ACE150X
Technology
Description
150KHz,2A, PWM Step-Down DC/DC Converter
The ACE150x series are monolithic IC designed for a step-down DC/DC converter, and own the ability of
driving 2A load without additional transistor. It saves board space.
The Internal compensation makes feedback control having 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 occurs and V
FB
is down below 0.5V, the switching frequency will be reduced.
The ACE150x series operate at a switching frequency of 150KHz. 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
chips are available in a standard 8-lead SOP-8 package..
Features
•
•
•
•
•
•
•
•
Guaranteed 2A output current
3.3V, 5V, 12V and adjustable output versions
Thermal shutdown and current limit protection
Internal oscillator of 150kHz fixed frequency.
Built-in TTL On/Off control
Application
One Channel switching regulators
LCD Monitors
High-efficiency step-down regulator
Absolute Maximum Ratings
Parameter
Input supply voltage
ON/OFF Pin Input Voltage
Feedback Pin Voltage
Output Voltage to Ground
Power Dissipation
Thermal resistance junction to ambient
SOP-8
Operating junction temperature
Storage temperature range
Operating temperature
into, negative out of the specified terminal.
Symbol
Max
Unit
V
CC
24
V
V
SD
-0.3 to +18
V
V
FB
-0.3 to +18
V
V
OUT
-1
V
P
D
Internally Limited W
θ
JA
T
J
T
STG
T
OPR
70
150
- 60 to 150
-40 to +125
O
C/W
O
O
C
C
O
C
Note : Exceeding these rating could cause damage to the device. All voltages are with respect to Ground. Currents are positive
VER 1.2
1
ACE150X
Technology
Packaging Type
SOP-8 (ACE1502XXFM+)
Vin
Vout
FB
SHDN
GND
GND
GND
GND
150KHz,2A ,PWM Step-Down DC/DC Converter
SOP-8 (ACE1501XXFM+)
NC
Vin
Vout
FB
GND
GND
GND
GND
Pin Description
Selection Guide
ACE150 X XX XX + H
Halogen - free
Pb - free
FM : SOP-8
Output Voltage:
3.3V/5.0V/12V/ADJ
Pin
Power Dissipation Table
T
A
=70
O
C
T
A
= 85
O
C
θ
JA
T
A
≤
25
O
C
Package
O
Df(mW/℃)TA≧25℃
( C /W )
Power rating(mW) Power rating(mW) Power rating (mW)
FM
70
6.06
1785
1142
928
Note:
1.Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator
will go into Thermal shutdown.
2.T
J
: Junction Temperature Calculation T
J
= T
A
+ ( P
D
x
θ
JA
)
The
θ
JA
numbers are guidelines for the thermal performance of the device/PC-board system. All of the above
assume no Ambient airflow.
3.θ
JA
: Thermal Resistance-Junction to Ambient, D
F
: Derating factor, Po: Power consumption
VER 1.2
2
ACE150X
Technology
Pin Description
No.
1
2
3
4
5
6
7
8
ACE1501
Pin Name
N.C.
V
IN
V
OUT
FB
GND
GND
GND
GND
Function
NC
Supply Voltage
Switch Pin.
Connect inductor/diode
h
Feedback Pin.
Ground Pin
Ground Pin
Ground Pin
Ground Pin
150KHz,2A ,PWM Step-Down DC/DC Converter
No.
1
2
3
4
5
6
7
8
ACE1502
Pin Name
V
IN
V
OUT
FB
SHDN
GND
GND
GND
GND
Function
Supply Voltage
Switch Pin. Connect inductor/diode
Feedback Pin.
Shutdown Control Input.
Active-Low into shutdown mode
Ground Pin
Ground Pin
Ground Pin
Ground Pin
Block Diagram
VER 1.2
3
ACE150X
Technology
Electrical Characteristics
150KHz,2A ,PWM Step-Down DC/DC Converter
T
A
=25℃, V
IN
=12V for 3.3V,5V, and Adjustable version and V
IN
=18V for the 12V version, Io = 0.5A, unless Otherwise
specified.
Parameter
Output
Voltage
Efficiency
Output
Voltage
Efficiency
Output
Voltage
Efficiency
Feedback
Voltage
Efficiency
Feedback bias Current
Oscillator Frequency
Oscillator Frequency OF Short
Circuit Protect
Saturation Voltage
Max. Duty Cycle ( ON)
Min. Duty Cycle ( OFF)
Current Limit
ACE1501/2-ADJ
ACE1501/2-1.2
ACE1501/2-5.0
ACE1501/2-3.3
Symbol
V
OUT
η
V
OUT
η
V
OUT
η
V
FB
η
I
FB
F
OSC
F
SCP
V
SAT
D
C
D
C
I
LIMIT
Conditions
5.5V<V
IN
<22V, 0.2A<I
LOAD
<2A
V
IN
=12V,I
LOAD
=2A
8V< V
IN
<22V , 0.2A<I
LOAD
<2A
V
IN
=12V,I
LOAD
=2A
15V<V
IN
<22V , 0.2A<I
LOAD
<2A
V
IN
=16V,I
LOAD
=2A
5V<V
IN
<22V, 0.2A<I
LOAD
<2A
V
IN
=12V,I
LOAD
=2A
V
FB
= 1.3V
(Adjustable Only)
T
J
=25
℃
When current limit occurred and
V
FB
<0.5V, T
A
=25℃
Io = 2A, No outside circuit and
V
FB
=0V force driver on
V
FB
= 0V force driver on
V
FB
= 12V force driver off
Peak current, No outside circuit and
V
FB
= 0V force driver on
Output Leakage Current No outside
circuit V
FB
=12V force driver off,
V
OUT
=0V
V
IN
=22V, V
OUT
=-1V
Quiescent Current
Standby Quiescent Current
ON/OFF Pin Logic Input
Threshold Voltage
ON/OFF Pin Logic Input Current
I
Q
I
STBY
V
IL
V
IH
V
IL
V
IH
V
FB
= 12V 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)
-0.1
Min.
3.168
-
4.800
-
11.52
-
1.193
-
-
127
5
-
-
-
3.6
Typ.
3.3
75
5.0
80
12
89
1.230
74
-10
150
15
1.4
100
0
4.5
Max.
3.432
-
5.200
-
12.48
-
1.267
-
-50
173
25
1.6
-
-
5.5
Unit
V
%
V
%
V
%
V
%
nA
KHz
KHz
V
%
%
A
Output Leakage Current
I
LEAK
-
-5
-
-
-
2.0
-
-
5
70
1.3
-200
30
10
156
0.6
-
-0.01
-1
µA
mA
µA
V
µA
VER 1.2
4
ACE150X
Technology
150KHz,2A ,PWM Step-Down DC/DC Converter
Notes:
Thermal Considerations:
The SOP-8 package needs a heat sink under most conditions. The size of the heat sink depends on the input
voltage, the load current and ambient temperature. The ACE150X junction temperature rises above ambient
temperature for a 2A load and different input and output voltages. The data for these curves was taken with the
ACE150X(SOP-8 package) operating as a buck-switching regulator in an ambient temperature of 25℃ (still air).
These temperature increments are all approximate and are affected by many factors.
Higher ambient temperatures require more heat sinker. For the best thermal performance, wide copper traces and
generous amounts of printed circuit board copper should be used in the board layout. ( One exception 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 increments are affected by a lot of factors. 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, 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 or 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.
Application Data
3A Diode
3A Diode
VR(V) Surface Mount Through Hole Surface Mount Through Hole
Scgittky
Schottky
Scgittky
Schottky
1N5820
1N5823
20
SK32
SR302
SR502
MBR320
MBR520
1N5821
1N5824
30
SK33
MBR330
50WQ03
SR503
31DQ03
SB530
1N5822
1N5825
SK34
SR304
50WQ04
SR504
40
MBRS340
MBR340
SB540
31DQ04
SR305
SB550
SK35
MBR350
50WQ05
50SQ080
50
MBRS360
31DQ05
50WF10
HER601
MUR320
MUR620
VER 1.2
5
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