LTC1574

Features:

High Efficiency: Up to 94%
Usable in Noise-Sensitive Products
Peak Inductor Current Independent of Inductor Value
Short-Circuit Protection
Internal Low Forward Drop Schottky Diode
Only Three External Components Required
Wide VIN Range: 4V to 18.5V (Absolute Maximum)
Low Dropout Operation
Low-Battery Detector
Pin Selectable Current Limit
Internal 0.9? Power Switch: VIN = 12V
Standby Current: 130A
Active Low Micropower Shutdown


Application

Inverting Converters
Step-Down Converters
Memory Backup Supply
Portable Instruments
Battery-Powered Equipment
Distributed Power Systems


Pinout




Specifications

(Voltage Referred to GND Pin)
Input Supply Voltage (Pin 5).................. 0.3V to 18.5V
Switch Current (Pin 3, 14) ........................................  1A
Switch Voltage (Pin 3, 14)..........................  V_IN 18.5V
Operating Temperature Range................. 0°C to 70°C
Junction Temperature (Note 1)............................ 125°C
Storage Temperature Range.............. 65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C


Description

The LTC^(R) 1574 is a family of easy-to-use current mode DC/DC converters ideally suited for 9V to 5V, 5V to 3.3V and inverting operation. With an internal 0.9? switch (at a supply voltage of 12V) and a low forward drop Schottky diode (0.450V typ at 200mA, T_A= 25 °C), the LTC1574 requires only three external components to construct a complete high efficiency DC/DC converter.

Under no load condition, the LTC1574 draws only 130A. In shutdown, it draws a mere 2A making this converter ideal for battery-powered applications. In dropout, the internal P-channel MOSFET switch is turned on continu- ously allowing the user to maximize the life of the battery source.

The maximum inductor current of the LTC1574 family is pin selectable to either 340mA or 600mA, optimizing efficiency for a wide range of applications. Operation up to 200kHz permits the use of small surface mount inductors
and capacitors.

For applications requiring higher output current or ultra- high efficiency, see the LTC1148 and LTC1265 data sheets. For detailed applications information, see the LTC1174 data sheet.