View SPX1587_132353.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

SPX1587
3A Low Dropout Voltage Regulator Adjustable & Fixed Output, 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
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
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 IQ of this device flows into the load, which 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.
PIN CONNECTIONS
TO-263-3 (T)
TO-220-3 (U)
TO-252 (R)
SPX1587
1 2 3
SPX1587
1 2 3
SPX1587
1 2 3
ADJ/GND VOUT VIN
ADJ/GND VOUT VIN
Front View
ADJ/GND VOUT VIN
Top View
Front View
Rev. 10/30/00
SPX1587
ABSOLUTE MAXIMUM RATINGS
Lead Temp. (Soldering, 10 Seconds) .............................. 300C Storage Temperature Range ............................ -65 to +150C Operating Junction Temperature Range ...................... SPX1587 Control Section.......................... -45C +125C SPX1587 Power Transistor.........................-45C +150C Maximum Input Voltage ...................................... 10V Input to Output Voltage Differential Max ........... 8.8V
ELECTRICAL CHARACTERISTICS (NOTE 1) at IOUT = 10mA, TA=25C, unless otherwise specified. SPX1587A PARAMETER CONDITIONS Typ
Min Max
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 (VREF) SPX1587-1.5V, 0 IOUT3A, 2.75VVIN 10V 1.5 1.5 2.5 2.5 3.3 3.3 5.0 5.0 1.485 1.470 2.475 2.450 3.270 3.240 4.95 4.90 1.238 1.225 1.515 1.530 2.525 2.550 3.330 3.360 5.05 5.10 1.263 1.270 10 0.2 0.2 0.3 0.3 1.2
SPX1587 Min Max
1.470 1.455 2.450 2.425 3.230 3.201 4.900 4.850 1.225 1.212 1.530 1.545 2.550 2.575 3.370 3.399 5.100 5.150 1.270 1.288 10 0.2 0.2 0.3 0.3 1.2
Units
V
SPX1587-2.5V, 0 IOUT3A, 4.0VVIN 10V
V
SPX1587-3.3V, 0 IOUT3A, 4.75VVIN 10V SPX1587-5.0V, 0 IOUT3A, 6.5VVIN 10V VIN 7V, P PMAX 1.5V (VIN -VOUT)(VIN-VOUT) MAX, 10mAIOUT3A 1.5V (VIN -VOUT) (VIN-VOUT) MAX 2.75VVIN 7V, IOUT=10mA, TJ=25C (Note 3) VIN 7V, IOUT=0mA, TJ=25C (Note 2) 10mAIOUT 3A, (VIN-VOUT)=3V, TJ=25C (Note 3) 0IOUT 3A, VIN=7V, TJ=25C (Note 2) IOUT =3A VREF=1% IOUT3A VIN=7V 1.4V (VIN- VOUT) (Note3) TA=125C, 1000 Hrs. TA=25C, 20 ms pulse
V
V
V
1.250 5 0.005 0.005 0.05 0.05 1.1
Min. Load Current (Note 3) Line Regulation (VREF (VIN))
mA % % % % V A
Load Regulation (VREF (IOUT))
Dropout Voltage Current Limit IOUT (MAX) Long Term Stability Thermal Regulation (VOUT (Pwr)) Temperature Stability (VOUT (T)) Output Noise, RMS Thermal Resistance
4.0 0.3 (Note 2) 0.01 0.25
3.2 1 0.020
3.2 1 0.020 % %/W % %V C/W
10Hz to 10kHz TA = 25c Junction to Tab TO-220 Junction to Ambient Junction to Tab DD Package Junction to Ambient
0.003 3.0 60 3.0 60 3.0 60 3.0 60
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
Rev. 10/30/00
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. Stability The output capacitor is part of the regulator's frequency compensation system. Either a 22F aluminum electrolytic capacitor or a 10F 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 (22F for an aluminum electrolytic capacitor, or 10F for a solid tantalum capacitor). If the ADJ pin is not bypass, the value of the output capacitor can be lowered to 10F for an electrolytic aluminum capacitor or 4.7F 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 * FR * R1) Where C = value of the capacitor in Farads (select an equal or larger standard value), FR = ripple frequency in Hz, R1 = value of resistor R1 in Ohms. 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 = VOUT / VREF Where M = multiplier for the ripple seen when the ADJ pin is optimally bypassed. VREF = Reference Voltage 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. 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: VIN = 10V, VOUT = 5V, IOUT = 1.5A, TA = 50C/W, Heatsink Case = 6C/W, Heatsink Case = 0.5C/W, JC = 3C/W Power dissipation under this condition PD = (VIN - VOUT) * IOUT = 7.5W Junction Temperature TJ = TA + PD * ( Case - HS+ HS + JC) For the Control Sections TJ = 50 + 7.5*(0.5 +6=3) = 121.25C 121.25C < TJ (max) for the Control & Power Sections. In both case reliable operation is insured by adequate junction temperature.
Rev. 10/30/00
SPX1587
Basic Adjustable Regulator
VIN
SPX1587
VREF IADJ
50A
VOUT R1
VIN 5V
SPX1587
C1 10uF
VOUT 3.3V C2 10uF
R2 VOUT = VREF * ( 1 + R /R1) + IADJ * R2 2
Basic Fixed Regulator
Fig.2 Basic Adjustable Regulator
Output Voltage Consider Figure 2. The resistance R1 generates 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. 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.
RP Parasitic Line Resistance
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.
VIN
SPX1587
Connect R to 1 Case of Regulator
R1
RL R2 Connect R to Load 2
Fig.3 Basic Adjustable Regulator
Rev. 10/30/00
SPX1587
TYPICAL APPLICATIONS
VIN C1
VIN IN
SPX1587
ADJ
OUT C1 R1
IN
SPX1587
ADJ
OUT R1 C2
VOUT
LOAD
VOUT = VREF (1 + R2 ) + IADJ R2 R1
R2
Fig. 4 3A Current output Regulator
Fig. 5 Typical Adjustable Regulator
(Note A) VIN
IN
5V
+ 10F
SPX1587
ADJ
OUT
VOUT
R1 121 1% 150F
VIN (Note A) +
IN
SPX1587
ADJ
OUT
5V 121 1% + 100F
10F 1k 2N3904 1k 365 1%
*C 1 improves ripple rejection. XC should be ~ R 1 at ripple frequency.
R2 365 1%
TTL Input
+
C1 10F*
Note A: V IN(MIN) = (Intended V OUT) + (VDROPOUT (MAX)) Note A: VIN(MIN)= (Intended V ) + (VDROPOUT (MAX)) OUT
Fig. 6
Improving Ripple Rejection
Fig.7 5V Regulator with Shutdown
Rev. 10/30/00
SPX1587
TYPICAL CHARACTERISTICS
Rev. 10/30/00
SPX1587
ORDERING INFORMATION Ordering No.
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
Precision
2% 2% 2% 2% 2% 1% 1% 1% 1% 1% 2% 2% 2% 2% 2% 1% 1% 1% 1% 1% 2% 2% 2% 2% 2% 1% 1% 1% 1% 1%
Output Voltage
Adj 1.5V 2.5V 3.3V 5.0V Adj 1.5V 2.5V 3.3V 5.0V Adj 1.5V 2.5V 3.3V 5.0V Adj 1.5V 2.5V 3.3V 5.0V Adj 1.5V 2.5V 3.3V 5.0V Adj 1.5V 2.5V 3.3V 5.0V
Packages
3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252
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.
Rev. 10/30/00

▲Up To Search▲

Price & Availability of SPX1587

	To Download SPX1587 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .