- Programmable output voltage by external resistors
- Output voltage could go down to 0.6V
- Iccq at VCCA less than 500uA
- Current limit protection and Short Circuit
protection
- Thermal shutdown protection
- Shutdown for standby or suspend mode operation
- Minimum external components
- 5-Lead TO252
Pb-free
Package
General Description
The AP1127 is a low cost linear regulator designed
to provide a desired output voltage or termination
voltage for various applications by converting
voltage supplies ranging from 1.6V to 6.0V. The
desired output voltage could be programmable by
two external voltage divider resistors.
The AP1127 is capable of sourcing or sinking up to
3A of current while regulating an output V
OUT
voltage to within 2% (DDR-I), 3%(DDR-II) or less.
The AP1127 provides low profile 5-lead TO-252
package to save system space.
Applications
- Mother Board
- PCI/AGP Graphics
- Game/Play Station
- Set Top Box
- SCSI-III Bus Terminator
- IPC
Pin Assignment
( Top View )
5
4
3
2
1
TO252-5L
VCCA
REFEN
GND
V
OUT
V
IN
Pin Descriptions
Pin
Name
V
IN
V
OUT
GND
REFEN
VCCA
Pin
No.
1
2
3
4
5
Descriptions
Input Power
Output Voltage
Ground
Reference Voltage Input and Chip
Enable
Voltage Supply for Internal Circuits
Ordering Information
AP1127 X X
Package
D: TO252-5L
Packing
Blank : Tube
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.1.1 Jan 17, 2005
1/4
AP1127
3A Bus Terminator Regulator
Typical Circuit
VCCA
V
IN
R1
100K
V
IN
REFEN
EN
Q1
CSS
R2
100K 1uF
GND
VCCA
V
OUT
C
OUT
200uF
C
VCCA
C
IN
470uF 10uF
V
OUT
Block Diagram
VCCA
V
IN
Current Limit
Protection
REFEN
Thermal
Control
+
-
V
OUT
GND
Absolute Maximum Ratings
(Note 1)
Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Symbol
Parameter
Rating
Unit
V
IN
Supply Voltage
7
V
VCCA
Voltage Supply for internal circuits
7
V
I
OUT
Output RMS Current, Source or Sink
3
A
o
T
STG
Storage Temperature
-65 to 125
C
o
T
Lead
Lead Temperature (Soldering, 5 sec)
260
C
o
θ
JC
Thermal Resistance
7.7
C/W
Anachip Corp.
www.anachip.com.tw
2/4
Rev.1.1 Jan 17, 2005
AP1127
3A Bus Terminator Regulator
Electrical Characteristics
Unless otherwise stated, these specifications apply T
A
=25 C; V
IN
=+2.5V and VCCA=+3.3V, V
REFEN
=1.25V) maximum ratings are stress
ratings only and functional device operating is not implied.
(Note 1)
o
Symbol
V
OS
I
OP
∣∆V
LOAD
∣
I
CCQ
I
SHDN
Parameter
Output Offset Voltage
Operating Current at VIN
Load Regulation (DDR I/II)
Quiescent Current at VCCA
Current in Shutdown Mode
V
IN
Input Voltage Range
(Note 3)
VCCA
Input Voltage Range
(Note 3)
Short Circuit Protection
I
LIMIT
Current Limit
I
SC, VIN
Short Current
I
SC, GND
Short Current
Over Thermal Protection
THSD
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
REFEN Function
REFEN Threshold
Conditions
I
OUT
=0A (Note 2)
No load, C
OUT
=200uF
I
L
: 0A~3A
I
L
: 0A~3A
At room temp.
REFEN < 0.2V,
R
L
=10Ω
No load
R
L
=10Ω
Sinking
Sourcing
3.75V
≤
VCCA
≤
6V
V
REFEN
< V
IN
V
REFEN
< VCCA-2.5V
Min.
-20
-
-
-
-
-
1.35/1
3.75
-
2
3
125
25
0.4
Typ.
-
-
0.8/1.2
0.8/1.2
190
90
2.5/1.8
-
5
-
-
150
30
0.5
Max.
20
1
2/3
2/3
230
110
6
6
-
-
-
-
35
0.6
Unit
mV
mA
%
µA
µA
V
V
A
A
A
o
o
C
C
V
Note 1:
Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions.
Note 2:
V
OS
=V
REFEN
-V
OUT
Note 3:
Keep VCCA
≥
VIN and VCCA
≥
V
REFEN
+ 2.5V on operation power on and power off sequences.
Note 4:
Guaranteed by design, not 100% test.
Function Description
The AP1127 is a linear regulator that is capable of
sinking and sourcing 3A of current without an
external heat sink.
The AP1127 integrates power MOSFETs that are
capable of source and sink 3A of current while
maintaining excellent voltage regulation. The output
voltage can be regulated within 3% or less by using
the external feedback. Separate voltage supply
inputs have been added to fit applications with
various power supplies for the data bus and power
buses.
Outputs
The output voltage pins (V
OUT
) are tied to the data
bus, address, or clock lines via an external inductor.
Output voltage is determined by the V
IN
.
Inputs
The input voltage pins (V
IN
) determine the output
voltages (V
OUT
). At AP1127, the desired output
voltage could be programmable by two external
voltage divider resistors. V
IN
is suggested to connect
to VDDQ of memory module for better tracking with
memory VDDQ.
Other Supply Voltages
VCCA provide the voltage supply to the logic section