ETC CX1084-5.0

Silicon Core
CX1084
Microelectronics
5A Low dropout voltage regulator
Corp.
GENERAL DESCRIPTION
The CX1084 series of adjustable and fixed voltage regulators are designed to provide 5A output
current and to operate down to 1V input-to-output differential. The dropout voltage of the device is
guaranteed maximum 1.5V at maximum output current, decreasing at lower load currents.
On-chip trimming adjusts the reference voltage to 1%. Current limit is also trimmed, minimizing the
stress under overload conditions on both the regulator and power source circuitry.
The CX1084 devices are pin compatible with older three-terminal regulators and are offered in 3 lead
TO-220,2 lead TO-252 package and 3 and 2 lead TO-263 (Plastic DD).
FEATURES
APPLICATIONS
Three Terminal Adjustable or Fixed Voltages*
5V, 1.8V, 2.5V, 2.85V, 3.3V and 5.0V
Output Current of 5A
Operates Down to 1V Dropout
Line Regulation: 0.2% Max.
Load Regulation: 0.4% Max.
TO-220 ,TO252and TO-263 package available
High Efficiency Linear Regulators
Post Regulators for Switching Supplies
 Microprocessor Supply
 Constant Current Regulators
 Battery Chargers
 Notebook/Personal Computer Supplies
 Portable Instrumentation
ORDERING INFORMATION
OPERATING JUNCTION
PACKAGE TYPE
3 LEAD TO-220
TO-252
CX1084
2&3 LEAD TO-263
CX1084
CX1084
TEMPERATURE RANGE
0 to 125　C
CX1084-1.5
CX1084-1.5
CX1084-1.5
0 to 125　C
CX1084-2.5
CX1084-2.5
CX1084-2.5
0 to 125　C
CX1084-2.85
CX1084-2.85
CX1084-2.85
0 to 125　C
CX1084-3.0
CX1084-3.0
CX1084-3.0
0 to 125　C
CX1084-3.3
CX1084-3.3
CX1084-3.3
0 to 125　C
CX1084-3.5
CX1084-3.5
CX1084-3.5
0 to 125　C
CX1084-5.0
CX1084-5.0
CX1084-5.0
0 to 125　C
PIN DESCRIPTIONS
FIXED VERSION
ADJUSTABLE VERSION
1- Ground
1- Adjust
2- VOUT
2- VOUT
3- VIN
3- VIN
Page 1 of 1
SPECIFICATION
CX1084
ABSOLUT MAXIMUM RATINGS(Note 1)
Power Dissipation
Internally limited
Soldering information
Input Voltage
22V
Lead Temperature (10 sec)
300°C
Thermal Resistance
Operating Junction Temperature
Control Section
0°C to 125°C
TO-220 package
Power Transistor
0°C to 150°C
TO-263 package
- 65°C to +150°C
* With package soldering to copper area over backside
Storage temperature
φ JA= 50°C/W
φ JA= 30°C/W*
ground plane or internal power plane φJA can vary from
20°C/W to >40°C/W depending on mounting technique and
the size of the copper area.
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at IOUT = 0 mA, and TJ = +25°C unless otherwise specified.
Parameter
Reference Voltage
(Note 2)
Device
CX1084
Conditions
Min
Typ
Max
Units
IOUT = 10 mA
1.238
1.250
1.262
V
10mA ≤IOUT ≤5A,
1.225
1.250
1.270
V
1.485
1.500
1.515
V
1.470
1.500
1.530
V
2.475
2.500
2.525
V
2.450
2.500
2.550
V
2.82
2.850
2.88
V
2.79
2.850
2.91
V
2.970
3.000
3.300
V
2.940
3.000
3.360
V
3.267
3.300
3.333
V
3.235
3.300
3.365
V
3.465
3.500
3.535
V
3.430
3.500
3.570
V
4.950
5.000
5.050
V
4.900
5.000
5.100
V
1.5V≤ (VIN - VOUT) ≤12V
Output Voltage
(Note 2)
CX1084-1.5
CX1084-2.5
CX1084-2.85
CX1084-3.0
CX1084-3.3
CX1084-3.5
CX1084-5.0
0≤IOUT ≤5A ,3.0V≤VIN ≤12V
0≤IOUT ≤5A ,4.0V≤VIN ≤12V
0≤IOUT ≤5A ,4.35V≤VIN ≤12V
0≤IOUT ≤5A ,4.5V≤VIN ≤12V
0≤IOUT ≤5A ,4.75V≤VIN ≤12V
0≤IOUT ≤5A ,5.0V≤VIN ≤12V
0≤IOUT ≤5A ,6.5V≤VIN ≤12V
Page 2 of 2
SPECIFICATION
Parameter
Line Regulation
Load Regulation
CX1084
Device
Min
Typ
Max
Units
CX1084/-1.5/-2.5/-2.85/
ILOAD = 10 mA ,
0.3
6
mV
-3.0/-3.3/-3.5/-5.0
1.5V≤(VIN – Vout ) ≤12V
0.6
10
mV
0.1
0.3
%
0.2
0.4
%
3
12
mV
6
20
mV
3
12
mV
6
20
mV
3
12
mV
6
20
mV
3
12
mV
6
20
mV
3
15
mV
7
25
mV
3
15
mV
6
25
mV
5
20
mV
10
35
mV`
1.3
1.5
V
6.00
7.00
A
5
10
mA
5
10
mA
CX1084-ADJ
(Notes 2, 3)
CX1084-1.5
CX1084-2.5
CX1084-2.85
CX1084-3.0
CX1084-3.3
CX1084-3.5
CX1084-5.0
Dropout Voltage
CX1084/-1.5/-2.5/-2.85/
(VIN - VOUT)
-3.0/-3.3/-3.5/-5.0
Current Limit
CX1084/-1.5/-2.5/-2.85/
-3.0/-3.3/-3.5/-5.0
Minimum Load
Conditions
CX1084
(VIN – Vout ) =3V, 10mA≤IOUT ≤5A
VIN = 5V, 0≤IOUT ≤5A
VIN = 5V, 0≤IOUT ≤5A
VIN = 5V, 0≤IOUT ≤5A
VIN = 5V, 0≤IOUT ≤5A
VIN = 5V, 0≤IOUT ≤5A
VIN = 5.25V, 0≤IOUT ≤5A
VIN = 8V, 0≤IOUT ≤5A
∆VOUT , ∆VREF = 1%, IOUT = 5 A
(Note 4)
(VIN - VOUT) = 5V
5.00
(VIN - VOUT) = 12V (Note 5)
Current
Quiescent Current
CX1084/-1.5/-2.5/-2.85/
-3.0/-3.3/-3.5/-5.0
Ripple Rejection
CX1084
VIN ≤12V
f =120Hz , COUT = 25　F Tantalum, IOUT =
60
75
dB
60
72
dB
60
72
dB
60
72
dB
60
72
dB
60
72
dB
60
72
dB
60
68
dB
5A,(VIN-VOUT ) = 3V, CADJ =25μF
CX1084-1.5
f =120Hz , COUT = 25　F Tantalum, IOUT = 5A,
VIN = 4.5V
CX1084-2.5
f =120Hz , COUT = 25　F Tantalum, IOUT = 5A,
VIN = 5.5V
CX1084-2.85
f =120Hz , COUT = 25　F Tantalum, IOUT = 5A,
VIN = 6V
CX1084-3.0
f =120Hz , COUT = 25　F Tantalum, IOUT = 5A
VIN = 6V
CX1084-3.3
f =120Hz , COUT = 25　F Tantalum, IOUT = 5A
VIN = 6.3V
CX1084-3.5
f =120Hz , COUT = 25　F Tantalum, IOUT = 5A
VIN = 6.5V
CX1084-5.0
f =120Hz , COUT = 25　F Tantalum, IOUT = 5A,
VIN = 8V
Page 3 of 3
SPECIFICATION
CX1084
Device
Parameter
Thermal Regulation
CX1084
Adjust Pin Current
CX1084
Adjust Pin Current
CX1084
Change
Conditions
TA = 25°C, 30ms pulse
RMS Output Noise
(% of VOUT )
Typ
0.008
10mA ≤IOUT ≤5A , 1.5V≤(VIN - VOUT) ≤12V
10mA ≤IOUT ≤5A , 1.5V≤(VIN - VOUT) ≤12V
Temperature Stability
Long Term Stability
Min
Max
0.04
55
0.2
0.3
120
µA
5.0
µA
%
1
%
%
0.003
TA = 25°C , 10Hz ≤f ≤10kHz
%W
µA
0.5
TA =125°C, 1000Hrs
Units
Thermal Resistance
M Package: Control Circuitry/ Power Transistor
1.5/4.0
°C/W
Junction-to-Case
T Package: Control Circuitry/ Power Transistor
1.5/4.0
°C/W
Parameters identified with boldface type apply over the full operating temperature range.
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. For guaranteed specifications and test
conditions, see the
Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed.
Note 2: Line and Load regulation are guaranteed up to the maximum power dissipation of 15W. Power dissipation is determined by the
input/output differential and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range.
Note 3:See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are measured at
a constant junction temperature by low duty cycle pulse testing. Load regulation is measured at the output lead ~1/8” from the package.
Note 4: Dropout voltage is specified over the full output current range of the device.
Note 5: Minimum load current is defined as the minimum output current required to maintain regulation. When (VIN - VOUT) = 12V the device
is guaranteed to regulate if the output current is greater than 10mA.
APPLICATION HINTS
The CX1084 series of adjustable and fixed regulators are easy to use and have all the protection features expected in
high performance voltage regulators: short circuit protection and thermal shut-down.
Pin compatible with older three terminal adjustable regulators, these devices offer the advantage of a lower dropout voltage,
more precise reference tolerance and improved reference stability with temperature.
current changes capacitor values on the order of 100uF are
Stability
The circuit design used in the CX1084 series
used in the output of many regulators. To further improve
requires the use of an output capacitor as part of the
stability and transient response of these devices larger
device frequency compensation. The addition of 150uF
values of output capacitor can be used.
aluminum electrolytic or a 22uF solid tantalum on the
Protection Diodes
output will ensure stability for all operating conditions.
Unlike older regulators, the CX1084 family does not
When the adjustment terminal is bypassed with a
need any protection diodes between the adjustment pin and
capacitor to improve the ripple rejection, the requirement
the output and from the output to the input to prevent
for an output capacitor increases. The value of 22uF
over-stressing the die. Internal resistors are limiting the
tantalum or 150uF aluminum covers all cases of
internal current paths on the CX1084 adjustment pin,
bypassing the adjustment terminal. Without bypassing
therefore even with capacitors on the adjustment pin no
the adjustment terminal smaller capacitors can be used
protection diode is needed to ensure device safety under
with equally good results.
short-circuit conditions.
To ensure good transient response with heavy load
Page 4 of 4
Diodes between the input and output are not usually
SPECIFICATION
CX1084
needed. Microsecond surge currents of 50A to 100A can be
Ripple Rejection
handled by the internal diode between the input and output
The ripple rejection values are measured with the
pins of the device. In normal operations it is difficult to get
adjustment pin bypassed. The impedance of the adjust pin
those values of surge currents even with the use of large
capacitor at the ripple frequency should be less than the
output capacitances. If high value output capacitors are
value of R1 (normally 100Ωto120Ω) for a proper bypassing
used, such as 1000uF to 5000uF and the input pin is
and ripple rejection approaching the values shown. The size
instantaneously shorted to ground, damage can occur. A
of the required adjust pin capacitor is a function of the input
diode from output to input is recommended, when a crowbar
ripple frequency. If R1=100Ωat 120Hz the adjust pin
circuit at the input of the CX1084 is used. Normal
capacitor should be 25uF. At 10kHz only 0.22uF is needed.
power supply cycling or even plugging and unplugging in
The ripple rejection will be a function of output voltage,
the system will not generate current large enough to do any
in circuits without an adjust pin bypass capacitor. The
damage. The adjustment pin can be driven on a transient
output ripple will increase directly as a ratio of the output
basis 25V, with respect to the output without any device
voltage to the reference voltage (VOUT / VREF).
degradation. As with any IC regulator, none the protection
Output Voltage
circuitry will be functional and the internal transistors will
The CX1084 series develops a 1.25V reference
break down if the maximum input to output voltage
voltage between the output and the adjust terminal. Placing
differential is exceeded.
a resistor between these two terminals causes a constant
current to flow through R1 and down through R2 to set the
overall output voltage.
D1
This current is normally the specified minimum load
current of 10mA. Because IADJ is very small and constant it
VIN
CX1084
IN
VOUT
OUT
ADJ
R1
represents a small error and it can usually be ignored.
COUT
CX1084
VIN
150uF
IN
ADJ
CADJ
10uF
R2
VOUT
OUT
VREF
IADJ
50uA
R1
R2
Overload Recovery
VOUT = VREF 1+ R2/R1)+IADJR2
When the power is first turned on, as the input voltage
rises, the output follows the input, permitting the regulator to
Figure 1. Basic Adjustable Regulator
start up into heavy loads. During the start-up, as the input
Load Regulation
voltage is rising, the input-to-output voltage differential
True remote load sensing it is not possible to provide,
remains small, allowing the regulator to supply large output
because the CX1084 is a three terminal device. The
currents. A problem can occur with a heavy output load
resistance of the wire connecting the regulator to the load
when the input voltage is high and the output voltage is low,
will limit the load regulation. The data sheet specification for
when the removal of an output short will not permit the
load regulation is measured at the bottom of the package.
output voltage to recover. The load line for such a load may
Negative side sensing is a true Kelvin connection, with the
intersect two points on the output current curve. In this
bottom of the output divider returned to the negative side of
case, there are two stable output operating points for the
the load.
regulator. With this double intersection, the power supply
The best load regulation is obtained when the top of the
may need to be cycled down to zero and brought up again
resistor divider R1 is connected directly to the case not to
to make the output recover.
the load. If R1 were connected to the load, the effective
Page 5 of 5
SPECIFICATION
CX1084
resistance between the regulator and the load would be:
junction-to-case thermal resistance specification, the data
RP x「( R2+R1 )/ R1」
section for these new regulators provides a separate
RP = Parasitic Line Resistance
thermal resistance and maximum junction temperature for
Connected as shown below,RP is not multiplied by the
both the Control Section and the Power Transistor.
divider ratio. Using 16-gauge wire the parasitic line
Calculations for both temperatures under certain conditions
resistance is about 0.004　per foot, translating to 4mV/ft at
of ambient temperature and heat sink resistance and to
1A load current. It is important to keep the positive lead
ensure that both thermal limits are met.
between regulator and load as short as possible and use
Thermal Considerations
large wire or PC board traces.
The CX1084 series have internal power and thermal limiting
circuitry designed to protect the device under overload
VIN
conditions. However maximum junction temperature ratings
CX1084
IN
OUT
ADJ
should not be exceeded under continuous normal load
conditions. Careful consideration must be given to all
Rp
sources of thermal resistance from junction to ambient,
R1*
including junction-to-case, case-to-heat sink interface and
RL
heat sink resistance itself. To ensure safe operating
temperatures and reflect more accurately the device
R2*
temperature, new thermal resistance specifications
have been developed. Unlike older regulators with a single
junction-to-case thermal resistance specification, the data
section for these new regulators provides a separate
thermal resistance and maximum junction temperature for
both the Control Section and the Power Transistor.
Thermal Considerations
Calculations for both temperatures under certain conditions
The CX1084 series have internal power and thermal limiting
of ambient temperature and heat sink resistance and to
circuitry designed to protect the device under overload
ensure that both thermal limits are met.
conditions. However maximum junction temperature ratings
Junction-to-case thermal resistance is specified from the IC
should not be exceeded under continuous normal load
junction to the bottom of the case directly below the die.
conditions. Careful consideration must be given to all
This is the lowest resistance path for the heat flow. In order
sources of thermal resistance from junction to ambient,
to ensure the best possible thermal flow from this area of
including junction-to-case, case-to-heat sink interface and
the package to the heat sink proper mounting is required.
heat sink resistance itself. To ensure safe operating
Thermal compound at the case-to-heat sink interface is
temperatures and reflect more accurately the device
recommended. A thermally conductive spacer can be used,
temperature, new thermal resistance specifications
if the case of the device must be electrically isolated, but its
have been developed. Unlike older regulators with a single
added contribution to thermal resistance has to be
circuitry designed to protect the device under overload
considered.
Page 6 of 6
SPECIFICATION
CX1084
TYPICAL PERFORMANCE CHARACTERISTICS
Page 7 of 7
SPECIFICATION
CX1084
PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted.
3 LEAD TO-220 PLASTIC PACKAGE
3 LEAD TO-263 PLASTIC
2 LEAD TO-263 PLASTIC
Page 8 of 8
SPECIFICATION
CX1084
TO-252 PLASTIC
Note: Silicon Core Microelectronics corporation assumes no responsibility for any errors which may
appear in this document. reserves the right to change devices or specifications detailed herein at
any time without notice.
Page 9 of 9