APW1172
Pin Function Description
No.
PIN
Description
1
OUT
Regulator Output.
2
3
4
SYNC
INH
Master/Slave synchonization.
A logical signal (active high) disables the device. If INH not used the pin must be
connected to GND. When it is open an internal pull-up disable the device.
COMP
E/A output for frequency compensation.
Feedback input. Connecting directly to this pin results in an output voltage of
1.235V(APW1172). An external resistive divider is required for higher output
voltages.
5
6
FB
VREF
3.3V reference voltage output, no Capacitor Is requested for stability.
7
8
GND
VCC
Ground.
Unregulated DC input voltage.
Thermal Characteristics
Symbol
Parameter
Junction to ambient thermal resistance in free air
Value
Unit
45.7
°C/W
qJA
* The area of the thermal pad is 4.5mm X 2mm and the GNDplane is 60mm X 60mm. Connect the thermal
pad and theGNDplane by 8 vias. TA=25°C.
Electrical Characteristics
The * denotes the specifications that apply over TA = -40 ~ 85oC. Typical values are at TA = 25oC.
VCC = 12V unless otherwise specified.
APW1172
Symbol
Parameter
Test condition
Unit
Min
4.7
3.8
Typ
Max
22
VCC Operating input voltage range VO = 1.235V; IO = 2A
*
*
V
V
V
V
A
UVLO threshold voltage
Hysteresis
VCC rising
4.2
0.3
1.0
3.8
250
250
4.6
VUVLO
Vd
Dropout voltage
VCC = 4.8V; IO = 2A
VCC = 4.8V to 22V
*
*
*
1.2
4.3
ILIM
Maximum limiting current
3.3
200
205
0
300
295
100
fs
Switching frequency
Duty cycle
Main design
KHz
%
Copyright ã ANPEC Electronics Corp.
3
www.anpec.com.tw
Rev. A.4 - Aug., 2005
ANPEC [ ANPEC ELECTRONICS COROPRATION ]
