User Manual

150kHz 3A BUCK DC-DC CONVERTER AP3003
Data Sheet
3
Aug. 2008 Rev. 1. 2 BCD Semiconductor Manufacturing Limited
Functional Block Diagram
Figure 3. Functional Block Diagram of AP3003
ON
/OFF
FEEDBACK
V
IN
OUTPUT
GND
+
_
+
_
+
_
+
_
START UP
2.5V
REGULATOR
1.23V
REFERENCE
LATCH
150KHz
OSC
DRIVER
&
INV
THERMAL
SHUTDOWN
EA
COMP
COMP
COMP
2.5V
Bias
Current
Frequency Shift
220
mV
200
mV
1:100
R2
R1
1
2
3
4
5
R1=2.49k Ω R2=4.18kΩ
R1=2.49k Ω R2=7.57kΩ
R1=2.49k Ω R2=21.8kΩ
For 3.3V
5V
12V
ADJ
4.4Ω
R1=Open R2=0Ω