LTC1552

Features:

Digitally Programmable 2.1V to 3.5V Fixed Output Voltage with 100mV Steps
Provides All Features Required by the Intel Pentium^® Pro Processor VRM 8.0 DC/DC Converter Specification
Flags for Power Good, Over Temperature and Over Voltage Fault
Output Current Exceeds 14A from a 5V or 12V Supply
Dual N-Channel MOSFET Synchronous Drive
Excellent Output Regulation: ±1% Over Line, Load and Temperature Variations
High Efficiency: Over 95% Possible
Adjustable Current Limit Without External Sense Resistors
Fast Transient Response
Available in SSOP-20 Package


Application

Power Supply for Pentium Pro, SPARC, ALPHA and PA-RISC Microprocessors
High Power 5V or 12V/2.1V - 3.5V Regulators


Pinout




Specifications

Supply Voltage
    V_CC ........................................................................ 7V
    PV_CC ...................................................................... 20V
Input Voltage
    I_FB ......................................................................... 0.3V to PV_CC + 0.3V
    I_MAX ......................................................................0.3V to 13V
    All Other Inputs .................................................... 0.3V to V_CC + 0.3V
Digital Output Voltage ..............................................0.3V to 13V
Operating Temperature Range ................................. 0°C to 70°C
Storage Temperature Range .................................... 65°C to 150°C
Lead Temperature (Soldering, 10 sec) ..................... 300°C


Description

The LTC^®1552 is a high power, high efficiency switching regulator controller optimized for 5V or 12V input to 2.1V - 3.5V output applications. It features digitally programmable output voltage, a precision internal reference and an internal feedback system that can provide output regulation of ±1% over temperature, load current and line voltage shifts. The LTC1552 uses a synchronous switching architecture with two external N-channel output devices, eliminating the need for a high power, high cost P-channel device. Additionally, it senses the output current across the on resistance of the upper N-channel FET, providing an adjustable current limit without an external low value sense resistor.

The LTC1552 free runs at 300kHz, and can be synchronized to a faster external clock if desired. It includes all the inputs and outputs required to implement a power supply conforming to the Intel Pentium Pro Processor VRM 8.0 DC/DC Converter Specification.