Cherry CS5205-1GDP3 5a adjustable, and 3.3v and 5v fixed linear regulator Datasheet

CS5205-1,-3,-5
CS5205-1,-3,-5
5A Adjustable, and 3.3V
and 5V Fixed Linear Regulators
Description
The CS5205-X series of linear regulators provides 5A at adjustable
and fixed voltages with an accuracy of ±1% and ±2% respectively.
The adjustable version uses two
external resistors to set the output
voltage within a 1.25V to 13V
range.
Features
The circuit is designed to operate
with dropout voltages as low as 1V
depending on the output current
level. The maximum quiescent current is only 10mA at full load.
The regulators are fully protected
against overload conditions with
protection circuitry for Safe
Operating Area (SOA), overcurrent
and thermal shutdown.
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 CS5205-X is pin compatible
with the LT1084 family of linear
regulators but has lower dropout
voltage.
■ Output Current to 5A
■ Output Trimmed to +/- 1%
■ Dropout Voltage
1.2V @ 5A
■ Fast Transient Response
■ Fault Protection Circuitry
Thermal Shutdown
Overcurrent Protection
Safe Area Protection
The regulators are available in TO220 and surface mount D2 packages.
Block Diagram
Package Options
CS5205-1
V OUT
V IN
3L D2PAK
3L TO-220
Tab (VOUT)
Output
Current
Limit
Thermal
Shutdown
-
+
Error
Amplifier
1
Bandgap
Adj
CS5205-3, -5
V OUT
1
V IN
Output
Current
Limit
Thermal
Shutdown
-
+
1
2
3
Error
Amplifier
CS5205-1
Adj
VOUT
VIN
1
2
3
CS5205-3, -5
Gnd
VOUT
VIN
Bandgap
Gnd
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: [email protected]
Web Site: www.cherry-semi.com
Rev. 6/12/97
1
A
¨
Company
CS5205-1,-3,-5
Absolute Maximum Ratings
Supply Voltage, VCC ..................................................................................................................................................................17V
Operating Temperature Range................................................................................................................................-40¡C to 70¡C
Junction Temperature ............................................................................................................................................................150¡C
Storage Temperature Range ..................................................................................................................................-60¡C to 150¡C
Lead Temperature Soldering: Wave Solder (through hole styles only)..........................................10 sec. max, 260¡C peak
Reflow (SMD styles only) ......................................................................................60 sec. max above 183¡C, 230¡C peak
Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VIN Ð VOUT=3V, VIN ² 15V, 0¡C ² TA ² 70¡C, TJ ² +150¡C,
unless otherwise specified, Ifull load = 5A.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
1.241
(-1%)
1.254
1.266
(+1%)
V
■ Adjustable Output Voltage (CS5205-1)
Reference Voltage
(Notes 1 and 2)
VINÐVOUT=1.5V; VAdj = 0V
10mA²IOUT²5A
Line Regulation
1.5V²VINÐVOUT²6V; IOUT=10mA
0.04
0.20
%
Load Regulation
(Notes 1 and 2)
VINÐVOUT=1.5V;
10mA²IOUT²5A
0.08
0.4
%
Dropout Voltage (Note 3)
IOUT=5A
1.2
1.3
V
Current Limit
VINÐVOUT=3V; TJ ³ 25¡C
VINÐVOUT=9V
Minimum Load Current
VINÐVOUT=7V
Adjust Pin Current
Adjust Pin Current Change
5.5
1.5V²VINÐVOUT²4V;
10mA²IOUT²5A
8.5
1.0
A
A
1.2
6
mA
50
0.2
100
5.0
µA
µA
Thermal Regulation
30ms pulse; TA=25¡C
0.003
%W
Ripple Rejection
f=120Hz; CAdj=25µF; IOUT=5A
82
dB
0.5
%
0.003
%VOUT
180
¡C
25
¡C
Temperature Stability
RMS Output Noise
10Hz²f²10kHz; TA=25¡C
Thermal Shutdown
150
Thermal Shutdown Hysteresis
Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VIN Ð VOUT=3V, VIN ² 10V, 0¡C ² TA ² 70¡C, TJ ² +150¡C,
unless otherwise specified, Ifull load = 5A.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
■ Fixed Output Voltage (CS5205-3, -5)
CS5205-5
(Notes 1 and 2)
VINÐVOUT=1.5V;
0²IOU T²5A
4.9
(-2%)
5.0
5.1
(+2%)
V
CS5205-3
(Notes 1 and 2)
VINÐVOUT=1.5V;
0²IOUT²5A
3.234
(-2%)
3.300
3.366
(+2%)
V
Line Regulation
1.5V²VINÐVOUT ² 6V; IOUT=10mA
0.04
0.20
%
Load Regulation
(Notes 1 and 2)
VINÐVOUT =1.5V;
10mA ² IOUT²5A
0.08
0.40
%
Dropout Voltage (Note 3)
IOUT=5A
1.2
1.3
V
Current Limit
VINÐVOUT=3V; TJ ³ 25¡C
VINÐVOUT=9V
5.5
8.5
1.0
A
A
Quiescent Current
VIN²9V; IOUT = 10mA
5.0
Thermal Regulation
30ms pulse; TA=25¡C
0.003
%/W
Ripple Rejection
f=120Hz; IOUT=5A
75
dB
0.5
%
Temperature Stability
2
10.0
mA
unless otherwise specified, Ifull load = 5A.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
■ Fixed Output Voltage (CS5205-3, -5): continued
RMS Output Noise (%VOUT)
10Hz²f²10kHz
Thermal Shutdown
150
Thermal Shutdown Hysteresis
0.003
%VOUT
180
¡C
25
¡C
Note 1: 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.
Note 2: Specifications apply for an external Kelvin sense connection at a point on the output pin 1/4Ó from the bottom of the package.
Note 3: Dropout voltage is a measurement of the minimum input/output differential at full load.
Package Pin Description
PACKAGE PIN #
CS5205 -1
3L TO-220
D2PAK
1
1
2
2
3
3
N/A
N/A
PIN SYMBOL
CS5205 -3, -5
D2PAK
3L TO-220
N/A
N/A
2
2
3
3
1
1
FUNCTION
Adj
VOUT
VIN
Gnd
Adjust pin (low side of the internal reference).
Regulated output voltage (case).
Input voltage.
Ground connection.
Typical Performance Characteristics
0.10
1.25
0.08
Dropout Voltage (V)
1.20
Output Voltage Deviation (%)
1.30
TCASE = 0°C
1.15
1.10
1.05
1.00
0.95
TCASE = 125°C
0.90
0.85
TCASE = 25°C
0.06
0.04
0.02
0.00
-0.02
-0.04
-0.06
0.80
-0.08
0.75
-0.10
-0.12
0.70
0
1
2
3
Output Current (A)
4
0
5
10
20
30
40
50
60
70
80
90 100 110 120 130
TJ (°C)
Dropout Voltage vs. Output Current
Reference Voltage vs. Temperature
2.500
0.200
Minimum Load Current (mA)
Output Voltage Deviation (%)
0.175
0.150
0.125
0.100
TCASE = 25°C
0.075
TCASE = 125°C
0.050
2.175
1.850
TCASE = 0°C
1.525
1.200
TCASE = 125°C
0.875
0.025
TCASE = 25°C
TCASE = 0°C
0.550
0.000
0
1
2
3
4
1
5
2
Output Current (A)
Load Regulation vs. Output Current
Minimum Load Current
3
3
4
5
VIN – VOUT (V)
6
7
8
9
CS5205-1,-3,-5
Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VIN Ð VOUT=3V, VIN ² 10V, 0¡C ² TA ² 70¡C, TJ ² +150¡C,
CS5205-1,-3,-5
Typical Performance Characteristics: continued
100.0
70.0
90.0
IO = 10mA
Ripple Rejection (dB)
Adjust Pin Current (mA)
65.0
60.0
55.0
50.0
80.0
70.0
60.0
50.0
TCASE = 25°C
IOUT = 5A
(VIN Ð VOUT) = 3V
VRIPPLE = 1.6VPP
40.0
30.0
20.0
45.0
10.0
0.0
40.0
0
10
20
30
40
50
60
70
80
101
90 100 110 120 130
102
103
Temperature (°C)
104
105
Frequency (Hz)
Adjust Pin Current vs. Temperature
Ripple Rejection vs. Frequency (Fixed Versions)
100.0
Ripple Rejection (dB)
90.0
80.0
70.0
60.0
50.0
TCASE = 25°C
IOUT = 5A
(VIN Ð VOUT) = 3V
VRIPPLE = 1.6VPP
CAdj = 25mF
40.0
30.0
20.0
10.0
0.0
101
102
103
104
105
Frequency (Hz)
Ripple Rejection vs. Frequency (Adjustable Version)
Applications Information
The CS5205-X family of linear regulators provide fixed or
adjustable voltages at currents up to 5A. 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 CS5205-X 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.
The output voltage is set according to the formula:
(
)
VOUT = VREF ´ R1 + R2 + IAdj ´ R2
R1
The term IAdj ´ R2 represents the error added by the adjust
pin current.
R1 is chosen so that the minimum load current is at least
10mA. 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.
Adjustable Operation
The adjustable regulator (CS5205-1) has an output voltage
range of 1.25V to 13V. An external resistor divider sets the
output voltage as shown in Figure 1. The regulator maintains a fixed 1.25V (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 1.25V across R1 and sets the
overall output voltage. The adjust pin current (typically
50µA) also flows through R2 and adds a small error that
should be taken into account if precise adjustment of VOUT
is necessary.
VIN
VOUT
VIN
C1
CS5205-1
VOUT
VREF
R1
C2
Adj
IAdj
CAdj
R2
Figure 1. Resistor divider scheme for the adjustable version.
4
Stability Considerations
IN4002
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 manufacturers data sheet provides this information.
A 22µF tantalum capacitor will work for most applications,
but with high current regulators such as the CS5205-X 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. The
ESR of the output capacitor causes an immediate drop in
output voltage given by:
VIN
(optional)
VOUT
VIN
C1
VOUT
CS5205-X
C2
Gnd
Figure 2b. Protection diode scheme for fixed output regulators.
Output Voltage Sensing
Since the CS5205-X 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 fixed regulators should be connected as shown in Figure 3.
ÆV = ÆI ´ ESR
VIN
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
load transient conditions. The output capacitor network
should be as close as possible to the load for the best results.
VOUT
VIN
RC
conductor parasitic
resistance
CS5205-X
RLOAD
Gnd
Protection Diodes
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-X family of linear regulators, 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 Figures 2a and 2b is recommended.
IN4002
VIN
C1
For the adjustable regulator, the best load regulation
occurs when R1 is connected directly to the output pin of
the regulator as shown in Figure 4. If R1 is connected to the
load, RC is multiplied by the divider ratio and the effective
resistance between the regulator and the load becomes
(
RC ´ R1 + R2
R1
)
RC = conductor parasitic resistance
VIN
(optional)
VOUT
VIN
Figure 3. Conductor parasitic resistance can be minimized with the
above grounding scheme for fixed output regulators.
VOUT
RC
VOUT
VIN
CS5205-1
CS5205-1
conductor parasitic
resistance
RLOAD
R1
Adj
R1
C2
Adj
R2
CAdj
R2
Figure 2a. Protection diode scheme for adjustable output regulator.
Figure 4. Grounding scheme for the adjustable output regulator to minimize parasitics.
5
CS5205-1,-3,-5
Applications Information: continued
CS5205-1,-3,-5
Applications Information: continued
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.
Calculating Power Dissipation and Heat Sink Requirements
The CS5205-X series of linear regulators 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.
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 RQJA, the total thermal resistance between the
junction and the surrounding air.
The case is connected to VOUT on the CS5205-X, electrical
isolation may be required for some applications. Thermal
compound should always be used with high current regulators such as these.
1. Thermal Resistance of the junction to case, RQJC (¡C/W)
2. Thermal Resistance of the case to Heat Sink, RQCS (¡C/W)
The thermal characteristics of an IC depend on the following four factors:
3. Thermal Resistance of the Heat Sink to the ambient air,
RQSA (¡C/W)
1. Maximum Ambient Temperature TA (¡C)
2. Power dissipation PD (Watts)
These are connected by the equation:
3. Maximum junction temperature TJ (¡C)
RQJA = RQJC + RQCS + RQSA
4. Thermal resistance junction to ambient RQJA (C/W)
The value for RQJA is calculated using equation (3) and the
result can be substituted in equation (1).
These four are related by the equation
TJ = TA + PD ´ RQJA
The value for RQJC is normally quoted as a single figure for
a given package type based on an average die size. For a
high current regulator such as the CS5205-X the majority of
the heat is generated in the power transistor section. The
value for RQSA depends on the heat sink type, while RQCS
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 RQJA can be calculated and the proper heat sink
selected. For further discussion on heat sink selection, see
application note ÒThermal Management for Linear
Regulators.Ó
(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)ÐVOUT(min)}IOUT(max)+VIN(max)IQ
(3)
(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).
6
CS5205-1,-3,-5
Package Specification
PACKAGE DIMENSIONS IN mm(INCHES)
PACKAGE THERMAL DATA
Thermal Data
RQJC
RQJA
typ
typ
3L
TO-220
1.6
50
3L
D2PAK
1.6
10 - 50*
ûC/W
ûC/W
*Depending on thermal properties of substrate. RQJA = RQJC + RQCA
3 Lead D2PAK (DP)
3 Lead TO-220 (T) Straight
10.31 (.406)
10.05 (.396)
1.40 (.055)
1.14 (.045)
1.68 (.066)
1.40 (.055)
4.83 (.190)
4.06 (.160)
10.54 (.415)
9.78 (.385)
6.55 (.258)
5.94 (.234)
1.40 (.055)
1.14 (.045)
8.53 (.336)
8.28 (.326)
3.96 (.156)
3.71 (.146)
2.87 (.113)
2.62 (.103)
15.75 (.620)
14.73 (.580)
2.74(.108)
2.49(.098)
14.99 (.590)
14.22 (.560)
1.40 (.055)
1.14 (.045)
2.79 (.110)
2.29 (.090)
0.91 (.036)
0.66 (.026)
2.54 (.100) REF
1.52 (.060)
1.14 (.045)
14.22 (.560)
13.72 (.540)
.254 (.010) REF
6.17 (.243) REF
1.40 (.055)
1.14 (.045)
4.57 (.180)
4.31 (.170)
0.10 (.004)
0.00 (.000)
1.02 (.040)
0.63 (.025)
0.56 (.022)
0.38 (.014)
2.79 (.110)
2.29 (.090)
5.33 (.210)
4.83 (.190)
2.92 (.115)
2.29 (.090)
Ordering Information
Part Number
CS5205-1GT3
CS5205-1GDP3
CS5205-1GDPR3
CS5205-3GT3
CS5205-3GDP3
CS5205-3GDPR3
CS5205-5GT3
Rev. 6/12/97
Type
5A, adj. output
5A, adj. output
5A, adj. output
Description
3 L TO-220 Straight
3 L D2PAK
3 L D2PAK
(tape & reel)
5A, 3.3V output 3 L TO-220 Straight
5A, 3.3V output 3 L D2PAK
5A, 3.3V output 3 L D2PAK
(tape & reel)
5A, 5V output
3 L TO-220 Straight
Cherry Semiconductor Corporation reserves the
right to make changes to the specifications without
notice. Please contact Cherry Semiconductor
Corporation for the latest available information.
7
© 1999 Cherry Semiconductor Corporation
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