LTC3853 Series

Triple Output, Multiphase Synchronous Step-Down Controller

Catalog

Triple Output, Multiphase Synchronous Step-Down Controller

Part	Output Phases	Output Type	Clock Sync	Synchronous Rectifier	Function	Topology	Duty Cycle (Max) [Max]	Operating Temperature [Min]	Operating Temperature [Max]	Control Features	Number of Outputs	Frequency - Switching [Min]	Frequency - Switching [Max]	Mounting Type	Package / Case	Supplier Device Package	Voltage - Supply (Vcc/Vdd) [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Output Configuration
Analog Devices LTC3853IUJ#PBF	3	Transistor Driver			Step-Down	Buck	98 %	-40 °C	125 ¯C	Current Limit Enable Frequency Control Power Good Soft Start Tracking	3	250 kHz	750 kHz	Surface Mount	40-WFQFN Exposed Pad	40-QFN (6x6)	4.5 V	24 V	Positive
Analog Devices LTC3853HUJ#TRPBF	3	Transistor Driver			Step-Down	Buck	98 %	-40 °C	150 °C	Current Limit Enable Frequency Control Power Good Soft Start Tracking	3	250 kHz	750 kHz	Surface Mount	40-WFQFN Exposed Pad	40-QFN (6x6)	4.5 V	24 V	Positive

Catalog

Triple Output, Multiphase Synchronous Step-Down Controller

Key Features

• Triple, 120° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise

• Configurable as a 180° Dual Phase Controller Plus a Single Phase Controller

• The Third Phase Can Regulate Up to a 13.5V Output

• High Efficiency: Up to 92%

• RSENSEor DCR Current Sensing

• ±0.75% 0.8V Output Voltage Accuracy

• Phase-Lockable Fixed Frequency 250kHz to 750kHz

• Supports Pre-Biased Outputs

• Dual N-Channel MOSFET Synchronous Drive

• Wide VINRange: 4.5V to 24V Operation (28V Abs Max)

• Adjustable Soft-Start Current Ramping or Tracking

• Foldback Output Current Limiting

• Output Overvoltage Protection

• Dual Power Good Output Voltage Monitors

• 40-Lead 6mm × 6mm QFN Package

Description

The LTC3853 is a high performance triple output stepdown switching regulator controller that drives all Nchannel synchronous power MOSFET stages. Power loss and supply noise are minimized by operating the output stages out of phase. The part can be configured as a dual phase controller plus a single phase controller if needed. The part can also be configured to provide a single 3-phase output for even higher output currents.A wide 4.5V to 24V (28V maximum) input voltage supply range encompasses most battery chemistries and intermediate bus voltages. Phase 3 can regulate output voltages up to 13.5V. A constant-frequency current mode architecture allows for a phase-lockable frequency up to 750kHz.Independent TK/SS pins for each output ramps the output voltages and can be configured for 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 or continuous inductor current modes.