AP1501
150Khz, 3A PWM Buck DC/DC Converter
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. A7 Feb. 10, 2004
1/11
Features
- Output voltage: 3.3V, 5V, 12V and adjustable
output version
- Adjustable version output voltage range, 1.23V to
37V+4%
- 150Khz +15% fixed switching frequency
- Voltage mode non-synchronous PWM control
- Thermal-shutdown and current-limit protection
- ON/OFF shutdown control input
- Operating voltage can be up to 40V
- Output load current: 3A
- TO220-5L TO220-5L(R) and TO263-5L packages
- Low power standby mode
- Built-in switching transistor on chip
Applications
- Simple High-efficiency step-down regulator
- On-card switching regulators
- Positive to negative converter
General Description
The AP1501 series are monolithic IC that design for
a step-down DC/DC converter, and own the ability
of driving a 3A load without additional transistor
component. Due to reducing the number of external
component, the board space can be saved easily.
The external shutdown function can be controlled
by logic level and then come into standby mode.
The internal compensation makes feedback control
have good line and load regulation without external
design. Regarding protected function, thermal
shutdown is to prevent over temperature operating
from damage, and current limit is against over
current operating of the output switch. The AP1501
series operates at a switching frequency of 150Khz
thus allowing smaller sized filter components than
what would be needed with lower frequency
switching regulators. Other features include a
guaranteed +4% tolerance on output voltage under
specified input voltage and output load conditions,
and +15% on the oscillator frequency. The output
version included fixed 3.3V, 5V, 12V, and an
adjustable type. The packages are available in a
standard 5-lead TO-220 package and a 5-lead
TO-263.
Pin Assignments
TO220-5L
( Top View )
( Top View )
TO263-5L
1 V
IN
5 SD
4 FB
3 Gnd
2 Output
Metal Tab GND
1 V
IN
5 SD
4 FB
3 Gnd
2 Output
Pin Descriptions
Name Description
VIN Operating voltage input
Output Switching output
Gnd Ground
FB Output voltage feedback control
SD ON/OFF Shutdown
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
2/11
Ordering Information
Package
T5: TO220-5L
K5: TO263-5L
Output version
AP1501 XX X X X
Packing
Blank : Tube
A : Taping
Blank : Adjustable
-33 : 3.3V
-50 : 5.0V
-12 : 12V
T5R: TO220-5L(R)
Lead Free
Blank : Normal
L : Lead Free Package
Block Diagram
Current
Source
bias
1.235V
Reference
2.5V
Regulator
150kHz
OSC.
Start
up
+
+
_
+
_
Thermal
Limit
Pre-driver
Comp
Comp
Gnd
Output
V
IN
SD
FB
220mV
200mV
3A
Switch
+
_
_
Amp
Comp
Frequecy
compen-
sation
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
3/11
Absolute Maximum Ratings
Symbol Parameter Rating Unit
VCC Supply Voltage +45 V
VSD ON/OFF Pin input voltage -0.3 to +25 V
VFB Feedback Pin voltage -0.3 to +25 V
VOUT Output voltage to Ground -1 V
PD Power dissipation Internally limited W
TST Storage temperature -65 to +150 oC
TOP Operating temperature -40 to +125 oC
VOP Operating voltage +4.5 to +40 V
Electrical Characteristics (All Output Voltage Versions)
Unless otherwise specified, VIN=12V for 3.3V, 5V, adjustable version and VIN=24V for the 12V version. ILOAD = 0.5A
Symbol Parameter Conditions Min. Typ. Max. Unit
60
IB Feedback bias current VFB=1.3V
(Adjustable version only) 40
100 nA
127 150 173
FOSC oscillator frequency 110 173
Khz
1.4
VSAT saturation voltage
IOUT=3A
no outside circuit
VFB=0V force driver on
1.3
1.5 V
Max. Duty Cycle(ON) VFB=0V force driver on 100
DC Min. Duty cycle(OFF) VFB=12V force driver off 0 %
5.5
ICL current limit
peak current
no outside circuit
VFB=0V force driver on
3.6 4.0 6.5 A
Output = 0 no outside circuit
VFB=12V force driver off 200 uA
IL
Output = -1
Output
leakage
current VIN=40V 2 60 mA
IQ Quiescent Current VFB=12V force driver off 5 10 mA
250
ISTBY Standby Quiescent
Current
ON/OFF pin=5V
VIN=40V 150
300 uA
VIL Low (regulator ON) - 0.6
VIH
ON/OFF pin logic input
threshold voltage High (regulator OFF) 2.0 1.3 - V
IH ON/OFF pin logic
input current VLOGIC=2.5V (OFF) 15 25
IL ON/OFF pin input current VLOGIC=0.5V (ON) 0.02 5
uA
TO220-5L 2.5
ΘJC Thermal Resistance TO263-5L
Junction to
case 3.5
oC/W
TO220-5L 28
ΘJA
Thermal Resistance
With copper area of
approximately 3 in2 TO263-5L
Junction to
ambient 23
oC/W
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
4/11
Electrical Characteristics (Continued)
Symbol Parameter Conditions Typ. Limit Unit
FB
V Output
Feedback
4.5V < VIN < 40V
0.2A < ILOAD < 3A
VOUT programmed for
3V
1.23
1.193/1.18
1.267/1.28
V
VMIN
VMAX
AP1501-ADJ
η Efficiency VIN = 12V, ILOAD=3A 73 %
OUT
V Output voltage 4.75V < VIN < 40V
0.2A < ILOAD < 3A 3.3 3.168/3.135
3.432/3.465
V
VMIN
VMAX
AP1501-3.3V
η
Efficiency VIN = 12V, ILOAD=3A 73 %
OUT
V Output voltage 7V < VIN < 40V
0.2A < ILOAD < 3A 5 4.8/4.75
5.2/5.25
V
VMIN
VMAX
AP1501-5V
η Efficiency VIN = 12V, ILOAD=3A 80 %
OUT
V Output voltage 15V < VIN < 40V
0.2A < ILOAD < 3A 12 11.52/11.4
12.48/12.6
V
VMIN
VMAX
AP1501-12V
η Efficiency VIN = 15V, ILOAD = 3A 90 %
Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC.
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
5/11
Typical Performance Characteristics
Typical Performance Characteristics
Normalized Output Voltage
4.90
4.95
5.00
5.05
5.10
-50 -25 0 25 50 75 100 125
OUTPUT VOLTAGE (V)
V
IN
=20V, I
LOAD
=3A
Normalized at T
J
=25
o
C
JUNCTION TEMPERATURE(
o
C)
JUNCTION TEMPERATURE(
o
C)
SWITCH CURRENT LIMIT (A)
Switch Current Limit
0.0
5.0
10.0
15.0
20.0
25.0
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERATURE(
o
C)
SUPPLY CURRENT (mA)
Operating Quiescent Current
JUNCTION TEMPERATURE(
o
C)
EFFICIENCY (%)
Efficiency
100
65
70
75
80
85
90
95
810152025
30 35 40
5V
3.3V
3A Load
0.60
0.80
1.00
1.20
1.40
1.60
0.5 123
SWITCH CURRENT(A)
SATURATION VOLTAGE (V)
1
2
3
1 : -40
o
C
2 : 25
o
C
3 : 125
o
C
Switch Saturation Voltage
3.50
4.00
4.50
5.00
5.50
-50 -25 0 25 50 75 100 125
V
IN
=12V, V
OUT
=5V
SUPPLY VOLOTAGE (V)
CURRENT (uA)
0.0
40.0
80.0
120.0
160.0
200.0
Shutdown Quiescent Current
10 20 30 40
V
ON/OFF
=5V
1 : -40
o
C
2 : 25
o
C
3 : 125
o
C
1
3
2
Switch ON
Switch OFF
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
6/11
Typical Performance Characteristics (Continued)
JUNCTION TEMPERATURE(
o
C)
BIAS CURRENT (nA)
Feedback Pin Bias Current
1.4 5 10152022232425
ON/OFF PIN VOLTAGE (V)
CURRENT (uA)
ON/OFF Pin Current (Sinking)
0.0
30.0
60.0
90.0
120.0
150.0
V
IN
=40V
-40
o
C T
J
125
o
C
≤≤
0.0
10.0
20.0
30.0
40.0
50.0
-50 -25 0 25 50 75 100 125
Adjustable Version Only
0.0
1.0
2.0
3.0
4.0
5.0
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERATURE (
o
C)
SUPPLY VOLTAGE (V)
Minimum Operating Supply Voltage
V
OUT
=1.23V
I
LOAD
=120mA
JUNCTION TEMPERATURE (
o
C)
THRESHOLD VOLTAGE (V)
ON/OFF Threshold Voltage
0.0
1.0
2.0
3.0
4.0
5.0
-50 -25 025 50 75 100 125
Switch Frequency
JUNCTION TEMPERATURE (
o
C)
FREQUENCY (kHz)
0.0
50.0
100.0
150.0
200.0
-50 -25 0 25 50 75 100 125
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
7/11
Typical Application Circuit
12
35
4
12V
DC Input
C
in
Capacitor
FB
SD
D1
Schottky Diode
Vin
Gnd
Output
AP1501
-33
Co
Capacitor
Inductor
L1 3.3V/3A
Output Load
Function Description
Pin Functions
+VIN
This is the positive input supply for the IC switching
regulator. A suitable input bypass capacitor must be
present at this pin to minimize voltage transients
and to supply the switching currents needed by the
regulator.
Ground
Circuit ground.
Output
Internal switch. The voltage at this pin switches
between (+VIN – VSAT) and approximately – 0.5V,
with a duty cycle of approximately VOUT / VIN. To
minimize coupling to sensitive circuitry, the PC
board copper area connected to this pin should be
kept a minimum.
Feedback
Senses the regulated output voltage to complete
the feedback loop.
ON /OFF
Allows the switching regulator circuit to be
shutdown using logic level signals thus dropping
the total input supply current to approximately
150uA. Pulling this pin below a threshold voltage of
approximately 1.3V turns the regulator on, and
pulling this pin above 1.3V (up to a maximum of
25V) shuts the regulator down. If this shutdown
feature is not needed, the ON /OFF pin can be
wired to the ground pin or it can be left open, in
either case the regulator will be in the ON condition.
Thermal Considerations
The AP1501 is available in two packages, a 5-pin
TO-220 and a 5-pin surface mount TO-263.
The TO-220 package needs a heat sink under most
conditions. The size of the heatsink depends on the
input voltage, the output voltage, the load current
and the ambient temperature. The AP1501 junction
temperature rises above ambient temperature for a
3A load and different input and output voltages.
The data for these curves was taken with the
AP1501 (TO-220 package) operating as a buck
switching regulator in an ambient temperature of
25oC (still air). These temperature rise numbers are
all approximate and there are many factors that can
affect these temperatures. Higher ambient
temperatures require more heat sinking.
The TO-263 surface mount package tab is
designed to be soldered to the copper on a printed
circuit board. The copper and the board are the
heat sink for this package and the other heat
producing components, such as the catch diode
and inductor. The PC board copper area that the
package is soldered to should be at least 0.4 in2,
and ideally should have 2 or more square inches of
2 oz. Additional copper area improves the thermal
characteristics, but with copper areas greater than
approximately 6 in2, only small improvements in
heat dissipation are realized. If further thermal
improvements are needed, double sided, multilayer
PC board with large copper areas and/or airflow are
recommended.
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
8/11
Function Description (Continued)
The AP1501 (TO-263 package) junction
temperature rise above ambient temperature with a
2A load for various input and output voltages. This
data was taken with the circuit operating as a buck
switching regulator with all components mounted on
a PC board to simulate the junction temperature
under actual operating conditions. This curve can
be used for a quick check for the approximate
junction temperature for various conditions, but be
aware that there are many factors that can affect
the junction temperature. When load currents
higher than 2A are used, double sided or multilayer
PC boards with large copper areas and/or airflow
might be needed, especially for high ambient
temperatures and high output voltages.
For the best thermal performance, wide copper
traces and generous amounts of printed circuit
board copper should be used in the board layout.
(Once exception to this is the output (switch) pin,
which should not have large areas of copper.)
Large areas of copper provide the best transfer of
heat (lower thermal resistance) to the surrounding
air, and moving air lowers the thermal resistance
even further.
Package thermal resistance and junction
temperature rise numbers are all approximate, and
there are many factors that will affect these
numbers. Some of these factors include board
size, shape, thickness, position, location, and even
board temperature. Other factors are, trace width,
total printed circuit copper area, copper thickness,
single or double-sided, multilayer board and the
amount of solder on the board. The effectiveness
of the PC board to dissipate heat also depends on
the size, quantity and spacing of other components
on the board, as well as whether the surrounding
air is still or moving. Furthermore, some of these
components such as the catch diode will add heat
to the PC board and the heat can vary as the input
voltage changes. For the inductor, depending on
the physical size, type of core material and the DC
resistance, it could either act as a heat sink taking
heat away from the board, or it could add heat to
the board.
Marking Information
(1) TO263-5L
AC
1501-XX
Output Type:
1501: ADJ
1501-33: 3.3V
1501-50: 5.0V
1501-12: 12V
Logo
ID code
Year:
( Top view )
"02" = 2002
"01" = 2001
YY WW X X
Xth week: 01~52
~
Blank: normal
L: Lead Free Package
(2) TO220-5L
AC
1501-XX
Output Type:
1501: ADJ
1501-33: 3.3V
1501-50: 5.0V
1501-12: 12V
Logo
ID code
Year:
( Top view )
"02" = 2002
"01" = 2001
YY WW X X
Xth week: 01~52
~
Blank: normal
L: Lead Free Package
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
9/11
Package Information
(1) Package Type: TO220-5L
D
Q
E
b
e1
A
J1
F
C
Φ
P
H1
L
e
Dimensions In Millimeters Dimensions In Inches
Symbol Min. Nom. Max. Min. Nom. Max.
A 4.07 4.45 4.82
0.160 0.175 0.190
b 0.76 0.89 1.02 0.030 0.035 0.040
C 0.36 0.50 0.64 0.014 0.020 0.025
D 14.22 14.86 15.50
0.560 0.585 0.610
E 9.78 10.16 10.54 0.385 0.400 0.415
e 1.57 1.71 1.85 0.062 0.067 0.073
e1 6.68 6.81 6.93 0.263 0.268 0.273
F 1.14 1.27 1.40 0.045 0.050 0.055
H1 5.46 6.16 6.86 0.215 0.243 0.270
J1 2.29 2.74 3.18 0.090 0.108 0.125
L 13.21 13.97 14.73 0.520 0.550 0.580
Øp 3.68 3.81 3.94 0.145 0.150 0.155
Q 2.54 2.73 2.92 0.100 0.107 0.115
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
10/11
Package Information (Continued)
(2) Package Type: TO263-5L
A
C2
C
E
L2
eB
D
L
F
L1
Dimensions In Millimeters Dimensions In Inches
Symbol Min. Nom. Max. Min. Nom. Max.
A 4.07 4.46 4.85 0.160 0.176 0.191
B 0.66 0.84 1.02 0.026 0.033 0.040
C 0.36 0.50 0.64 0.014 0.020 0.025
C2 1.14 1.27 1.40 0.045 0.050 0.055
D 8.65 9.15 9.65 0.341 0.360 0.380
E 9.78 10.16 10.54 0.385 0.400 0.415
e 1.57 1.71 1.85 0.062 0.068 0.073
F 6.60 6.86 7.11 0.260 0.270 0.280
L 14.61 15.24 15.88 0.575 0.600 0.625
L1 2.29 2.54 2.79 0.090 0.100 0.110
L2 - - 2.92 - - 0.115
AP1501
150Khz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.A7 Feb. 10, 2004
11/11
Package Information (Continued)
(3) Package Type: TO220-5L(R) Mechanical drawing
E
Q
D
b
A
F
H1
d1
d2
J3
J1
J2
e
H2
H3
A
J1
J2
J3
E
Dimensions In Millimeters Dimensions In Inches
Symbol Min. Nom. Max. Min. Nom. Max.
A 4.4 4.6 4.7 0.175 0.180 0.185
b 0.7 0.8 0.9 0.027 0.032 0.037
D 8.4 8.7 8.9 0.330 0.340 0.350
d1 1.0 0.039
d2 6.3 0.248
E 9.91 10.16 10.41 0.390 0.400 0.410
e 1.6 1.7 1.8 0.062 0.067 0.072
F 1.2 1.25 1.3 0.048 0.050 0.052
H1 6.4 0.250
H2 20.8 21.6 22.4 0.820 0.850 0.880
H3 23.9 24.7 25.5 0.942 0.972 1.002
J1 2.7 0.105
J2 3.7 4.5 5.3 0.147 0.177 0.207
J3 8.4 0.331
Q 2.5 2.8 3.0 0.100 0.110 0.120
