SPX2941 ® 1A Low Dropout Voltage Regulator, Adjustable Output, Fast Response FEATURES ■ Adjustable Output Down To 1.25V ■ Low Quiescent Current ■ Guaranteed 1.5A Peak Output Current ■ Low Dropout Voltage of 280mV @ 1A ■ Extremely Tight Load and Line Regulation ■ Extremely Fast Transient Response ■ Reverse-battery Protection ■ Internal Thermal and Current Limit Protection ■ Zero Current Shutdown ■ Error Flag Output for Out of Regulation State ■ Standard TO-220 and TO-263 packages ■ Replacement for LM2941 and AS2941 SPX2941 5 Pin TO-263 GND VOUT VIN ADJUST ENABLE 1 2 3 4 5 Now Available in Lead Free Packaging APPLICATIONS ■ Powering VGA & Sound Card ■ LCD Monitors ■ USB Power Supply ■ Power PC Supplies ■ SMPS Post-Regulator ■ High Efficiency Linear Power Supplies ■ Battery Charger ■ Portable Instrumentation ■ Constant Current Regulators ■ Adjustable Power Supplies DESCRIPTION The SPX2941 is a 1A, accurate voltage regulator with a low drop out voltage of 280mV(typ.) 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. Other features include Enable, and Error Flag. The SPX2941 is offered in 5-pin TO-220 & TO-263 packages. For a 3A version, refer to the SPX29300 data sheet. TYPICAL APPLICATIONS CIRCUIT 4 VIN 6.8µF + EN 2 SPX2941 3 5 1 ADJ GND VOUT + R1 10µF R2 Figure 1. Adjustable Output Linear Regulator Date: 08/25/04 SPX2941 1A Low Dropout Voltage Regulator 1 © Copyright 2004 Sipex Corporation 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 Supply Voltage (NOTE 7) .... .....................................16V ELECTRICAL CHARACTERISTICS VIN=VOUT + 1V, IOUT=10mA, CIN=6.8µF, COUT=10µF, TA = 25°C, unless otherwis specified. The boldface applies over the junction temperature range. Adjustable versions are set at +5.0V. PARAMETER Reference Voltage CONDITIONS Adjustable version only MIN. TYP. MAX UNIT 1.228 1.215 1.240 1.252 1.265 80 120 V Adjust Pin Bias Current Reference Voltage Temperature Coefficient Adjust Pin Bias Current Temperature Coefficient Line Regulation Load Regulation Dropout Voltage (Note1) (except 1.8V version) Ground Current (Note3) 40 (NOTE 4) IOUT=10mA, (VOUT+1V)≤VIN≤16V VIN=VOUT+1V, 10mA≤IOUT≤IFULL IOUT=100mA IOUT=1A IOUT=750mA, VIN=VOUT+1V IOUT=1A Ground Pin Current at VIN=0.1V less than specified VOUT, Dropout IOUT=10mA Current Limit VOUT=0V (Note2) Output Noise Voltage 10Hz to 100kHz, IOUT =100mA, CL=10µF CL=33µF ERROR COMPARATOR (FLAG OUTPUT) Output Leakage Current VOH=16V Output Low Voltage 20 ppm/°C 0.1 nA/°C 0.2 0.3 70 280 12 18 1.2 1.5 Device set for 5V (Note 5) 75 Hysteresis Input Logic Voltage LOW (OFF) HIGH (ON) Device set for 5V (Note 5) 15 ENABLE Input Pin Current VEN=16V 200 1 2 300 400 60 A mV mV 95 140 mV mV 0.8 V 600 750 µA 1 2 µA 2.4 100 VEN=0.8V Date: 08/25/04 mA µVRMS Lower Threshold Voltage TO-263 mA 400 260 Upper Threshold Voltage Regulator Output Current in Shutdown Thermal Resistance TO-220 % % mV A Device set for 5V, VIN=4.5, IOL=250µA Device set for 5V (Note 5) VIN<10V 1.0 1.5 200 550 25 2.2 0.1 40 25 V (NOTE 6) 10 µA 500 Junction to Case, at Tab Junction to Ambient 3 60 °C/W Junction to Case, at Tab Junction to Ambient 3 60 °C/W SPX2941 1A Low Dropout Voltage Regulator 2 © Copyright 2004 Sipex Corporation NOTE 1: Dropout voltage is defined as the input to output differential at which the output voltage drops to 99% of its nominal value. NOTE 2: VIN=VOUT(NOMINAL)+1V; for example, 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 and ground currents. 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: Comparator threshold is expressed in terms of a voltage differential at the Adjust terminal below the nominal reference voltage measured 6V input. To express these thresholds in terms of output voltage change, multiply the error amplifier gain = VOUT/VREF = (R1 + R2)/R2. For example, at a programmable output voltage of 5V, the Error output is guaranteed to go low when the output drops by 95mVx 5V/ 1.240V = 38mV. Threshold remain constant as a percent of VOUT as VOUT is varied, with the dropout warning occurring at typically 5% below nominal, 7.7% guaranteed. NOTE 6: VEN ≤ 0.8V and VIN ≤ 16V, VOUT = 0. NOTE7: Maximum positive supply voltage of 20V must be of limited duration ( <100ms) and duty cycle (<1%). The maximum continuous supply voltage is 16V. NOTE 8: VREF ≤ VOUT ≤ (VIN-1), 2.5V ≤ VIN ≤ 16V, 10 mA ≤ IC ≤ IFL, TJ < TJMAX. BLOCK DIAGRAM IN OUT O.V I LIMIT FLAG 28V + 1.180V Reference 1.240V + - R1* ADJ EN Thermal Shutdown R2* GND Figure 2. SP2941 Block Diagram Date: 08/25/04 SPX2941 1A Low Dropout Voltage Regulator 3 © Copyright 2004 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS 3.320 3.310 3.315 3.305 3.305 VOUT (V) VOUT (V) 3.310 3.300 3.295 3.3V Device IL = 10mA CL = 10µF 3.290 3.285 6 8 10 12 3.295 3.290 3.3V Device VIN = 4.3V CL = 10µF 3.285 3.280 4 3.300 14 3.280 0.00 16 0.25 0.50 VIN (V) 0.75 1.00 1.25 1.50 IL (A) Figure 3. Line Regulation for 3.3V Device Figure 4. Load Regulation for 3.3V Device 80.0 300 70.0 280 IGnd (µA) IGnd (mA) 60.0 50.0 40.0 30.0 260 240 220 20.0 3.3V Device VIN = 4.3V CL = 10µF 10.0 0.0 0.00 0.25 0.50 0.75 1.00 1.25 3.3V Device IL = 10mA CL = 10µF 200 180 1.50 4 6 8 IL (A) 10 12 14 16 VIN (V) Figure 5. Ground Current vs Load Current for 3.3V Device Figure 6. Ground Current vs Input Current 100 600 90 500 VDROPOUT (mV) 80 IGnd (mA) 70 60 50 40 30 3.3V Device VIN = 3.2V CL = 10µF 20 10 0 0.00 0.25 0.50 0.75 1.00 1.25 400 300 200 0 0.00 1.50 IL (A) 0.25 0.50 0.75 1.00 1.25 1.50 IL (A) Figure 7. Ground Current vs Load Current in Dropout Date: 08/25/04 3.3V Device CL = 10µF 100 Figure 8. Dropout Voltage vs Load Current for 3.3V Device SPX2941 1A Low Dropout Voltage Regulator 4 © Copyright 2004 Sipex Corporation 280 3.320 270 3.310 260 3.300 250 3.290 VOUT (V) IGnd (µA) TYPICAL PERFORMANCE CHARACTERISTICS 240 230 220 3.3V Device VIN = 4.3V IL = 10mA CL = 10µF 210 200 190 180 -40 -20 0 20 40 60 80 100 3.280 3.270 3.260 3.3V Device VIN = 4.3V IL = 10mA CL = 10µF 3.250 3.240 3.230 3.220 -40 120 -20 0 Figure 9. Ground Current vs Temperature at ILOAD=10mA 100 120 6.20 6.00 5.80 27 26 25 24 5.60 23 5.40 22 5.20 21 -20 0 20 40 60 80 100 3.3V Device VIN = 3.2V IL = 750mA CL = 10µF 28 IGnd (mA) IGnd (mA) 6.40 20 -40 120 -20 0 Temperature (°C) 20 40 60 80 100 120 Temperature (°C) Figure 11. Ground Current vs Temperature at ILOAD=500mA Figure 12. Ground Current vs Temperature in Dropout at ILOAD=750mA 100 52.0 50.0 95 48.0 IGnd (mA) IGnd (mA) 80 29 3.3V Device VIN = 4.3V IL = 500mA CL = 10µF 6.60 46.0 44.0 42.0 3.3V Device VIN = 4.3V IL = 1.5A CL = 10µF 40.0 38.0 -20 0 20 40 60 80 100 90 85 80 75 70 -40 120 3.3V Device VIN = 3.2V IL = 1.5A CL = 10µF -20 0 20 40 60 80 100 120 Temperature (°C) Temperature (°C) Figure 13. Ground Current vs Temperature at ILOAD=1.5A Date: 08/25/04 60 30 6.80 36.0 -40 40 Figure 10. Output Voltage vs Temperature at ILOAD=10mA 7.00 5.00 -40 20 Temperature (°C) Temperature (°C) Figure 14. Ground Current vs Temperature in Dropout at ILOAD=1.5A SPX2941 1A Low Dropout Voltage Regulator 5 © Copyright 2004 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS 350 500 330 480 VDROPOUT (mV) VDROPOUT (mV) 310 290 270 250 230 3.3V Device IL = 750mA CL = 10µF 210 190 170 150 -40 460 440 420 400 3.3V Device IL = 1.5A CL = 10µF 380 360 340 -20 0 20 40 60 80 100 320 -40 120 -20 0 Temperature (°C) 20 40 60 80 Figure 15. Dropout Voltage vs Temperature at ILOAD=750mA 2.00 1.90 30 3.3V Device VIN = 3.2V IL = 750mA CL = 10µF 1.70 20 1.60 VTH (V) IEN (µA) 1.80 25 15 10 3.3V Device VIN = 3.2V IL = 750mA CL = 10µF 5 -20 0 20 40 60 80 100 1.50 1.40 1.30 1.20 1.10 1.00 -40 120 -20 Temperature (°C) 0 20 40 60 80 100 120 Temperature (°C) Figure 17. Enable Current vs Temperature for 3.3V Devices Date: 08/25/04 120 Figure 16. Dropout Voltage vs Temperature at ILOAD=1.5A 35 0 -40 100 Temperature (°C) Figure 18. Enable Threshold vs Temperature for 3.3V Devices SPX2941 1A Low Dropout Voltage Regulator 6 © Copyright 2004 Sipex Corporation APPLICATION INFORMATION The SPX2941 incorporates protection against over-current faults, reversed load insertion, over temperature operation, and positive and negative transient voltage. The power calculated under these conditions is: Thermal Considerations Although the SPX2941 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. Since the tab of the device is electrically connected to GND, the tab must be electrically isolated using a thermally conductive spacer, which itself contributes some small additional thermal resistance. Consult heatsink manufacturer for thermal resistance and design of heatsink. TJ = 50 + 5.0 * (1 + 2 + 3) = 80°C. PD = (VIN – VOUT) * IOUT = 5W, and the junction temperature is calculated as TJ = TA + PD * (θHA + θCH + θ JC) or Reliable operation is insured. 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. TO-220 Design Example: Assume that VIN = 10V, VOUT = 5V, IOUT = 1A, TA = 50°C, θHA= 1°C/W, θCH = 2°C/W, and θ JC = 3°C/W, where Minimum Load Current To ensure a proper behavior of the regulator under light load, a minimum load of 5mA for SPX2941 is required. TA = ambient temperature, θHA = heatsink to ambient thermal resistance, Typical Application Circuit Figure 18 shows a typical applications circuit for an adjustable output regulator. The values of R1 and R2 set the output voltage value as follows: VOUT = VREF * [1 + (R1/R2)]. For best results, the total series resistance should be small enough to pass a minimum regulator load current of 5 mA. θCH = case to heatsink thermal resistance, θJC = junction to case thermal resistance. 4 VIN 6.8µF + EN 2 SPX2941 GND 3 5 VOUT + 1 ADJ A minimum value of 10kΩ is recommended for R2 with a range between 10kΩ to 47k Ω. R1 10µF R2 Figure 19. Adjustable Output Linear Regulator Date: 08/25/04 SPX2941 1A Low Dropout Voltage Regulator 7 © Copyright 2004 Sipex Corporation PACKAGE: 5PIN TO-263 SEATING PLANE A (DATUM A) C2 H E 1 2 3 5 4 c L2 (E) E L1 D1 5X b E1 4X e 5 PIN TO-263 JEDEC TO-263 (BB) Variation Dimensions in (mm) MIN NOM MAX A .160 - A1 0 - .010 b .020 - .039 c .015 - .029 c2 .045 .190 - D1 .270 - - E .380 - .420 E1 .245 - - e L3 L (b) .067 BSC H .575 - .625 L .070 - .110 L1 - - .066 L2 - - .070 L3 0º-8º .023 WITH PLATING c .010 BSC BASE METAL CONTACT AREA 5 PIN TO-263 Date: 08/25/04 SPX2941 1A Low Dropout Voltage Regulator 8 © Copyright 2004 Sipex Corporation PACKAGE: 5PIN TO-220 E A B E/2 SEATING PLANE A øP Q F H1 D D1 D L1 D C C CHAMFER OPTIONAL D L A b e C1 e1 J1 5 PIN TO-220 Dimensions in (inches) MIN NOM MAX A .160 - .190 b .015 - .040 C1 .014 - .022 D .560 - .590 E e .385 - .415 .385 - .415 e1 .062 - .072 F H1 .045 - .055 .234 - .258 J1 L .090 - .115 .540 - .560 L1 - .250 ∆P .146 - .156 Q .103 - .113 U - .30 - V - .24 - Date: 08/25/04 5 PIN TO-220 SPX2941 1A Low Dropout Voltage Regulator 9 © Copyright 2004 Sipex Corporation PACKAGE PINOUTS TO-263-5 Package (T5) 1 2 3 TO-220-5 Package (U5) SPX2941 1) ADJUST 2) Enable 3) GND 4) VIN 5) VOUT 4 5 Top View 1 2 3 4 5 Top View ORDERING INFORMATION PART NUMBER .................... ACCURACY ... OUTPUT VOLTAGE ...................... PACKAGE SPX2941T5 ............................ 3% ........................ Adj ............................. 5 lead TO-263 SPX2941T5/TR ...................... 3% ........................ Adj ............................. 5 lead TO-263 SPX2941U5 ........................... 3% ........................ Adj ............................. 5 lead TO-220 Available in lead free packaging.To order add "-L" suffix to part number. Example: SPX2941T5/TR = standard; SPX2941T5-L/TR = lead free /TR = Tape and Reel Pack quantity is 500 for TO-263. Corporation ANALOG EXCELLENCE Sipex Corporation Headquarters and Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 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 herein; neither does it convey any license under its patent rights nor the rights of others. Date: 08/25/04 SPX2941 1A Low Dropout Voltage Regulator 10 © Copyright 2004 Sipex Corporation