LTC3851 Series
Synchronous Step-Down Switching Regulator Controller
Manufacturer: Analog Devices Inc./Maxim Integrated
Catalog
Synchronous Step-Down Switching Regulator Controller
| Part | Output Type | Output Configuration | Synchronous Rectifier | Mounting Type | Frequency - Switching [Min] | Frequency - Switching [Max] | Topology | Supplier Device Package | Voltage - Supply (Vcc/Vdd) [Min] | Voltage - Supply (Vcc/Vdd) [Max] | Operating Temperature [Min] | Operating Temperature [Max] | Control Features | Function | Package / Case | Package / Case | Duty Cycle (Max) [Max] | Output Phases | Clock Sync | Number of Outputs | Package / Case [x] | Package / Case [y] |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 235 kHz | 750 kHz | Buck | 16-MSOP-EP | 4 V | 38 V | -40 °C | 150 °C | Current Limit Enable Frequency Control Soft Start Tracking | Step-Down | 16-TFSOP Exposed Pad | 0.118 in 3 mm | 99 % | 1 | 1 | ||||
 Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 250 kHz | 750 kHz | Buck | 16-SSOP | 4 V | 38 V | -40 ¯C | 85 C | Current Limit Enable Frequency Control Soft Start Tracking | Step-Down | 16-SSOP | 99 % | 1 | 1 | 0.154 in | 3.9 mm | |||
 Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 235 kHz | 750 kHz | Buck | 16-QFN (3x3) | 4 V | 38 V | -40 C | 125 °C | Current Limit Enable Frequency Control Soft Start Tracking | Step-Down | 16-WFQFN Exposed Pad | 99 % | 1 | 1 | |||||
Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 235 kHz | 750 kHz | Buck | 16-MSOP-EP | 4 V | 38 V | -40 °C | 150 °C | Enable Frequency Control Power Good Soft Start Tracking | Step-Down | 16-TFSOP Exposed Pad | 0.118 in 3 mm | 99 % | 1 | 1 | ||||
Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 235 kHz | 750 kHz | Buck | 16-QFN (3x3) | 4 V | 38 V | -40 C | 125 °C | Enable Frequency Control Power Good Soft Start Tracking | Step-Down | 16-WFQFN Exposed Pad | 99 % | 1 | 1 | |||||
 Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 250 kHz | 750 kHz | Buck | 16-MSOP-EP | 4 V | 38 V | -40 ¯C | 85 C | Current Limit Enable Frequency Control Soft Start Tracking | Step-Down | 16-TFSOP Exposed Pad | 0.118 in 3 mm | 99 % | 1 | 1 | ||||
Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 235 kHz | 750 kHz | Buck | 16-QFN (3x3) | 4 V | 38 V | -40 C | 125 °C | Current Limit Enable Frequency Control Soft Start Tracking | Step-Down | 16-WFQFN Exposed Pad | 99 % | 1 | 1 | |||||
 Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 235 kHz | 750 kHz | Buck | 16-MSOP-EP | 4 V | 38 V | -55 °C | 150 °C | Enable Frequency Control Power Good Soft Start Tracking | Step-Down | 16-TFSOP Exposed Pad | 0.118 in 3 mm | 99 % | 1 | 1 | ||||
Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 235 kHz | 750 kHz | Buck | 16-MSOP-EP | 4 V | 38 V | -40 C | 125 °C | Enable Frequency Control Power Good Soft Start Tracking | Step-Down | 16-TFSOP Exposed Pad | 0.118 in 3 mm | 99 % | 1 | 1 | ||||
Analog Devices Inc./Maxim Integrated | Transistor Driver | Positive | Surface Mount | 250 kHz | 750 kHz | Buck | 16-MSOP-EP | 4 V | 38 V | -40 ¯C | 85 C | Enable Frequency Control Power Good Soft Start Tracking | Step-Down | 16-TFSOP Exposed Pad | 0.118 in 3 mm | 99 % | 1 | 1 |
Description
AI
The LTC3851A-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 LTC3851A-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 LTC3851A-1 contains an improved PLL compared to the LTC3851-1.The LTC3851A-1 is identical to the LTC3851A except that the ILIMpin is replaced by PGOOD.FeaturesLTC3851Not Recommended For New DesignsLTC3851-1Not Recommended For New DesignsLTC3851AAdjustable Current LimitLTC3851A-1PGOOD OutputApplicationsAutomotive SystemsTelecom SystemsIndustrial EquipmentDistributed DC Power Systems