LT1578-2.5_1154784

Input Voltage .......................................................... 16V
BOOST Pin Above Input Voltage ............................. 10V
SHDN Pin Voltage ..................................................... 7V
SENSE Pin Voltage .................................................... 4V
FB Pin Voltage (Adjustable Part) ............................ 3.5V
FB Pin Current (Adjustable Part) ............................ 1mA
SYNC Pin Voltage ..................................................... 7V
Operating Junction Temperature Range
LT1578C ............................................... 0°C to 125° C
LT1578I ...........................................  40°C to 125°C
Storage Temperature Range ................  65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C


Description

The LT 1578 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 LT1578 is a modified version of the LT1507 that has been optimized for noise sensitive applications. It will operate over a 4V to 15V input range. In addition, the reference voltage has been lowered to allow the device 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 transition times have been slowed to reduce EMI generation. 

The oscillator frequency of LT1578 has been reduced to 200kHz maintain high efficiency over a wide output current range. The pinout has been changed to improve PC layout by allowing the high current, high frequency switching circuitry to be easily isolated from low current, noise sensitive control circuitry. 

The new SO-8 package includes a fused ground lead that significantly reduces the thermal resistance of the device to extend the ambient operating temperature range. Standard surface mount external parts can be used including the inductor and capacitors.