LTC3876 Series

Dual DC/DC Controller for DDR Power with Differential VDDQ Sensing and ±50mA VTT Reference

Catalog

Dual DC/DC Controller for DDR Power with Differential VDDQ Sensing and ±50mA VTT Reference

Part	Applications	Voltage - Output	Number of Outputs	Voltage - Input [Min]	Voltage - Input [Max]	Mounting Type	Package / Case	Operating Temperature [Max]	Operating Temperature [Min]	Supplier Device Package
Analog Devices LTC3876EUHF#PBF	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-WFQFN Exposed Pad	125 °C	-40 °C
Analog Devices LTC3876IUHF#TRPBF	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-WFQFN Exposed Pad	125 °C	-40 °C
Analog Devices LTC3876IFE#TRPBF	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-TFSOP	125 °C	-40 °C	38-TSSOP-EP
Analog Devices LTC3876EFE	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-TFSOP	125 °C	-40 °C	38-TSSOP-EP
Analog Devices LTC3876EFE#PBF	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-TFSOP	125 °C	-40 °C	38-TSSOP-EP
Analog Devices LTC3876IFE	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-TFSOP	125 °C	-40 °C	38-TSSOP-EP
Analog Devices LTC3876IUHF#PBF	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-WFQFN Exposed Pad	125 °C	-40 °C
Analog Devices LTC3876EUHF#TRPBF	Controller DDR	Adjustable	2	4.5 V	38 V	Surface Mount	38-WFQFN Exposed Pad	125 °C	-40 °C

Key Features

• Complete DDR Power Solution with VTT Reference

• Wide VINRange: 4.5V to 38V, VDDQ: 1V to 2.5V

• ±0.67% VDDQ Output Voltage Accuracy

• VDDQ and VTT Termination Controllers

• ±1.2% ±50mA Linear VTTR Reference Output

• Controlled On-Time, Valley Current Mode Control

• Frequency Programmable from 200kHz to 2MHz Synchronizable to External Clock

• tON(MIN)= 30ns, tOFF(MIN)= 90ns

• RSENSEor Inductor DCR Current Sensing

• Power Good Output Voltage Monitor

• Overvoltage Protection and Current Limit Foldback

• Thermally Enhanced 38-Pin (5mm × 7mm) QFN and TSSOP Packages

Description

The LTC3876 is a complete DDR power solution, compatible with DDR1, DDR2, DDR3 and future DDRX lower voltage standards. The LTC3876 includes VDDQ and VTT DC/DC controllers and a precision linear VTT reference. A differential output sense amplifier and precision internal reference combine to offer an accurate VDDQ supply. The VTT controller tracks the precision VTTR linear reference with less than 20mV total DC error. The precision VTTR reference maintains 1.2% regulation accuracy tracking onehalf VDDQ over temperature for a ±50mA reference load.The LTC3876 allows operation from 4.5V to 38V maximum at the input. The VDDQ output can range from 1.0V to 2.5V, with a corresponding VTT and VTTR output range of 0.5V to 1.25V. Voltage tracking soft-start, PGOOD and fault protection features are provided.ApplicationsMotherboard MemoryServers