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SPX1587T

Datasheet SPX1587AR, SPX1587AR-1.5, SPX1587AR-2.5, SPX1587AR-3.3, SPX1587AT Datasheet (Sipex Corporation)

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Page 1
3A Low Dropout Voltage Regulator
Adjustable & Fixed Output,
SPX1587
Fast Response
FEATURES
Adjustable Output Down To 1.2V
•
Fixed Output Voltages 1.5, 2.5, 3.3, 5.0V
•
Output Current Of 3A
•
Low Dropout Voltage 1.1V Typ.
•
Extremely Tight Load And Line Regulation
•
Current & Thermal Limiting
•
Standard 3-Terminal Low Cost TO-220, TO-263 & TO-252
•
Similar To Industry Standard LT1085/LT1585
•
PRODUCT DESCRIPTION
The SPX1587 is a low power 3A adjustable and fixed voltage regulator that is very easy to use. It requires only 2 external resistors to set the output voltage for adjustable version. The SPX1587 are designed for low voltage applications that offers lower dropout voltage and faster transient response. This device is an excellent choice for use in powering low voltage microprocessor 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 applications. The SPX1587 features low dropout of a maximum 1.2 volts.
The SPX1587 offers over current limit and full protection against reversed input polarity, reversed load insertion, and positive and negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The I increases efficiency.
The SPX1587 are offered in a 3-pin TO-220, TO-263 & TO-252 packages compatible with other 3 terminal regulators. For a 5A low dropout regulator refer to the SPX1585 data sheet.
APPLICATIONS
Powering VGA & Sound Card
•
Power PC Supplies
•
SMPS Post-Regulator
•
High Efficiency “Green” Computer Systems
•
High Efficiency Linear Power Supplies
•
Portable Instrumentation
•
Constant Current Regulators
•
Adjustable Power Supplies
•
Battery charger
•
of this device flows into the load, which
Q
TO-263-3 (T)
ADJ/GND
PIN CONNECTIONS
TO-220-3 (U)
SPX1587
1
2
V
OUT
Top View
3
V
IN
SPX1587
ADJ/GND
Front View
1
23
V
OUT
TO-252 (R)
SPX1587
2
3
1
ADJ/GND VINV
V
IN
OUT
Front View
Rev. 10/30/00
Page 2
SPX1587
ABSOLUTE MAXIMUM RATINGS
Lead Temp. (Soldering, 10 Seconds) .............................. 300°C Maximum Input Voltage ...................................... 10V
Storage Temperature Range ............................ -65° to +150°C Input to Output Voltage Differential Max ........... 8.8V
Operating Junction Temperature Range ......................
SPX1587 Control Section.......................... -45°C +125°C
SPX1587 Power Transistor.........................-45°C +150°C
ELECTRICAL CHARACTERISTICS
PARAMETER
1.5V Version Output Voltage (Note 2)
2.5V Version
Output Voltage (Note 2)
3.3V Version
Output Voltage (Note 2)
5.0V Version Output Voltage (Note 2)
All Voltage Options Reference Voltage (V
Min. Load Current (Note 3)
Line Regulation (∆V
Load Regulation (∆V (I
))
OUT
Dropout Voltage
Current Limit I
OUT (MAX
Long Term Stability
Thermal Regulation (∆V Temperature Stability (∆V Output Noise, RMS
Thermal Resistance TO-220
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
OUT
OUT
)
(Pwr))
(T))
)
REF
REF (VIN
REF
SPX1587-1.5V, 0 ≤I
SPX1587-2.5V, 0 ≤I
SPX1587-3.3V, 0 ≤I
SPX1587-5.0V, 0 ≤I
V
7V, P≤ P
≤
IN
1.5V≤ (V 10mA≤I
1.5V≤ (V
)) 2.75V≤V
IN -VOUT
≤
OUT
IN -VOUT
≤
IN
(Note 3) V
7V, I
≤
IN
OUT
(Note 2) 10mA≤I
OUT
(Note 3) 0≤I
OUT
3A, V
≤
(Note 2)
=1% I
V
∆
REF
I
=7V
V
IN
1.4V≤ (VIN- V =125°C, 1000 Hrs.
T
A
=25°C, 20 ms pulse
T
A
0.25 %
10Hz to 10kHz T
DD Package
(NOTE 1) at I
CONDITIONS Typ
= 10mA, TA=25°C, unless otherwise specified.
OUT
SPX1587A
Min Max
3A, 2.75V≤V
≤
OUT
3A, 4.0V≤V
≤
OUT
3A, 4.75V≤V
≤
OUT
3A, 6.5V≤V
≤
OUT
MAX
)≤(VIN-V
3A
)≤ (VIN-V
7V, I
=10mA, TJ=25°C
OUT
=0mA, TJ=25°C
3A, (V
≤
IN-VOUT
=7V, TJ=25°C
IN
OUT
OUT
) (Note3)
OUT
= 25°c
A
Junction to Tab Junction to Ambient Junction to Tab Junction to Ambient
IN
IN
OUT) MAX
,
OUT) MAX
)=3V, TJ=25°C
=3A
3A
≤
IN
IN
≤
10V
≤
≤
10V
≤
10V
10V
1.5
1.5
2.5
2.5
3.3
3.3
5.0
5.0
1.250
5 10 10 mA
0.005 0.2 0.2 %
0.005 0.2 0.2 %
0.05 0.3 0.3 %
0.05 0.3 0.3 %
1.1 1.2 1.2 V
4.0
0.3
(Note 2)
0.01 0.020 0.020 %/W
0.003 %V
1.485
1.470
2.475
2.450
3.270
3.240
4.95
4.90
1.238
1.225
3.2 1 1 %
SPX1587
Min Max
1.515
1.530
2.525
2.550
3.330
3.360
5.05
5.10
1.263
1.270
3.0 60
3.0 60
1.470
1.455
2.450
2.425
3.230
3.201
4.900
4.850
1.225
1.212
3.2
Units
1.530
1.545
2.550
2.575
3.370
3.399
5.100
5.150
1.270
1.288
A
3.0 60
3.0 60
°
V
V
V
V
V
C/W
Rev. 10/30/00
Page 3
SPX1587
APPLICATION HINTS
The SPX1587 incorporates protection against over-current faults, reversed load insertion, over temperature operation, and positive and negative transient voltage. However, the use of an output capacitor is required in order to improve the stability and the performances.
Reducing parasitic resistance and inductance
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
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 operating conditions. However, in order to minimize overshoot and undershoot, and therefore optimize the design, please refer to the section ‘Ripple Rejection’.
Ripple Rejection
Ripple rejection can be improved by adding a capacitor between the ADJ pin and ground as shown in figure 6. When ADJ pin bypassing is used, the value of the output capacitor required increases to its maximum (22µF for an aluminum electrolytic capacitor, or 10µF for a solid tantalum capacitor). If the ADJ pin is not bypass, the value of the output capacitor can be lowered to 10µF for an electrolytic aluminum capacitor or 4.7µF for a solid tantalum capacitor. However the value of the ADJ-bypass capacitor should be chosen with respect to the following equation: C = 1 / (6.28 * F
* R1)
R
Where C = value of the capacitor in Farads (select an equal or larger standard value), F R
= ripple frequency in Hz,
R
= value of resistor R1 in Ohms.
1
If an ADJ-bypass capacitor is use, the amplitude of the output ripple will be independent of the output voltage. If an ADJ­bypass capacitor is not used, the output ripple will be proportional to the ratio of the output voltage to the reference voltage: M = V
OUT
/ V
REF
Where M = multiplier for the ripple seen when the ADJ pin is optimally bypassed. V
= Reference Voltage
REF
Thermal Consideration
Although the SPX1587 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 insure the best thermal flow of the component, a proper mounting is required. Note that the case of the device is electrically connected to the output. In case the case has to be electrically isolated, a thermally conductive spacer can be used. However do not forget to consider its contribution to thermal resistance.
Assuming: V
= 10V, V
IN
θ
Heatsink Case
= 5V, I
OUT
= 6°C/W, θ
= 1.5A, TA = 50°C/W,
OUT
Heatsink Case
= 0.5°C/W, θ JC = 3°C/W
Power dissipation under this condition P
= (VIN – V
D
OUT
) * I
= 7.5W
OUT
Junction Temperature T
= TA + PD * (θ
J
Case - HS
+ θ
+ θ JC)
HS
For the Control Sections T
= 50 + 7.5*(0.5 +6=3) = 121.25°C
J
121.25°C < T
for the Control & Power Sections.
J (max)
In both case reliable operation is insured by adequate junction temperature.
Rev. 10/30/00
Page 4
SPX1587
Basic Adjustable Regulator
V
IN
SPX1587
I
ADJ
50µA
V
REF
V
= V
OUT
* ( 1 + R2/R1) + I
REF
ADJ
* R
2
V
OUT
R
1
R
2
Fig.2 Basic Adjustable Regulator
Output Voltage
Consider Figure 2. The resistance R
generates a constant
1
current flow, normally the specified load current of 10mA. This current will go through the resistance R output voltage. The current I
is very small and constant.
ADJ
to set the overall
2
Therefore its contribution to the overall output voltage is very small and can generally be ignored.
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 R
resistance from the resistor divider to the case,
1
and not to the load. For the same reason, it is best to connect the resistor R
to the Negative side of the load.
2
RP Parasitic Line
V
IN
SPX1587
Resistance
Connect R1 to Case of Regulator
R
1
R
2
Connect R2 to Load
Fig.3 Basic Adjustable Regulator
R
L
V
IN
5V
SPX1587
C1
10uF
Basic Fixed Regulator
Output Voltage
The fixed voltage LDO voltage regulators are simple to use regulators since the V
is preset to the specifications. It is
OUT
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.
V
3.3V
C2
10uF
OUT
Rev. 10/30/00
Page 5
SPX1587
TYPICAL APPLICATIONS
V
IN
(Note A)
V
IN
*C1 improves ripple rejection.
should be ~ R
Note A: V
IN(MIN)
IN
C
1
SPX1587
ADJ
OUT
Fig. 4 3A Current output Regulator
IN OUT
OUT
SPX1587
X
C
) + (V
DROPOUT (MAX)
ADJ
R
365Ω
1%
)
+
10µF
at ripple frequency.
1
= (Intended V
Fig. 6 Improving Ripple Rejection
R
1
LOAD
5V
R
1
121Ω
1%
2
+
C
1
10µF*
V
OUT
150µF
V
IN
V
OUT
= V
IN
C
1
(1 + R2 ) + I
REF
R
1
SPX1587
ADJ
ADJ R2
OUT
R
1
R
2
V
OUT
C
2
Fig. 5 Typical Adjustable Regulator
V
IN
(Note A)
TTL
Input
Note A: V
+
IN OUT
SPX1587
10µF
1k
1k
= (Intended V
IN(MIN)
ADJ
2N3904
OUT
) + (V
121Ω
1%
365Ω
1%
DROPOUT (MAX)
5V
+
100µF
)
Fig.7 5V Regulator with Shutdown
Rev. 10/30/00
Page 6
SPX1587
TYPICAL CHARACTERISTICS
Rev. 10/30/00
Page 7
SPX1587
ORDERING INFORMATION
Ordering No. Precision Output Voltage Packages
SPX1587T SPX1587T-1.5 SPX1587T-2.5 SPX1587T-3.3 SPX1587T-5.0 SPX1587AT SPX1587AT-1.5 SPX1587AT-2.5 SPX1587AT-3.3 SPX1587AT-5.0 SPX1587U SPX1587U-1.5 SPX1587U-2.5 SPX1587U-3.3 SPX1587U-5.0 SPX1587AU SPX1587AU-1.5 SPX1587AU-2.5 SPX1587AU-3.3 SPX1587AU-5.0 SPX1587R SPX1587R-1.5 SPX1587R-2.5 SPX1587R-3.3 SPX1587R-5.0 SPX1587AR SPX1587AR-1.5 SPX1587AR-2.5 SPX1587AR-3.3 SPX1587AR-5.0
2% Adj 3 Lead TO-263 2% 1.5V 3 Lead TO-263 2% 2.5V 3 Lead TO-263 2% 3.3V 3 Lead TO-263 2% 5.0V 3 Lead TO-263 1% Adj 3 Lead TO-263 1% 1.5V 3 Lead TO-263 1% 2.5V 3 Lead TO-263 1% 3.3V 3 Lead TO-263 1% 5.0V 3 Lead TO-263 2% Adj 3 Lead TO-220 2% 1.5V 3 Lead TO-220 2% 2.5V 3 Lead TO-220 2% 3.3V 3 Lead TO-220 2% 5.0V 3 Lead TO-220 1% Adj 3 Lead TO-220 1% 1.5V 3 Lead TO-220 1% 2.5V 3 Lead TO-220 1% 3.3V 3 Lead TO-220 1% 5.0V 3 Lead TO-220 2% Adj 3 Lead TO-252 2% 1.5V 3 Lead TO-252 2% 2.5V 3 Lead TO-252 2% 3.3V 3 Lead TO-252 2% 5.0V 3 Lead TO-252 1% Adj 3 Lead TO-252 1% 1.5V 3 Lead TO-252 1% 2.5V 3 Lead TO-252 1% 3.3V 3 Lead TO-252 1% 5.0V 3 Lead TO-252
SIGNAL PROCESSING EXCELLENCE
Corporation
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.
Rev. 10/30/00
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