LTC1430A

Features:

High Power 5V to 1.xV-3.xV Switching Controller:Can Exceed 10A Output
Maximum Duty Cycle > 90% Permits 3.3V to 2.xV Conversion Using a Low Power 5V Supply
All N-Channel External MOSFETs
Fixed Frequency Operation-Small L
Excellent Output Regulation: ±1% Over Line, Load and Temperature Variations
High Efficiency: Over 95% Possible
No Low Value Sense Resistor Needed
Outputs Can Drive External FETs with Up to 10,000pF Gate Capacitance
Quiescent Current: 350µA Typ, 1µA in Shutdown
Fast Transient Response
Adjustable or Fixed 3.3V Output
Available in 8-Lead SO and 16-Lead GN and SO Packages


Application

Power Supply for Pentium®II and AMD-K6®
Microprocessors
High Power 5V to 3.xV Regulators
Local Regulation for Dual Voltage Logic Boards
Low Voltage, High Current Battery Regulation


Pinout




Specifications

Supply VoltageVCC ........................................................................  9V
PVCC1, 2 ......................................................................................  13V
Input VoltageIFB ...........................................................  0.3V to 18V
All Other Inputs ...............................................  0.3V to (VCC + 0.3V)
Junction Temperature................................................................ 150°C
Operating Temperature Range
                        LTC1430AC ............................................. 0°C to 70°C
                       LTC1430AI ........................................  40°C to 85°C
Storage Temperature Range ..................................  65°C to 150°C
Lead Temperature (Soldering, 10 sec) .....................................  300°C


Description

The LTC®1430A is a high power, high efficiency switching regulator controller optimized for 5V to 1.xV-3.xV applications. It includes 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 LTC-1430A uses a synchronous switching architecture with two N-channel output devices, eliminating the need for a high power, high cost P-channel device. Additionally, it senses output current across the drain-source resistance of the upper N-channel FET,  providing an adjustable current limit without an external low value sense resistor.
The LTC1430A includes a fixed frequency PWM oscillator for low output ripple under virtually all operating conditions. The 200kHz free-running clock fre-quency can be externally adjusted from 100kHz to above 500kHz. The LTC1430A's maximum duty cycle is typically 93.5% compared to 88% for the LTC1430. This permits 3.3V to 2.xV conversion using a low power 5V supply. The LTC1430A features low 350µA quiescent current, allowing greater than 90% efficiency op-eration in converter designs from 1A to greater than 50A output current. Shutdown mode drops the LTC1430A supply current to 1µA.