AP1506
150KHz, 3A PWM BUCK DC/DC CONVERTER
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 components, 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 TO263 and TO220.
Pin Assignments
( Top View )
5 SD
4 FB
3 Gnd
2 Output
1 V
IN
Metal Tab GND
TO263-5L
( Top View )
5 SD
4 FB
3 Gnd
2 Output
1 V
IN
TO220-5L/TO220-5L(R)
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
Lead Free packages: TO263-5L and TO220-5L(R)
TO263-5L and TO220-5L(R): Available in “Green”
Molding Compound (No Br, Sb)
Low Power standby mode
Built-in Switching Transistor On Chip
Lead Free Finish/RoHS Compliant (Note 1)
Applications
•
•
•
Simple High-Efficiency Step-Down Regulator
On-Card Switching Regulators
Positive to Negative Converter
Notes:
1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html
.
AP1506
Document number: DS31015 Rev. 7 - 2
1 of 14
www.diodes.com
June 2010
© Diodes Incorporated
AP1506
150KHz, 3A PWM BUCK DC/DC CONVERTER
Typical Application Circuit
(1) Fixed Type Circuit
FB
12V
DC Input
1
V
IN
5
C
IN
Capacitor
SD
4
AP1506
- 33
3
2
Output
L1
33uH
Inductor
D1*
Schottky Diode
3.3V/3A
Output Load
GND
Co
Capacitor
(2) Adjustable Type Circuit
R2
FB
12V
DC Input
V
IN
C
IN
Capacitor
1
5
SD
4
AP1506
3
GND
D1*
Schottky Diode
Co
Capacitor
2
Output
L1
47uH
5V/ 3A
Output Load
R1
V
out
= V
FB
×
(1 +
V
FB
= 1.23V
R2 = 1K ~ 3K
R1
R2
)
(3) Delay Start Circuit
R2
FB
12V
DC Input
V
IN
C
DELAY
C
IN
Capacitor
0.1uF
1
5
SD
R
DELAY
10K
4
AP1506
3
GND
D1*
Schottky Diode
Co
Capacitor
2
Output
L1
47uH
5V / 3A
Output Load
R1
Notes:
2. For up to
2A
=
DFLS230L
(V
f
= 0.42V)
For up to
3A
=
B340LA, B340LB
(V
f
= 0.45V)
AP1506
Document number: DS31015 Rev. 7 - 2
2 of 14
www.diodes.com
June 2010
© Diodes Incorporated
AP1506
150KHz, 3A PWM BUCK DC/DC CONVERTER
Pin Descriptions
Pin Name
V
IN
Output
GND
FB
SD
Description
Operating Voltage Input
Switching Output
Ground
Output Voltage Feedback Control
ON/OFF
Shutdown
Functional Block Diagram
SD
V
IN
200mV
Current
Source
bias
1.235V
Reference
2.5V
Regulator
Start
up
+
Comp
-
Comp
+
+
Amp
-
Frequecy
compen-
sation
-
220mV
FB
Comp
+
Pre-driver
3A
Switch
AP1506
Document number: DS31015 Rev. 7 - 2
3 of 14
www.diodes.com
-
Output
150KHz
OSC.
Thermal
Shutdown
GND
June 2010
© Diodes Incorporated
AP1506
150KHz, 3A PWM BUCK DC/DC CONVERTER
Absolute Maximum Ratings
Symbol
ESD MM
V
CC
V
SD
V
FB
V
OUT
P
D
T
ST
T
OP
Parameter
Machine Model ESD Protection
Supply Voltage
ON/OFF Pin Input Voltage
Feedback Pin Voltage
Output Voltage to Ground
Power Dissipation
Storage Temperature
Operating Junction Temperature
Rating
400
+24
-0.3 to +18
-0.3 to +18
-1
Internally Limited
-65 to +150
-40 to +125
Unit
V
V
V
V
V
W
o
C
o
C
Recommended Operating Conditions
Symbol
V
OP
T
A
Operating Voltage
Operating Ambient Temperature
Parameter
Min
4.5
-20
Max
22
85
Unit
V
o
C
AP1506
Document number: DS31015 Rev. 7 - 2
4 of 14
www.diodes.com
June 2010
© Diodes Incorporated
AP1506
150KHz, 3A PWM BUCK DC/DC CONVERTER
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
Specifications with
boldface type
are for full operating temperature range, the other type are for T
J
= 25ºC.
Symbol
I
FB
F
OSC
F
SCP
V
SAT
DC
Parameter
Feedback Bias Current
Oscillator Frequency
Oscillator Frequency of
Short Circuit Protect
Saturation Voltage
Max. Duty Cycle (ON)
Min. Duty Cycle (OFF)
Current Limit
Output
Leakage
Output = -1V Current
Quiescent Current
Output = 0V
Standby Quiescent
Current
ON/OFF Pin Logic Input
Threshold Voltage
ON/OFF Pin Logic
Input Current
ON/OFF
Pin Input
Current
Thermal Resistance
Junction to Ambient
Thermal Resistance
Junction to Case
Conditions
V
FB
= 1.3V
(Adjustable version only)
Min
-
127
110
Typ.
-10
150
-
30
1.4
100
0
4.5
-
-5
5
70
1.3
-
-0.1
37
31
6
5
Max
-50
-100
173
173
50
1.6
Unit
nA
KHz
KHz
V
%
A
µA
mA
mA
µA
V
I
CL
I
L
I
Q
I
STBY
V
IL
V
IH
I
H
I
L
θ
JA
θ
JC
Notes:
When current limit occurred
and V
FB
< 0.5V, T
a
= 25
o
C
I
OUT
= 3A
No outside circuit
V
FB
= 0V force driver on
V
FB
= 0V force driver on
V
FB
= 12V force driver off
Peak current
No outside circuit
V
FB
= 0 force driver on
No outside circuit
V
FB
= 12 force driver off
V
IN
= 22V
V
FB
= 12 force driver off
ON/OFF pin = 5V
V
IN
= 22V
Low (regulator ON)
High (regulator OFF)
V
LOGIC
= 2.5V (OFF)
V
LOGIC
= 0.5V (ON)
TO263-5L (Note 3)
TO220-5L(R) (Note 3)
TO263-5L (Note 3)
TO220-5L(R) (Note 3)
2
10
-
-
-
3.6
-
-
-
-
-
2.0
-
-
1.7
-
-
5.5
6.5
-200
-
10
150
200
0.6
-
-0.01
µA
-1
-
-
-
-
o
o
C/W
C/W
3. Test condition: Device mounted with copper area of approximately 3 in , no air flow.
AP1506
Document number: DS31015 Rev. 7 - 2
5 of 14
www.diodes.com
June 2010
© Diodes Incorporated
