CM2596S
3A S
TEP
D
OWN
V
OLTAGE
R
EGULATOR
GENERAL DESCRIPTION
The CM2596S series are step-down switching regulators with
all required active functions. It is capable of driving 3A load
with excellent line and load regulations. These devices are
available in fixed output voltages of 3.3V, 5V, and an
adjustable output version.
The CM2596S series offers a high-efficiency replacement for
popular three-terminal linear regulators. Also it requires a
minimum number of external components. It substantially not
only reduces the area of board size but also the size of the
heat sink, and in some cases no heat sink is required.
±4% tolerance on output voltage within specified input
voltages and output load conditions is guaranteed. Also, the
oscillator frequency accuracy is within ±15%. External
shutdown is included, featuring 150μA (typical) standby
current. The output switch includes cycle-by-cycle current
limiting, as well as thermal shutdown for full protection under
fault conditions.
FEATURES
Guaranteed 3A output current
3.3V, 5V, and adjustable versions
Wide input voltage range, up to 40V
Internal oscillator of 150KHz fixed frequency
Wide adjustable version output voltage range, from
1.23V to 37V±4% max over line and load conditions
Low standby current, typ. 150μA, at shutdown mode
Requires only 4 external components
Thermal shutdown and current limit protection
Requires only 4 external components
Excellent line and load regulation specifications
TTL shutdown capability
APPLICATIONS
LCD Monitors
ADD-ON Cards Switching Regulators
High Efficiency Step-Down Regulators
Efficient Pre-regulator for Linear Regulators
ORDERING INFORMATION
Package Type
TO-220
CM2596SSCN220
CM2596SZJCN220
CM2596SCN220
CM2596SGSCN220
CM2596SGZJCN220
CM2596SGCN220
CM2596SGCN220B
TO-263
CM2596SSCN263
CM2596SZJCN263
CM2596SCN263
CM2596SGSCN263
CM2596SGZJCN263
CM2596SGCN263
Output Voltage
3.3V
5.0V
ADJ.
3.3V
5.0V
ADJ.
ADJ
CM2596S X
X X X
Lead Free
Blank: Normal
G: Lead Free package
Output Voltage
C: Adjustable
SC: 3.3V
ZJC: 5V
Package Type
N: TO package
Package
220:TO-220
263:TO-263
2006/11/27 Rev 1.0
Champion Microelectronic Corporation
Page 1
CM2596S
3A S
TEP
D
OWN
V
OLTAGE
R
EGULATOR
PIN CONFIGURATION
TO-220
Top View
TO-220B
Top View
TO-263
Top View
ENABLE
FB
GND
V
OUT
GND
ENABLE
5
4
3
2
1
V
IN
FB
V
OUT
V
IN
1 2
3
4
5
ABSOLUTE MAXIMUM RATINGS
Input Voltage (V
POWER
)
…….………………………………………….……. +45V
ENABLE
Pin Input Voltage ….…………………………………. –0.3V
≦V≦25V
Storage Temperature ………………………………….….…... -65℃ to +150℃
Lead Temperature (10 sec.) ……..……………………..….…………….... 260℃
Operating Temperature
……..……………………..….……………....... -40℃ to +125℃
POWER DISSIPATION TABLE
Package
Θ
JA
(℃/W)
Derating factor (mW/℃)
T
A
>= 25℃
TO-220(B)
TO-263
28
23
22.2
22.2
T
A
<= 25℃
Power rating (mW)
2775
2775
T
A
= 70℃
T
A
= 85℃
Power rating (mW) Power rating (mW)
1776
1776
1443
1443
Note:
1.
Θ
JA
: Thermal Resistance-Junction to Ambient, D
F
: Derating factor, P
O
: Power consumption.
2.
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
Θ
JA
), P
O
= D
F
x (T
J
– T
A
)
The
Θ
JA
numbers are guidelines for the thermal performance of the device/PC-board system.
All of the above assume no ambient airflow.
Θ
JT
: Thermal Resistance-Junction to Ambient, T
C
: case (Tab) temperature, T
J
= T
C
+ (P
D
x
Θ
JA
)
2006/11/27 Rev 1.0
Champion Microelectronic Corporation
Page 2
CM2596S
3A S
TEP
D
OWN
V
OLTAGE
R
EGULATOR
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I
OUT
= 0mA, and T
J
= +25℃; unless otherwise noted
Unless otherwise specified, Vin=12V for 3.3V,5V,adjustable version. I
Load
=0.3A
Parameter
Output Voltage
(Note 1)
Output Voltage
(Note 1)
Output Voltage
(Note 1)
Feedback Voltage
(Note 1)
Feedback Voltage
(Note 1)
Feedback Voltage
(Note 1)
Efficiency
Device
CM2596SS
CM2596SZJ
CM2596SS
CM2596SZJ
CM2596SS
CM2596SZJ
CM2596S (Adj)
CM2596S (Adj)
CM2596S (Adj)
CM2596SS
CM2596SZJ
CM2596S(adj)
Oscillator Frequency
(Note 2)
Quiescent Current
Standby Current
Saturation Voltage
Feedback Bias Current
Duty Cycle (ON)
Current Limit
Output Leakage Current
Note 2,4
Note 3
V
IH
(V
OUT
=0V)
Test Conditions
Test circuit of Figure 1
6V<=V
IN
<=40V
8V<=V
IN
<=40V
6V<=V
IN
<=40V
8V<=V
IN
<=40V
Test circuit of Figure 2
8V<=V
IN
<=40V, V
OUT
=5V
Test circuit of Figure 2
8V<=V
IN
<=40V, V
OUT
=5V
Test circuit of Figure 2
I
LOAD
=3A
I
LOAD
=3A, V
OUT
=5V
Thermal Equilibrium
Note 3
T
J
=25℃
-40℃<=T
J
<=125℃
127
110
0.2A<=I
LOAD
<=3A
0.2A<=I
LOAD
<=3A,
-40℃<=T
J
<=125℃
Test circuit of Figure 1
V
OUT
=5V
0.5A<=I
LOAD
<=3A
0.5A<=I
LOAD
<=3A,
-40℃<=T
J
<=125℃
CM2596S
Min.
3.234
4.900
3.168
4.800
3.135
4.750
1.217
1.193
1.180
Typ.
3.300
5.000
3.300
5.000
3.300
5.000
1.230
1.230
1.230
73
80
73
150
150
5
150
T
J
=25℃
-40℃<=T
J
<=125℃
T
J
=25℃
-40℃<=T
J
<=125℃
Note 5
T
J
=25℃
-40℃<=T
J
<=125℃
V
OUT
=0V
V
OUT
=1V
T
J
=25℃
-40℃<=T
J
<=125℃
T
J
=25℃
-40℃<=T
J
<=125℃
15
0.02
2
2.2
1.3
0.6
25
5
3.6
3.6
100
4.5
4.5
0.3
2
1.3
30
5.5
6.5
50
1.3
173
173
10
250
1.4
1.5
100
500
Max.
3.366
5.100
3.432
5.200
3.482
5.250
1.243
1.267
1.286
Unit
V
V
V
V
V
V
V
V
V
%
%
kHz
mA
μA
V
nA
%
A
mA
V
V
μA
ENABLE
= 5V
I
LOAD
=3A (Note 4)
V
OUT
=5V
(Adj. Version only)
ENABLE
Threshold Voltage
V
IL
(V
OUT
= Normal Output
Voltage)
ENABLE
Input Current
I
IH
(
ENABLE
= 5V)
I
IL
(
ENABLE
= 0V)
2006/11/27 Rev 1.0
Champion Microelectronic Corporation
Page 3
CM2596S
3A S
TEP
D
OWN
V
OLTAGE
R
EGULATOR
Note 1:
External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system
performance. Refer to Application Information for details.
Note 2:
The oscillator frequency reduces to approximately 11KHz in the event of fault conditions, such as output short or
overload. And the regulated output voltage will drop approximately 40% from the nominal output voltage. This self-protection
feature lowers the average power dissipation by lowering the minimum duty cycle from 5% down to approximately 2%.
Note 3:
For these parameters, FB is removed from V
OUT
and connected to +12V to force the output transistor OFF.
Note 4:
V
OUT
pin sourcing current. No diode, inductor or capacitor connect to V
OUT
.
Note 5:
FB is removed from V
OUT
and connected to 0V.
BLOCK DIAGRAM
Vin
1
150KHz
Thermal Shutdown
&
Current Limit
Requlator
With
Enable
FB
4
R2*
Oscillator
5
ENABLE
Comparator
-
+
.
+
.
.
.
.
.
.
R1*
.
-
Error Amplifier
Driver
2
Vout
1.23V
Reference
GND 3
.
Reset
2006/11/27 Rev 1.0
Champion Microelectronic Corporation
Page 4
CM2596S
3A S
TEP
D
OWN
V
OLTAGE
R
EGULATOR
APPLICATION CIRCUIT
Figure1. Fixed Output Voltage
Figure2. Adjustable Output Voltage
Vout = Vref ( 1 + R2 / R1 )
R2 = R1 ( Vout / Vref – 1 )
Where Vref = 1.23V , R1 between 1K and 5K
2006/11/27 Rev 1.0
Champion Microelectronic Corporation
Page 5
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