851||Not Recommended For New Designs|
|LTC3851-1||Not Recommended For New Designs|
|LTC3851A||Adjustable Current Limit|
- Automotive Systems
- Telecom Systems
- Industrial Equipment
- Distributed DC Power Systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Documentation & Resources
R526 Reliability Data3/26/2018365 K
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|Part Number||Material Declaration||Reliability Data||Pin/Package Drawing||CAD Symbols, Footprints & 3D Models|
|LTC3851EMSE-1#PBF||Material Declaration||Reliability Data||16-Lead MSOP w/ EP|
|LTC3851EMSE-1#TRPBF||Material Declaration||Reliability Data||16-Lead MSOP w/ EP|
|LTC3851EUD-1#PBF||Material Declaration||Reliability Data||16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)|
|LTC3851EUD-1#TRPBF||Material Declaration||Reliability Data||16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)|
|LTC3851IMSE-1#PBF||Material Declaration||Reliability Data||16-Lead MSOP w/ EP|
|LTC3851IMSE-1#TRPBF||Material Declaration||Reliability Data||16-Lead MSOP w/ EP|
|Wafer Fabrication Data||R526 Reliability Data|
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