CS5205−2
5.0 A, 1.5 V Fixed Linear
Regulator
The CS5205−2 linear regulator provides 5.0 A @ 1.5 V with an
accuracy of ±2.0%.
The regulator is intended for use as an active termination for the
GTL bus on Intel based motherboards. The fast loop response and low
dropout voltage make these regulators ideal for applications where
low voltage operation and good transient response are important.
The circuit is designed to operate with dropout voltages as low as 1.0 V
depending on the output current level. The maximum quiescent current is
only 10 mA at full load.
The regulator is fully protected against overload conditions with
protection circuitry for Safe Operating Area (SOA), overcurrent and
thermal shutdown.
The CS5205−2 is available in TO−220−3 and surface mount D2PAK−3
packages.
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TO−220−3
T SUFFIX
CASE 221A
1
2
3
D2PAK−3
D2T SUFFIX
CASE 418AB
Features
•
•
•
•
•
Tab = VOUT
Pin 1. GND
2. VOUT
3. VIN
12
Output Current to 5.0 A
Output Voltage Trimmed to ±2.0%
Dropout Voltage 1.2 V @ 5.0 A
Fast Transient Response
Fault Protection Circuitry
− Thermal Shutdown
− Overcurrent Protection
− Safe Area Protection
3
MARKING DIAGRAMS
TO−220−3
D2PAK−3
CS5205−2
AWLYWW
CS5205−2
AWLYWW
1
VOUT
VIN
1
A
WL, L
YY, Y
WW, W
Output
Current
Limit
Thermal
Shutdown
= Assembly Location
= Wafer Lot
= Year
= Work Week
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 5 of this data sheet.
− + Error
Amplifier
Bandgap
GND
Figure 1. Block Diagram
Semiconductor Components Industries, LLC, 2004
January, 2004 − Rev. 8
1
Publication Order Number:
CS5205−2/D
CS5205−2
MAXIMUM RATINGS*
Parameter
Supply Voltage, VCC
Operating Temperature Range
Junction Temperature
Storage Temperature Range
Lead Temperature Soldering:
Wave Solder (through hole styles only) Note 1
Reflow (SMD styles only) Note 2
Value
Unit
17
V
−40 to +70
°C
150
°C
−60 to +150
°C
260 Peak
230 Peak
°C
°C
1. 10 second maximum.
2. 60 second maximum above 183°C
*The maximum package power dissipation must be observed.
ELECTRICAL CHARACTERISTICS (CIN = 10 F, COUT = 22 F Tantalum, VIN − VOUT = 3.0 V, VIN ≤ 10 V, 0°C ≤ TA ≤ 70°C,
TJ ≤ +150°C, unless otherwise specified, Ifull load = 5.0 A)
Test Conditions
Characteristic
Min
Typ
Max
Unit
1.47
(−2.0%)
1.50
1.53
(+2.0%)
V
Fixed Output Voltage
Output Voltage (Notes 3 and 4)
VIN − VOUT = 1.5 V;
0 ≤ IOUT ≤ 5.0 A
Line Regulation
1.5 V ≤ VIN − VOUT ≤ 6.0 V; IOUT = 10 mA
−
0.04
0.20
%
Load Regulation (Notes 3 and 4)
VIN − VOUT = 1.5 V; 10 mA ≤ IOUT ≤ 5.0 A
−
0.08
0.40
%
Dropout Voltage (Note 5)
IOUT = 5.0 A
−
1.2
1.3
V
Current Limit
VIN − VOUT = 3.0 V; TJ ≥ 25°C
VIN − VOUT = 9.0 V
5.5
−
8.5
1.0
−
−
A
A
Quiescent Current
VIN ≤ 9.0 V; IOUT = 10 mA
−
5.0
10
mA
Thermal Regulation
30 ms Pulse, TA = 25°C
−
0.003
−
%/W
Ripple Rejection
f = 120 Hz; IOUT = 5.0 A
−
75
−
dB
−
−
0.5
−
%
−
0.003
−
%/VOUT
Temperature Stability
RMS Output Noise (%VOUT)
10 Hz ≤ f ≤ 10 kHz
Thermal Shutdown
−
150
180
−
°C
Thermal Shutdown Hysteresis
−
−
25
−
°C
3. Load regulation and output voltage are measured at a constant junction temperature by low duty cycle pulse testing. Changes in output
voltage due to thermal gradients or temperature changes must be taken into account separately.
4. Specifications apply for an external Kelvin sense connection at a point on the output pin 1/4” from the bottom of the package.
5. Dropout voltage is a measurement of the minimum input/output differential at full load.
PACKAGE PIN DESCRIPTION
Package Pin Number
TO−220−3
D2PAK−3
Pin Symbol
1
1
GND
Ground connection.
2
2
VOUT
Regulated output voltage (case).
3
3
VIN
Function
Input voltage.
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2
CS5205−2
TYPICAL PERFORMANCE CHARACTERISTICS
0.10
0.08
Output Voltage Deviation (%)
Dropout Voltage (V)
1.30
1.25
1.20
1.15
1.10
1.05
TCASE = 0°C
1.00
0.95
TCASE = 125°C
0.90
0.85
TCASE = 25°C
0.80
0.06
0.04
0.02
0.00
−0.02
−0.04
−0.06
−0.08
−0.10
0.75
0.70
−0.12
0
1
2
3
4
5
0
TJ (°C)
Figure 2. Dropout Voltage vs. Output
Current
Figure 3. Reference Voltage vs.
Temperature
0.200
2.500
Minimum Load Current (mA)
0.175
0.150
0.125
0.100
TCASE = 25°C
0.075
0.050
TCASE = 125°C
0.025
TCASE = 0°C
0
1
2
3
4
2.175
TCASE = 0°C
1.850
1.525
TCASE = 25°C
1.200
0.875
TCASE = 125°C
0.000
0.550
5
1
2
Output Current (A)
3
4
5
6
7
VIN − VOUT (V)
Figure 4. Load Regulation vs.
Output Current
Figure 5. Minimum Load Current
100
90
80
Ripple Rejection (dB)
Output Voltage Deviation (%)
10 20 30 40 50 60 70 80 90 100 110 120 130
Output Current (A)
70
60
50
40
30
20
TCASE = 25°C
IOUT = 5.0 A
(VIN − VOUT) = 3.0 V
VRIPPLE = 1.6 VPP
10
0
101
102
103
104
Frequency (Hz)
Figure 6. Ripple Rejection vs. Frequency
(Fixed Versions)
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3
105
8
9
CS5205−2
APPLICATIONS INFORMATION
Protection Diodes
The regulator is protected against short circuit, and
includes thermal shutdown and safe area protection (SOA)
circuitry. The SOA protection circuitry decreases the
maximum available output current as the input−output
differential voltage increase.
The CS5205−2 has a composite PNP−NPN output
transistor and requires an output capacitor for stability. A
detailed procedure for selecting this capacitor is included in
the Stability Considerations section.
When large external capacitors are used with a linear
regulator it is sometimes necessary to add protection diodes.
If the input voltage of the regulator gets shorted, the output
capacitor will discharge into the output of the regulator. The
discharge current depends on the value of the capacitor, the
output voltage and the rate at which VIN drops. In the
CS5205−2 linear regulator, the discharge path is through a
large junction and protection diodes are not usually needed.
If the regulator is used with large values of output
capacitance and the input voltage is instantaneously shorted
to ground, damage can occur. In this case, a diode connected
as shown in Figure 7 is recommended.
Stability Considerations
The output or compensation capacitor helps determine
three main characteristics of a linear regulator: start−up
delay, load transient response, and loop stability.
The capacitor value and type is based on cost, availability,
size and temperature constraints. A tantalum or aluminum
electrolytic capacitor is best, since a film or ceramic
capacitor with almost zero ESR can cause instability. The
aluminum electrolytic capacitor is the least expensive
solution. However, when the circuit operates at low
temperatures, both the value and ESR of the capacitor will
vary considerably. The capacitor manufacturer’s data sheet
provides this information.
A 22 F tantalum capacitor will work for most
applications, but with high current regulators such as the
CS5205−2 the transient response and stability improve with
higher values of capacitance. The majority of applications
for this regulator involve large changes in load current so the
output capacitor must supply the instantaneous load current.
The ESR of the output capacitor causes an immediate drop
in output voltage given by:
IN4002 (Optional)
VIN
VOUT
VIN
VOUT
CS5205−2
C1
C2
GND
Figure 7. Protection Diode Scheme for Fixed
Output Regulators
Output Voltage Sensing
Since the CS5205−2 is a three terminal regulator, it is not
possible to provide true remote load sensing. Load
regulation is limited by the resistance of the conductors
connecting the regulator to the load. For best results the
regulator should be connected as shown in Figure 8.
V I ESR
For microprocessor applications it is customary to use an
output capacitor network consisting of several tantalum and
ceramic capacitors in parallel. This reduces the overall ESR
and reduces the instantaneous output voltage drop under
transient load conditions. The output capacitor network
should be as close to the load as possible for the best results.
VIN
VIN
VOUT
RC
Conductor Parasitic
Resistance
CS5205−2
RLOAD
Figure 8. Conductor Parasitic Resistance Effects
Can Be Minimized With the Above Grounding
Scheme for Fixed Output Regulators
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4
CS5205−2
Calculating Power Dissipation and Heat Sink
Requirements
A heat sink effectively increases the surface area of the
package to improve the flow of heat away from the IC and
into the surrounding air.
Each material in the heat flow path between the IC and the
outside environment has a thermal resistance. Like series
electrical resistances, these resistances are summed to
determine RJA, the total thermal resistance between the
junction and the surrounding air.
1. Thermal Resistance of the junction to case, RJC
(°C/W)
2. Thermal Resistance of the case to Heat Sink, RCS
(°C/W)
3. Thermal Resistance of the Heat Sink to the ambient
air, RSA (°C/W)
These are connected by the equation:
The CS5205−2 includes thermal shutdown and safe
operating area circuitry to protect the device. High power
regulators such as these usually operate at high junction
temperatures so it is important to calculate the power
dissipation and junction temperatures accurately to ensure
that an adequate heat sink is used.
The case is connected to VOUT on the CS5205−2,
electrical isolation may be required for some applications.
Thermal compound should always be used with high current
regulators such as these.
The thermal characteristics of an IC depend on the
following four factors:
1.
2.
3.
4.
Maximum Ambient Temperature TA (°C)
Power dissipation PD (Watts)
Maximum junction temperature TJ (°C)
Thermal resistance junction to ambient RJA (°C/W)
RJA RJC RCS RSA
The value for RJA is calculated using equation (3) and the
result can be substituted in equation (1).
RJC is 1.6°C/Watt for the CS5205−2. For a high current
regulator such as the CS5205−2 the majority of the heat is
generated in the power transistor section. The value for RSA
depends on the heat sink type, while RCS depends on
factors such as package type, heat sink interface (is an
insulator and thermal grease used?), and the contact area
between the heat sink and the package. Once these
calculations are complete, the maximum permissible value
of RJA can be calculated and the proper heat sink selected.
For further discussion on heat sink selection, see application
note “Thermal Management,” document number
AND8036/D, available through the Literature Distribution
Center or via our website at http://onsemi.com.
These four are related by the equation
TJ TA PD RJA
(3)
(1)
The maximum ambient temperature and the power
dissipation are determined by the design while the
maximum junction temperature and the thermal resistance
depend on the manufacturer and the package type.
The maximum power dissipation for a regulator is:
PD(max) {VIN(max) VOUT(min)}IOUT(max) VIN(max)IQ
(2)
where:
VIN(max) is the maximum input voltage,
VOUT(min) is the minimum output voltage,
IOUT(max) is the maximum output current, for the
application
IQ is the maximum quiescent current at IOUT(max).
ORDERING INFORMATION
Type
Package
Shipping†
5.0 A, 1.5 V Output
TO−220−3, STRAIGHT
50 Units / Rail
CS5205−2GDP3
5.0 A, 1.5 V Output
D2PAK−3
50 Units / Rail
CS5205−2GDPR3
5.0 A, 1.5 V Output
D2PAK−3
750 / Tape & Reel
Orderable Part Number
CS5205−2GT3
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
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5
CS5205−2
PACKAGE DIMENSIONS
TO−220
THREE LEAD
T SUFFIX
CASE 221A−08
ISSUE AA
−T−
F
−B−
SEATING
PLANE
C
T
S
4
Q
A
1 2 3
U
H
−Y−
K
L
R
V
G
J
D 3 PL
0.25 (0.010)
M
B
M
Y
N
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6
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
DIM
A
B
C
D
F
G
H
J
K
L
N
Q
R
S
T
U
V
INCHES
MIN
MAX
0.560
0.625
0.380
0.420
0.140
0.190
0.025
0.035
0.139
0.155
0.100 BSC
−−−
0.280
0.012
0.045
0.500
0.580
0.045
0.060
0.200 BSC
0.100
0.135
0.080
0.115
0.020
0.055
0.235
0.255
0.000
0.050
0.045
−−−
MILLIMETERS
MIN
MAX
14.23
15.87
9.66
10.66
3.56
4.82
0.64
0.89
3.53
3.93
2.54 BSC
−−−
7.11
0.31
1.14
12.70
14.73
1.15
1.52
5.08 BSC
2.54
3.42
2.04
2.92
0.51
1.39
5.97
6.47
0.00
1.27
1.15
−−−
CS5205−2
PACKAGE DIMENSIONS
D2PAK−3
DP SUFFIX
CASE 418AB−01
ISSUE O
For D2PAK Outline and
Dimensions − Contact Factory
PACKAGE THERMAL DATA
Parameter
TO−220−3
D2PAK−3
Unit
RJC
Typical
1.6
1.6
°C/W
RJA
Typical
50
10−50*
°C/W
*Depending on thermal properties of substrate. RJA = RJC + RCA
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7
CS5205−2
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
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For additional information, please contact your
local Sales Representative.
CS5205−2/D