1.5A Low Dropout Positive Fixed-Mode Regulator
AP033
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. A2 Mar. 4, 2004
1/5
Features
• 3-Terminal and Fixed 3.3V
• 1.4V Maximum Dropout at Full Load Current.
• Fast Transient Response.
• Built-in Thermal Shutdown.
• Output Current Limiting.
Applications
• PC peripheral
• Communication
General Description
AP033 is a low dropout positive fixed-mode
regulator with minimum of 1.5A output current
capability. The product is specifically designed to
provide well-regulated supply for low voltage IC
applications such as high-speed bus termination
and low current 3.3V logic supply. AP033 is
guaranteed to have <1.4V dropout at full load
current making it ideal to provide well regulated
outputs of 3.3V with 4.7V to 12V input supply by
different output voltage.
Ordering Information
AP 033 X X X
LDO Regulator Package Packing
033 Vout = 3.3V D : TO252-3L Blank : Tube
A : Taping
Lead Free
Blank : Normal
L : Lead Free Package
Pin Assignments
3 PIN TO252
3
2
1
GND
V
IN
V
OUT
Tab is GND
Pin Descriptions
Name Pin # Function
VIN 1
The input pin of regulator.
Typically a large storage
capacitor is connected from this
pin to ground to insure that the
input voltage does not sag below
the minimum dropout voltage
during the load transient
response. This pin must always
be 1.4V higher than VOUT in
order for the device to regulate
properly.
GND 2 Ground
VOUT 3
The output of the regulator. A
minimum of 10µF capacitor
must be connected from this pin
to ground to insure stability.
Ground
1.5A Low Dropout Positive Fixed-Mode Regulator
AP033
Anachip Corp.
www.anachip.com.tw Rev. A2 Mar. 4, 200
4
2/5
Block Diagram
1
THERMAL
SHUTDOWN 2
3 Vout
GND
1.25V +
+
CURRENT
LIMIT
Vin
－
+
－
+
Absolute Maximum Ratings
Symbol Parameter Rating Unit
Vin DC Supply Voltage -0.3 to 14 V
PD Power Dissipation Internally Limited
TST Storage Temperature -65 to +150 o
C
TOP Operating Junction Temperature Range 0 to +150 o
C
Electrical Characteristics (Under Operating Conditions)
Parameter Conditions Min. Typ. Max. Units
Output Voltage VIN = 5V, IOUT = 0mA, TJ = 25oC
4.7V<VIN<12V, 0<IOUT<1.5A
3.267
3.235
3.300
3.300
3.333
3.365
V
V
Line Regulation 4.7V<VIN<12V, IOUT = 0mA, TJ=25oC
0.5
1.0
10
10
mV
mV
Load Regulation VIN = 5V, 0<IOUT<1.5A, TJ=25oC (Notes1.2) 3
8
15
33
mV
mV
Dropout Voltage
(VIN-VOUT) ∆VOUT, ∆VREF = 1%, IOUT =1.5A (Note 3) 1.3 1.4 V
Current Limit (VIN-VOUT)>1.4V, ∆VOUT=100mV (Note 4) 1.6 A
Quiescent Current VIN <12V 5 10 mA
Thermal Regulation TA=25 oC, 30ms pulse 0.008 0.04 %/W
F=120Hz, COUT=25uF Tantalum, IOUT=1.5A
Ripple Rejection AP033 VIN=6.3V 60 72 dB
Temperature Stability 0.5 %
Thermal Resistance
Junction-to-Ambient
(No heat sink ;No air
flow)
TO-252 101
o
C/W
Thermal Resistance
Junction-to-Case TO-252: Control Circuitry/Power Transistor 10 o
C/W
Note 1: See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are
measured at a constant junction temperature by low duty cycle pulse testing.
Note 2: Line and load regulation are guaranteed up to the maximum power dissipation of 2W. Power dissipation is determined by the
input/output differential and the output current.
Note 3: Dropout voltage is specified over the full output current range of the device.
Note 4: AP033 is guaranteed to operate at higher peak current than 1.6 Amp. See the thermal regulation specifications for changes in
output voltage due the heating effects.
1.5A Low Dropout Positive Fixed-Mode Regulator
AP033
Anachip Corp.
www.anachip.com.tw Rev. A2 Mar. 4, 200
4
3/5
Typical Application
5V to 3.3V Fixed Mode Regulator
5V
3.3V/
1.5A
Tab is GND
AP033
V
OUT
GND
V
IN
C2
100uF
C1
100uF
Function Description
Introduction
The AP033 fixed-mode Low Dropout (LDO)
regulator is a 3 terminal device. The AP033 only
needs 1.4V differential between VIN and VOUT to
maintain output regulation. In addition, the output
voltage tolerances are also extremely tight and they
include the transient response as part of the
specification. For example, Intel VRE specification
calls for a total of +/- 100mV including initial
tolerance, load regulation and 0 to 1.5A load step.
The AP033 is specifically designed to meet the fast
current transient needs as well as providing an
accurate initial voltage, reducing the overall system
cost with the need for fewer output capacitors.
Load Regulation
Since the AP033 is only a 3 terminal device, it is not
possible to provide true remote sensing of the
output voltage at the load. But it can supply good
load regulation by internal feedback bypass the
external loss such as adjustable mode.
Stability
The AP033 requires the use of an output capacitor
as part of the frequency compensation in order to
make the regulator stable. For most applications a
minimum of 10uF aluminum electrolytic capacitor
insures both stability and good transient response.
Thermal Design
The AP033 incorporates an internal thermal
shutdown that protects the device when the junction
temperature exceeds the maximum allowable
junction temperature. Although this device can
operate with junction temperatures in the range of
150oC, it is recommended that the selected heat
sink be chosen such that during maximum
continuous load operation the junction temperature
is kept below the temperature.
Layout Consideration
The output capacitors must be located as close to
the VOUT terminal of the device as possible. It is
recommended to use a section of a layer of the PC
board as a plane to connect the VOUT pin to the
output capacitors to prevent any high frequency
oscillation that may result due to excessive trace
inductance.
1.5A Low Dropout Positive Fixed-Mode Regulator
AP033
Anachip Corp.
www.anachip.com.tw Rev. A2 Mar. 4, 200
4
4/5
Typical Performance Characteristics
Dropout Voltage (VIN-VOUT)
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 200 400 600 800
Output Current (mA)
Dropout Voltage (V)
TJ=25oC
TJ=125oC
Load Regulation
-2
-1.8
-1.6
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
-25 0 25 50 75 100
Temperature(oC)
Output Voltage Deviation(%)
ILOAD=1.5A
Temperature Stability
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-50 -25 0 25 50 75 100 125 150
Temperature (oC)
Output Voltage Chang (%)
Line regulation
0
0.2
0.4
0.6
0.8
1
579111315
Input Voltage(V)
Output Voltage Deviation(%)
AP033 Load Transient Response
-30
-20
-10
0
10
20
30
0 102030405060708090100
Output Voltage Dev iation (mV)
-1
0
1
2
0 102030405060708090100
TIME(µs )
Load Current(A)
CIN = 10µ F
COUT= 10µF Tantalum
VIN =4.8V
Preload= 0.1A
AP033 Line Transient Response
4.5
5.5
6.5
7.5
0 20 40 60 80 100 120 140 160 180 200
Input Voltage (V)
CIN=1µF
COU T= 10µ F Tantalum
-40
-20
0
20
40
0 20 40 60 80 100 120 140 160 180 200
TIME( µs )
Output Voltage Dev iation(mV)
1.5A Low Dropout Positive Fixed-Mode Regulator
AP033
Anachip Corp.
www.anachip.com.tw Rev. A2 Mar. 4, 200
4
5/5
Marking Information
AC
AP033
Part Number
Logo
ID Code
Xth Week: 01~52
Year:
(Top view)
"02" = 2002
"01" = 2001
X X X X X X
~
Blank: normal
L: Lead Free Package
TO252-3L
Package Dimension
TO252-3L
b2
E
e
b
L2
e1
DL1
A
C1
C
A1
H
SEATING PLANE
SEE NOTE2
L
Notes:
1. JEDEC Outline: TO-252 AB
2. Mils suggested for positive contact at mounting.
Dimensions In Millimeters Dimensions In Inches
Symbol Min. Nom. Max. Min. Nom. Max.
A 2.18 2.29 2.39 0.086 0.090 0.094
A1 1.02 1.15 1.27 0.040 0.045 0.050
b 0.61 TYP. 0.024 TYP.
b2 5.20 5.35 5.50 0.205 0.211 0.217
C 0.46 0.52 0.58 0.018 0.020 0.023
C1 0.46 0.52 0.58 0.018 0.020 0.023
D 5.33 5.57 5.80 0.210 0.219 0.228
E 6.35 6.58 6.80 0.250 0.259 0.268
e 2.25 BSC. 0.089 BSC.
e1 4.50 BSC. 0.177 BSC.
H 9.00 9.70 10.40 0.354 0.382 0.409
L 0.51 - - 0.020 - -
L1 0.64 0.83 1.02 0.025 0.033 0.040
L2 1.52 1.78 2.03 0.060 0.070 0.080
