LTC3858-1 Series

Low IQ, Dual 2-Phase Synchronous Step-Down Controller

Manufacturer: Analog Devices Inc./Maxim Integrated

Catalog

Low IQ, Dual 2-Phase Synchronous Step-Down Controller

Part	Function	Operating Temperature (Max)	Operating Temperature (Min)	Mounting Type	Voltage - Supply (Vcc/Vdd) Minimum	Voltage - Supply (Vcc/Vdd) Maximum	Control Features	Output Phases	Duty Cycle (Max)	Number of Outputs	Frequency - Switching (Max)	Frequency - Switching (Min)	Package Width	Package Name	Package Length	Synchronous Rectifier	Package / Case	Topology	Output Type	Output Configuration	Clock Sync
Analog Devices Inc./Maxim Integrated LTC3858IUFD-1#PBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	5 mm	28-QFN	4 mm	Yes	28-WFQFN Exposed Pad	Buck	Transistor Driver	Positive	No
Analog Devices Inc./Maxim Integrated LTC3858EGN-1#TRPBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	3.9 mm	28-SSOP	0.154 in	Yes		Buck	Transistor Driver	Positive	No
Analog Devices Inc./Maxim Integrated LTC3858IGN-1#TRPBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	3.9 mm	28-SSOP	0.154 in	Yes		Buck	Transistor Driver	Positive	No
Analog Devices Inc./Maxim Integrated LTC3858IGN-1#PBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	3.9 mm	28-SSOP	0.154 in	Yes		Buck	Transistor Driver	Positive	No
Analog Devices Inc./Maxim Integrated LTC3858EUFD-1#PBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	5 mm	28-QFN	4 mm	Yes	28-WFQFN Exposed Pad	Buck	Transistor Driver	Positive	No
Analog Devices Inc./Maxim Integrated LTC3858IUFD-1#TRPBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	5 mm	28-QFN	4 mm	Yes	28-WFQFN Exposed Pad	Buck	Transistor Driver	Positive	No
Analog Devices Inc./Maxim Integrated LTC3858EGN-1#PBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	3.9 mm	28-SSOP	0.154 in	Yes		Buck	Transistor Driver	Positive	No
Analog Devices Inc./Maxim Integrated LTC3858EUFD-1#TRPBF	Step-Down	125 °C	-40 °C	Surface Mount	4 V	38 V	Enable Frequency Control Power Good Soft Start	2	99.4 %	2	535 kHz 835 kHz	105 kHz 350 kHz	5 mm	28-QFN	4 mm	Yes	28-WFQFN Exposed Pad	Buck	Transistor Driver	Positive	No

Catalog

Low IQ, Dual 2-Phase Synchronous Step-Down Controller

Description

The LTC3858-1 is a high performance dual step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz. Power loss and noise due to the input capacitor ESR are minimized by operating the two controller outputs out of phase.The 170μA no-load quiescent current extends operating life in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3858-1 features a precision 0.8V reference and a power good output indicator. A wide 4V to 38V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries.Independent soft-start pins for each controller ramp the output voltages during start-up. The output latch-off feature protects the circuit in short-circuit conditions.For a leadless 32-pin QFN package with the additional features of adjustable current limit, clock out, phase modulation and two PGOOD outputs, see the LTC3858 data sheet.LTC3858LTC3858-1LTC3858-2FeaturesAdjustable Current Limit, Clock Output, Phase Modulation, 2 PGOOD OutputsFixed Current Limit, One PGOOD OutputOvervoltage protection crowbar and short-circuit latchoff disabledPackageQFN-32SSOP-28QFN-32ApplicationsAutomotive SystemsBattery Operated Digital DevicesDistributed DC Power Systems