LT3150

Features:

Fast Transient Response Optimized with Ceramic Output Capacitors
FET RDS(ON) Defines Dropout Voltage
±1% Reference Tolerance Over Temperature
Multifunction LDO Shutdown Pin with Latchoff
Fixed Frequency 1.4MHz Boost Converter Generates MOSFET Gate Drive
Internally Compensated Boost Converter Uses Tiny Capacitors and Inductor
Independent Boost Converter Shutdown Control Permits LDO Output Voltage Supply Sequencing
 16-Lead SSOP Package


Application

Microprocessor, ASIC and I/O Supplies
Very Low Dropout Input-to-Output Conversion
 Logic Termination Supplies


Specifications

VIN1, SHDN1 Voltage .............................................. 10V
SW Voltage ..............................................  0.4V to 36V
FB1 Voltage ................................................ VIN1 + 0.3V
Current into FB1, FB2 Pin .................................... ±1mA
VIN2, IPOS, INEG ....................................................... 22V
SHDN2.................................................................... VIN2
Operating Ambient Temperature Range ..... 0°C to 70°C
Junction Temperature (Note 2) ........................... 125°C
Storage Temperature Range ................ 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C

Description

The LT®3150 drives a low cost external N-channel MOSFET as a source follower to produce a fast transient response, very low dropout voltage linear regulator. Selection of the
N-channel MOSFET RDS(ON) allows dropout voltages below 300mV for low VIN to low VOUT applications.

The LT3150 includes a fixed frequency boost regulator
that generates gate drive for the N-channel MOSFET. The nternally compensated current mode PWM architecture combined with the 1.4MHz switching frequency permits the use of tiny, low cost capacitors and inductors.

The LT3150's transient load performance is optimized with ceramic output capacitors. A precision 1.21V reference accommodates low voltage supplies. Protection includes a high side current limit amplifier that activates a fault timer circuit. A multifunction shutdown pin provides either current limit time-out with latchoff,overvoltage

protection or thermal shutdown. Independentshutdown control of the boost converter provides on/off
and sequencing control of the LDO output voltage.