DATASHEET ISL9104, ISL9104A FN6829 Rev 5.00 500mA 4.3MHz Low I High Efficiency Synchronous Buck Converter Q The ISL9104, ISL9104A is a 500mA, 4.3MHz step-down Features regulator, which is ideal for powering low-voltage High Efficiency Integrated Synchronous Buck Regulator with microprocessors in compact devices such as PDAs and cellular up to 93% Efficiency phones. It is optimized for generating low output voltages down to 0.8V. The supply voltage range is from 2.7V to 6V 2.7V to 6.0V Supply Voltage allowing the use of a single Li+ cell, three NiMH cells or a 4.3MHz PWM Switching Frequency regulated 5V input. It has guaranteed minimum output current 500mA Guaranteed Output Current of 500mA. A high switching frequency of 4.3MHz pulse-width modulation (PWM) allows using small external components. 3% Output Accuracy Over-Temperature and Line for Fixed Under light load condition, the device operates at low I skip Q Output Options mode with typical 20A quiescent current for highest light 20A Quiescent Supply Current in Skip Mode load efficiency to maximize battery life, and it automatically switches to fixed frequency PWM mode under heavy load Less than 1A Logic Controlled Shutdown Current condition. 100% Maximum Duty Cycle for Lowest Dropout The ISL9104, ISL9104A includes a pair of low ON-resistance Ultrasonic Switching Frequency at Skip Mode to Prevent P-Channel and N-Channel internal MOSFETs to maximize Audible Frequency Noise (For ISL9104A Only) system efficiency and minimize the external component count. Discharge Output Capacitor when Disabled 100% duty-cycle operation allows less than 300mV dropout Internal Digital Soft-Start voltage at 500mA. Peak Current Limiting, Short Circuit Protection The ISL9104, ISL9104A offers internal digital soft-start, enable for power sequence, overcurrent protection and Over-Temperature Protection thermal shutdown functions. In addition, the ISL9104, Chip Enable ISL9104A offers a quick bleeding function that discharges the Small 6 Pin 1.6mmx1.6mm TDFN Package output capacitor when the IC is disabled. Pb-Free (RoHS Compliant) The ISL9104, ISL9104A is offered in a 1.6x1.6mm TDFN 2 package. The complete converter occupies less than 0.5CM . Related Literature Applications See AN1522, ISL9104xxxxEVAL1Z, ISL9104AxxxxEVAL1Z Evaluation Board Application Manual Single Li-ion Battery-Powered Equipment Mobile Phones and MP3 Players PDAs and Palmtops WCDMA Handsets Portable Instruments 100 Pin Configuration 95 ISL9104, ISL9104A (6 LD 1.6x1.6 TDFN) 90 TOP VIEW 85 80 VIN 1 6 SW 75 EN 2 5 GND 70 65 NC 3 4 FB V = 2.7V 60 IN V = 1.8V OUT 55 L = 1H 50 1 10 100 1000 I (mA) OUT FIGURE 1. EFFICIENCY vs OUTPUT CURRENT FN6829 Rev 5.00 Page 1 of 14 EFFICIENCY (%)ISL9104, ISL9104A Pin Descriptions PIN NUMBER PIN NAME DESCRIPTION 1 VIN Input supply voltage. Typically connect a 10F ceramic capacitor to ground. 2 EN Regulator enable pin. Enable the device when driven to high. Shut down the chip and discharge output capacitor when driven to low. Do not leave this pin floating. 3 NC No connect leave floating. 4 FB Buck converter output feedback pin. For adjustable output version, its typical value is 0.8V and connect it to the output through a resistor divider for desired output voltage for fixed output version, directly connect this pin to the converter output. 5 GND Ground connection. 6 SW Switching node connection. Connect to one terminal of inductor. Typical Applications ISL9104, ISL9104A ADJUSTABLE OUTPUT L OUTPUT 1.0H INPUT: 2.7V TO 6V UP TO 500mA SW VIN C2 C1 4.7F R1 C3 4.7F 100k 47pF R2 ENABLE 100k EN FB DISABLE GND ISL9104, ISL9104A FIXED OUTPUT L OUTPUT UP TO 500mA 1.0H INPUT: 2.7V TO 6V VIN SW C2 C1 4.7F 4.7 F ENABLE EN FB DISABLE GND FIGURE 2. TYPICAL APPLICATIONS DIAGRAM Note: For adjustable output version, the internal feedback resistor divider is disabled and the FB pin is directly connected to the error amplifier. FN6829 Rev 5.00 Page 2 of 14