SPX1581U-L [SIPEX]
Adjustable Positive LDO Regulator, 1.2V Min, 0.5V Dropout, PSFM3, TO-220, 3 PIN;
| 型号： | SPX1581U-L |
| 厂家： | 
SIPEX CORPORATION |
| 描述： | Adjustable Positive LDO Regulator, 1.2V Min, 0.5V Dropout, PSFM3, TO-220, 3 PIN 局域网 输出元件 调节器 |
| 文件： | 总5页 (文件大小：174K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SPX1581
5A Ultra Low Dropout Voltage Regulator
Fast Response, Adjustable & Fixed
FEATURES
APPLICATIONS
• Low Dropout Voltage 500mV at 5A Full Load Current
• Adjustable Output Down to 1.2V from ATX Power Supply
• Fixed Output Voltages of 3.3V, 2.8V & 2.5V
• Extremely Tight Voltage and Line Regulation
• Standard 5-Terminal Low Cost TO-220 & TO-263
• 3.3V to 2.8V ATX Power Supplies
• 3.3V to 2.9V for Portable PENTIUM Processor
• 5V to 3.5V VRE Supply
• High Efficiency “Green” Computer Systems
PRODUCT DESCRIPTION
The SPX1581 is a 5A Low Dropout Regulator with extremely low dropout voltage. The adjustable version requires only two external
resistors to set the output voltage. The fixed version has a preset output of 3.3V, 2.8V or 2.5V and does not require any external
resistors. The SPX1581 features a low dropout of less than 400mV(typ.) and offers fast transient response. This device is suitable
for Pentium applications requiring 2.8V or 2.5V from 3.3V ATX power supplies, where a low current input voltage 1V greater
than the output voltage is needed. With an external sense pin the load regulation is less than 1mV. This device is an excellent choice
for the use in powering low voltage microprocessors that require a lower dropout, fast transient response to regulate from 3.3V and 5V
supplies. The SPX1581 is also an excellent choice as a post regulator for switching supplies applications.
The SPX1581 offers full protection against over-current faults, reversed input polarity, over temperature operation and positive and
negative transient voltage.
The SPX1581 is offered in a 5 pin TO-220 and TO-263 compatible with industry standard 5-terminal regulators. For 7A, 3A and 1.5A
ultra low dropout versions refer to SPX1580, SPX1582 and SPX1583 data sheets respectively.
PIN CONNECTIONS
TO-220-5 (U)
TO-263-5 (T)
SPX1581
1. SENSE
2. ADJ or FIXED
3. VOUT
4. VCTRL
5. VIN
1. SENSE
2. ADJ or FIXED
3. VOUT
SPX1581
1
2
3
4
5
1
2
4
3 5
4. VCTRL
5. VIN
Top View
Front View
Date: 5/14/04
SPX1581
ABSOLUTE MAXIMUM RATINGS
Power Dissipation.................................................... Internally Limited Input Supply Voltage ..........................................................6V
VCTRL Input Voltage ..........................................................13V
Lead Temp (soldering, 10 seconds)........................................... 300°C
Storage Temperature Range ...................................... -65ºC to +150ºC
Operating Junction Temperature Range
SPX1581 Control Section .............................................0ºC to +125ºC
SPX1581 Power Transistor .......................................... 0ºC to +150ºC
ELECTRICAL CHARACTERISTICS at VS =14V, Ta=25°C, Io=10mA, C2=100µF, unless otherwise specified. (Note 1)
(Boldface applies over full temperature range).
Parameters
Conditions
SPX1581
Typ
Units
Min
Max
2.5V Version
Output Voltage
VCTRL=6.0V to 12V, VIN=3.0V to 5.0V, IO=10mA
2.450
2.400
2.500
2.550
2.600
V
IO=10mA to
5A
2.8V Version
Output Voltage
VCTRL=6.3V to 12V, VIN=3.3V to 12V, IO=10mA
IO=10mA to 5A
2.744
2.800
3.300
2.856
V
V
2.688
2.912
3.3V Version
Output Voltage
VCTRL=6.3V to 12V, VIN=3.3V to 12V, IO=10mA
IO=10mA to 5A
3.234
3.168
3.366
3.462
All Voltage Options
Reference Voltage
VCTRL=2.75V, VIN=2.00V, IO=10mA
1.238
1.250
1.263
V
V
CTRL=2.7V to 12V, VIN=2.05V to 5.5V, IO=10mA to
5A
Line Regulation
VCTRL=2.5V to 12V, VIN=1.75V to 5.5V, IO=10mA
VADJ=0V
mV
mV
1.0
1.0
3.0
5.0
Load Regulation (Note1)
VCTRL=2.75V, VIN=2.1V, IO=10mA to 5A,VADJ=0V
Dropout Voltage Minimum VCTRL(Note2)
VADJ=0V
V
V
A
1.10
1.25
(VCTRL – VOUT
)
V
IN=2.05V, IO=1A
VADJ=0V
IN=2.75V, IO=5A
Dropout Voltage Minimum VIN(Note2)
0.40
0.50
(VIN - VOUT
)
V
Current Limit
VCTRL=2.75V, VIN=2.05V,dVO=100mV,VADJ=0V
5.1
Minimum Load Current
Thermal Regulation
Ripple Rejection
VCTRL=5V, VIN=3.3V,VADJ=0V
30ms Pulse
mA
%W
dB
5
10
0.002
80
0.02
VCTRL=3.75V VIN=3.75V, IO=2.5A,VADJ=0V
TJ=25, VRIPPLE=1Vpp at 120Hz
VADJ=0V
60
Control Pin Current
Adjustable Pin Current
Thermal Resistance
60
120
120
V
CTRL =2.75V, VIN=2.05V, IO=5A
mA
µA
VCTRL=2.75V, VIN=2.05V,VADJ=0V IO=10mA
50
TO-220-5
TO-263-5
3
50
3
Junction to Case (θJC
Junction to Ambient (θJA
Junction to Case (θJC
Junction to Ambient (θJA
)
°C/W
°C/W
°C/W
°C/W
)
)
60
)
The Bold specifications applying to the over full operating temperature range.
Note 1: Low duty cycle pulse testing with Kelvin connections are required to order to maintain accurate data.
Note 2: Dropout voltage is defined as the minimum differential between VIN and VOUT or VCTRL and VOUT required to maintain regulation at VOUT
99% Nominal VOUT.
Note 3: VREF is measured across the Adjust pin to Sense pin.
Date: 5/14/04
SPX1581
PIN DESCRIPTION
1. Sense = Allows Kelvin sense of VOUT at the load. (Positive side of the reference voltage of the
device).
2. ADJ = Negative side of the reference voltage for the device. Adding a small bypass capacitor
from the ADJ pin to ground will improve the transient response.
3.
4.
V
V
OUT = Power output of the device.
CTRL = Supply pin for the control circuitry of the device. The current flow into this pin will be
about 1% of the output current. VCTRL must be between 1.0V and 1.3V greater than the output
voltage for the device to regulate.
5. VIN = Output load current is supplied through this pin. VIN must be between 0.1V and 0.8V
greater than the output voltage for the device to regulate.
BLOCK DIAGRAM
(4) VCTRL
VIN (5)
S.O.A
CURRENT
LIMIT
LIMIT
AMPLIFIER
VOUT (3)
SENSE (1)
ADJ (2)
SENSE
THERMAL OVERLOAD
VOLTAGE
REGULATION
AMPLIFIER
VREF
APPLICATIONS NOTES
The SPX1581 is designed as a high performance and low cost
solution for application requiring a lower dropout than
traditional NPN regulators.
Adjustable Regulator Design
1.25V reference voltage is being developed between the
SENSE pin and the ADJ pin of the SPX1581. Adding two
external resistors (see fig 1.) will allow setting the output
voltage from 1.25V to 6V. R1 is chosen so that this current is
specified minimum load current of 10mA. R2 is given by the
formula: VOUT = VREF (1+ R2/R1) + IADJ (R2). The current
flowing from the ADJ pin is typically 50µA. This ADJ pin
contributes to the final VOUT but is usually neglected.
Connecting the sense pin to the top of the resistor divider will
improve load regulation.
The SPX1581 uses a separate input voltage VCTRL (VCTRL
≥
V
OUT+ 1.3V) to minimize the dropout voltage. This allows the
2.5V power for the load to come from a 3.3V system supply.
As added benefit this will reduce the heat dissipation, and
lower heatsink and cooling fan cost. A typical application
would use 5V for Vin and 3.3V for VCTRL from a motherboard
power supply to provide a nominal 2.5V output. Using the
sense pin allows to Kelvin measure the output, reducing
resistive-associated errors.
The SPX1581 can power the 2.5V core voltage for
microprocessors such as Pentium, P55C, AMD5k86
and K6 and the IBM PowerPC 603EV and 604EV
processors.
Lowering Noise
Using the SENSE pin to Kelvin the load will increase accuracy
of the output voltage during load regulation. For the fixed
voltage devices, adding a capacitor at the GND pin will
improve transient response. This capacitor is chosen in the
range of 1µF to 0.1µF and will depend on the amount of
output capacitance in the system.
*The reduction of heat dissipation is a result of the increase of the regulator
efficiency (efficiency = VOUT / VIN).
Date: 5/14/04
SPX1581
TYPICAL APPLICATION
Fig. 1 Adjustable Regulator
3.3V
VIN
VIN
VOUT
2.5V
VOUT
C1
SPX1581
330uF
5V
VCTRL
VCTRL
SENSE
R1
124
Ω
Ω
ADJ
C2
10uF
C4
2 X 330uF
R2
124
C3
.033uF
(1) VCTRL needed when VIN < 5V.
(2) VOUT = VREF (1 + R2/ R1) + I ADJ R2.
(3) VREF is measured across adjust to sense.
Fig.2 Typical Fixed Regulator
3.3V
VIN
VOUT
2.5V
VOUT
V
IN
SPX1581
C1
330uF
5V
VCTRL
VCTRL
SENSE
GND
C2
10uF
C4
2 X 330uF
(1) VCTRL is needed when V <5V.
IN
Date: 5/14/04
SPX1581
ORDERING INFORMATION
Ordering No.
SPX1581U
Precision
0.6%
Output Voltages
Packages
5 Lead TO-220
5 Lead TO-220
5 Lead TO-220
5 Lead TO-220
5 Lead TO-263
5 Lead TO-263
5 Lead TO-263
5 Lead TO-263
Adj
2.5V
2.8V
3.3V
Adj
0.6%
SPX1581U-2.5
SPX1581U-2.8
SPX1581U-3.3
SPX1581T
0.6%
0.6%
0.6%
0.6%
2.5V
2.8V
3.3V
SPX1581T-2.5
SPX1581T-2.8
SPX1581T-3.3
0.6%
0.6%
Corporation
ANALOG EXCELLENCE
Sipex Corporation
Headquarters and Main Offices:
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: 5/14/04
相关型号：
SPX1581U5-2.5-L
Fixed Positive LDO Regulator, 2.5V, 0.5V Dropout, PSFM5, LEAD FREE, TO-220, 5 PIN
EXAR
SPX1581U5-2.8-L
Fixed Positive LDO Regulator, 2.8V, 0.5V Dropout, PSFM5, LEAD FREE, TO-220, 5 PIN
SIPEX
©2020 ICPDF网 联系我们和版权申明