Document
Global Mixed-mode Technology Inc.
2.5A Buck Converter
G5644
Features
4.75V to 20V Supply Voltage Operating Range Fixed 500kHz Switching Frequency Current-Mode Buck PWM Converter Built-in P-Channel Power MOSFET 2.5A Output Current 0.8V Internal Reference Shutdown Control Thermal-Shutdown and Internal Soft Start Cycle-by-Cycle Current-Limit Short Circuit Protection Under-Voltage Lockout Protection SOP-8 Package
Applications
Distributed Power Systems Battery Charger Palmtop Computers, PDAs DSL Modems
Pin Configuration
General Description
The G5644 is a high efficiency, 2.5A buck converter with a high-side low RDS(ON) switch. It operates from 4.75V to 20V input voltage range, and provides up to 2.5A continuous output current with the output voltage adjustable down to 0.8V. Whenever the load is light, the G5644 automatically change the PWM operation mode to PFM operation to minimize the power consumption. Hence it is suitable for battery-powered devices.
It uses a fixed switching frequency up to 500kHz. When a short circuit is detected on the output, the device change switching frequency to 50kHz to protect IC from damage.
The G5644 is available in a SOP-8 package.
Ordering Information
ORDER NUMBER
MARKING
G5644P11U
G5644
Note: P1: SOP-8
1: Bonding Code
U : Tape & Reel
TEMP. RANGE
-40°C to +85°C
PACKAGE (Pb free)
SOP-8
Typical Application Circuit
IN 1 EN 2 COMP 3 FB 4
G5644 SOP-8
8 NC 7 LX 6 GND 5 NC
V IN 5 V~18V
CC2 opt io nal
G5644
IN
10µ F OFF ON
CC 1.5nF
RC 20kΩ
EN
COMP GND
LX FB
4. 7µ H D1 SS34 R1/3kΩ
R2/ 12 kΩ
VOUT 1V / 2. 5A
47 µF MLCC
V IN 5 V~18V
CC2 1 0p F
G5644
IN LX
10µ F OFF ON EN
CC 47 0pF
COMP GND
RC 60kΩ
FB
( )R1
V OUT = 0 .8 V x
1+ R2
4. 7µ H D1 SS34 R1/3kΩ
R2/ 1 2kΩ
VOUT 1V / 2. 5A 0 .1 µF
100 µF/ 22 0µ F Electr olytic
Ver: 0.1 Sep 05, 2008
TEL: 886-3-5788833 http://www.gmt.com.tw
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