LT1171

Features:

 Wide Input Voltage Range: 3V to 60V
 Low Quiescent Current: 6mA
 Internal 5A Switch (2.5A for LT1171,
    1.25A for LT1172)
Shutdown Mode Draws Only 50µA Supply Current
Very Few External Parts Required
 Self-Protected Against Overloads
 Operates in Nearly All Switching Topologies
Flyback-Regulated Mode Has Fully Floating Outputs
 Comes in Standard 5-Pin Packages
LT1172 Available in 8-Pin MiniDIP and Surface Mount
    Packages
 Can Be Externally Synchronized


Application

Logic Supply 5V at 10A
 5V Logic to ±15V Op Amp Supply
 Battery Upconverter
 Power Inverter (+ to ) or ( to +)
Fully Floating Multiple Outputs


Pinout




Specifications

Supply Voltage
     LT1170/71/72HV (Note 2) ..................................   60V
     LT1170/71/72 (Note 2) .......................................  40V
Switch Output Voltage
     LT1170/71/72HV ................................................  75V
     LT1170/71/72 .....................................................  65V
     LT1172S8 ...........................................................  60V
Feedback Pin Voltage (Transient, 1ms) ................  ±15V
Storage Temperature Range ............. 65°C to 150°C
Lead Temperature (Soldering, 10 sec) ................ 300°C


Description

The LT^® 1170/LT1171/LT1172 are monolithic high power switching regulators. They can be operated in all standard switching configurations including buck, boost, flyback, forward, inverting and "Cuk." A high current, high efficiency switch is included on the die along with all oscilla-
tor, control and protection circuitry. Integration of all functions allows the LT1170/LT1171/LT1172 to be built in a standard 5-pin TO-3 or TO-220 power package as well as the 8-pin packages (LT1172). This makes them extremely easy to use and provides "bust proof" operation similar to
that obtained with 3-pin linear regulators.

The LT1170/LT1171/LT1172 operate with supply voltages from 3V to 60V, and draw only 6mA quiescent current. They can deliver load power up to 100W with no external power devices. By utilizing current-mode switching techniques, they provide excellent AC and DC load and line regulation.

The LT1170/LT1171/LT1172 have many unique features not found even on the vastly more difficult to use low power control chips presently available. They use adaptive antisat switch drive to allow very wide ranging load currents with no loss in efficiency. An externally activated shutdown mode reduces total supply current to 50µA typically for standby operation.