ISL9104
500mA 4.3MHz Low I_Q High Efficiency Synchronous Buck Converter

Key Features

• High Efficiency Integrated Synchronous Buck Regulator with up to 93% Efficiency
• 2.7V to 6.0V Supply Voltage
• 4.3MHz PWM Switching Frequency
• 500mA Guaranteed Output Current
• 3% Output Accuracy Over-Temperature and Line for Fixed Output Options
• 20µA Quiescent Supply Current in Skip Mode
• Less than 1µA Logic Controlled Shutdown Current
• 100% Maximum Duty Cycle for Lowest Dropout
• Ultrasonic Switching Frequency at Skip Mode to Prevent Audible Frequency Noise (For ISL9104A Only)
• Discharge Output Capacitor when Disabled
• Internal Digital Soft-Start
• Peak Current Limiting, Short Circuit Protection
• Over-Temperature Protection
• Chip Enable
• Small 6 Pin 1.6mmx1.6mm µTDFN Package
• Pb-Free (RoHS Compliant)

Description

The ISL9104, ISL9104A is a 500mA, 4.3MHz step-down regulator, which is ideal for powering low-voltage microprocessors in compact devices such as PDAs and cellular phones. It is optimized for generating low output voltages down to 0.8V. The supply voltage range is from 2.7V to 6V allowing the use of a single Li+ cell, three NiMH cells or a regulated 5V input. It has guaranteed minimum output current of 500mA. A high switching frequency of 4.3MHz pulse-width modulation (PWM) allows using small external components. Under light load condition, the device operates at low I_Q skip mode with typical 20µA quiescent current for highest light load efficiency to maximize battery life, and it automatically switches to fixed frequency PWM mode under heavy load condition.

The ISL9104, ISL9104A includes a pair of low ON-resistance P-Channel and N-Channel internal MOSFETs to maximize system efficiency and minimize the external component count. 100% duty-cycle operation allows less than 300mV dropout voltage at 500mA.

The ISL9104, ISL9104A offers internal digital soft-start, enable for power sequence, overcurrent protection and thermal shutdown functions. In addition, the ISL9104, ISL9104A offers a quick bleeding function that discharges the output capacitor when the IC is disabled.

The ISL9104, ISL9104A is offered in a 1.6x1.6mm µTDFN package. The complete converter occupies less than 0.5CM².

Applications

• Single Li-ion Battery-Powered Equipment
• Mobile Phones and MP3 Players
• PDAs and Palmtops
• WCDMA Handsets
• Portable Instruments