LTC1436ACGN-PLL High Efficiency Low Noise Synchronous Step-Down Switching Regulators

In Broadband networking and high speed computing applications, multiple high current, low voltage power supplies are needed to power FPGAs Flash memory, DSPs and Microprocessors One such example calls for a maximum of 60A of current to power the CPU at 1. 5V and up to 15A to power the memory at 2. 5V from a 12V input. While a customized DC/DC module

is usually expensive, the external circuitry for synchronization further increases the cost of individual supplies. The newly released LTC ® 1628-SYNC PolyPhase TM con- troller CAN provide a simple and low cost solution. Com- pared to the LTC1628 the LTC1628-SYNC has a PLLIN pin that enables external synchronization. By combining the LTC1628-SYNC with the LTC1629 a true 3-phase circuit CAN be achieved for the 60A CPU supply and the second output of the LTC1628-SYNC circuit CAN be used to generate the memory power supply. Because the channel used for the memory power is interleaved out of phase from the other three channels used for CPU power, the net ripple current seen by the input bus is further reduced. In addition, the LTC1629 ½ ½s Differential Amplifier enables true remote sensing to ensure accurate voltage regulation at the CPU supply pins.

Leave Comment

characters left:

New Circuits