Features and Benefits
- Complete DDR Power Solution with VTT Reference
- Wide VIN Range: 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
- RSENSE or 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
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.
- Motherboard Memory
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.
Evaluation Kits (1)
Demonstration circuit 1631A is a dual output DDR2 or DDR3 power supply that provides 20A at 1.8V or 1.5V (jumper-selectable) for VDDQ and ±10A for VTT (VTT = 0.5VDDQ). It also has a ±50mA VTTR reference output. The demo board has an operating voltage range of 4.5V to 14V and a nominal 400kHz switching frequency.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
Technical Articles (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.