Features: * Operates from +5V Input
* 0.8VtoV Output Range IN
- 0.8V Internal Reference
- ±1.5% Over Line Voltage and Temperature
* Drives N-Channel MOSFETs
* Simple Single-Loop Control Design
- Voltage-Mode PWM Control
* Fast Transient Response
* Lossless, Programmable Overcurrent Protection
- Uses Upper MOSFET's rDS(ON)
* Small Converter Size
- 300kHz Fixed Frequency Oscillator
- Internal Soft Start
- 8 Lead SOIC Package
* High Conversion Efficiency
* Synchronous/Standard Buck ConfigurationApplication* Cable Modems, Set Top Boxes, and DSL Modems
* DSP and Core Communications Processor Supplies
* Power Supplies for Microprocessors and Embedded Controllers
* Memory Supplies
* Personal Computer Peripherals
* Industrial Power Supplies
* 5V-Input DC-DC Regulators
* Low-Voltage Distributed Power SuppliesPinout
SpecificationsSupply Voltage, VCC..................................................+6.0V
Absolute Boot Voltage, VBOOT ................................+15.0V
Upper Driver Supply Voltage, VBOOT -VPHASE ............+6.0V
Input, Output or I/O Voltage. . . . GND -0.3V to VCC +0.3V
ESDClassification......................................................Class2DescriptionThe ISL6431 is a high efficiency, fixed frequency, synchronous buck PWM controller. It is designed for use in applications that convert 5V to lower distributed voltages required for set-top box, cable modem, DSL modem and residential home gateway core processor, memory and peripheral power supplies.
This device makes simple work out of implementing a complete control and protection scheme for a DC-DC stepdown converter. Designed to drive N channelMOSFETs in a synchronous buck topology, the ISL6431 integrates the control, output adjustment, monitoring and protection functions into a single 8-pin package.
The ISL6431 provides simple, single feedback loop, voltage- mode control with fast transient response. The output voltage can be precisely regulated to as low as 0.8V, with a maximum tolerance of ±1.5% over temperature and line voltage variations. A fixed frequency oscillator reduces design complexity, while balancing typical application cost and efficiency.
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 cycles range from 0% to 100%.
Protection from overcurrent conditions is provided by monitoringthe r ofthe upperMOSFET toinhibitPWM DS(ON) operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sense resistor.