Linear Technology has introduced the LTC3634, a high-efficiency, dual-channel monolithic synchronous step-down regulator for power supply and bus termination rails for DDR1, DDR2 and DDR3 SDRAM controllers.
The LTC3634 operates from an input voltage from 3.6V to 15V, making it well suited for dual cell Li-Ion applications as well as 5V and 12V intermediate bus systems. The LTC3634 incorporates a constant frequency/controlled on-time, current mode architecture. Its termination voltage, VTT, is set to ½ of VDDQ down to 0.6V with accuracy of ±1.6%. The combination of a monolithic design and switching frequencies as high as 4MHz, which enable the use of tiny, low cost capacitors and inductors, is designed to provide a very compact, high efficiency solution for DDR power applications.
- 3.6V to 15V Input Voltage Range
- VDDQ, VTT, VTTR Outputs
- Up to ±3A Output Current
- Up to 95% Efficiency
- Selectable 90°/180° Phase Shift Between Channels
- Adjustable Switching Frequency: 500kHz to 4MHz
- 10mA Buffered?VTTR = VDDQ/2 = VTT Reference
- ± 1.6% Accurate VTTR at 0.75V
- Optimal VOUT Range: 0.6V to 3V
The LTC3634EUFD is available in a 4mm x 5mm QFN-28 whereas the LTC3634EFE is available in a 28-lead TSSOP package. Pricing starts at $4.25 and $4.40 each, respectively, in 1,000-piece quantities. Industrial grade versions, the LTC3634IUFD and LTC3634IFE, are guaranteed to operate over the -40°C to 125°C operating junction temperature range and are priced at $4.72 and $4.89 each, respectively, in 1,000-piece quantities. All versions are available from stock.
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