G5217 Datasheet, PDF (1/1 Pages) Global Mixed-mode Technology Inc – 24V Input Voltage-Mode Buck PWM Controller

Global Mixed-mode Technology Inc.
G5217
24V Input Voltage-Mode Buck PWM Controller
Features
„ Drives Two N-Channel MOSFETs
„ Operates at 5V to 24V Supply Voltage
„ Internal Bootstrap Diode Circuit
„ Voltage-Mode PWM Control
„ Fast Transient Response
„ 0.8V, 2% Accuracy Reference Voltage
„ Internal Soft Start
„ Constant 300kHz Switching Frequency
„ Over-Current Fault Monitors by Using
Low-Side MOSFET R_DS(ON)
„ Output Under-Voltage Protection
Applications
„ 16V to 30V Input High Power DC-DC Regulators
„ Low-Voltage Distributed Power Supplies
Ordering Information
ORDER
NUMBER
G5217P11U
Note: P1: SOP-8
1: Bonding Code
U: Tape & Reel
MARKING
G5217
General Description
The G5217 provides complete control and protection
for a DC-DC converter for high power applications. It is
designed to drive two N-channel MOSFETs in a syn-
chronous-rectified buck topology. The G5217 inte-
grates all of the control, bootstrap diode and protection
functions into a single package.
The G5217 provides simple, single feedback loop,
voltage-mode control with fast transient response. It
includes a 300kHz free-running triangle-wave oscilla-
tor. The error amplifier features a 15MHz gain-band-
width product which provides high converter band-
width for fast transient performance. The resulting
PWM duty ratio ranges from 0% to 80%. The refer-
ence voltage is 0.8V, 2% accuracy.
The G5217 has internal soft start and executes cy-
cle-by-cycle current limit during soft start interval. The
G5217 monitors the current by using the R_DS(ON) of the
low-side MOSFET which eliminates the need for a
current sensing resistor. The under-voltage protection
function monitors voltage at FB pin. The over-current
and under-voltage events after soft-start interval trig-
ger hiccup mode protection.
TEMP.
RANGE
-40°C~ +85°C
PACKAGE
(Green)
SOP-8
Pin Configuration
Typical Application Circuit
UGATE 1
LX 2
LGATE 3
GND 4
G5217
SOP-8
8 BOOT
7 VCC
6 OCSET
5 FB
SHDN
10Ω
G5217
VCC
4.7µF
BOOT
ROCSET
OCSET
UGATE
LX
LGATE
FB
GND
5V ~ 24V
220µF
0.1µF
3µH
VO=13.5V
2000µF
10nF
620Ω
39Ω
Ver: 0.2
Jan 13, 2010
TEL: [phone]
http://www.gmt.com.tw
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