SPX1585AU/ER-L [EXAR]
Regulator, 1 Output, BIPolar,;
| 型号： | SPX1585AU/ER-L |
| 厂家： | 
EXAR CORPORATION |
| 描述： | Regulator, 1 Output, BIPolar, |
| 文件： | 总7页 (文件大小：324K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SPX1585
5A Low Dropout Voltage Regulator
Adjustable & Fixed Output,
Fast Response
FEATURES
APPLICATIONS
• Adjustable Output Down To 1.2V
• Fixed Output Voltages 1.5V, 2.5V, 3.3V
• Output Current Of 5A
• Powering VGA & Sound Card
• Power PC Supplies
• SMPS Post-Regulator
• Low Dropout Voltage 1.1V Typ @ 5A.
• Extremely Tight Load And Line Regulation
• Current & Thermal Limiting
• High Efficiency “Green” Computer Systems
• High Efficiency Linear Power Supplies
• Portable Instrumentation
• Standard 3-Terminal Low Cost TO-220 & TO-263
• Similar To Industry Standard LT1085/LT1585
• Constant Current Regulators
• Adjustable Power Supplies
• Battery charger
Now Available in Lead Free Packaging
PRODUCT DESCRIPTION
The SPX1585 is a low power 5A adjustable and fixed voltage regulator that is very easy to use. It requires only 2 external resistors to set
the output voltage for the adjustable version. The SPX1585 devices are designed for low voltage applications that offer lower dropout
voltage and faster transient response. This device is an excellent choice for use in powering low voltage microprocessors that require a
lower dropout, faster transient response to regulate from +2.5V to 3.8V supplies, and as a post regulator for switching supplies applica-
tions. The SPX1585 features low dropout of a maximum 1.2 volts.
The SPX1585 offers full protection against over-current faults, reversed input polarity, reversed load insertion, and positive and negative
transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The IQ of this device flows into the load, which increases
efficiency.
The SPX1585 devices are offered in a 3-pin TO-220 and TO-263 package compatible with other 3 terminal regulators. For an 8A low
dropout regulator, refer to the SPX1584 data sheet.
PIN CONNECTIONS
TO-263-3 (T)
TO-220-3 (U)
VIN
3
VIN
3
2
1
VOUT
SPX1585
SPX1585
2
1
VOUT
ADJ/GND
ADJ/GND
Front View
Top View
Note that TAB is connected to VOUT for both package types.
Date: 05/14/04
SPX1585
ABSOLUTE MAXIMUM RATINGS
Lead Temp. (Soldering, 10 Seconds) .............................. 300°C
Storage Temperature Range ............................-65° to +150°C
Operating Junction Temperature Range
Input Voltage........................................................ 10V
Input to Output Voltage Differential .................... 10V
SPX1585 Control Section.......................... -45°C +125°C
SPX1585 Power Transistor.........................-45°C +150°C
ELECTRICAL CHARACTERISTICS (NOTE 1) at IOUT = 10mA, T =25 C, unless otherwise specified.
°
Typ
A
PARAMETER
CONDITIONS
SPX1585A
SPX1585
UNITS
Min
Max
Min
Max
1.5V Version
Output Voltage (Note 2)
SPX1585-1.5V, 0 < IOUT < 5A, 3.3V<VIN<10V
SPX1585-2.5V, 0 < IOUT < 5A, 4.0V<VIN<10V
SPX1585-3.3V, 0 < IOUT< 5A, 4.8V<VIN<10V
1.5
1.485
1.515
1.47
1.53
V
V
V
1.47
1.53
1.455
1.545
2.5V Version
Output Voltage (Note 2)
2.5
2.475
2.525
2.45
2.55
2.45
2.55
2.425
2.575
3.3V Version
Output Voltage (Note 2)
3.3
3.267
3.333
3.234
3.366
3.234
3.366
3.069
3.399
All Voltage Options
Reference Voltage (Vref)
V
1.250
1.225
1.270
1.225
1.270
VIN≤ 7V, P≤ PMAX
1.5V≤ (VIN -VOUT)≤5.75V, 10mA≤IOUT≤5A
Min. Load Current (Note 3)
V
5
10
10
1.5V≤ (VIN –VOUT)≤5.75V
0.005
0.2
0.2
%
Line Regulation (∆Vref(Vin))
2.75V≤VIN ≤7V, Iout=10mA, TJ=25ºC
(Note 3)
0.005
0.05
0.05
1.1
0.2
0.3
0.3
1.2
0.2
0.3
0.3
1.2
V
IN ≤7V, IOUT=0mA, TJ=25ºC (Note 2)
%
Load Regulation(∆Vref(Iout))
10mA≤IOUT ≤5A, (VIN-VOUT)=3V, TJ=25ºC (Note 3)
0≤IOUT ≤5A, VIN=7V, TJ=25ºC (Note 2)
Dropout Voltage
∆VREF=1%
IOUT = 5A (Note 3)
IOUT < 5A (Note 2)
Current Limit
Iout(MAX)
VIN=7V
6
5.2
5.2
A
1.4V ≤ (VIN - VOUT) (Note3)
TA=125ºC, 1000 Hrs.
Long Term Stability
0.3
(Note 2)
0.01
1
1
%
%/W
%
Thermal Regulation
(∆Vout(Pwr))
TA=25ºC, 20 ms pulse
0.020
0.020
Temperature Stability
(∆Vout(T))
0.25
Output Noise, RMS
10Hz to 10kHz TA=25ºC
0.003
% Vo
ºC/W
Thermal Resistance
TO-220
Junction to Tab
3.0
60
3.0
60
Junction to Ambient
DD Package
Junction to Tab
3.0
60
3.0
60
Junction to Ambient
The Bold specifications apply to the full operating temperature range.
Note 1: Changes in output voltage due to heating effects are covered under the specification for thermal regulation.
Note 2: Fixed Version Only
Note 3: Adjustable Version Only
Date: 05/14/04
SPX1585
APPLICATION HINTS
Reducing parasitic resistance and inductance
The SPX1585 incorporates protection against over-current
faults, reversed load insertion, over temperature operation, and
positive and negative transient voltages. However, the use of an
output capacitor is required in order to insure the stability and
the performance of the device.
One solution to minimize parasitic resistance and inductance is
to connect in parallel capacitors. This arrangement will
improve the transient response of the power supply if your
system requires rapidly changing current load condition.
Stability
Thermal Consideration
The output capacitor is part of the regulator’s frequency
compensation system. Either a 22µF aluminum electrolytic
capacitor or a 10µF solid tantalum capacitor between the output
terminal and ground guarantees stable operation for all operat-
ing conditions. The recommended value for ESR is 0.5Ohms or
less.
Although the SPX1585 offers some limiting circuitry for
overload conditions, it is necessary not to exceed the maximum
junction temperature, and therefore to be careful about thermal
resistance. The heat flow will follow the lowest resistance path,
which is the Junction-to-case thermal resistance. In order to in-
sure the best thermal flow of the component, a proper mounting
is required. Note that the case of the device is electrically con-
nected to the output. If the case must be electrically isolated, a
thermally conductive spacer can be used. However do not for-
get to consider its contribution to thermal resistance.
However, in order to minimize overshoot and undershoot, and
therefore optimize the design, please refer to the section ‘Ripple
Rejection’.
Ripple Rejection
Assuming:
Ripple rejection can be improved by adding a capacitor between
the ADJ pin and ground. When ADJ pin bypassing is used, the
value of the output capacitor required increases to its maximum
(220µF for an aluminum electrolytic capacitor, or 47µF for a
solid tantalum capacitor). If the ADJ pin is not bypassed, the
value of the output capacitor can be lowered to 10µF for an elec-
trolytic aluminum capacitor or 4.7µF for a solid tantalum
capacitor.
V
IN = 10V, VOUT = 5V, IOUT = 1.5A, TA = 50°C/W,
θHeatsink Case= 6°C/W, θHeatsink Case = 0.5°C/W, θ JC = 3°C/W
Power dissipation under this condition
PD = (VIN – VOUT) * IOUT = 7.5W
Junction Temperature
TJ = TA + PD * (θCase – HS + θ HS θ JC
)
However the value of the ADJ-bypass capacitor should be
chosen with respect to the following equation:
For the Control Section
C = 1 / ( 6.28 * FR * R1 )
TJ = 50 + 7.5*(0.5 + 6=3) = 121.25°C
Where C
= value of the capacitor in Farads
121.25°C < TJ (max) for the Control & Power Sections.
(select an equal or larger standard value),
FR = ripple frequency in Hz,
In both conditions, reliable operation is insured by adequate
junction temperature.
R1 = value of resistor R1 in Ohms.
If an ADJ-bypass capacitor is used, the amplitude of the output
ripple will be independent of the output voltage. If an ADJ-
bypass capacitor is not used, the output ripple will be proportional
to the ratio of the output voltage to the reference voltage:
M = VOUT / VREF
Where M = multiplier for the ripple seen when the ADJ pin
is optimally bypassed.
VREF = Reference Voltage
Date: 05/14/04
SPX1585
Basic Adjustable Regulator
Load Regulation
Parasitic line resistance can degrade load regulation. In order
not to affect the behavior of the regulator, it is best to connect
directly the R1 resistance from the resistor divider to the case,
and not to the load. For the same reason, it is best to connect
the resistor R2 to the Negative side of the load.
VIN
VOUT
SPX1585
R1
VREF
ADJ
IADJ
50uA
R2
VOUT = VREF * ( 1 + R/R1) + IADJ * R
2
2
VIN
VOUT
5V
3.3V
SPX1585
C2
10uF
Fig.2 Basic Adjustable Regulator
C1
10uF
Output Voltage
Basic Fixed Regulator
Consider Figure 2. The resistance R1generates a constant
current flow, normally the specified load current of 10mA. This
current will go through the resistance R2 to set the overall output
voltage. The current IADJ is very small and constant. Therefore
its contribution to the overall output voltage is very small and
can generally be ignored.
Output Voltage
The fixed voltage LDO voltage regulators are simple to use
regulators since the VOUT is preset to the specifications. It is
important, however, to provide the proper output capacitance
for stability and improvement. For most operating conditions a
capacitance of 22uF tantalum or 100uF electrolytic will ensure
stability and prevent oscillation.
RP Parasitic Line
Resistance
VOUT
VIN
SPX1585
Connect R 1 to
Case of Regulator
ADJ
R1
RL
R2
Connect R 2 to Load
Fig.3 Basic Adjustable Regulator
Date: 05/14/04
SPX1585
TYPICAL APPLICATIONS
VIN
VOUT
VIN
OUT
IN
SPX1585
OUT
IN
SPX1585
C2
C1
C1
R1
ADJ
R1
ADJ
R2
VOUT = VREF (1 + R ) + IADJ R2
R21
LOAD
Fig. 5 Typical Adjustable Regulator
Fig. 4 5A Current output Regulator
(Note A)
VIN
5V
VIN
(Note A)
IN
SPX1585 OUT
ADJ
5V
IN
OUT
VOUT
SPX1585
+
10µF
121Ω
ADJ
R1
1%
+
121Ω
+
10µF
1k
1%
100µF
TTL
Input
150µF
2N3904
1k
*C1 improves ripple rejection. Xc
should be ~ R 1 at ripple frequency.
365Ω
R2
365Ω
1%
1%
+
C1
10µF*
Note A: VIN(MIN)= (Intended VOUT) + (VDROPOUT (MAX)
)
Note A: VIN(MIN)= (Intended VOUT) + (VDROPOUT (MAX)
)
Fig. 6 Improving Ripple Rejection
Fig.7 5V Regulator with Shutdown
Date: 05/14/04
SPX1585
TYPICAL CHARACTERISTICS
Date: 05/14/04
SPX1585
ORDERING INFORMATION
Ordering No.
SPX1585U
Precision
Output Voltage
Packages
2%
2%
2%
2%
Adj
3 Lead TO-220
3 Lead TO-220
3 Lead TO-220
3 Lead TO-220
1.5V
2.5V
3.3V
SPX1585U-1.5
SPX1585U-2.5
SPX1585U-3.3
1%
1%
1%
1%
Adj
3 Lead TO-220
3 Lead TO-220
3 Lead TO-220
3 Lead TO-220
SPX1585AU
1.5V
2.5V
3.3V
SPX1585AU-1.5
SPX1585AU-2.5
SPX1585AU-3.3
2%
2%
2%
2%
Adj
3 Lead TO-263
3 Lead TO-263
3 Lead TO-263
3 Lead TO-263
SPX1585T
1.5V
2.5V
3.3V
SPX1585T-1.5
SPX1585T-2.5
SPX1585T-3.3
1%
1%
1%
1%
Adj
3 Lead TO-263
3 Lead TO-263
3 Lead TO-263
3 Lead TO-263
SPX1585AT
1.5V
2.5V
3.3V
SPX1585AT-1.5
SPX1585AT-2.5
SPX1585AT-3.3
Available in Lead free packaging.
To order add "-L" suffix to the part number.
EXAMPLE: SPX1585U /ER = standard,
SPX1585U /ER-L = lead free.
Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Headquarters and Main Offices:
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 935-7600
FAX: (408) 934-7500
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described
hereing; neither does it convey any license under its patent rights nor the rights of others.
Date: 05/14/04
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