Out in Front: December 21, 1995

The LTC1430 power-regulator controller from Linear Technology converts a 5V source to a 3.xV output, supplying more than 10A of current for Pentium and P6-class processors. Its synchronous switching architecture uses two N-channel output MOSFETs, eliminating the need for a more expensive P-channel device. In addition, the LT1430 does not need an external low-value current-sense resistor: Its voltage-feedback architecture determines output current by sensing across the drain-source resistance of one of the output FETs.

With careful design, the LT1430 can provide more than 95% efficiency, even at maximum load current. Line, load, and temperature regulation are better than 1%. The LT1430 can drive external FETs with gate capacitances as high as 10,000 pF, common in such high-current devices. You can adjust its 200-kHz free-running clock to operate from 100 to 500 kHz to the best size for the external inductor. In shutdown mode, the IC requires 1 µA of supply current. The LTC1430 is available in a 16-lead DIP and SOIC packages for $3.80 (1000) and in an eight-pin version that eliminates the soft-start, current-limiting, and variable-frequency options. It costs $3.20 (1000). -- by Bill Schweber

Linear Technology Corp, Milpitas, CA. (800) 454-6327.