www.fairchildsemi.com FAN1587A 3A Adjustable/Fixed Low Dropout Linear Regulator Features Description • • • • • • The FAN1587A, FAN1587A-1.5, and FAN1587A-3.3 are low dropout three-terminal 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 FAN1587A is ideal for low voltage microprocessor applications requiring a regulated output from 1.5V to 3.6V with an input supply of 12V or less. The FAN1587A-1.5 offers fixed 1.5V with 3A current capability for GTL+ bus VTT termination. The FAN1587A-3.3 offers fixed 3.3V current capability for logic IC operation. Fast transient response Low dropout voltage at up to 3A Load regulation: 0.05% typical Trimmed current limit On-chip thermal limiting Standard TO-220, TO-263, TO-263 center cut, and TO-252 packages Applications • • • • • Pentium® Class GTL+ bus supply Low voltage logic supply Post regulator for switching supply 12V to 5V linear regulator 3.3V to 1.5V linear regulator Current limit is trimmed to ensure specified output current and 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 FAN1587A, FAN1587A-1.5, and FAN1587A-3.3 are available in the industry-standard TO-220, TO-263, TO-263 center cut, and TO-252 (DPAK) power packages. Typical Applications FAN1587A VIN VOUT VIN = 12V 22µF + 9V at 3A + ADJ R1 124Ω VOUT = VREF (1+R2/R1)+IADJ*R2 22µF R2 768Ω FAN1587A-3.3 VIN VIN = 9V + 22µF VOUT GND 3.3V at 3A + 22µF 65-1587-16 Pentium is a registered trademark of Intel Corporation. REV. 1.0.5 11/10/03 FAN1587A PRODUCT SPECIFICATION Pin Assignments FAN1587AM-1.5 FAN1587AM FRONT VIEW FRONT VIEW 2 3 1 GND OUT IN 2 FAN1587AT-1.5, -3.3V FRONT VIEW FRONT VIEW Tab is Out. Tab is Out. 1 FAN1587AT 1 2 1 3 2 3 3 ADJ OUT IN ADJ OUT IN GND OUT IN 3-Lead Plastic TO-220 θJC = 3°C/W 3-Lead Plastic TO-263 θJC = 3°C/W* FAN1587AMC-1.5, 3.3 FAN1587AMC FAN1587AD-1.5, 3.3 FAN1587AD FRONT VIEW FRONT VIEW FRONT VIEW FRONT VIEW Tab is Out. Tab is Out. 1 2 3 1 2 1 IN ADJ 3 1 IN ADJ 2 3 3 GND GND 2 IN IN 3-Lead Plastic TO-252 θJC = 3°C/W* 3-Lead Plastic TO-263 Center Cut θJC = 3°C/W* * 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. 2 REV. 1.0.5 11/10/03 PRODUCT SPECIFICATION FAN1587A Absolute Maximum Ratings Parameter Min. Max. Unit 18 V VIN (VIN – VOUT) * IOUT See Figure 1 Operating Junction Temperature Range Storage Temperature Range 0 125 °C -65 150 °C 300 °C Lead Temperature (Soldering, 10 sec.) IOUT (Amps) 4 3 2 1 0 0 2 4 6 8 10 12 14 VIN–VOUT (V) Figure 1. Absolute Maximum Safe Operating Area REV. 1.0.5 11/10/03 3 PRODUCT SPECIFICATION FAN1587A Electrical Characteristics Tj = 25°C unless otherwise specified. The • denotes specifications which apply over the specified operating temperature range. Parameter Conditions Min. Typ. Max Units 1.5V ≤ (VIN – VOUT) ≤ 8.25V, 10mA ≤ IOUT ≤ 3A • 1.225 (-2%) 1.250 1.275 (+2%) V Output Voltage4, 6 3.0V ≤ VIN ≤ 8.5V 10mA ≤ IOUT ≤ 3A • 1.47 1.5 1.53 V Output Voltage5, 6 4.8V ≤ VIN ≤ 10.3V 10mA ≤ IOUT ≤ 3A • 3.234 3.3 3.366 V Line Regulation1, 2 (VOUT + 1.5V) ≤ VIN ≤ 12V, IOUT = 10mA • 0.005 0.2 % Load Regulation1, 2 (VIN – VOUT) = 3V 10mA ≤ IOUT ≤ 3A • 0.05 0.5 % Dropout Voltage ∆VREF = 1%, IOUT = 3A • 1.150 1.300 Current Limit (VIN – VOUT) = 2V • Reference Voltage3 4 V A • 35 120 µA 1.5V ≤ (VIN – VOUT) ≤ 12V, 10mA ≤ IOUT ≤ 3A • 0.2 5 µA 4 13 Adjust Pin Current3 Adjust Pin Current Change3, 6 3.1 Minimum Load Current 1.5V ≤ (VIN – VOUT) ≤ 12V • Quiescent Current VIN = 5V • Ripple Rejection f = 120Hz, COUT = 22µF Tantalum, (VIN – VOUT) = 3V, IOUT = 3A Thermal Regulation TA = 25°C, 30ms pulse 60 mA 72 0.004 • Temperature Stability 10 mA dB 0.02 0.5 %/W % Long-Term Stability TA = 125°C, 1000 hrs. 0.03 RMS Output Noise (% of VOUT) TA = 25°C, 10Hz ≤ f ≤ 10kHz 0.003 % Thermal Resistance, Junction to Case TO-220 3 °C/W 3 °C/W 150 °C Thermal Shutdown TO-263, TO-252 1.0 % 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 currrent. Guaranteed maximum output power will not be available over the full input/ output voltage range. 3. FAN1587A only. 4. FAN1587A-1.5 only. 5. FAN1587A-3.3 only. 6. Output current must be limited to meet the absolute maximum ratings of the part. REV. 1.0.5 11/10/03 4 FAN1587A PRODUCT SPECIFICATION Typical Performance Characteristics 0.10 1.2 1.1 T=0°C 0.9 T=125°C T=25°C 0.8 0.7 0.6 0.5 0 0.5 1 1.5 2 2.5 0.05 0 -0.05 -0.10 -0.15 -0.20 -75 -50 -25 3.0 Figure 2. Dropout Voltage vs. Output Current 1.275 3.70 1.270 3.65 1.265 3.60 1.260 1.255 1.250 1.245 1.240 1.235 VOUT SET WITH 1% RESISTORS VOUT = 3.6V1 3.55 3.50 3.45 3.40 VOUT = 3.3V 3.35 0 25 50 75 100 125 150 175 3.20 -75 -50 -25 Note: 1. FAN1587A Only 2. FAN1587A, -3.3 0 Figure 4. Reference Voltage vs. Temperature Figure 5. Output Voltage vs. Temperature 100 5 Note: 1. FAN1587A Only 3 2 0 -75 -50 -25 65-1587-07 1 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) Figure 6. Minimum Load Current vs. Temperature 80 70 60 50 40 30 20 65-1587-08 4 ADJUST PIN CURRENT (µA) 90 MINIMUM LOAD CURRENT (mA) 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) JUNCTION TEMPERATURE (°C) 5 2 3.30 3.25 1.230 1.225 -75 -50 -25 25 50 75 100 125 150 175 Figure 3. Load Regulation vs. Temperature REFERENCE VOLTAGE (V) REFERENCE VOLTAGE (V) 0 JUNCTION TEMPERATURE (°C) OUTPUT CURRENT (A) 65-1587-06 1.0 ∆I = 3A 65-1587-04 1.3 65-1587-03 DROPOUT VOLTAGE (V) 1.4 OUTPUT VOLTAGE DEVIATION (%) 1.5 10 0 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) Figure 7. Adjust Pin Current vs. Temperature REV. 1.0.5 11/10/03 PRODUCT SPECIFICATION FAN1587A Typical Performance Characteristics (continued) 90 5.0 4.0 3.5 3.0 -75 -50 -25 0 25 50 75 100 125 150 175 70 60 50 40 30 (VIN – VOUT) ≤ 3V 0.5V ≤ VRIPPLE ≤ 2V IOUT = 3A 20 10 0 10 100 JUNCTION TEMPERATURE (°C) 1K 10K 100K FREQUENCY (Hz) Figure 8. Short-Circuit Current vs. Temperature Figure 9. Ripple Rejection vs. Frequency 15 65-1587-11 10 5 0 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (°C) Figure 10. Maximum Power Dissipation REV. 1.0.5 11/10/03 OUTPUT CAPACITANCE ESR, (Ω) 2.5 20 POWER (W) 65-1587-10 RIPPLE REJECTIONS (dB) 4.5 65-1587-09 SHORT-CIRCUIT CURRENT (A) 80 2 1.5 Area of Instability 1 0.5 Stable Area 0 0 1000 2000 3000 LOAD CURRENT (mA) Figure 11. Stability Region VIN/VOUT = 5V/1.5V 6 PRODUCT SPECIFICATION FAN1587A Applications Information General The FAN1587A, FAN1587A-1.5, and FAN1587A-3.3 are three-terminal regulators optimized for GTL+ VTT termination 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 FAN1587A 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+. D1 1N4002 (OPTIONAL) FAN1587A VIN IN + C1 22µF OUT ADJ + R1 VOUT C2 22µF + CADJ R2 Stability The FAN1587A series require 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. It is recommended to use bypass capacitors such as a 22µF tantalum or a 100µF aluminum on the adjust pin of the FAN1587A for low ripple and fast transient response. When these bypassing capacitors are not used at the adjust pin, larger values of output capacitors provide equally good results. Refer to Typical Performance Characteristics for graph of stability of output capacitance ESR vs load current. D1 1N4002 (OPTIONAL) FAN1587A-1.5, -3.3 VIN C1 22µF IN + OUT GND + VOUT C2 22µF 65-1587-13 Figure 11. Optional Protection Ripple Rejection Protection Diodes In normal operation, the FAN1587A series does not require any protection diodes. For the FAN1587A, 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 shortcircuit conditions. A protection diode between the input and output pins is usually not needed. An internal diode between the input and output pins on the FAN1587A 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 11. Usually, normal power supply cycling or system “hot plugging and unplugging” will not generate current large enough to do any damage. The adjust pin can be driven on a transient basis ±7V with respect to the output, without any device degradation. As with any IC regulator, exceeding the maximum input-tooutput voltage differential causes the internal transistors to break down and none of the protection circuitry is then functional. REV. 1.0.5 11/10/03 In applications that require improved ripple rejection, a bypass capacitor from the adjust pin of the FAN1587A 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 100Ω to 120Ω) in the feedback divider network in Figure 11. Therefore, the value of the required adjust pin capacitor is a function of the input ripple frequency. For example, if R1 equals 100Ω and the ripple frequency equals 120Hz, the adjust pin capacitor should be 22µF. At 10kHz, only 0.22µF is needed. Output Voltage The FAN1587A regulator develops a 1.25V reference voltage between the output pin and the adjust pin (see Figure 12). 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. The current out of the adjust pin adds to the current from R1 and is typically 35µA. Its output voltage contribution is small and only needs consideration when very precise output voltage setting is required. 7 FAN1587A PRODUCT SPECIFICATION FAN1587A VIN + OUT IN C1 22µF ADJ + VREF IADJ 35µA R1 FAN1587A VOUT C2 22µF VIN IN RP PARASITIC LINE RESISTANCE OUT ADJ R1* R2 RL VOUT = VREF (1 + R2/R1) + IADJ (R2) 65-1587-14 * CONNECT R1 TO CASE CONNECT R2 TO LOAD Figure 12. Basic Regulator Circuit Load Regulation 65-1587-15 It is not possible to provide true remote load sensing because the FAN1587A series are three-terminal devices. Load regulation is limited by the resistance of the wire connecting the regulators to the load. Load regulation per the data sheet specification is measured at the bottom of the package. For fixed voltage devices, negative side sensing is a true Kelvin connection with the ground pin of the device returned to the negative side of the load. This is illustrated in Figure 13. VIN FAN1587A-1.5, -3.3 OUT IN R2* RP PARASITIC LINE RESISTANCE GND RL Figure 14. Connection for Best Load Regulation Thermal Considerations The FAN1587A 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-to-ambient. 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. For example, look at using an FAN1587AT to generate 3A @ 1.5V ± 2% from a 3.3V source (3.2V to 3.6V). Assumptions: 65-1587-17 Figure 13. Connection for Best Load Regulation For adjustable voltage devices, negative side sensing is a true Kelvin connection with the bottom of the output divider returned to the negative side of the load. The best load regulation is obtained when the top of resistor divider R1 connects directly to the regulator output and not to the load. Figure 14 illustrates this point. • • • • • VIN = 3.6V worst case VOUT = 1.46V worst case IOUT = 3A continuous TA = 70°C θCase-to-Ambient = 3°C/W (assuming both a heatsink and a thermally conductive material) The power dissipation in this application is: PD = (VIN – VOUT) * (IOUT) = (3.6 – 1.46) * (3) = 6.42W If R1 connects to the load, then the effective resistance between the regulator and the load would be: From the specification table: RP × (1 + R2/R1), RP = Parasitic Line Resistance TJ = TA + (PD) * (θCase-to-Ambient + θJC) = 70 + (6.42) * (3 + 3) = 109°C The connection shown in Figure 14 does not multiply RP by the divider ratio. As an example, RP is about four milliohms per foot with 16-gauge wire. This translates to 4mV per foot at 1A load current. At higher load currents, this drop represents a significant percentage of the overall regulation. It is important to keep the positive lead between the regulator and the load as short as possible and to use large wire or PC board traces. 8 The junction temperature is below the maximum rating. REV. 1.0.5 11/10/03 FAN1587A PRODUCT SPECIFICATION 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. The cases of the FAN1587A series are directly connected to the output of the device. U1 FAN1587A VIN 12V C1 22µF + ADJ + C2 100µF VOUT 9V VOUT VIN R1 124Ω + C3 100µF R2 768Ω 65-1587-18 Figure 15. Application Circuit (FAN1587A) Table 1. Bill of Materials for Application Circuit for the FAN1587A Item C1 Quantity Manufacturer Part Number 1 Xicon L16V22 L10V100 Description 22µF, 16V Aluminum C2, C3 2 Xicon R1 1 Generic 124Ω, 1% R2 1 Generic 768Ω, 1% U1 1 Fairchild 9 FAN1587AT 100µF, 10V Aluminum 3A Regulator REV. 1.0.5 11/10/03 FAN1587A PRODUCT SPECIFICATION Mechanical Dimensions 3-Lead TO-263 Package Symbol Inches Millimeters Notes Min. Max. Min. Max. A b b2 c2 D E e .160 .020 .190 .036 4.06 0.51 4.83 0.91 L L1 L2 R α .575 .090 — .017 0° .049 .051 .045 .055 .340 .380 .380 .405 .100 BSC .625 .110 .055 .019 8° 1.25 1.30 1.14 1.40 8.64 9.65 9.65 10.29 2.54 BSC 14.61 2.29 — 0.43 0° Notes: 1. Dimensions are exclusive of mold flash and metal burrs. 2. Standoff-height is measured from lead tip with ref. to Datum -B-. 3. Foot length is measured with ref. to Datum -A- with lead surface (at inner R). 4. Dimensiuon exclusive of dambar protrusion or intrusion. 5. Formed leads to be planar with respect to one another at seating place -C-. 15.88 2.79 1.40 0.78 8° E @PKG/ @HEATSINK L2 c2 D E-PIN L R (2 PLCS) b2 L1 b e -B- -A- A -C- 10 REV. 1.0.5 11/10/03 PRODUCT SPECIFICATION FAN1587A Mechanical Dimensions (continued) 3-Lead TO-263 Center Cut Package Inches Symbol Millimeters Notes Min. Max. Min. Max. A b b2 c2 D E e .160 .020 .190 .036 4.06 0.51 4.83 0.91 L L1 L2 .575 .090 — .050 .017 0° .049 .051 .045 .055 .340 .380 .380 .405 .100 BSC L3 R α .625 .110 .055 .070 .019 8° 1.25 1.30 1.14 1.40 8.64 9.65 9.65 10.29 2.54 BSC 14.61 2.29 — 1.27 0.43 0° Notes: 1. Dimensions are exclusive of mold flash and metal burrs. 2. Standoff-height is measured from lead tip with ref. to Datum -B-. 3. Foot length is measured with ref. to Datum -A- with lead surface (at inner R). 4. Dimensiuon exclusive of dambar protrusion or intrusion. 5. Formed leads to be planar with respect to one another at seating place -C-. 15.88 2.79 1.40 1.78 0.78 8° E @PKG/ @HEATSINK L2 c2 D E-PIN L R (2 PLCS) b2 L1 L3 b e -B- -A- A -C- REV. 1.0.5 11/10/03 11 PRODUCT SPECIFICATION FAN1587A Mechanical Dimensions (continued) 3-Lead TO-220 Package Inches Symbol Min. A b b1 c1 øP D E e Millimeters Max. Min. .140 .190 .015 .040 .045 .070 .014 .022 .139 .161 .560 .650 .380 .420 .090 .110 .190 .210 .045 — .020 .055 .230 .270 .080 .115 .500 .580 .250 BSC .100 .135 3° 7° e1 e3 F H1 J1 L L1 Q α Notes Max. 3.56 4.83 .38 1.02 1.14 1.78 .36 .56 3.53 4.09 14.22 16.51 9.65 10.67 2.29 2.79 4.83 5.33 1.14 — .51 1.40 5.94 6.87 2.04 2.92 12.70 14.73 6.35 BSC 2.54 3.43 3° 7° Notes: 1. Dimension c1 apply for lead finish. H1 Q L e3 b1 e e1 E b L1 E-PIN øP α (5X) c1 A J1 D REV. 1.0.5 11/10/03 F 12 FAN1587A PRODUCT SPECIFICATION Mechanical Dimensions (continued) 3-Lead TO-252 Package Symbol Inches Millimeters Notes: Notes Min. Max. Min. Max. A b b2 b3 c c2 .086 .025 .030 .205 .018 .018 .094 .035 2.19 0.64 0.76 5.21 0.46 0.46 2.39 0.89 D E e H 5.33 6.22 6.35 6.73 2.29 BSC 9.40 10.41 1.40 1.78 2.74 REF 1 L L1 .210 .245 .250 .265 .090 BSC .370 .410 .055 .070 .108 REF L3 L4 .035 .025 0.89 0.64 4 .045 .215 .024 .023 .080 .040 1.14 5.46 0.61 0.58 2.03 1.02 E @PKG/ @HEATSINK b3 4 1 1. Dimensions are exclusive of mold flash, metal burrs or interlead protrusion. 2. Stand off-height is measured from lead tip with ref. to Datum -B-. 3. Foot length is measured with ref. to Datum -A- with lead surface. 4. Thermal pad contour optional within dimension b3 and L3. 5. Formed leads to be planar with respect to one another at seating place -C-. 6. Dimensions and tolerances per ASME Y14.5M-1994. 3 L3 c2 D E-PIN H L4 b2 L1 L b e -B- α = 0° – 10° -A- A -C- 13 REV. 1.0.5 11/10/03 FAN1587A PRODUCT SPECIFICATION Ordering Information Product Number Package FAN1587AMX TO-263 in tape-and-reel FAN1587AMCX TO-263 center cut in tape-and-reel FAN1587AT TO-220 FAN1587ADX TO-252 in tape-and-reel FAN1587AM15X TO-263 in tape-and-reel FAN1587AMC15X TO-263 center cut in tape-and-reel FAN1587AT15 TO-220 FAN1587AD15X TO-252 in tape-and-reel FAN1587AM33X TO-263 in tape-and-reel FAN1587AMC33X TO-263 center cut in tape-and-reel FAN1587AT33 TO-220 FAN1587AD33X TO-252 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. 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. www.fairchildsemi.com 11/10/03 0.0m 003 Stock#DS30001587A 2002Fairchild Semiconductor Corporation