Datasheet
- LTC3876 - Dual DC/DC Controller for DDR Power with Differential VDDQ Sensing and ±50mA VTT Reference
Design Note
Reliability Data
Press Release
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Features
- 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
Typical Application
Description
The LTC®3876 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.
5x7 QFN-38,TSSOP-38
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3876EFE#PBF | TSSOP | 38 | E | $4.54 | $3.18 |
| LTC3876EFE#TRPBF | TSSOP | 38 | E | $3.24 | |
| LTC3876EUHF#PBF | QFN | 38 | E | $4.20 | $2.94 |
| LTC3876EUHF#TRPBF | QFN | 38 | E | $3.00 | |
| LTC3876IFE#PBF | TSSOP | 38 | I | $5.22 | $3.65 |
| LTC3876IFE#TRPBF | TSSOP | 38 | I | $3.71 | |
| LTC3876IUHF#PBF | QFN | 38 | I | $4.79 | $3.35 |
| LTC3876IUHF#TRPBF | QFN | 38 | I | $3.41 |
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1631A | LTC3876EUHF Demo Board | DDR2/3, VIN = 4.5V to 14V, VDDQ = 1.8V/1.5V @ 20A, VTT = 0.9V/0.75V @ ±10A | $150.00 |