AP1515
150KHz, 1.5A 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.1.0 Oct 29, 2004
1/6
Features
-
Output voltage: 3.3V 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
- Operating voltage can be up to 22V
- Output load current: 1.5A
- SIP-4L Pb-Free package
- Low power standby mode
- Built-in switching transistor on chip
- Very Low Cost
Applications
- Simple High-efficiency step-down regulator
- On-card switching regulators
- Positive to negative converter
General Description
The AP1515 series are monolithic IC designed for a
step-down DC/DC converter, and own the ability of
driving a 1.5A 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. If current
limit function occurred and V
FB
is down to 0.5V
below, the switching frequency will be reduced.
The AP1515 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
and an adjustable type. The packages are available
in a standard 4-lead SIP-4L package.
Pin Assignments
1515
1 2
4
3
1 : V
IN
2 : Output
3 : FB
4 : GND
(Front View)
SIP-4L
Pin Descriptions
Name
Description
V
IN
Operating voltage input
Output Switching
output
FB Output
voltage
feedback
control
GND Ground
AP1515
150KHz, 1.5A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 29, 2004
2/6
Ordering Information
Package
P: SIP-4L
Output version
AP1515 XX X
Blank : Adjustable
-33 : 3.3V
(Bulk)
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
FB
220mV
200mV
1.5A
Switch
+
_
_
Amp
Comp
Frequecy
compen-
sation
AP1515
150KHz, 1.5A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 29, 2004
3/6
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
1.4
V
SAT
Saturation
voltage
I
OUT
=2A
No outside circuit
V
FB
=0V force driver on
- 1.25
1.5
V
Max. Duty Cycle (ON)
V
FB
=0V force driver on
-
100
-
DC
Min. Duty Cycle (OFF)
V
FB
=12V force driver off
-
0
-
%
I
CL
Current
limit
Peak current
No outside circuit
V
FB
=0V force driver on
2 - - A
Output = 0
No outside circuit
V
FB
=12V force driver off
- -
-200
uA
I
L
Output = -1
Output
leakage
current
V
IN
=22V -
-5
mA
I
Q
Quiescent
Current
V
FB
=12V force driver off
-
5
10
mA
150
I
STBY
Standby Quiescent
Current
ON/OFF pin=5V
V
IN
=22V
- 70
200
uA
JC
Thermal Resistance
Junction to case
-
30
-
o
C/W
JA
Note 1
Junction to ambient
-
100
-
o
C/W
Part Number
Symbol
Parameter
Conditions
Typ.
Limit
Unit
FB
V
Output
Feedback
4.5V < V
IN
< 22V
0.2A < I
LOAD
< 1.5A
V
OUT
programmed for 3V
1.23
1.193/1.18
1.267/1.28
V
V
MIN
V
MAX
AP1515-ADJ
Efficiency V
IN
= 12V, I
LOAD
=1.5A 78
%
OUT
V
Output voltage
4.75V < V
IN
< 22V
0.2A < I
LOAD
< 1.5A
3.3
3.168/3.135
3.432/3.465
V
V
MIN
V
MAX
AP1515-3.3V
Efficiency V
IN
= 12V, I
LOAD
=1.5A 80
%
Specifications with boldface type are for full operating temperature range, the other type are for T
J
=25C.
Note 1: Pin 4(GND) (< 1 mm length) & direct connect to internal GND layer.
AP1515
150KHz, 1.5A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 29, 2004
4/6
Typical Application Circuit
(1) Fixed Type Circuit
1
2
4
3
12V
DC Input
Cin
Capacitor
FB
D1
Schottky
Diode
Vin
Output
AP1515
-33
Co
Capacitor
Inductor
L1
56uH
3.3V/1.5A
Output Load
GND
(2) Adjustable Type Circuit
1
2
3
12V
DC Input
Cin
Capacitor
FB
D1
Schottky
Diode
Vin
Output
AP1515
Co
Capacitor
Inductor
L1
47uH
2.5V/1.5A
Output Load
GND
4
R1
R2
Vout = V
FB
(1
+
R2
R1
)
V
FB
= 1.23V
R2 = 1K ~ 3K
Typical Performance Characteristics
AP1515 Output Voltage v.s. Temperature
(Vin=12V ,Io=1.5A)
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)
Vout (V)
AP1515 Efficiency v.s. Temperature
(Vin=12V,Vout=3.3V,Io=1.5A)
74
75
76
77
78
79
80
81
82
-50 -30 -10 10
30
50
70
90 110 130 150
Temperature (TA) (C)
Ef
f
i
c
i
enc
y (
%
)
AP1515
150KHz, 1.5A PWM Buck DC/DC Converter
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Oct 29, 2004
5/6
Typical Performance Characteristics (Continued)
AP1515 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
-50
-25
0
25
50
75
100
125
Temperature (TA)(C)
Sat
u
r
a
t
i
on Vol
t
age (
V
)
1.5A
1A
0.5A
AP1515 Switch Current Limit v.s. Temperature
(Vcc=12V,Vfb=0V)
2
2.5
3
3.5
-50
-30
-10
10
30
50
70
90
Temperature (TA) (C)
Swi
t
ch Cur
r
ent
Li
m
i
t
(
A
)
AP1515 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)
Suppl
y Current
(mA)
Switch ON
30
35
40
45
50
55
60
-50 -30 -10 10
30
50
70
90 110 130 150
Temperature (TA) (C)
Suppl
y Current
(uA)
Switch OFF
AP1515 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)
F
r
equency (KHz)
AP1515 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)
F
eedback Cur
r
ent (
n
A)
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