Global Mixed-mode Technology Inc.
G5503
300KHz, 3A Buck Converter
The G5503 is a voltage-mode buck PWM converter
capable of driving up to 3A loads over a wide input
supply range. High efficiency is obtained through the
use of a low RDS(ON) P-channel power switch. The in-
ternal compensation makes feedback control have
excellent line and load regulation characteristics with-
out external designs.
Features
Voltage Mode Asynchronous PWM Control
3.3V, 5V and Adjustable Output Version
Operation Voltage can be up to 20V
Adjustable Version Output Voltage Range, 0.8V
to 16V±2%
300KHz Fixed Frequency Internal Oscillator
Built-in Switching Transistor on Chip
3A Output Load Current
Thermal Shutdown and Current Limit Protec-
tion
ON/OFF Shutdown Control
Iq of Low Power Standby Mode 1µA
Available in SOP-8 Packages
It uses a fixed switching frequency of 300KHz. The
output voltage is 3.3V, 5V and an user-programmable
version via an external resistive voltage divider. The
built-in soft-start can reduce inrush current on the input
source at turn on.
The device also has built-in current-limit, thermal
shutdown, under-voltage lockout and an ON/OFF
logic-control that can power down the regulator to a
shutdown mode. When current limit function occurred
and VFB is down to 0.3V below, the device changes
switching frequency to 120KHz to protect IC from
damage.
Applications
Simple high-efficiency step-down regulator
On-card switching regulators
Positive to negative converter
G5503 is available in SOP-8 package.
General Description
Ordering Information
ORDER
NUMBER
TEMP.
RANGE
PACKAGE
(Pb free)
SOP-8
MARKING
VOLTAGE
G5503-ADJP11U
G5503-33P11U
G5503-50P11U
5503A
5503B
5503C
Adjustable
3.3V
-40°C~85°C
-40°C~85°C
-40°C~85°C
SOP-8
5.0V
SOP-8
Note: P1: SOP-8
1: Bonding Code
U: Tape & Reel
Pin Configuration
Typical Application Circuit
G5503
G5503
33µH
8
7
6
5
NC
1
2
3
4
FB
EN
NC
IN
VOUT
3.3V/2A
VIN
6V~18V
LX
IN
D1
SCD36
*
1µF
GND
LX
220µF
R1/31.25K
R2/10K
1µF
470µF
EN
FB
GND
NC
R1
R2
SOP-8
VOUT = 0.8 x ( 1 +
)
* optional
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver: 0.1
May 02, 2008
1