REF3112 REF3120 REF3125 REF3130 REF3133 REF3140 SBVS046A – DECEMBER 2003 – REVISED JANUARY 2004 15ppm/°C Max, 100µA, SOT23-3 SERIES VOLTAGE REFERENCE FEATURES DESCRIPTION ● MicroSIZE PACKAGE: SOT23-3 The REF31xx is a family of precision, low power, low dropout, series voltage references available in the tiny SOT23-3 package. ● LOW DROPOUT: 5mV ● HIGH OUTPUT CURRENT: ±10mA ● HIGH ACCURACY: 0.2% max ● LOW IQ: 115µA max ● EXCELLENT SPECIFIED DRIFT PERFORMANCE: 15ppm/°C (max) from 0°C to +70°C 20ppm/°C (max) from –40°C to +125°C The REF31xx’s small size and low power consumption (100µA typ) make it ideal for portable and battery-powered applications. The REF31xx does not require a load capacitor, but is stable with any capacitive load and can sink/source up to 10mA of output current. Unloaded, the REF31xx can be operated on supplies down to 5mV above the output voltage. All models are specified for the wide temperature range of –40°C to +125°C. APPLICATIONS ● PORTABLE, BATTERY-POWERED EQUIPMENT PRODUCT VOLTAGE (V) REF3112 1.25 REF3120 2.048 ● MEDICAL EQUIPMENT REF3125 2.5 ● HAND-HELD TEST EQUIPMENT REF3130 3.0 ● DATA ACQUISITION SYSTEMS IN OUT 1 2 REF3112 REF3120 REF3125 REF3130 REF3133 REF3140 3 REF3133 3.3 REF3140 4.096 GND SOT23-3 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. Copyright © 2003-2004, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. www.ti.com ABSOLUTE MAXIMUM RATINGS(1) ELECTROSTATIC DISCHARGE SENSITIVITY Supply Voltage, V+ to V– ................................................................... 7.0V Output Short-Circuit ................................................................. Continuous Operating Temperature .................................................. –55°C to +135°C This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. Storage Temperature ..................................................... –65°C to +150°C Junction Temperature .................................................................... +150°C Lead Temperature (soldering, 10s) ............................................... +300°C NOTES: (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these, or any other conditions beyond those specified, is not implied. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. PACKAGE/ORDERING INFORMATION(1) PRODUCT REF3112 " REF3120 " REF3125 " REF3130 " REF3133 " REF3140 " PACKAGE-LEAD PACKAGE DESIGNATOR SPECIFIED TEMPERATURE RANGE PACKAGE MARKING ORDERING NUMBER TRANSPORT MEDIA, QUANTITY SO T23-3 DBZ –40°C to +125°C R31A " " " " REF3112AIDBZT REF3112AIDBZR Tape and Reel, 250 Tape and Reel, 3000 SOT23-3 DBZ –40°C to +125°C R31B " " " " REF3120AIDBZT REF3120AIDBZR Tape and Reel, 250 Tape and Reel, 3000 SOT23-3 DBZ –40°C to +125°C R31C " " " " REF3125AIDBZT REF3125AIDBZR Tape and Reel, 250 Tape and Reel, 3000 SOT23-3 DBZ –40°C to +125°C R31E " " " " REF3130AIDBZT REF3130AIDBZR Tape and Reel, 250 Tape and Reel, 3000 SOT23-3 DBZ –40°C to +125°C R31F " " " " REF3133AIDBZT REF3133AIDBZR Tape and Reel, 250 Tape and Reel, 3000 SOT23-3 DBZ –40°C to +125°C R31D " " " " REF3140AIDBZT REF3140AIDBZR Tape and Reel, 250 Tape and Reel, 3000 NOTES: (1) For the most current package and ordering information, see the Package Option Addendum located at the end of this data sheet. ELECTRICAL CHARACTERISTICS Boldface limits apply over the specified temperature range, TA = –40°C to +125°C. At TA = +25°C, ILOAD = 0mA, VIN = 5V, unless otherwise noted. REF31xx PARAMETER CONDITIONS MIN TYP MAX UNITS 1.2475 –0.2 1.25 1.2525 0.2 V % REF3112(1) - 1.25V OUTPUT VOLTAGE Initial Accuracy VOUT NOISE Output Voltage Noise Voltage Noise f = 0.1Hz to 10Hz f = 10Hz to 10kHz µVPP µVrms 17 24 REF3120 – 2.048 OUTPUT VOLTAGE Initial Accuracy VOUT NOISE Output Voltage Noise Voltage Noise 2.0439 –0.2 f = 0.1Hz to 10Hz f = 10Hz to 10kHz 2.048 2.0521 0.2 V % µVPP µVrms 27 39 REF3125 – 2.5V OUTPUT VOLTAGE Initial Accuracy NOISE Output Voltage Noise Voltage Noise 2 VOUT 2.4950 –0.2 f = 0.1Hz to 10Hz f = 10Hz to 10kHz 2.50 33 48 2.5050 0.2 V % µVPP µVrms REF3112, 3120, 3125, 3130, 3133, 3140 www.ti.com SBVS046A ELECTRICAL CHARACTERISTICS Boldface limits apply over the specified temperature range, TA = –40°C to +125°C. At TA = +25°C, ILOAD = 0mA, VIN = +5V, unless otherwise noted. REF31xx PARAMETER CONDITIONS MIN TYP MAX UNITS 2.9940 –0.2 3.0 3.0060 0.2 V % REF3130 – 3.0V OUTPUT VOLTAGE Initial Accuracy VOUT NOISE Output Voltage Noise Voltage Noise f = 0.1Hz to 10Hz f = 10Hz to 10kHz µVPP µVrms 39 57 REF3133 – 3.3V OUTPUT VOLTAGE Initial Accuracy VOUT 3.2934 –0.2 NOISE Output Voltage Noise Voltage Noise f = 0.1Hz to 10Hz f = 10Hz to 10kHz 3.30 3.3066 0.2 V % µVPP µVrms 43 63 REF3140 – 4.096V OUTPUT VOLTAGE Initial Accuracy VOUT 4.0878 –0.2 NOISE Output Voltage Noise Voltage Noise f = 0.1Hz to 10Hz f = 10Hz to 10kHz 4.096 4.1042 0.2 V % µVPP µVrms 53 78 REF3112, REF3120, REF3125, REF3130, REF3133, REF3140 OUTPUT VOLTAGE TEMP DRIFT(2) dVOUT/dT 0°C ≤ TA ≤ +70°C –40°C ≤ TA ≤ +125°C 5 10 15 20 ppm/°C ppm/°C 0-1000h VREF + 0.05(1) ≤ VIN ≤ 5.5V 70 20 65 ppm ppm/V 0mA < ILOAD < 10mA, VIN = VREF + 250mV(1) –10mA < ILOAD < 0mA, VIN = VREF + 100mV(1) 10 30 µV/mA 20 50 µV/mA LONG-TERM STABILITY LINE REGULATION LOAD REGULATION(3) Sourcing dVOUT/dILOAD Sinking THERMAL HYSTERESIS(4) First Cycle Additional Cycles DROPOUT VOLTAGE(1) OUTPUT CURRENT SHORT-CIRCUIT CURRENT Sourcing Sinking dT 100 25 VIN – VOUT ILOAD TEMPERATURE RANGE Specified Range Operating Range Storage Range Thermal Resistance SOT23-3 Surface-Mount NOTES: (1) (2) (3) (4) (5) –10 to 0.1% at VIN = +5V with CL = 0 mV 10 mA 50 40 mA mA 400 µs IL = 0 VREF + 0.05(1) VS IQ 100 115 –40 –55 –65 θJA 336 5.5 115 135 V µA µA +125 +135 +150 °C °C °C °C/W Minimum supply voltage for REF3112 is 1.8V. Box Method used to determine temperature drift. Typical value of load regulation reflects measurements using force and sense contacts, see section Load Regulation. Thermal hysteresis is explained in more detail in Applications Information section of data sheet. For IL > 0, see Typical Characteristic curves. REF3112, 3120, 3125, 3130, 3133, 3140 SBVS046A 50 ISC TURN-ON SETTLING TIME POWER SUPPLY Voltage Quiescent Current Over Temperature 5 ppm ppm 3 www.ti.com TYPICAL CHARACTERISTICS At TA = +25°C, VIN = +5V power supply, REF3125 is used for typical characteristics, unless otherwise noted. TEMPERATURE DRIFT (0°C to +70°C) TEMPERATURE DRIFT (–40°C to +125°C) 18 25 20 14 Percentage of Units Percentage of Units 16 12 10 8 6 4 15 10 5 2 0 0 0 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Drift (ppm/°C) Drift (ppm/°C) DROPOUT VOLTAGE vs LOAD CURRENT OUTPUT VOLTAGE vs TEMPERATURE 120 0.16 0.14 100 Dropout Voltage (mV) 0.12 Output Drift (%) 0.10 0.08 0.06 0.04 0.02 0 80 60 40 20 −0.02 −0.04 0 −60 −40 −20 0 20 40 60 80 –15 100 120 140 –10 –5 0 5 10 15 Load Current (mA) Temperature (°C) QUIESCENT CURRENT vs TEMPERATURE OUTPUT IMPEDANCE vs FREQUENCY 120 100 Output Resistance (Ω) Quiescent Current (µA) 100 80 60 40 10 1 0.1 20 0 0.01 –60 –40 –20 0 20 40 60 80 100 120 140 Temperature (°C) 4 1 10 100 1k 10k 100k 1M Frequency (Hz) REF3112, 3120, 3125, 3130, 3133, 3140 www.ti.com SBVS046A TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VIN = +5V power supply, REF3125 is used for typical characteristics, unless otherwise noted. OUTPUT vs SUPPLY 2.505 80 2.504 +125°C 70 2.503 60 Output (V) Power-Supply Rejection Ratio (dB) PSRR vs FREQUENCY 90 50 40 30 2.502 2.501 +25°C 2.500 20 −40°C 2.499 10 2.498 0 1 10 100 1k 10k 2.0 100k 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Frequency (Hz) Supply (V) OUTPUT VOLTAGE vs LOAD CURRENT STEP RESPONSE, CL = 0, 5V STARTUP 6.0 6.5 2.505 5V/div Output Voltage (V) 2.503 VIN 1V/div +125°C 2.504 VOUT 2.502 2.501 2.500 +25°C 2.499 −40°C 2.498 2.497 –15 –10 –5 0 5 10 15 100µs/div Load Current (mA) REF3112 LONG TERM STABILITY 0.1Hz TO 10Hz NOISE 20 0 10µV/div Drift (ppm) –20 –40 –60 –80 –100 –120 0 400ms/div 100 200 300 400 500 600 700 800 900 1000 Time (Hrs) REF3112, 3120, 3125, 3130, 3133, 3140 SBVS046A 5 www.ti.com TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VIN = +5V power supply, REF3125 is used for typical characteristics, unless otherwise noted. 500mV/div LINE TRANSIENT CL = 10µF VIN VIN VOUT 20mV/div 20mV/div 500mV/div LINE TRANSIENT CL = 0pF VIN VOUT 20µs/div 100µs/div LOAD TRANSIENT CL = 0pF, ±10mA OUTPUT PULSE LOAD TRANSIENT CL = 1µF, ±10mA OUTPUT PULSE +10mA VIN +10mA –10mA –10mA VOUT 50mV/div 200mV/div +10mA +10mA VIN VOUT 40µs/div 40µs/div LOAD TRANSIENT CL = 0pF, ±1mA OUTPUT PULSE LOAD TRANSIENT CL = 1µF, ±1mA OUTPUT PULSE +1mA +1mA VIN –1mA +1mA +1mA –1mA 20mV/div 100mV/div VOUT 40µs/div 6 VOUT 40µs/div REF3112, 3120, 3125, 3130, 3133, 3140 www.ti.com SBVS046A The REF31xx is a family of series, CMOS, precision bandgap voltage references. The basic bandgap topology is shown in Figure 1. Transistors Q1 and Q2 are biased such that the current density of Q1 is greater than that of Q2. The difference of the two base-emitter voltages, Vbe1 – Vbe2, has a positive temperature coefficient and is forced across resistor R1. This voltage is gained up and added to the base-emitter voltage of Q2, which has a negative temperature coefficient. The resulting output voltage is virtually independent of temperature. 100µA, and the maximum quiescent current over temperature is just 135µA. The quiescent current typically changes less than 2µA over the entire supply range, as shown in Figure 3. QUIESCENT CURRENT vs POWER SUPPLY 100.5 Quiescent Current (µA) THEORY OF OPERATION 100.0 99.5 99.0 98.5 VBANDGAP 98.0 1.5 + + Vbe1 Vbe2 – Q1 I 2.5 3.5 4.5 5.5 Power Supply (V) R1 – FIGURE 3. Supply Current vs Supply Voltage. N Q2 FIGURE 1. Simplified Schematic of Bandgap Reference. APPLICATION INFORMATION Supply voltages below the specified levels can cause the REF31xx to momentarily draw currents greater than the typical quiescent current. This can be prevented by using a power supply with a fast rising edge and low output impedance. THERMAL HYSTERESIS The REF31xx does not require a load capacitor and is stable with any capacitive load. Figure 2 shows typical connections required for operation of the REF31xx. A supply bypass capacitor of 0.47µF is recommended. Thermal hysteresis for the REF31xx is defined as the change in output voltage after operating the device at 25°C, cycling the device through the specified temperature range, and returning to 25°C. It can be expressed as: abs VPRE – VPOST 6 VHYST = • 10 (ppm) VNOM VIN Where: VHYST = Thermal hysteresis 1 0.47µF VOUT REF31xx VPRE = Output voltage measured at 25°C pretemperature cycling 3 VPOST = Output voltage measured after the device has been cycled through the specified temperature range of –40°C to +125°C and returned to 25°C. 2 TEMPERATURE DRIFT FIGURE 2. Typical Connections for Operating REF31xx. SUPPLY VOLTAGE The REF31xx family of references features an extremely low dropout voltage. With the exception of the REF3112, which has a minimum supply requirement of 1.8V, these references can be operated with a supply of only 5mV above the output voltage in an unloaded condition. For loaded conditions, a typical dropout voltage versus load is shown in the typical curves. The REF31xx features a low quiescent current, which is extremely stable over changes in both temperature and supply. The typical room temperature quiescent current is The REF31xx is designed to exhibit minimal drift error, defined as the change in output voltage over varying temperature. The drift is calculated using the “box” method which is described by the following equation: VOUTMAX – VOUTMIN 6 V • 10 ppm • TemperatureRange OUT The REF31xx features a typical drift coefficient of 5ppm from 0°C to 70°C—the primary temperature range for many applications. For the industrial temperature range of –40°C to 125°C, the REF31xx family drift increases to a typical value of 10ppm. REF3112, 3120, 3125, 3130, 3133, 3140 SBVS046A 7 www.ti.com APPLICATION CIRCUITS NOISE PERFORMANCE Typical 0.1Hz to 10Hz voltage noise can be seen in the Typical Characteristic Curve, 0.1 to 10Hz Voltage Noise. The noise voltage of the REF31xx increases with output voltage and operating temperature. Additional filtering may be used to improve output noise levels, although care should be taken to ensure the output impedance does not degrade the AC performance. LONG-TERM STABILITY Long-term stability refers to the change of the output voltage of a reference over a period of months or years. This effect lessens as time progresses, as is shown by the long-term stability curves. The typical drift value for the REF31xx is 70ppm from 0-1000 hours. This parameter is characterized by measuring 30 units at regular intervals for a period of 1000 hours. Negative Reference Voltage For applications requiring a negative and positive reference voltage, the REF31xx and OPA703 can be used to provide a dual supply reference from a ±5V supply. Figure 5 shows the REF3125 used to provide a ±2.5V supply reference voltage. The low drift performance of the REF31xx complement the low offset voltage and low drift of the OPA703 to provide an accurate solution for split-supply applications. +5V +2.5V REF3125 LOAD REGULATION 10kΩ 10kΩ Load regulation is defined as the change in output voltage due to changes in load current. The load regulation of the REF31xx is measured using force and sense contacts as pictured in Figure 4. The force and sense lines reduce the impact of contact and trace resistance, resulting in accurate measurement of the load regulation contributed solely by the REF31xx. For applications requiring improved load regulation, force and sense lines should be used. +5V OPA703 –2.5V –5V FIGURE 5. REF3125 Combined with OPA703 to Create Positive and Negative Reference Voltages. Output Pin Contact and Trace Resistance + VOUT – Force Line IL Sense Line Load DATA ACQUISITION Data acquisition systems often require stable voltage references to maintain accuracy. The REF31xx family features stability and a wide range of voltages suitable for most microcontrollers and data converters. Figure 6, Figure 7, and Figure 8 show basic data acquisition systems. Meter FIGURE 4. Accurate Load Regulation of REF31xx. 8 REF3112, 3120, 3125, 3130, 3133, 3140 www.ti.com SBVS046A 3.3V REF3133 V+ 5Ω GND + 1µF to 10µF VS ADS7822 VREF VCC + 0.1µF VIN +In CS –In DOUT GND 1µF to 10µF Microcontroller DCLOCK FIGURE 6. Basic Data Acquisition System 1. 2.5V Supply 5Ω 2.5V + VIN VS ADS8324 REF3112 VOUT = 1.25V VREF VCC + 0.1µF 0V to 1.25V GND 1µF to 10µF +In CS –In DOUT GND 1µF to 10µF Microcontroller DCLOCK FIGURE 7. Basic Data Acquisition System 2. 5V REF3140 0.1µF 1µF VOUT = 4.096V 1kΩ 10Ω 22µF +5V 1kΩ VIN VREF 10Ω ADS8381 THS4031 6800pF 0.22µF 500Ω –5V FIGURE 8. REF3140 Provides an Accurate Reference for Driving the ADS8381. REF3112, 3120, 3125, 3130, 3133, 3140 SBVS046A 9 www.ti.com MECHANICAL DATA MPDS108 – AUGUST 2001 DBZ (R-PDSO-G3) PLASTIC SMALL-OUTLINE 3,04 2,80 2,05 1,78 0,60 0,45 1,03 0,89 1,40 1,20 2,64 2,10 0,51 0,37 1,12 0,89 0,100 0,013 0,55 REF 0,180 0,085 4203227/A 08/01 NOTES: A. B. C. D. All linear dimensions are in millimeters. This drawing is subject to change without notice. Dimensions are inclusive of plating. Dimensions are exclusive of mold flash and metal burr. 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