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
up to 93% Efficiency
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.
• 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
Under light load condition, the device operates at low I skip
Q
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.
• 20µA Quiescent Supply Current in Skip Mode
• Less than 1µA Logic Controlled Shutdown Current
• 100% Maximum Duty Cycle for Lowest Dropout
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.
• 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
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.
• Chip Enable
• Small 6 Pin 1.6mmx1.6mm µTDFN Package
• Pb-Free (RoHS Compliant)
The ISL9104, ISL9104A is offered in a 1.6x1.6mm µTDFN
package. The complete converter occupies less than 0.5CM .
2
Related Literature
• See AN1522, “ISL9104xxxxEVAL1Z, ISL9104AxxxxEVAL1Z
Evaluation Board Application Manual”
Applications
• Single Li-ion Battery-Powered Equipment
• Mobile Phones and MP3 Players
• PDAs and Palmtops
• WCDMA Handsets
• Portable Instruments
100
95
90
85
80
75
70
65
Pin Configuration
ISL9104, ISL9104A
(6 LD 1.6x1.6 µTDFN)
TOP VIEW
VIN
EN
NC
1
2
3
6
5
4
SW
GND
FB
V
= 2.7V
= 1.8V
L = 1µH
60
55
50
IN
OUT
V
1
10
100
1000
I
(mA)
OUT
FIGURE 1. EFFICIENCY vs OUTPUT CURRENT
FN6829 Rev 5.00
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