CS52015-1GDPR3 [CHERRY]
1.5A Adjustable Linear Regulator; 1.5A可调线性稳压器
| 型号： | CS52015-1GDPR3 |
| 厂家： | 
CHERRY SEMICONDUCTOR CORPORATION |
| 描述： | 1.5A Adjustable Linear Regulator |
| 文件： | 总7页 (文件大小：175K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
CS52015-1
1.5A Adjustable Linear Regulator
Description
Features
The CS52015-1 linear regulator pro-
The circuit is designed to operate
with dropout voltages less than
1.4V at 1.5A output current. Device
protection includes overcurrent and
thermal shutdown.
■ Output Current to 1.5A
vides 1.5A with an accuracy of ±1%.
The device uses two external resis-
tors to set the output voltage within
a 1.25V to 5.5V range.
■ Output Accuracy to ±1%
Over Temperature
■ Dropout Voltage (typical)
The regulator is intended for use as
a post regulator and microprocessor
supply. The fast loop response and
low dropout voltage make this reg-
ulator ideal for applications where
low voltage operation and good
transient response are important.
The CS52015-1 is pin compatible
with the LT1086 family of linear
regulators but has lower dropout
voltage.
1.05V @ 1.5A
■ Fast Transient Response
■ Fault Protection
Current Limit
The regulator is available in TO-
220, surface mount D2, and SOT-223
packages.
Thermal Shutdown
Application Diagram
Package Options
3L TO-220
3L D2PAK
Tab (VOUT
)
Tab (VOUT
)
VOUT
CS52015-1
5.0V
VIN
3.3V @ 1.5A
124W
1%
1
Adj
22mF
5V
10 mF
5V
0.1mF
5V
Tantalum
SOT-223
Tab (VOUT
)
200W
1%
1
CS52015 -1
1
2
3
Adj
VOUT (Tab)
VIN
1
Consult factory for fixed output voltage
versions.
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
Rev. 2/17/98
1
A
¨
Company
Absolute Maximum Ratings
Supply Voltage, VCC ....................................................................................................................................................................7V
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
ESD Damage Threshold............................................................................................................................................................2kV
Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VOUT + VDROPOUT < VIN < 7V, 0¡C ² TA ² 70¡C, TJ ² +150¡C,
unless otherwise specified, Ifull load = 1.5A.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
■ Adjustable Output Voltage (CS52015-1)
Reference Voltage
(Notes 1 and 2)
V
INÐVOUT=1.5V; VAdj = 0V
1.241
(-1%)
1.254
1.266
(+1%)
V
10mA²IOUT²1.5A
Line Regulation
1.5V²VINÐVOUT²5.75V; IOUT=10mA
VINÐVOUT=1.5V; 10mA²IOUT²1.5A
0.02
0.04
0.20
0.4
%
%
Load Regulation
(Notes 1 and 2)
Dropout Voltage (Note 3)
Current Limit
IOUT=1.5A
1.05
3.1
1.4
V
VINÐVOUT=3V; TJ ³ 25¡C
1.6
A
Minimum Load Current (Note 4) VIN=7V ; VAdj=0
0.6
2.0
mA
µA
%/W
dB
Adjust Pin Current
VINÐVOUT=3V; IOUT=10mA
50
100
Thermal Regulation (Note 5)
Ripple Rejection (Note 5)
30ms pulse; TA=25¡C
0.002
80
0.020
f=120Hz; IOUT=1.5A; VINÐVOUT=3V;
VRIPPLE=1VPP
Thermal Shutdown (Note 6)
150
180
25
210
¡C
¡C
Thermal Shutdown Hysteresis
(Note 6)
Note 1: Load regulation and output voltage are measured at a constant junction temperature by low duty cycle pulse testing. Changes in out-
put voltage due to 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.
Note 4: The minimum load current is the minimum current required to maintain regulation. Normally the current in the resistor divider used
to set the output voltage is selected to meet the minimum requirement.
Note 5: Guaranteed by design, not 100% tested in production.
Note 6: Thermal shutdown is 100% functionally tested in production.
Package Pin Description
PACKAGE PIN #
PIN SYMBOL
FUNCTION
D2PAK
TO-220
SOT-223
1
2
3
1
2
3
1
2
3
Adj
Adjust pin (low side of the internal reference.
Regulated output voltage (case).
Input voltage
VOUT
VIN
2
Block Diagram
VOUT
VIN
Output
Current
Limit
Thermal
Shutdown
-
+
Error
Amplifier
Bandgap
Adj
Typical Performance Characteristics
1.05
1.00
0.10
0.08
0.06
0.04
T
CASE
0ûC
0.95
0.90
0.85
0.80
0.75
0.02
0.00
T
25ûC
CASE
-0.02
-0.04
-0.06
-0.08
-0.10
-0.12
T
CASE
125ûC
0
10 20 30 40 50 60 70 80 90 100 110 120 130
0
300
600
900
1200
1500
TJ (°C)
I
(mA)
OUT
Dropout Voltage vs. Output Current
Reference Voltage vs. Temperature
0.65
0.60
0.100
0.075
T
= 0°C
CASE
0.55
T
= 125°C
CASE
0.050
T
= 125°C
CASE
T
CASE
= 25°C
0.50
0.45
T
= 25°C
CASE
0.025
0.000
C
=C
=22mF Tantalum
IN
OUT
T
= 0°C
CASE
0.40
1
2
3
4
5
6
7
0
1
2
V
– V
(V)
IN
OUT
Output Current (A)
Minimum Load Current vs VIN-VOUT
Load Regulation vs. Output Current
3
Typical Performance Characteristics
70.0
65.0
60.0
55.0
50.0
45.0
40.0
85
75
65
I
= 10mA
O
55
T
= 25°C
= 1.5A
CASE
45
35
25
15
I
OUT
(V Ð V
IN
V
C
) = 3V
OUT
= 1.0V
PP
RIPPLE
= 0.1mF
Adj
5
1
2
3
4
6
0
20 30 40 50 60
Temperature (°C)
90 100
110 120 130
10
70 80
10
10
10
10
10
10
Frequency (Hz)
Adjust Pin Current vs. Temperature
Ripple Rejection vs. Frequency
3.5
3.3
3.1
2.9
200
100
0
2.7
2.5
2.3
2.1
1.9
1.7
1.5
V
=3.3V
OUT
=0.1mF
-100
-200
OUT
C
C
=C =22mF Tantalum
IN
Adj
1500
750
0
0
1
2
3
4
5
6
7
8
9
10
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
- V (V)
Time mS
V
IN
OUT
Transient Response
Short Circuit Current vs VIN-VOUT
Applications Information
The CS52015-1 linear regulator provides adjustable volt-
ages at currents up to 1.5A. The regulator is protected
against overcurrent conditions and includes thermal
shutdown.
50µA) also flows through R2 and adds a small error that
should be taken into account if precise adjustment of VOUT
is necessary.
The output voltage is set according to the formula:
The CS52015-1 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.
R1 + R2
VOUT = VREF
´
+ IAdj ´ R2
(
)
R1
The term IAdj ´ R2 represents the error added by the adjust
pin current.
Adjustable Operation
R1 is chosen so that the minimum load current is at least
2mA. R1 and R2 should be the same type, e.g. metal film
for best tracking over temperature. While not required, a
bypass capacitor from the adjust pin to ground will
improve ripple rejection and transient response. A 0.1µF
tantalum capacitor is recommended for Òfirst cutÓ design.
Type and value may be varied to obtain optimum perfor-
mance vs price.
The 52015-1 has an output voltage range of 1.25V to 5.5V.
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 cur-
rent 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
4
Applications Information: continued
EXTERNAL SUPPLY
VIN
VOUT
VOUT
VIN
C1
CS52015-1
VREF
R
C2
1
V
IN
Adj
V
OUT
IAdj
V
Adj
R
2
CAdj
V
OUT
Figure 1. Resistor divider scheme.
Figure 2: Short Circuit Protection Circuit for High Voltage Application.
Stability Considerations
The CS52015-1 linear regulator has an absolute maximum
specification of 7V for the voltage difference between VIN
and VOUT. However, the IC may be used to regulate volt-
ages in excess of 7V. The main considerations in such a
design are power-up and short circuit capability.
The output or compensation capacitor helps determine
three main characteristics of a linear regulator: start-up
delay, load transient response and loop stability.
In most applications, ramp-up of the power supply to VIN
is fairly slow, typically on the order of several tens of mil-
liseconds, while the regulator responds in less than one
microsecond. In this case, the linear regulator begins
charging the load as soon as the VIN to VOUT differential is
large enough that the pass transistor conducts current. The
load at this point is essentially at ground, and the supply
voltage is on the order of several hundred millivolts, with
the result that the pass transistor is in dropout. As the sup-
ply to VIN increases, the pass transistor will remain in
dropout, and current is passed to the load until VOUT
reaches the point at which the IC is in regulation. Further
increase in the supply voltage brings the pass transistor
out of dropout. The result is that the output voltage fol-
lows the power supply ramp-up, staying in dropout until
the regulation point is reached. In this manner, any output
voltage may be regulated. There is no theoretical limit to
the regulated voltage as long as the VIN to VOUT differen-
tial of 7V is not exceeded.
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 capaci-
tor with almost zero ESR can cause instability. The alu-
minum electrolytic capacitor is the least expensive solu-
tion. However, when the circuit operates at low tempera-
tures, both the value and ESR of the capacitor will vary
considerably. The capacitor manufacturersÕ data sheet pro-
vides this information.
A 22µF tantalum capacitor will work for most applications,
but with high current regulators such as the CS52015-1 the
transient response and stability improve with higher val-
ues of capacitance. The majority of applications for this
regulator involve large changes in load current so the out-
put capacitor must supply the instantaneous load current.
The ESR of the output capacitor causes an immediate drop
in output voltage given by:
ÆV = ÆI ´ ESR
However, the possibility of destroying the IC in a short
circuit condition is very real for this type of design. Short
circuit conditions will result in the immediate operation of
the pass transistor outside of its safe operating area. Over-
voltage stresses will then cause destruction of the pass
transistor before overcurrent or thermal shutdown circuit-
ry can become active. Additional circuitry may be required
to clamp the VIN to VOUT differential to less than 7V if fail-
safe operation is required. One possible clamp circuit is
illustrated in figure 2; however, the design of clamp cir-
cuitry must be done on an application by application basis.
Care must be taken to ensure the clamp actually protects
the design. Components used in the clamp design must be
able to withstand the short circuit condition indefinitely
while protecting the IC.
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 net-
work should be as close as possible to the load for the best
results.
Protection Diodes
When large external capacitors are used with a linear regu-
lator 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 capaci-
tor, the output voltage and the rate at which VIN drops. In
the CS52015-1 linear regulator, the discharge path is
through a large junction and protection diodes are not usu-
ally needed. If the regulator is used with large values of
output capacitance and the input voltage is instantaneous-
ly shorted to ground, damage can occur. In this case, a
diode connected as shown in Figure 2 is recommended.
5
Applications Information: continued
Thermal compound should always be used with high cur-
rent regulators such as these.
IN4002
(optional)
VOUT
The thermal characteristics of an IC depend on the follow-
ing four factors:
VIN
VOUT
VIN
1. Maximum Ambient Temperature TA (¡C)
2. Power dissipation PD (Watts)
C1
CS52015-1
R
C2
1
3. Maximum junction temperature TJ (¡C)
4. Thermal resistance junction to ambient RQJA (C/W)
Adj
These four are related by the equation
R
2
CAdj
TJ = TA + PD ´ RQJA
(1)
The maximum ambient temperature and the power dissi-
pation are determined by the design while the maximum
junction temperature and the thermal resistance depend on
the manufacturer and the package type.
Figure 3. Protection diode scheme for Large Output Capacitors.
Output Voltage Sensing
The maximum power dissipation for a regulator is:
Since the CS52015-1 is a three terminal regulator, it is not
possible to provide true remote load sensing. Load regula-
tion is limited by the resistance of the conductors connect-
ing the regulator to the load.
P
D(max)={VIN(max)ÐVOUT(min)}IOUT(max)+VIN(max) Q
I
(2)
where
VIN(max) is the maximum input voltage,
VOUT(min) is the minimum output voltage,
For the adjustable regulator, the best load regulation occurs
when R1 is connected directly to the output pin of the regu-
lator as shown in Figure 3. If R1 is connected to the load,
RC is multiplied by the divider ratio and the effective resis-
tance between the regulator and the load becomes
IOUT(max) is the maximum output current, for the application
IQ is the maximum quiescent current at IOUT(max).
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.
R1 + R2
RC ´
(
)
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.
R1
RC = conductor parasitic resistance
conductor parasitic
resistance
R
C
VIN
VOUT
VIN
1. Thermal Resistance of the junction to case, RQJC (¡C/W)
2. Thermal Resistance of the case to Heat Sink, RQCS (¡C/W)
3. Thermal Resistance of the Heat Sink to the ambient air,
CS52015-1
R
LOAD
R
1
Adj
R
QSA (¡C/W)
R
2
These are connected by the equation:
QJA = RQJC + RQCS + RQSA
R
(3)
The value for RQJA is calculated using equation (3) and the
result can be substituted in equation (1).
Figure 4. Grounding scheme for the adjustable output regulator to mini-
mize parasitic resistance effects.
The value for RQJC is 3.5ûC/W. For a high current regula-
tor such as the CS52015-1 the majority of the heat is gener-
ated in the power transistor section. The value for RQSA
depends on the heat sink type, while RQCS depends on fac-
tors such as package type, heat sink interface (is an insula-
tor and thermal grease used?), and the contact area
between the heat sink and the package. Once these calcula-
tions are complete, the maximum permissible value of RQJA
can be calculated and the proper heat sink selected. For fur-
ther discussion on heat sink selection, see application note
ÒThermal Management for Linear Regulators.Ó
Calculating Power Dissipation and Heat Sink Requirements
The CS52015-1 linear regulator includes thermal shutdown
and current limit 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 CS52015-1, and elec-
trical isolation may be required for some applications.
6
Package Specification
PACKAGE DIMENSIONS IN mm (INCHES)
PACKAGE THERMAL DATA
3L
Thermal Data TO-220
3L
3L
3 Lead TO-220 (T) Straight
D2PAK SOT-223
RQJC
RQJA
typ
typ
3.5
50
3.5
10 - 50*
15
156
ûC/W
ûC/W
*Depending on thermal properties of substrate. RQJA = RQJC + RQCA
1.40 (.055)
1.14 (.045)
4.83 (.190)
10.54 (.415)
4.06 (.160)
9.78 (.385)
3.96 (.156)
2.87 (.113)
3.71 (.146)
2.62 (.103)
6.55 (.258)
5.94 (.234)
3 Lead SOT-223 (ST)
14.99 (.590)
14.22 (.560)
6.70 (.264)
6.30 (.248)
3.15 (.124)
7.30 (.287)
6.70 (.264)
2.95 (.116)
1.52 (.060)
1.14 (.045)
6.17 (.243) REF
14.22 (.560)
13.72 (.540)
1.40 (.055)
1.14 (.045)
3.70 (.146)
3.30 (.130)
1.02 (.040)
0.63 (.025)
1.05 (.041)
0.85 (.033)
0.56 (.022)
0.38 (.014)
2.79 (.110)
2.29 (.090)
2.30 (.090)
5.33 (.210)
4.83 (.190)
0.35 (.014)
0.25 (.010)
2.92 (.115)
2.29 (.090)
1.70 (.067)
1.50 (.060)
1.30 (.051)
1.10 (.043)
0.85 (.033)
0.65 (.026)
0.10 (.004)
0.02 (.001)
10° MAX
3 Lead D2PAK (DP)
4.60 (.181)
10.31 (.406)
10.05 (.396)
1.40 (.055)
1.14 (.045)
1.68 (.066)
1.40 (.055)
8.53 (.336)
8.28 (.326)
15.75 (.620)
14.73 (.580)
2.74(.108)
2.49(.098)
1.40 (.055)
1.14 (.045)
2.79 (.110)
2.29 (.090)
0.91 (.036)
0.66 (.026)
2.54 (.100) REF
.254 (.010) REF
0.10 (.004)
0.00 (.000)
4.57 (.180)
4.31 (.170)
Ordering Information
Type Description
Part Number
CS52015-1GT3
1.5A, adj. output 3 L TO-220 Straight
CS52015-1GDP3 1.5A, adj. output 3 L D2PAK
CS52015-1GDPR3 1.5A, adj. output 3 L D2PAK
(tape & reel)
Ch erry Sem icon du ctor Corporation reserves th e
righ t to m ake ch an ges to th e specification s with ou t
n otice. Please con tact Ch erry Sem icon du ctor
Corporation for th e latest available in form ation .
CS52015-1GST3
CS52015-1GSTR3 1.5A, adj. output SOT-223 (tape & reel)
1.5A, adj. output SOT-223
Rev. 2/17/98
© 1999 Cherry Semiconductor Corporation
7
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