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FAN1582
3A Adjustable/Fixed Ultra Low Dropout Linear Regulator
Features
• • • • • • • Ultra Low dropout voltage, 0.4V typical at 3A Remote sense operation Fast transient response Load regulation: 0.05% typical 0.5% initial accuracy On-chip thermal limiting 5-Pin TO-252 DPAK, and TO-263 packages
Description
The FAN1582, FAN1582-1.5, and FAN1582-2.5 are ultra-low dropout regulators with 3A 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 FAN1582 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 FAN1582-1.5 offers fixed 1.5V with 3A current capabilities for GTL+ bus VTT termination. The FAN1582-2.5 offers fixed 2.5V with 3A 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 FAN1582 series regulators are available in the 5-Pin TO-252 DPAK, and TO-263 power 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 10µF VIN = 3.3V 10µF VCNTL = 5V + VIN VSENSE VCNTL = 5V 1µF 2.1V at 3A 124Ω 86.6Ω + 22µF VIN = 5.75V 10µF VCNTL = 12V + VIN VSENSE + + VIN VSENSE FAN1582–2.5 VOUT VCNTL GND
2.5V at 3A + 22µF
FAN1582 VOUT VCNTL Adj
FAN1582 VOUT VCNTL Adj 124Ω 374Ω + 22µF
5V at 3A
Pentium is a registered trademark of Intel Corporation. PowerPC is a trademark of IBM Corporation.
REV. 1.1.3 11/9/03
FAN1582
PRODUCT SPECIFICATION
Pin Assignments
FAN1582M-1.5, -2.5 FRONT VIEW FAN1582M FRONT VIEW FAN1582D FRONT VIEW FAN1582D-1.5, -2.5 FRONT VIEW
1 2 345
1 2 345
1
2
3
4
5
1
2
3
4
5
S GND OUT CNTL IN
S ADJ OUT CNTL IN
ADJ
S
IN
S
GND
OUT
CNTL
OUT
5-Lead Plastic TO-263 ΘJC=3°C/W* Tab is out.
5-Lead Plastic TO-252 DPAK ΘJC=3°C/W* Tab is out.
*With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane, θJA 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
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 FAN1582, this pin forms the feedback to determine the output voltage. On the FAN1582-1.5 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 FAN1582 circuitry. Connect to a voltage higher than VIN, as shown in the applications circuits. Input Voltage.
2
3 4
VOUT VCNTL
5
VIN
Internal Block Diagram
4 VCNTL, Control 5 Vin, Power
Thermal Shutdown Current Limit 3 Output 1 Sense 2 Adj
Vref
Voltage Loop Amplifier
2
CNTL
IN
REV. 1.1.3 11/9/03
PRODUCT SPECIFICATION
FAN1582
Absolute Maximum Ratings
Parameter VIN VCNTL Operating Junction Temperature Range Lead Temperature (Soldering, 10 sec.) Storage Temperature Range -65 0 Min. Max. 7 13.2 125 300 150 Unit V V °C °C °C
Electrical Characteristics
TJ=25°C, VOUT = VS, VADJ = 0V unless otherwise specified. The • denotes specifications which apply over the specified operating temperature range. Parameter Reference Voltage3 Reference Voltage3 Conditions VIN = 2.0V, VCNTL = 2.75V, IOUT = 10mA 2.05V ≤ VIN ≤ 5.5V, 2.7V ≤ VCNTL ≤ 12V, 10mA ≤ IOUT ≤ 3A 3V ≤ VIN ≤ 7V (function of Vout), 10mA ≤ IOUT ≤ 3A 3V ≤ VIN ≤ 7V, 10mA ≤ IOUT ≤ 3A 5.1V ≤ VIN ≤ 7V, 10mA ≤ IOUT ≤ 3A 1.75V ≤ VIN ≤ 5.5V, 2.5V ≤ VCNTL ≤ 12V, IOUT = 10mA VIN = 2.1V, VCNTL = 2.75V, 10mA ≤ IOUT ≤ 3A VIN = 2.05V, ∆VREF = 1%, IOUT = 3A VCNTL = 2.75V, ∆VREF = 1%, IOUT = 3A VCNTL = 2.75V, ∆VREF = 1%, IOUT = 3A 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 = 22µF Tantalum, IOUT = 1.5A TO-263/TO-252 SPAK TA = 25°C, 30ms pulse Min. 1.243 • 1.237 Typ. 1.250 1.250 Max. 1.257 1.263 Units V V
Adjustable Output Voltage Output Voltage4 Output Voltage5 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
1.5 1.5 2.5 1 1 1.05 0.4
5.7 1.53 2.526 3 5 1.18 0.5 0.6
V V V mV mV V V V A mA µA mA dB °C/W
• • • • • 60 3.1
0.5
2 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. FAN1582 only. 4. FAN1582-1.5 only. 5. FAN1582-2.5 only.
REV. 1.1.3 11/9/03
3
FAN1582
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 4 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 ∆Ι=3A
T=125°C T=25°C T=0°C
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 2.5V
Reference Voltage vs. Temperature
Output Voltage vs. Temperature
MINIMUM LOAD CURRENT (mA)
10 ADJUST PIN CURRENT (µA) -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. 1.1.3 11/9/03
PRODUCT SPECIFICATION
FAN1582
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 LOAD CURRENT, A FAN1582 Stability
3
REV. 1.1.3 11/9/03
5
FAN1582
PRODUCT SPECIFICATION
General
The FAN1582, FAN1582-1.5, and FAN1582-2.5 are threeterminal regulators optimized for 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 150°C. The FAN1582 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+.
output pins on the FAN1582 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 1000µF to 5000µF, 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)
VIN and VCNTL Functions
The FAN1582 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 FAN1582 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.
VOUT VIN + C1 10µF
Vcntl Vin
Vsense + R1 Adj Vout VOUT C2 22µF
FAN1582
+
CADJ
R2
D1 1N4002 (OPTIONAL)
VCNTL VIN + C1 10µF
Vcntl Vin
Vsense + VOUT C2 22µF Gnd Vout
FAN1582–1.5, 2.5
Stability
The FAN1582 series requires an output capacitor as a part of the frequency compensation. It is recommended to use a 22µF solid tantalum or a 100µF 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