Low Dropout Voltage Regulator

www.DataSheet4U.com ® SPX2940 1A Low Dropout Voltage Regulator Fixed Output, Fast Response FEATURES ■ Guaranted 1.5A Peak Current ■ Low Quiescent Current ■ Low Dropout Voltage of 280mV at 1A ■ Extremely Tight Load and Line Regulation ■ Extremely Fast Transient Response ■ Reverse-battery Protection ■ Internal Thermal Protection ■ Internal Short Circuit Current Limit ■ Replacement for LM2940, MIC2940A, AS2940 ■ Standard TO-220 and TO-263 packages APPLICATIONS ■ Powering VGA & Sound Card ■ LCD Monitors ■ USB Power Supply ■ Power PCTM Supplies ■ SMPS Post-Regulator SPX2940 3 Pin TO-263 1 2 3 VIN GND VOUT Now Available in Lead Free Packaging ■ ■ ■ ■ ■ ■ PDA or Notebook Computer High Efficiency Linear Power Supplies Portable Instrumentation Constant Current Regulators Cordless Telephones Automotive Electronics DESCRIPTION The SPX2940 is a 1A, accurate voltage regulators with a low drop out voltage of 280mV (typical) at 1A. These regulators are specifically designed for low voltage applications that require a low dropout voltage and a fast transient response. They are fully fault protected against over-current, reverse battery, and positive and negative voltage transients. The SPX2940 is offered in 3-pin TO-220 & TO-263 packages. For a 3A version, refer to the SPX29300 data sheet. TYPICAL APPLICATIONS CIRCUIT VIN 6.8µF + 1 SPX2940 2 3 + 10µF VOUT Figure 1. Fixed Output Linear Regulator. Date: 5/25/04 SPX2940 1A Low Dropout Voltage Regulator © Copyright 2004 Sipex Corporation 1 ABSOLUTE MAXIMUM RATINGS Lead Temperature (soldering, 5 seconds) ................................. 260°C Storage Temperature Range ..................................... -65°C to +150°C Operating Junction Temperature Range ................... -40°C to +125°C Input Voltage (Note 5) ................................................................... 16V ELECTRICAL CHARACTERISTICS at VIN=VOUT + 1V and IOUT = 10 mA, CIN = 6.8 µF, COUT = 10µF; TA= 25°C, unless otherwise specified. The Boldface applies over the junction temperature range. Adjustable versions are set at 5.0V. PARAMETER 1.8V Version Output Voltage 2.5V Version Output Voltage 3.3V Version Output Voltage 5.0V Version Output Voltage All Voltage Options Line Regulation Load Regulation ∆V ∆T Dropout Voltage (Note 1) (except 1.8V version) Ground Current (Note 3) IGNDDO Ground Pin Current at Dropout Current Limit Output Noise Voltage 10Hz to 100kHz) IL=100mA Thermal Resistance CONDITIONS IOUT = 10mA 10mA≤IOUT≤1A, 6V≤VIN≤16V IOUT = 10mA 10mA≤IOUT ≤1A, 6V≤VIN≤16V IOUT = 10mA 10mA≤IOUT ≤1A, 6V≤VIN≤16V IOUT = 10mA 10mA≤IOUT ≤1A, 6V≤VIN≤16V IO=10mA, (VOUT+1V)≤VIN≤16V VIN=VOUT+1V, 10mA≤IOUT≤1A Output Voltage Temperature Coef. IO =100mA IO =1A IO =750mA, VIN=VOUT, + 1V IO =1A VIN=0.1V less than specified VOUT IOUT= 10mA VOUT=0V (Note 2) CL= 10µF TYP 1.8 1.8 2.5 2.5 3.3 3.3 5.0 5.0 0.2 0.3 20 70 280 12 18 1.2 2.2 400 MIN 1.746 1.710 2.425 2.375 3.201 3.135 4.850 4.750 MAX UNITS 1.854 1.890 2.575 2.625 3.399 3.465 5.150 5.250 1.0 1.5 100 200 550 25 V V V V % % ppm/°C mV mA mA 1.5 A µVRMS CL=33µF 260 TO-220 Junction to Case, at Tab 3 TO-220 Junction to Ambient 60 TO-263 Junction to Case, at Tab 3 TO-263 Junction to Ambient 60 °C/W NOTES: Note 1: Dropout voltage is defined as the input to output differential when the output voltage drops to 99% of its normal value. Note 2: VIN=VOUT (NOMINAL) + 1V. For example, use VIN=4.3V for a 3.3V regulator. Employ pulse-testing procedures to minimize temperature rise. Note 3: Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the load current to the ground current. Note 4: Thermal regulation is defined as the change in the output voltage at a time T after a change in power dissipation is applied, excluding load or line regulation effects. Note 5: Maximum positive supply voltage of 20V must be of limited duration (<100ms) and duty cycle (<1%). The maximum continuous supply voltage is 16V. Date: 5/25/04 SPX2940 1A Low Dropout Voltage Regulator © Copyright 2004 Sipex Corporation 2 BLOCK DIAGRAM IN O.V I LIMIT Reference 1.240V + Ibias 28V R1 OUT Thermal Shutdown R2 GND TYPICAL PERFORMANCE CHARACTERISTICS 3.320 3.315 3.310 3.310 3.305 3.300 3.295 3.290 3.285 3.280 0.00 VOUT (V) 3.300 3.295 3.290 3.285 3.280 4 6 8 10 12 14 16 3.3V Device IL = 10mA CL = 10µF VOUT (V) 3.305 3.3V Device VIN = 4.3V CL = 10µF 0.25 0.50 0.75 1.00 1.25 1.50 VIN (V) IL (A) Figure 2. Line Regulation Figure 3. Load Regulation 80.0 70.0 300 280 IGnd (mA) 60.0 IGnd (mA) 50.0 40.0 30.0 20.0 10.0 0.0 0.00 260 240 220 3.3V Device VIN = 4.3V CL = 10µF 0.25 0.50 0.75 1.00 1.25 1.50 200 180 4 6 8 10 12 3.3V Device IL = 10mA CL = 10µF 14 16 IL (A) VIN (V) Figure 4. Ground Current vs Load Current Figure 5. Ground Current vs Input Voltage Date: 5/25/04 SPX2940 1A Low Dropout Voltage Regulator © Copyright 2004 Sipex Corporation 3 TYPICAL PERFORMANCE CHARACTERISTICS 100 90 600 500 70 VDROPOUT (mV) 80 IGnd (mA) 400 300 200 100 0 0.00 60 50 40 30 20 10 0 0.00 0.25 0.50 0.75 1.00 3.3V Device VIN = 3.2V CL = 10µF 1.25 1.50 3.3V Device CL = 10µF 0.25 0.50 0.75 1.00 1.25 1.50 IL (A) IL (A) Figure 6. Ground Current vs Current in Dropout Figure 7. Dropout Voltage vs Load Current 280 270 260 250 3.320 3.310 3.300 3.290 IGnd (µA) VOUT (V) 240 230 220 210 200 190 180 -40 -20 0 20 40 60 80 3.3V Device VIN = 4.3V IL = 10mA CL = 10µF 100 120 3.280 3.270 3.260 3.250 3.240 3.230 3.220 -40 -20 0 20 40 60 80 3.3V Device VIN = 4.3V IL = 10mA CL = 10µF 100 120 Temperature (°C) Temperature (°C) Figure 8. Ground Current vs Temperature at ILOAD = 10mA Figure 9. Output Voltage vs Temperature at ILOAD=10mA 7.00 6.80 6.60 3.3V Device VIN = 4.3V IL = 500mA CL = 10µF 30 29 28 3.3V Device VIN = 3.2V IL = 750mA CL = 10µF IGnd (mA) IGnd (mA) 6.40 6.20 6.00 5.80 5.60 5.40 5.20 5.00 -40 -20 0 20 40 60 80 27 26 25 24 23 22 21 20 -40 100 120 -20 0 20 40 60 80 100 120 Temperature (°C) Temperature (°C) Figure 10. Ground Current vs Temperature at ILOAD=500mA Figure 11. Ground Current vs Temperature in Dropout at ILOAD=750mA Date: 5/25/04 SPX2940 1A Low Dropout Voltage Regulator © Copyright 2004 Sipex Corporation 4 TYPICAL PERFORMANCE CHARACTERISTICS 52.0 50.0 100 95 IGnd (mA) IGnd (mA) 48.0 46.0 44.0 42.0 40.0 38.0 36.0 -40 -20 0 20 40 60 80 3.3V Device VIN = 4.3V IL = 1.5A CL = 10µF 100 120 90 85 80 75 70 -40 3.3V Device VIN = 3.2V IL = 1.5A CL = 10µF -20 0 20 40 60 80 100 120 Temperature (°C) Temperature (°C) Figure 12. Ground Current vs Temperature at ILOAD= 1.5A Figure 13. Ground Current vs Temperature in Dropout at ILOAD=1.5A 350 330 310 500 480 VDROPOUT (mV) 290 270 250 230 210 190 170 150 -40 -20 0 20 40 60 80 100 120 3.3V Device IL = 750mA CL = 10µF VDROPOUT (mV) 460 440 420 400 380 360 340 320 -40 -20 0 20 40 60 80 100 120 3.3V Device IL = 750A CL = 10µF Temperature (°C) Temperature (°C) Figure 14. Dropout Voltage vs Temperature at ILOAD= 750mA Figure 15. Dropout Voltage vs Temperature at ILOAD= 1.5mA 35 30 25 2.00 1.90 1.80 1.70 1.60 3.3V Device VIN = 3.2V IL = 750mA CL = 10µF IEN (µA) VTH (V) 20 15 10 5 0 -40 -20 0 20 40 60 80 3.3V Device VIN = 3.2V IL = 750mA CL = 10µF 100 120 1.50 1.40 1.30 1.20 1.10 1.00 -40 -20 0 20 40 60 80 100 120 Temperature (°C) Temperature (°C) Figure 16. Enable Current vs Temperature for VEN= 16V Figure 17. Enable Threshold vs Temperature Date: 5/25/04 SPX2940 1A Low Dropout Voltage Regulator © Copyright 2004 Sipex Corporation 5 APPLICATION INFORMATION The SPX2940 incorporates protection against over-current faults, reversed load insertion, over temperature operation, and positive and negative transient voltage. Thermal Considerations Although the SPX2940 offers limiting circuitry for overload conditions, it is still necessary to insure that the maximum junction temperature is not exceeded in the application. Heat will flow through the lowest resistance path, the junction-to-case path. In order to insure the best thermal flow of the component, proper mounting is required. Consult heatsink manufacturer for thermal resistance and design of heatsink. For example, TO-220 design: Assume that VIN = 10V, VOUT = 5V, IOUT = 1.5A, TA = 50°C/W, θHA= 1°C/W, θCH = 2°C/W, and θJC = 3°C/W. Where TA = ambient temperature θHA = heatsink to ambient thermal resistance θCH = case to heatsink thermal resistance θJC = junction to case thermal resistance The power calculated under these conditions is: PD = (VIN - VOUT) * IOUT = 7.5W. And the junction temperature is calculated as TJ = TA + PD * (θHA + θCH + θJC) or TJ = 50 + 7.5 * (1 + 2 + 3) = 95°C Reliable operation is insured. VIN 6.8µF + 1 SPX2940 2 3 + 10µF VOUT Figure 18. Fixed Output Linear Regulator. Capacitor Requirements The output capacitor is needed to insure stability and minimize the output noise. The value of the capacitor varies with the load. However, a minimum value of 10µF aluminum capacitor will guarantee stability over all load conditions. A tantalum capacitor is recommended if a faster load transient response is needed. If the power source has a high AC impedance, a 0.1µF ceramic capacitor between input & ground is recommended. Minimum Load Current To ensure a proper behavior of the regulator under light load, a minimum load of 5mA for SPX2940 is required. Date: 5/25/04 SPX2940 1A Low Dropout Voltage Regulator © Copyright 2004 Sipex Corporation 6 PACKAGE: 3 PIN TO-263 E E/2 L1 SEATING PLANE A C2 D H 1 2 3 B B c e See View C b2 b GAUGE PLANE 0º-8º A1 View C SEATING PLANE L 3-PIN TO-263 JEDEC TO-263 (AA) Variation A A1 b c D D1 E E1 e H L L1 L2 L3 .575 .070 Dimensions in inches MIN .160 .000 .020 .015 .330 .270 .380 .245 .100 BSC .625 .110 .066 .070 NOM MAX .