View FAN1581T_348802.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

www.fairchildsemi.com
FAN1581
5A Adjustable/Fixed Ultra Low Dropout Linear Regulator
Features
* * * * * * * * Ultra Low dropout voltage, 0.4V typical at 5A 1.2V Versions available for GTL termination Remote sense operation Fast transient response Load regulation: 0.05% typical 0.5% typical initial accuracy On-chip thermal limiting TO-263, TO-252 and TO-220 packages
Description
The FAN1581, FAN1581-1.2, FAN1581-1.5, and FAN15812.5 are ultra-low dropout regulators with 5A output current capability. These devices have been optimized for low voltage applications including VTT bus termination, where transient response and minimum input voltage are critical. The FAN1581 is ideal for low voltage microprocessor applications requiring a regulated output from 1.3V to 5.7V with a power input supply of 1.75V to 6.5V. The FAN1581-1.5 offers fixed 1.5V with 5A current capabilities for GTL+ bus VTT termination. Additionally, the FAN1581-1.2 offers fixed 1.2V output for CPU Bus termination. The FAN1581-2.5 offers fixed 2.5V with 5A current capability for logic IC operation and processors while minimizing the overall power dissipation. Current limit ensures controlled short-circuit current. On-chip thermal limiting provides protection against any combination of overload and ambient temperature that would create excessive junction temperatures. The FAN1581 series regulators are available in the 5-pin TO-263, TO-252 and TO-220 packages.
Applications
* * * * * * Support of GTL+ bus supply Low voltage logic supply Embedded Processor supplies Split plane regulator 2.5V, and 1.8V Logic Families DDR Termination Supply
Typical Applications
VIN = 3.3V + 10F VIN = 3.3V + 10F VCNTL = 5V + 1F VCNTL = 5V + 1F 2.1V at 5A + 124 22F VIN = 5.75V + 86.6 10F VCNTL = 12V + VIN = 3.3V + 10F VCNTL = 5V + 1F VIN VSENSE 1F VIN VSENSE VIN VSENSE FAN1581-2.5 VOUT VCNTL GND
2.5V at 5A + 22F
VIN
VSENSE
FAN1581 VOUT VCNTL Adj
FAN1581 VOUT VCNTL Adj 124 + 22F
5V at 5A
FAN1581-1.2 VOUT VCNTL Gnd
374 1.2V at 5A 22F
Pentium is a registered trademark of Intel Corporation. PowerPC is a trademark of IBM Corporation.
REV. 1.2.0 11/6/03
FAN1581
PRODUCT SPECIFICATION
Pin Assignments
FAN1581T FAN1581M-1.2, -1.5, -2.5 FRONT VIEW FAN1581M FRONT VIEW FAN1581D FRONT VIEW FAN1581D-1.2, -1.5, -2.5 FRONT VIEW FRONT VIEW
1 2 345
1 2 345
1
2
3
4
5
1
2
3
4
5
123
45
S GND OUT CNTL IN
S ADJ OUT CNTL IN
CNTL
CNTL
OUT
OUT
ADJ
GND
5-Lead Plastic TO-263 JC=3C/W* Tab is out.
5-Lead TO-220 JC=3C/W* Tab is VOUT.
5-Lead Plastic TO-252 DPAK JC=3C/W* Tab is out.
*With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane, JA can vary from 30 C/W to more than 40 C/W. Other mounting techniques can provide a thermal resistance lower than 30 C/W.
Pin Definitions
Pin Number
1
Pin Name VSense ADJ/GND VOUT VCNTL VIN
Pin Function Descrition Remote Voltage Sense. Connect this pin to the load to permit true remote sensing and avoid trace drops. Adjust or Ground. On the FAN1581, this pin forms the feedback to determine the output voltage. On the FAN1581-1.2, -1.5 and -2.5, connect this pin to ground. Output Voltage. This pin and the tab are output. Control Voltage. This pin draws small-signal power to control the FAN1581 circuitry. Connect to a voltage higher than VIN, as shown in the applications circuits. Input Voltage.
2
3 4 5
Internal Block Diagram
4 VCNTL, Control 5 Vin, Power
Thermal Shutdown Current Limit 3 Output 1 Sense 2 Adj
Vref
Voltage Loop Amplifier
2
REV. 1.2.0 11/6/03
CNTL IN
IN
IN
S ADJ OUT
S
S
PRODUCT SPECIFICATION
FAN1581
Absolute Maximum Ratings
Parameter VIN VCNTL Operating Junction Temperature Range Lead Temperature (Soldering, 10 sec.) Storage Temperature Range Min. Max. 7 13.2 125 300 150 Unit V V C C C
0 -65
Electrical Characteristics
TJ=25C, VOUT = VSENSE, VADJ = 0V unless otherwise specified. The * denotes specifications which apply over the specified operating temperature range. Parameter Reference Voltage3 Conditions 2.05V VIN 5.5V, 2.7V VCNTL 12V, 10mA IOUT 5A 3V VIN 7V (function of Vout), 10mA IOUT 5A 3V VIN 7V, 10mA IOUT 5A 4V VIN 7V, 10mA IOUT 5A 2.7V VIN 7V, 10mA IOUT 5A 1.75V VIN 5.5V, 2.5V VCNTL 12V, IOUT = 10mA VIN = 2.1V, VCNTL = 2.75V, 10mA IOUT 5A VIN = 2.05V, VREF = 1%, IOUT = 5A VCNTL = 2.75V, VREF = 1%, IOUT = 5A VCNTL = 2.75V, VREF = 1%, IOUT = 5A VIN = 2.05V, VCNTL = 2.75V VIN = 2.05V, VCNTL = 2.75V, IOUT = 10mA VIN = 2.05V, VCNTL = 2.75V VIN = 3.3V, VCNTL = 5V VIN = 3.75V, VCNTL = 3.75V, f = 120Hz, COUT = 22F Tantalum, IOUT = 2.5A TO-263 SPAK TA = 25C, 30ms pulse * Min. 1.237 Typ. 1.250 Max. 1.263 Units V
Adjustable Output Voltage Output Voltage4 Output Voltage5 Output Voltage6 Line Regulation1,2 Load Regulation1,2 Dropout Voltage Minimum (VCNTL-VOUT) Dropout Voltage Minimum (VIN-VOUT) Dropout Voltage Minimum VIN Current Limit Control Pin Current Adjust Pin Current3 Minimum Load Current Ripple Rejection Thermal Resistance, Junction to Case Thermal Regulation Thermal Shutdown
* * * * * * *
Vref 1.47 2.474 1.176
1.5 1.5 2.5 1.200 1 1 1.05 0.4
5.7 1.53 2.526 1.224 3 5 1.18 0.5 0.6
V V V V mV mV V V V A mA A mA dB C/W
* * * * * 60 5.2
0.5
3 50 5.0 80 3 2 0.002 150
6 120 10
0.02
%/W C
Notes: 1. See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are measured at a constant junction temperature by low duty cycle pulse testing. 2. Line and load regulation are guaranteed up to the maximum power dissipation (18W). Power dissipation is determined by input/output differential and the output current. Guaranteed maximum output power will not be available over the full input/ output voltage range. 3. FAN1581 only. 4. FAN1581-1.5 only. 5. FAN1581-2.5 only. 6. FAN1581-1.2 only.
REV. 1.2.0 11/6/03
3
FAN1581
PRODUCT SPECIFICATION
Typical Perfomance Characteristics
0.8 0.7 DROPOUT VOLTAGE (V) 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 1 2 3 4 5 6 OUTPUT CURRENT (A) Dropout Voltage vs. Output Current OUTPUT VOLTAGE DEVIATION (%) 0.10 0.05 0 -0.05 -0.10 -0.15 -0.20 -50 -25 0 25 50 75 100 125 JUNCTION TEMPERATURE (C) Load Regulation vs. Temperature 150 =5A
T=125C
T=25C
T=0C
1.30 REFERENCE VOLTAGE OUTPUT VOLTAGE (V) 1.28 1.26 1.24 1.22 1.20 -75 -50 -25
2.60 2.35 2.10 1.85 1.60 1.35 1.10 0 25 50 75 TJ (C) 100 125 150 175 -75 -50 -25 0 25 50 TJ (C) 75 100 125 150 175 1.5V 1.2V 2.5V
Reference Voltage vs. Temperature
Output Voltage vs. Temperature
MINIMUM LOAD CURRENT (mA)
10 ADJUST PIN CURRENT (A) -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (C) Mimimum Load Current vs. Temperature 8 6 4 2 0
70 60 50 40 30 20 10 0 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (C) Adjust Pin Current vs. Temperature
4
REV. 1.2.0 11/6/03
PRODUCT SPECIFICATION
FAN1581
Typical Perfomance Characteristics (continued)
3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (C) Control Pin Current vs. Temperature SHORT-CIRCUIT CURRENT (A) CONTROL PIN CURRENT (mA) 11
10mA Load
9
7
5
3 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (C) Short-Circuit Current vs.Temeperature
90 80 RIPPLE REJECTIONS (dB) 70 POWER (W) (VIN--VOUT) 3V 0.5V VRIPPLE 2V IOUT = 5A 10 100 1K 10K FREQUENCY (HZ) 100K 60 50 40 30 20 10 0
20
15
10
5
0 25 45 65 85 105 CASE TEMPERATURE 125
Ripple Rejection vs. Frequency
Maximum Power Dissipation
1.4 MAX. ACCEPTABLE ESR, OHM 1.2 1.0 0.8 0.6 0.4 0.2 0 0
1
2 3 LOAD CURRENT, A FAN1581 Stability
4
5
REV. 1.2.0 11/6/03
5
FAN1581
PRODUCT SPECIFICATION
General
The FAN1581, FAN1581-1.2, FAN1581-1.5, and FAN1581-2.5 are three-terminal regulators optimized for DDR and GTL+ VTT termination and logic applications. These devices are short-circuit protected, and offer thermal shutdown to turn off the regulator when the junction temperature exceeds about 150C. The FAN1581 series provides low dropout voltage and fast transient response. Frequency compensation uses capacitors with low ESR while still maintaining stability. This is critical in addressing the needs of low voltage high speed microprocessor buses like GTL+.
VIN and VCNTL Functions
The FAN1581 utilizes a dual supply approach to maximize efficiency. The collector of the power device is brought out to the VIN pin to minimize internal power dissipation under high current loads. VCNTL provides power for the control circuitry and the drive for the output NPN transistor. VCNTL should be at least 1.2 V higher than the output voltage. Special care was taken to ensure there are no supplysequencing problems. The output voltage will not turn on until both supplies are operating. If the control voltage comes up first, the output current will be typically limited to about 3.0 mA until the power input voltage comes up. If the power input voltage comes up first the output will not turn on at all until the control voltage comes up. The output can never come up unregulated. The FAN1581 can also be used as a single supply device with the control and power inputs tied together. In this mode, the dropout is determined by the minimum control voltage.
A protection diode between the input and output pins is usually not needed. An internal diode between the input and the output pins on the FAN1581 series can handle microsecond surge currents of 50A to 100A. Even with large value output capacitors it is difficult to obtain those values of surge currents in normal operation. Only with large values of output capacitance, such as 1000F to 5000F, and with the input pin instantaneously shorted to ground can damage occur. A crowbar circuit at the input can generate those levels of current; a diode from output to input is then recommended, as shown in Figure 1. Usually, normal power supply cycling or system "hot plugging and unplugging" will not generate current large enough to do any damage.
D1 1N4002 (OPTIONAL)
VOUT VIN + C1 10F
Vcntl Vin
Vsense + R1 Adj Vout VOUT C2 22F
FAN1581
+
CADJ
R2
D1 1N4002 (OPTIONAL)
VCNTL VIN + C1 10F
Vcntl Vin
Vsense + VOUT C2 22F Gnd Vout
FAN1581
Stability
The FAN1581 series requires an output capacitor as a part of the frequency compensation. It is recommended to use a 22F solid tantalum or a 100F aluminum electrolytic on the output to ensure stability. The frequency compensation of these devices optimizes the frequency response with low ESR capacitors. In general, it is suggested to use capacitors with an ESR of < 0.3. It is also recommended to use bypass capacitors such as a 22F tantalum or a 100F aluminum on the adjust pin of the FAN1581 for low ripple and fast transient response. When these bypassing capacitors are not used at the adjust pin, smaller values of output capacitors provide equally good results. A graph showing stability of output capacitance ESR vs load current can be found under Typical Performance Characteristics.
Figure 1. Optional Protection Diode
Ripple Rejection
In applications that require improved ripple rejection, a bypass capacitor from the adjust pin of the FAN1581 to ground reduces the output ripple by the ratio of VOUT/1.25V. The impedance of the adjust pin capacitor at the ripple frequency should be less than the value of R1 (typically in the range of 100 to 120) in the feedback divider network in Figure 1. Therefore, the value of the required adjust pin capacitor is a function of the input ripple frequency. For example, if R1 equals 100 and the ripple frequency equals 120Hz, the adjust pin capacitor should be 22F. At 10kHz, only 0.22F is needed.
Protection Diodes
In normal operation, the FAN1581 series does not require any protection diodes. For the FAN1581, internal resistors limit internal current paths on the adjust pin. Therefore, even with bypass capacitors on the adjust pin, no protection diode is needed to ensure device safety under short-circuit conditions.
Output Voltage
The FAN1581 regulator develops a 1.25V reference voltage between the output pin and the adjust pin (see Figure 2). Placing a resistor R1 between these two terminals causes a constant current to flow through R1 and down through R2 to set the overall output voltage. Normally, this current is the specified minimum load current of 10mA.
REV. 1.2.0 11/6/03
6
PRODUCT SPECIFICATION
FAN1581
The current out of the adjust pin adds to the current from R1 and is typically 50A. Its output voltage contribution is small and only needs consideration when a very precise output voltage setting is required.
Vcntl VIN + C1 10F IADJ 50A VOUT = VREF (1+R2/R1) + IADJ (R2) Vcntl Vsense VOUT VREF + R1 C2 22F
maximum junction temperature for both the control circuitry and the power transistor. Calculate the maximum junction temperature for both sections to ensure that both thermal limits are met. For example, look at using an FAN1581M-1.5 to generate 5A @ 1.5V 2% from a 3.3V source (3.2V to 3.6V). Assumptions: * * * * * Vin = 3.6V worst case VOUT = 1.47V worst case IOUT = 5A continuous TA = 40C Case-to-Ambient = 5C/W (assuming both a heatsink and a thermally conductive material)
FAN1581 Vin Adj Vout
R2
Figure 2. Basic Regulator Circuit
Load Regulation
The FAN1581 family provides true remote sensing, eliminating output voltage errors due to trace resistance. To utilize remote sensing, connect the VSENSE pin directly to the load, rather than at the VOUT pin. If the load is more than 1" away from the FAN1581, it may be necessary to increase the load capacitance to ensure stability.
The power dissipation in this application is: PD = (VIN - VOUT) * (IOUT) = (3.6-1.47) * (5) = 10.65W From the specification table, TJ = TA + (PD) * ( Case-to-Ambient + JC) = 40 + (10.65) * (5 + 3) = 125C The junction temperature is within the maximum rating. Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the die. This is the lowest resistance path for heat flow. Proper mounting ensures the best thermal flow from this area of the package to the heat sink. Use of a thermally conductive material at the case-to-heat sink interface is recommended. Use a thermally conductive spacer if the case of the device must be electrically isolated and include its contribution to the total thermal resistance.
Thermal Considerations
The FAN1581 series protect themselves under overload conditions with internal power and thermal limiting circuitry. However, for normal continuous load conditions, do not exceed maximum junction temperature ratings. It is important to consider all sources of thermal resistance from junction-toambient. These sources include the junction-to-case resistance, the case-to-heat sink interface resistance, and the heat sink resistance. Thermal resistance specifications have been developed to more accurately reflect device temperature and ensure safe operating temperatures. The electrical characteristics section provides a separate thermal resistance and
REV. 1.2.0 11/6/03
7
FAN1581
PRODUCT SPECIFICATION
U1 VIN = 3.3V 10F + C1 VIN VSENSE
FAN1581 VOUT VCNTL Adj 10F C3 R1 + 124 100F C2
2.1V at 5A
VCNTL = 5V 1F C4
R2
86.6
Figure 3. Application Circuit (FAN1581) Table 1. Bill of Materials for Application Circuit for the FAN1581
Item C1, C3 C2 C4 R1 R2 U1
Quantity 2 1 1 1 1 1
Manufacturer Xicon Xicon Any Generic Generic Fairchild
Part Number L10V10 L10V100
Description 10F, 10V Aluminum 100F, 10V Aluminum 1F Ceramic 124, 1% 86.6, 1%
FAN1581P
5A Regulator
U1 VIN = 2.5V 10F C1 VCNTL = 3.3V 1F C2 + VIN VSENSE
FAN1581-1.5 VOUT VCNTL GND
1.5V at 5A + 100F C3
Figure 4. Application Circuit (FAN1581-1.5) Table 2. Bill of Materials for Application Circuit for the FAN1581-1.5
Item C1 C2 C3 U1
Quantity 1 1 1 1
Manufacturer Xicon Any Xicon Fairchild
Part Number L10V10 L10V100 FAN1581P-1.5
Description 10F, 10V Aluminum 1F Ceramic 100F, 10V Aluminum 5A Regulator
8
REV. 1.2.0 11/6/03
PRODUCT SPECIFICATION
FAN1581
U1 VIN = 3.3V + 10F C1 VCNTL = 5V + 1F C2 VIN VSENSE
FAN1581-2.5 VOUT VCNTL GND
2.5V at 5A + 100F C3
Figure 5. Application Circuit (FAN1581-2.5) Table 3. Bill of Materials for Application Circuit for the FAN1581-2.5
Item C1 C2 C3 U1
Quantity 1 1 1 1
Manufacturer Xicon Any Xicon Fairchild
Part Number L10V10 L10V100 FAN1581P-2.5
Description 10F, 10V Aluminum 1F Ceramic 100F, 10V Aluminum 5A Regulator
REV. 1.2.0 11/6/03
9
PRODUCT SPECIFICATION
FAN1581
Mechanical Dimensions
5-Lead TO-263 Package
A 10.20 9.80 1.40 1.00
9.50 MIN
9.40 9.00
9.00 MIN
5.10 4.70 1 (1.28) 1.70 6.80 5 1.37 1.17 0.90 0.70 0.25
M
10.00
4.00 MIN
1.70 B AM 6.80
1.20 MIN
LAND PATTERN RECOMMENDATION
-B- (8.00) (4.40) R0.45 (1.75) 1.40 1.14 4.70 4.30
(0.90)
(6.80) SEE DETAIL A 15.60 15.00
5
1 NOTES: UNLESS OTHERWISE SPECIFIED A) ALL DIMENSIONS ARE IN MILLIMETERS. B) STANDARD LEAD FINISH: 200 MICROINCHES/ 5.08 MICROMETERS MIN. LEAD/TIN 15/85 ON COPPER. C) NO PACKAGE STANDARD REFERENCE AS OF JUNE 2002. D) DIMENSIONING AND TOLERANCING PER ANSI Y14.5M - 1982. 0.10 B 8 0
GAGE PLANE R0.56 0.75 0.45 0.25
SEATING PLANE
2.84 2.24
DETAIL A, ROTATED 90
SCALE: 10X
REV. 1.2.0 11/6/03
10
FAN1581
PRODUCT SPECIFICATION
Mechanical Dimensions (continued)
5-Lead TO-252 Package
A 6.80 6.35 5.64 5.04 6.00 MIN
1.27 0.50
6.56 MIN
6.30 5.90 1.02 0.60
6.25
3.00 MIN C 1 (0.44) 0.570.07 0.25 M A M C 1.27 LAND PATTERN RECOMMENDATION 5.08 B 2.40 2.18 (5.09) 0.60 0.40 2 3 4 5 1.27 0.690.15 1 1.27 1.00 3.81
(4.05) 10.42 9.20
SEE DETAIL A
3 5 4 2
1 0.10 B
GAGE PLANE
0.60 0.40
0.51 (1.54) NOTES: UNLESS OTHERWISE SPECIFIED A) ALL DIMENSIONS ARE IN MILLIMETERS. B) THIS PACKAGE CONFORMS TO JEDEC, TO-252, ISSUE C, VARIATION AA, DATED NOV. 1999. 0.13 MAX SEATING PLANE
10 0
1.78 1.40 (2.90)
DETAIL A
(ROTATED 90) SCALE: 2X
11
REV. 1.2.0 11/6/03
FAN1581
PRODUCT SPECIFICATION
Mechanical Dimensions (continued)
TO-220 Package
3.96 O 3.53 10.54 9.90 B 4.82 4.19 1.39 0.88
A
7 15.87 14.47
13.69 11.81 9.39 8.38
5
5
26.54 24.00
(1.30) 1.70 6.80
1.01 0.50 0.36 M B A L
0.635 0.304 2.92 2.15
3
3
NOTES: UNLESS OTHERWISE SPECIFIED A) B) C) D) STANDARD LEAD FINISH: 200 MICROINCHES / 5.08 MICROMETERS MIN. LEAD/TIN 15/85 ON COPPER. REFERENCE JEDEC, TS-001, ISSUE A, VARIATION AA, DATED AUGUST 1989 ALL DIMENSIONS ARE IN MILLIMETERS. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994.
12
REV. 1.2.0 11/6/03
FAN1581
PRODUCT SPECIFICATION
Ordering Information
Product Number FAN1581MX FAN1581DX FAN1581M12X FAN1581D15X FAN1581M25X FAN1581D25X FAN1581T Package TO-263 in Tape and Reel TO-252 DPAK in Tape and Reel TO-263 in Tape and Reel TO-252 DPAK in Tape and Reel TO-263 in Tape and Reel TO-252 DPAK in Tape and Reel TO-220 in Tape and Reel
DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user.
www.fairchildsemi.com 11/6/03 0.0m 002 Stock#DS30001581 2003 Fairchild Semiconductor Corporation
2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.

▲Up To Search▲

Price & Availability of FAN1581T

	To Download FAN1581T Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .