AP1506
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.1.1 Oct 29, 2004
1/12
Features
- Output voltage: 3.3V, 5V, 12V and adjustable
output version
- Adjustable version output voltage range, 1.23V to
18V+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 22V
- Output load current: 3A
- TO220-5L 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 AP1506 series are monolithic IC designed for a
step-down DC/DC converter, and own the ability of
driving a 3A load without external transistor. 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 to prevent over current operating
of the output switch. If current limit function
occurred and V
FB
is down to 0.5V below, the
switching frequency will be reduced. The AP1506
series operate 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 or 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
V
IN
Operating
voltage
input
Output Switching
output
GND Ground
FB
Output voltage feedback control
SD
ON
/OFF Shutdown
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
2/12
Ordering Information
Package
T5: TO220-5L
K5: TO263-5L
Output version
AP1506 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
Shutdown
Pre-driver
Comp
Comp
Gnd
Output
V
IN
SD
FB
220mV
200mV
3A
Switch
+
_
_
Amp
Comp
Frequecy
compen-
sation
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
3/12
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
V
CC
Supply
Voltage
+24
V
V
SD
ON /OFF Pin input voltage
-0.3 to +18
V
V
FB
Feedback Pin voltage
-0.3 to +18
V
V
OUT
Output voltage to Ground
-1
V
P
D
Power
dissipation
Internally limited
W
T
ST
Storage temperature
-65 to +150
o
C
T
OP
Operating temperature
-40 to +125
o
C
V
OP
Operating voltage
+4.5 to +22
V
Electrical Characteristics (All Output Voltage Versions)
Unless otherwise specified, V
IN
=12V for 3.3V, 5V, adjustable version and V
IN
=18V for the 12V version. I
LOAD
= 0.5A
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Unit
-50
I
FB
Feedback bias current
V
FB
=1.3V
(Adjustable version only)
-10
-100
nA
127 150 173
F
OSC
Oscillator
frequency
110 173
KHz
F
SCP
Oscillator frequency of
short circuit protect
When current limit occurred
and V
FB
< 0.5V, Ta=25
o
C
5 15 25
KHz
1.6
V
SAT
Saturation
Voltage
I
OUT
=3A
No outside circuit
V
FB
=0V force driver on
1.4
1.7
V
Max. Duty Cycle (ON)
V
FB
=0V force driver on
100
DC
Min. Duty Cycle (OFF)
V
FB
=12V force driver off
0
%
5.5
I
CL
Current
limit
Peak current
No outside circuit
V
FB
=0 force driver on
3.6 4.5
6.5
A
Output = 0V
No outside circuit
V
FB
=12 force driver off
-200
uA
I
L
Output =-1V
Output
leakage
current V
IN
=22V
-5
mA
I
Q
Quiescent
Current
V
FB
=12 force driver off
5
10
mA
150
I
STBY
Standby Quiescent
Current
ON
/OFF pin=5V
V
IN
=22V
70
200
uA
V
IL
Low (regulator ON)
-
0.6
V
IH
ON
/OFF pin logic input
threshold voltage
High (regulator OFF)
2.0
1.3
-
V
I
H
ON
/OFF pin logic
input current
V
LOGIC
=2.5V (OFF)
-0.01
I
L
ON
/OFF pin input
current
V
LOGIC
=0.5V (ON)
-0.1
-1
uA
TO220-5L
2.5
JC
Thermal
Resistance
TO263-5L
Junction to
case
3.5
o
C/W
TO220-5L
28
JA
Thermal Resistance
With copper area of
approximately 3 in
2
TO263-5L
Junction to
ambient
23
o
C/W
Specifications with boldface type are for full operating temperature range, the other type are for T
J
=25C.
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
4/12
Electrical Characteristics (Continued)
Symbol
Parameter
Conditions
Typ.
Limit
Unit
FB
V
Output
Feedback
5V < V
IN
< 22V
0.2A < I
LOAD
< 3A
V
OUT
programmed for
3V
1.23
1.193/1.18
1.267/1.28
V
V
MIN
V
MAX
AP1506-ADJ
Efficiency V
IN
= 12V, I
LOAD
=3A
74
%
OUT
V
Output voltage
5.5V < V
IN
< 22V
0.2A < I
LOAD
< 3A
3.3
3.168/3.135
3.432/3.465
V
V
MIN
V
MAX
AP1506-3.3V
Efficiency V
IN
= 12V, I
LOAD
=3A
75
%
OUT
V
Output voltage
8V < V
IN
< 22V
0.2A < I
LOAD
< 3A
5
4.8/4.75
5.2/5.25
V
V
MIN
V
MAX
AP1506-5V
Efficiency V
IN
= 12V, I
LOAD
=3A
80
%
OUT
V
Output voltage
15V < V
IN
< 22V
0.2A < I
LOAD
< 3A
12
11.52/11.4
12.48/12.6
V
V
MIN
V
MAX
AP1506-12V
Efficiency V
IN
= 16V, I
LOAD
= 3A
89
%
Specifications with boldface type are for full operating temperature range, the other type are for T
J
=25C.
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
5/12
Typical Performance Characteristics
AP1506 Efficiency v.s. Temperature
(Vin=12V,Vout=5V,Io=3A)
72
73
74
75
76
77
78
79
80
81
82
83
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (C)
Efficiency (%)
AP1506 Efficiency v.s. Temperature
(Vin=12V,Vout=3.3V,Io=3A)
70
71
72
73
74
75
76
77
78
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (C)
Efficie
n
c
y (%)
AP1506 Saturation Voltage v.s. Temperature
(Vcc=12V,Vfb=0V,VSD=0)
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
-50
-25
0
25
50
75
100
125
Temperature (TA)(C)
S
a
turati
on V
o
l
t
age (V
)
3A
2A
1A
0.5A
AP1506 Switch Current Limit v.s. Temperature
(Vcc=12V,Vfb=0V)
3
3.5
4
4.5
5
5.5
-50
-30
-10
10
30
50
70
90
Temperature (TA) (C)
Swi
t
ch Current Li
mi
t (A)
AP1506 Supply Current v.s. Temperature
(Vcc=12V , No Load ,Von/off =0V(Switch ON) ,Von/off =5V(Switch OFF))
5
6
7
8
9
10
11
12
13
14
15
-50 -30 -10 10
30
50
70
90 110 130 150
Temperature (TA) (C)
Supply
Current (m
A)
Switch ON
30
35
40
45
50
55
60
-50 -30 -10 10
30
50
70
90 110 130 150
Temperature (TA) (C)
Supply
Current (uA)
Switch OFF
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
6/12
Typical Performance Characteristics (Continued)
AP1506 Threshold Voltage v.s. Temperature
(Vcc=12V , Io=100mA)
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
-50 -30 -10 10 30
50
70
90 110 130 150
Temperature (TA) (C)
Thres
hold Voltage (V)
AP1506 ON/OFF Current v.s. ON/OFF Voltage
(Vin=12V)
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
0
3
6
9
12
15
18
21
ON/OFF Voltage (V)
ON/OFF Current (nA)
AP1506 Frequency v.s. Temperature
(Vcc=12V , Io=500mA ,Vout=5V)
140
145
150
155
160
165
170
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (C)
Frequenc
y
(K
Hz
)
AP1506 Feedback Current v.s. Temperature
(Vcc=12V , Vout=5V,Vfb=1.3V)
-50
-40
-30
-20
-10
0
10
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (C)
Feedback Current (nA)
AP1506 Output Voltage v.s. Temperature
(Vin=12V ,Io=3A)
2.9
2.95
3
3.05
3.1
3.15
3.2
3.25
3.3
3.35
3.4
3.45
3.5
-40 -20
0
20 40 60 80 100 120 140 160
Temperature (TA) (C)
V
out (V
)
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
7/12
Typical Application Circuit
(1) Fixed Type Circuit
1
2
3
5
4
12V
DC Input
Cin
Capacitor
FB
SD
D1
Schottky
Diode
Vin
Gnd
Output
AP1506
-33
Co
Capacitor
Inductor
L1
33uH
3.3V/3A
Output Load
(2) Adjustable Type Circuit
1
2
3
5
4
12V
DC Input
Cin
Capacitor
FB
SD
D1
Schottky Diode
Vin
Gnd
Output
AP1506
Co
Capacitor
L1
47uH
5V/ 3A
Output Load
R2
R1
Vout = V
FB
(1
+
R2
R1
)
V
FB
= 1.23V
R2 = 1K ~ 3K
(3) Delay Start Circuit
1
2
3
5
4
12V
DC Input
Cin
Capacitor
FB
SD
D1
Schottky Diode
Vin
Gnd
Output
AP1506
Co
Capacitor
L1
47uH
5V/ 3A
Output Load
R2
R1
C
DELAY
0.1uF
10K
R
DELAY
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
8/12
Function Description
Pin Functions
+V
IN
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 (+V
IN
V
SAT
) and approximately 0.5V,
with a duty cycle of approximately V
OUT
/ V
IN
. To
minimize coupling to sensitive circuitry, the PC
board copper area connected to this pin should be
kept a minimum.
Feedback (FB)
Senses the regulated output voltage to complete
the feedback loop.
ON
/OFF (SD)
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
18V) shuts the regulator down. If this shutdown
feature is not needed, the ON / OFF pin can be
wired to the ground pin.
Thermal Considerations
The AP1506 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 AP1506 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
AP1506 (TO-220 package) operating as a
buck-switching regulator in an ambient temperature
of 25
o
C (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 was
designed to be soldering 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 0.8 in
2
,
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 in
2
, only small improvements in
heat dissipation are realized. If further thermal
improvements are needed, double sided,
multi-layer PC board with large copper areas and/or
airflow will be recommended.
The AP1506 (TO-263 package) junction
temperature rises 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 3A are used,
double sided or multi-layer 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.
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
9/12
Function Description
(Continued)
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, multi-layer 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
1506-XX
Output Type:
1506: ADJ
1506-33: 3.3V
1506-50: 5.0V
1506-12: 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
1506-XX
Output Type:
1506: ADJ
1506-33: 3.3V
1506-50: 5.0V
1506-12: 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
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
10/12
Package Information
(1) Package Type: TO220-5L
D
Q
E
b
e1
A
J1
F
C
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
p 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
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
11/12
Package Information(Continued)
(2) Package Type: TO263-5L
E
L2
e
B
D
L
A
C2
C
L1
1.0
2.
5
15
.
7
10.9
9.
1
1.7
Land Pattern Recommendation (Unit: mm)
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
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
AP1506
150KHz, 3A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw Rev.1.1 Oct 29, 2004
12/12
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
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