• Product Introduction

LT1578IS8

1.5A, 200kHz buck switching regulator

peculiarity

• 1.5A switching current
• High efficiency, low loss 0.2Ohms switch
• Constant 200kHz switching frequency
• 4V to 15V input VoltageRange
• Minimum output: 1.21V
• Low supply current: 1.9 mA
• Low shutdown current: 20μA
• Easily synchronized up to 400kHz
• Cycle-by-cycle current limit
• Reduce EMI generation
• Low thermal resistance SO-8 package
• Small, low-inductance values are used

description

® The LT 1578 is a 200kHz monolithic buck-mode switching regulator. A 1.5A switch is the one that contains all the necessary oscillator, control and logic circuitry to die together. The topology enables a current pattern with 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 in the input range of 4V to 15V. In addition, this reference voltage has been reduced to allow the output voltage generated by the device to drop to 1.2V. Quiescent current has been reduced by two factors. The switching of resistance has been reduced by 30%. The transition time of the switch has been slowed down to reduce EMI generation. The frequency of the oscillator has been reduced to 200kHz to maintain high efficiency over a wide output current range. The pins have been changed to allow for high current, high frequency switching circuits can be easily isolated from low-current, noise-sensitive control circuits to improve the layout of the PC. The new SO-8 package, which includes a fused ground wire, greatly reduces the thermal resistance of the device and extends the operating ambient temperature range. Standard surface-mount external components, including inductors and capacitors, can be used.