The ISL9103, ISL9103A is a 500mA, 2.4MHz 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 2.4MHz 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 ISL9103, ISL9103A 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 ISL9103, ISL9103A offers internal digital soft-start, enable for power sequence, overcurrent protection and thermal shutdown functions. In addition, the ISL9103, ISL9103A offers a quick bleeding function that discharges the output capacitor when the IC is disabled.

The ISL9103, ISL9103A is offered in a 1.6x1.6mm μTDFN package. The complete converter occupies less than 0.5cm².

• High Efficiency Integrated Synchronous Buck Regulator with up to 95% Efficiency
• 2.7V to 6.0V Supply Voltage
• 2.4MHz 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 ISL9103A 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)

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