ISL9104

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 a 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 conditions, the device operates at low I_Q skip mode with a typical 20µA quiescent current for the highest light-load efficiency to maximize battery life, and it automatically switches to fixed-frequency PWM mode under heavy-load conditions. The ISL9104 and ISL9104A include 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 sequencing, 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 and ISL9104A are offered in a 1.6 x 1.6mm µTDFN package. The complete converter occupies less than 0.5cm².