CS5203A−1, CS5203A−2,
CS5203A−3, CS5203A−5
3.0 A Adjustable, and
Fixed 1.5 V, 3.3 V and 5.0 V
Linear Regulators
The CS5203A series of linear regulators provides 3.0 A at
adjustable and fixed voltages with an accuracy of
±1.0%
and
±2.0%
respectively. The adjustable version uses two external resistors to set
the output voltage within a 1.25 V to 13 V range.
The regulators are intended for use as post regulators and
microprocessor supplies. 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 regulators are fully protected against overload conditions with
protection circuitry for Safe Operating Area (SOA), overcurrent and
thermal shutdown.
The CS5203A is pin compatible with the LT1085 family of linear
regulators but has lower dropout voltage.
The regulators are available in TO−220−3 and surface mount
2
PAK−3 packages.
D
Features
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TO−220
THREE LEAD
T SUFFIX
CASE 221A
1
2
Adjustable
Output
Tab = V
OUT
Pin 1. Adj
2. V
OUT
3. V
IN
Fixed
Output
Tab = V
OUT
Pin 1. GND
2. V
OUT
3. V
IN
3
D
2
PAK−3
DP SUFFIX
CASE 418AB
12
3
D
2
PAK−3
(Short Lead)
DPS SUFFIX
CASE 418F
12
•
•
•
•
•
•
3
Pb−Free Package is Available
Output Current to 3.0 A
Output Trimmed to
±1.0%
Dropout Voltage 1.05 V @ 3.0 A
Fast Transient Response
Fault Protection Circuitry
♦
Thermal Shutdown
♦
Overcurrent Protection
♦
Safe Area Protection
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 8 of this data sheet.
DEVICE MARKING INFORMATION
See general marking information in the device marking
section on page 8 of this data sheet.
V
OUT
V
IN
Output
Current
Limit
Thermal
Shutdown
− +
Error
Amplifier
Adj
Bandgap
Figure 1. Block Diagram − CS5203A−1
©
Semiconductor Components Industries, LLC, 2004
1
June, 2004 − Rev. 7
Publication Order Number:
CS5203A/D
CS5203A−1, CS5203A−2, CS5203A−3, CS5203A−5
V
OUT
V
IN
Output
Current
Limit
Thermal
Shutdown
− +
Error
Amplifier
Bandgap
GND
Figure 2. Block Diagram − CS5203A−2, −3, −5
MAXIMUM RATINGS
Parameter
Supply Voltage, V
CC
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
17
−40 to +70
150
−60 to +150
260 Peak
230 Peak
Unit
V
°C
°C
°C
°C
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit
values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied,
damage may occur and reliability may be affected.
1. 10 second maximum.
2. 60 second maximum above 183°C.
ELECTRICAL CHARACTERISTICS
(C
IN
= 10
mF,
C
OUT
= 22
mF
Tantalum, V
IN
− V
OUT
= 3.0 V, V
IN
≤
15 V,
0°C
≤
T
A
≤
70°C, T
J
≤
+150°C, unless otherwise specified, I
full load
= 3.0 A.)
Characteristic
Adjustable Output Voltage (CS5203A−1)
Reference Voltage (Notes 3 and 4)
V
IN
− V
OUT
= 1.5 V; V
Adj
= 0 V,
10 mA
≤
I
OUT
≤
3.0 A
1.5 V
≤
V
IN
− V
OUT
≤
6.0 V; I
OUT
= 10 mA
V
IN
− V
OUT
= 1.5 V; 10 mA
≤
I
OUT
≤
3.0 A
I
OUT
= 3.0 A
V
IN
− V
OUT
= 3.0 V; T
J
≥
25°C
V
IN
− V
OUT
= 15 V
V
IN
− V
OUT
= 7.0 V
−
1.5 V
≤
V
IN
− V
OUT
≤
4.0 V;
10 mA
≤
I
OUT
≤
3.0 A
30 ms pulse; T
A
= 25°C
1.241
(−1%)
−
−
−
3.2
−
−
−
−
1.254
1.266
(+1%)
0.20
0.4
1.15
−
−
6.0
100
5.0
V
Test Conditions
Min
Typ
Max
Unit
Line Regulation
Load Regulation (Notes 3 and 4)
Dropout Voltage (Note 5)
Current Limit
0.04
0.03
1.05
5.5
2.5
1.2
50
0.2
%
%
V
A
A
mA
mA
mA
%/W
Minimum Load Current
Adjust Pin Current
Adjust Pin Current Change
Thermal Regulation
−
0.003
−
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.
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2
CS5203A−1, CS5203A−2, CS5203A−3, CS5203A−5
ELECTRICAL CHARACTERISTICS (continued)
(C
IN
= 10
mF,
C
OUT
= 22
mF
Tantalum, V
IN
− V
OUT
= 3.0 V, V
IN
≤
15 V,
0°C
≤
T
A
≤
70°C, T
J
≤
+150°C, unless otherwise specified, I
full load
= 3.0 A.)
Characteristic
Adjustable Output Voltage (CS5203A−1) (continued)
Ripple Rejection
Temperature Stability
RMS Output Noise
Thermal Shutdown
Thermal Shutdown Hysteresis
f = 120 Hz; C
Adj
= 25
mF;
I
OUT
= 3.0 A
−
10 Hz
≤
f
≤
10 kHz; T
A
= 25°C
−
−
−
−
−
150
−
85
0.5
0.003
180
25
−
−
−
−
−
dB
%
%V
OUT
°C
°C
Test Conditions
Min
Typ
Max
Unit
ELECTRICAL CHARACTERISTICS
(C
IN
= 10
mF,
C
OUT
= 22
mF
Tantalum, V
IN
− V
OUT
= 3.0 V, V
IN
≤
15 V,
0°C
≤
T
A
≤
70°C, T
J
≤
+150°C, unless otherwise specified, I
full load
= 3.0 A.)
Characteristic
Test Conditions
Min
Typ
Max
Unit
Fixed Output Voltage (CS5203A−2, CS5203A−3, CS5203A−5)
Reference Voltage (Notes 6 and 7)
CS5203A−5
CS5203A−3
CS5203A−2
Line Regulation
Load Regulation (Notes 6 and 7)
Dropout Voltage (Note 8)
Current Limit
V
IN
− V
OUT
= 1.5 V; 0
≤
IOUT
≤
3.0A
V
IN
− V
OUT
= 1.5 V; 0
≤
IOUT
≤
3.0A
V
IN
− V
OUT
= 1.5 V; 0
≤
IOUT
≤
3.0A
1.5 V
≤
V
IN
− V
OUT
≤
6.0 V; I
OUT
= 10 mA
V
IN
− V
OUT
= 1.5 V; 10 mA
≤
I
OUT
≤
3.0 A
I
OUT
= 3.0 A
V
IN
− V
OUT
= 3.0 V; T
J
≥
25°C
V
IN
− V
OUT
= 15 V
V
IN
≤
9.0 V; I
OUT
= 10 mA
30 ms pulse; T
A
= 25°C
f = 120 Hz; I
OUT
= 3.0 A
−
10 Hz
≤
f
≤
10 kHz
−
−
4.9 (−2%)
3.234 (−2%)
1.47 (−2%)
−
−
−
3.2
−
−
−
−
−
−
150
−
5.0
3.3
1.5
0.04
0.03
1.05
5.5
2.5
5.0
0.003
78
0.5
0.003
180
25
5.1 (+2%)
3.366 (+2%)
1.53 (+2%)
0.20
0.4
1.15
−
−
10
−
−
−
−
−
−
V
V
V
%
%
V
A
A
mA
%/W
dB
%
%V
OUT
°C
°C
Quiescent Current
Thermal Regulation
Ripple Rejection
Temperature Stability
RMS Output Noise (%V
OUT
)
Thermal Shutdown
Thermal Shutdown Hysteresis
6. 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.
7. Specifications apply for an external Kelvin sense connection at a point on the output pin 1/4” from the bottom of the package.
8. Dropout voltage is a measurement of the minimum input/output differential at full load.
PACKAGE PIN DESCRIPTION
Package Pin Number
CS5203A−1
D
2
PAK−3
1
2
3
N/A
TO−220−3
1
2
3
N/A
CS5203A−2, −3, −5
D
2
PAK−3
N/A
2
3
1
TO−220−3
N/A
2
3
1
Pin Symbol
Adj
V
OUT
V
IN
GND
Function
Adjust pin (low side of the internal reference).
Regulated output voltage (case).
Input voltage.
Ground connection.
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3
CS5203A−1, CS5203A−2, CS5203A−3, CS5203A−5
TYPICAL PERFORMANCE CHARACTERISTICS
1.15
Output Voltage Deviation (%)
3
0.10
0.08
T
CASE
= 0°C
1.10
Dropout Voltage (V)
1.05
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0
1
2
T
CASE
= 25°C
T
CASE
= 125°C
0.06
0.04
0.02
0.00
−0.02
−0.04
−0.06
−0.08
−0.10
−0.12
0
10 20 30 40 50 60 70 80 90 100 110 120 130
Output Current (A)
T
J
(°C)
Figure 3. Dropout Voltage vs. Output
Current
0.100
Output Voltage Deviation (%)
Minimum Load Current (mA)
2.500
2.175
Figure 4. Reference Voltage vs.
Temperature
0.075
T
CASE
= 0°C
1.850
1.525
T
CASE
= 25°C
0.050
T
CASE
= 125°C
T
CASE
= 25°C
1.200
0.875
T
CASE
= 125°C
0.025
T
CASE
= 0°C
0.000
0
1
2
3
0.550
1
2
3
4
5
6
7
8
9
Output Current (A)
V
IN
− V
OUT
(V)
Figure 5. Load Regulation vs. Output
Current
70
I
O
= 10 mA
Figure 6. Minimum Load Current
100
90
80
Ripple Rejection (dB)
70
60
50
40
30
20
10
T
CASE
= 25°C
65
Adjust Pin Current (mA)
60
55
50
45
40
I
OUT
= 3.0 A
(V
IN
− V
OUT
) = 3.0 V
V
RIPPLE
= 1.6 V
PP
0
10 20 30 40 50 60 70 80 90 100 110 120 130
0
10
1
10
2
10
3
10
4
10
5
Temperature (°C)
Frequency (Hz)
Figure 7. Adjust Pin Current vs.
Temperature
Figure 8. Ripple Rejection vs. Frequency
(Fixed Versions)
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4
CS5203A−1, CS5203A−2, CS5203A−3, CS5203A−5
100
90
80
Ripple Rejection (dB)
70
60
50
40
30
20
10
0
10
1
T
CASE
= 25°C
I
OUT
= 3.0 A
(V
IN
− V
OUT
) = 3.0 V
V
RIPPLE
= 1.6 V
PP
C
Adj
= 25
mF
10
2
10
3
10
4
10
5
Frequency (Hz)
Figure 9. Ripple Rejection vs. Frequency
(Adjustable Versions)
APPLICATIONS INFORMATION
The CS5203A family of linear regulators provides fixed
or adjustable voltages at currents up to 3.0 A. The regulators
are protected against short circuit, and include thermal
shutdown and safe area protection (SOA) circuitry. The
SOA protection circuitry decreases the maximum available
output current as the input−output differential voltage
increases.
The CS5203A 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.
Adjustable Operation
V
IN
C
1
V
IN
V
OUT
V
REF
R
1
C
2
V
OUT
CS5203A−1
Adj
I
Adj
C
Adj
R
2
The adjustable regulator (CS5203A−1) has an output
voltage range of 1.25 V to 13 V. An external resistor divider
sets the output voltage as shown in Figure 10. The regulator
maintains a fixed 1.25 V (typical) reference between the
output pin and the adjust pin.
A resistor divider network R1 and R2 causes a fixed
current to flow to ground. This current creates a voltage
across R2 that adds to the 1.25 V across R1 and sets the
overall output voltage. The adjust pin current (typically
50
mA)
also flows through R2 and adds a small error that
should be taken into account if precise adjustment of V
OUT
is necessary.
The output voltage is set according to the formula:
VOUT
+
VREF
R1
)
R2
)
I
Adj
R1
R2
Figure 10. Resistor Divider Scheme for the
Adjustable Version
Stability Considerations
The term I
Adj
×
R2 represents the error added by the adjust
pin current.
R1 is chosen so that the minimum load current is at least
10 mA. R1 and R2 should be the same type, e.g. metal film
for best tracking over temperature. The adjust pin is
bypassed to improve the transient response and ripple
rejection of the regulator.
The output or compensation capacitor helps determine
three main characteristics of a linear regulator: satrtup 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 manufacturers data sheet
provides this information.
A 22
mF
tantalum capacitor will work for most
applications, but with high current regulators such as the
CS5203A the transient response and stability improve with
higher values of capacitor. The majority of applications for
this regulator involve large changes in load current so the
output capacitor must supply the instantaneous load current.
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