LT1576

The LT1576 is a 200kHz monolithic buck mode switching regulator. A 1.5A switch is included on the die along with all the necessary oscillator, control and logic circuitry. The topology is current mode for fast transient response and good loop stability. The LT1576 is a modified version of the industry standard LT1376 optimized for noise sensitive applications.

In addition, the reference voltage has been lowered to allow LT1576 to produce output voltages down to 1.2V. Quiescent current has been reduced by a factor of two. Switch on resistance has been reduced by 30%. Switch tran- sition times have been slowed to reduce EMI generation. The oscillator frequency has been reduced to 200kHz to maintain high efficiency over a wide output current range.

The pinout of LT1576 has been changed to improve PC layout by allowing the high current high frequency switching cir- cuitry to be easily isolated from low current noise sensitive control circuitry. The new SO-8 package includes a fused ground lead which significantly reduces the thermal resis- tance of the device to extend the ambient operating tem- perature range. There is an optional function of shutdown or synchronization. Standard surface mount external parts can be used including the inductor and capacitors.