G5108 Datasheet, PDF (1/1 Pages) Global Mixed-mode Technology Inc – Low-Noise Step-up DC-DC Converter

Global Mixed-mode Technology
G5108
Low-Noise Step-up DC-DC Converter
Features
„ 90% Efficiency
„ Adjustable Output from V_IN to 20V
„ 0.2Ω, 24V Power MOSFET
„ Cycle-by-Cycle 2A Current Limit
„ 2.5V to 5.5V Input Range
„ 600kHz/1.2MHz Switching Frequency
„ MSOP-8, TDFN3X3-8 Package
Applications
„ LCD Displays
„ Portable Applications
„ Hand-Held Devices
General Description
The G5108 boost converter in corporate high-per-
formance, current-mode, frequency selectable pulse
width modulation (PWM) circuitry with a built-in 0.2Ω
n-channel MOSFET to provide a highly efficient regu-
lator.
High switching frequency allows easy filtering and
faster loop performance. An external compensation
pin provides the user flexibility in determining loop dy-
namics, allowing the use of small, low ESR ceramic
output capacitors. The device can produce an output
voltage as high as 20V. User programmed soft-start
with an external capacitor determines the input current
ramp rate.
The G5108 is available in a space-saving MSOP-8
and TDFN3X3-8 package.
Ordering Information
ORDER
NUMBER
MARKING
G5108P8U
G5108
G5108RDU
5108
Note: P8: MSOP-8 RD:TDFN3X3-8
U: Tape & Reel
Pin Configuration
TEMP.
RANGE
-40°C ~ +85°C
-40°C ~ +85°C
PACKAGE
(Green)
MSOP-8
TDFN3X3-8
Typical Application Circuit
G5108
G5108
COMP 1
FB 2
SHDN 3
GND 4
8 SS ^{COMP 1}
7 FSL
FB 2
6 VCC SHDN 3
5 SW
GND 4
Thermal
Pad
8 SS
7 FSL
6 VCC
5 SW
MSOP-8
TDFN3X3-8
Note: Recommend connecting the Thermal Pad to
the Ground for excellent power dissipation.
V_IN
2.5V to 5.5V
ON ^OFF
C1
22µF
6
VCC
3
SHDN
5
SW
1.2MHz ^{600kHz 7} FSL
4
GND
L1
4.7µH~10µH
C2
22µF
8 _SS
2
FB
R1
COMP
R2
10nF
1
RC
24k
CC
2.2nF
V_OUT =1.24
x
(1+
R1
R2
)
V_OUT
8V
200mA
Ver: 1.6
Nov 03, 2011
TEL: [phone]
http://www.gmt.com.tw
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