ISL6430

Features:

* Drives Two N-Channel MOSFETs
* Operates From +5V or +12V Input
* Simple Single-Loop Control Design
   - Voltage-Mode PWM Control
* Fast Transient Response
   - High-Bandwidth Error Amplifier
   - Full 0% to 100% Duty Ratio
* Excellent Output Voltage Regulation
   - 1.27V Internal Reference
   - ±1% Over Line Voltage and Temperature
* Over-Current Fault Monitor
   - Does Not Require Extra Current Sensing Element
   - Uses MOSFETs r DS(ON)
* Small Converter Size
   - Constant Frequency Operation
   - 200kHz Free-Running Oscillator Programmable from  50kHz to Over 1MHz
* 14-Lead SOIC and 16-Lead QFN


Application

* Cable Modems, Set-Top Boxes and DSL Modems
* DSP and Core Communications Processor Supplies
* High-Power 5V Input DC-DC Regulators
* Low-Voltage Distributed Power Supplies


Pinout




Specifications

Supply Voltage, V_CC  . . . . . . . . . . . . ............... . . +15.0V
Boot Voltage, V_BOOT  - V_PHASE  .. .. . ................ . . +15.0V
Input, Output or I/O Voltage. .. .GND -0.3V to V_CC  +0.3V
ESD Classification. . . . . . . . . . . . . . . . . . . .. . . . . .Class 2


Description

The ISL6430 provides complete control and protection for a  DC-DC converter optimized for high-performance broadband  gateway applications. It is designed to drive two N Channel  MOSFETs in a synchronous-rectified buck topology. The  ISL6430 integrates all of the control, output adjustment,  monitoring and protection functions into a single package.

The output voltage of the converter can be precisely  regulated to as low as 1.27V, with a maximum tolerance of  ±1% over temperature and line voltage variations.

The ISL6430 provides simple, single feedback loop, voltage- mode control with fast transient response. It includes a  200kHz free-running triangle-wave oscillator that is  adjustable from below 50kHz to over 1MHz. The error  amplifier features a 15MHz gain-bandwidth product and  6V/s slew rate which enables high converter bandwidth for  fast transient performance. The resulting PWM duty ratio  ranges from 0% to 100%.

The ISL6430 protects against over-current conditions by  inhibiting PWM operation. The ISL6430 monitors the current  by using the r  of the upper MOSFET which eliminates  DS(ON) the need for a current sensing resistor.