designs for power-supply regulator. All the functions
include an on-chip 1.25V reference output, an error
amplifier, an adjustable oscillator, a soft-start,
UVLO, SCP circuitry, and a push-pull output circuit.
Switching frequency is adjustable by trimming CT.
During low VCC situation, the UVLO makes sure
that the outputs are off until the internal circuit
operates normally.
Applications
- Backlight inverter
- LCD Monitor
- XDROM, XDSL Product
- DC/DC converters in computers, etc.
Pin Assignment
( Top View )
OUT
VCC
COMP
FB
1
2
3
4
8
7
6
5
Pin Descriptions
Name
GND
CT
SS
SCP
Description
Timing Capacitor
Voltage Feedback
Soft-Start.
Feedback Loop Compensation
PWM Output
Ground
Supply Voltage
Short Circuit Protection
CT
FB
SS
COMP
OUT
GND
VCC
SCP
PDIP/SOP
Ordering Information
AP2004 X
Package
N: PDIP-8L
S: SOP-8L
X
X
Lead Free
Packing
Blank : Tube
Blank : Normal
L : Lead Free Package A : Taping
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev. 0.4 Arpr 6, 2004
1/8
AP2004
PWM Buck Controller
Block Diagram
VCC
SS
CT
1.25V
Bandgap
Reference
2.5V
Internal use
UVLO
Oscillator
VCC
MAX.500KHz
Iss
PWM Amplifier
FB
+
+
-
Error Amplifier
COMP
-
1.5V
+
0.7V
-
+
OUT
SCP
GND
Absolute Maximum Ratings
Symbol
V
CC
V
I
V
O
I
SOURCE
I
SINK
T
OP
T
ST
T
LEAD
Supply voltage
Amplifier input voltage
Collector output voltage
Source current
Sink current
Operating temperature range
Storage temperature range
Lead temperature 1.6 mm(1/16 inch) from case for 10 seconds