REF101 ® Precision VOLTAGE REFERENCE FEATURES APPLICATIONS ● +10.00V OUTPUT ● HIGH ACCURACY: ±0.005V ● VERY LOW DRIFT: 1ppm/°C max ● PRECISION CALIBRATED VOLTAGE STANDARD ● TRANSDUCER EXCITATION ● D/A AND A/D CONVERTER REFERENCE ● PRECISION CURRENT REFERENCE ● EXCELLENT STABILITY: 50ppm/1000hrs ● LOW NOISE: 6µVp-p typ, 0.1Hz to 10Hz ● ACCURATE COMPARATOR THRESHOLD REFERENCE ● WIDE SUPPLY RANGE: Up to 35V ● LOW QUIESCENT CURRENT: 6mA max ● USEFUL MATCHED RESISTOR PAIR INCLUDED ● DIGITAL VOLTMETERS ● TEST EQUIPMENT DESCRIPTION The REF101 is a precision voltage reference which provides a +10.00V output. The drift is laser-trimmed to 1ppm/°C max (KM grade) over the full specification range. This is in contrast to some references which guarantee drift over a limited portion of their specification temperature range. The REF101 achieves its precision without a heater. This results in low quiescent current (4.5mA typ), fast warm-up (1ms to 0.1%), excellent stability (50ppm/1000hrs typ), and low noise (25µVp-p max, 0.1Hz to 10Hz). The output can be adjusted with minimal effect on drift or stability. Additionally, the REF101 contains a matched pair of user-accessible precision 20kΩ resistors which are useful in a variety of applications. Single supply operation over 13.5V to 35V supply range and excellent overall specifications make the REF101 an ideal choice for the most demanding applications such as precision system standards, D/A and A/D references, transducer excitation etc. International Airport Industrial Park • Mailing Address: PO Box 11400 Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP • © 1982 Burr-Brown Corporation R4 165kΩ VTRIM 2 R2 7kΩ R1 12kΩ 7 A1 VZ 5 3 +VCC VOUT 6 R3 2kΩ Feedback 20kΩ 8 DZ1 RA 20kΩ 4 1 Common RB • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706 Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 PDS-485D Printed in U.S.A. October, 1993 SPECIFICATIONS ELECTRICAL At TA = +25°C and +15VDC power supply, unless otherwise noted. REF101JM, KM, RM, SM PARAMETER OUTPUT VOLTAGE Initial Trim Range(1) vs Temperature(2) KM JM SM RM vs Supply (line regulation) vs Output Current (load regulation) vs Time CONDITIONS MIN TYP MAX UNITS TA = +25°C 9.995 –0.100 10.000 10.005 +0.250 V V 1 2 3 6 0.002 ppm/°C ppm/°C ppm/°C ppm/°C %/V 0°C to +70°C 0°C to +70°C –55°C to +125°C –55°C to +125°C VCC = 13.5 to 35V 0.001 IL = 0 to ±10mA TA = +25°C 0.001 50 0.002 %/mA ppm/1000hrs 6 25 µVp-p NOISE 0.1Hz to 10Hz OUTPUT CURRENT Source or Sink ±10 INPUT VOLTAGE RANGE mA 13.5 QUIESCENT CURRENT IOUT = 0 4.5 WARM-UP TIME To 0.1% 10 UNCOMMITTED RESISTORS Resistance Match TCR TCR Tracking V 6 mA µs 20 ±0.01 50 2 TEMPERATURE RANGE Specification JM, KM RM, SM Operating JM, KM RM, SM Storage 35 kΩ % ppm/°C ppm/°C ±0.05 0 –55 +70 +125 °C °C –25 –55 –65 +85 +125 +125 °C °C °C NOTES : (1) Triming the offset voltage will affect the drift slightly. See Installation and Operating Instructions for details. (2) The “box method” is used to specify output voltage drift vs temperature. See the Discussion of Performance section. ORDERING INFORMATION MODEL REF101JM REF101KM REF101RM REF101SM PIN CONFIGURATION PACKAGE TEMPERATURE RANGE MAX DRIFT (ppm/°C) Metal Metal Metal Metal 0°C to +70°C 0°C to +70°C –55°C to +125°C –55°C to +125°C 2 1 6 3 TO-99 TO-99 TO-99 TO-99 Top View TO-99 Tab 8 20kΩ RA 20kΩ RB 1 7 +VCC 7kΩ 165kΩ PACKAGE INFORMATION MODEL PACKAGE REF101JM REF101KM REF101RM REF101SM Metal Metal Metal Metal TO-99 TO-99 TO-99 TO-99 VTRIM PACKAGE DRAWING NUMBER(1) 2 001 001 001 001 6 12kΩ 6.3V VZ 3 +10V 5 VOUT NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix D of Burr-Brown IC Data Book. 4 Common ABSOLUTE MAXIMUM RATINGS 20kΩ Input Voltage ....................................................................................... 40V Power Dissipation at +25°C .......................................................... 200mW Operating Temperature Range JM, KM ......................................................................... –25°C to +85°C RM, SM ...................................................................... –55°C to +125°C Storage Temperature Range ......................................... –65°C to +125°C Lead Temperature (soldering, 10s) ............................................... +300°C Short-Circuit Protection at +25°C To Common or +15VDC ...................................................... Continuous ® REF101 Feedback 2 Optional Voltage Trim NOISE TEST CIRCUIT OPTIONAL OUTPUT VOLTAGE FINE ADJUSTMENT CIRCUIT +VCC 2kΩ 20Ω The TCR of RS can effect VOUT drift if RS is made small. 1µF Tantalum 8kΩ 100µF 7 6 Feedback OPA27 DUT 2µF Oscilloscope REF101 5 2 15.8kΩ Gain = 100V/V f3dB = 0.1Hz and 10Hz VOUT RS(1) VTRIM 4 20kΩ Output Voltage Adjust +10V NOTE: (1) See Output Voltage Adjustment vs RS Curve. TYPICAL PERFORMANCE CURVES At TA = +25°C and +15VDC power supply, unless otherwise noted. TYPICAL HEATED ZENER NOISE 6 6 4 4 Noise Voltage (µV) Noise Voltage (µV) TYPICAL REF101 NOISE 2 0 –2 –4 –6 2 0 –2 –4 –6 Low Frequency Noise (see Noise Test Ciruit) Low Frequency Noise (see Noise Test Ciruit) POWER TURN-ON RESPONSE TYPICAL BANDGAP REFERENCE NOISE 20 Error From Final Value (mV) Noise Voltage (µV) 6 4 2 0 –2 –4 15 10 5 0 –5 –10 –15 –6 –20 Power Turn-On Low Frequency Noise (see Noise Test Ciruit) ® 3 REF101 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C and +15VDC power supply, unless otherwise noted. RESPONSE TO THERMAL SHOCK POWER SUPPLY REJECTION vs FREQUENCY 100 Power Supply Rejection (dB) Output Voltage Change (µV) 400 200 0 –200 Device immersed in +70°C fluorinert bath. TA = +25°C –400 TA = +70°C 0 90 80 70 60 50 40 30 5 10 15 20 100 1k Time (s) LOAD REGULATION vs TEMPERATURE 100k QUIESCENT CURRENT vs TEMPERATURE 4 5 3 Negative Current (Sink) Quiescent Current (mA) Load Regulation (ppm/mA) 10k Frequency (Hz) 2 1 0 Positive Current (Sink) –1 –2 4 3 2 –3 –4 –75 –50 –25 0 25 50 75 100 125 –50 –25 Temperature (°C) 100 See Optional Output Voltage Fine Adjustment Circuit Junction Temperature Rise Above Ambient (°C) Output Voltage Adjustment (mV) 25 50 75 100 125 JUNCTION TEMPERATURE RISE vs OUTPUT CURRENT OUTPUT VOLTAGE ADJUSTMENT vs RS 10k 1k Voltage Increase 100 Voltage Decrease 10 0 Temperature (°C) Max. Temp. Rise for +85°C Ambient 80 VCC = 35V V V CC Max. Temp. Rise for +125°C Ambient 60 = 30 V CC = 25V V 40 V CC = 20 20 VCC = 15V 0 1 10k 100k 1M 10M 0 100M ® REF101 2 4 6 Output Current (mA) RS (Ω) 4 8 10 THEORY OF OPERATION temperature range of 0°C to +70°C. The “box” height (V1 to V2) is 700µV and upper bound and lower bound voltages are a maximum of 700µV away from the voltage at +25°C. The following discussion refers to the diagram on the first page. In operation, approximately 6.3V is applied to the noninverting input of op amp A1 by zener diode DZ1. This voltage is amplified by A1 to produce the 10.00V output. The gain is determined by R1 and R2: G = (R1 + R2)/R1. R1 and R2 are actively laser-trimmed to produce an exact 10.00V output. The zener operating current is derived from the regulated output voltage through R3. This feedback arrangement provides closely regulated zener current. R3 is actively laser-trimmed to set the zener current to a level which results in low drift at the output of A1. The adjustment of output voltage and zener current is interactive and several iterations may be used to achieve the desired results. R4 allows user-trimming of the output voltage by providing for a small external adjustment of amplifier gain. Since the TCR of R4 closely matches the TCR of the gain setting resistors, the voltage trim has minimal effect on the drift of the reference. VUPPER BOUND +10.0007 V1 Output Voltage (V) Typical Drift p 1p VLOWER BOUND 0 (TLOW) 25 70 (THIGH) Temperature (°C) FIGURE 1. REF101KM Output Voltage Drift. INSTALLATION AND OPERATING INSTRUCTIONS The REF101 is designed for applications requiring a precision voltage reference where both the initial value at room temperature and the drift over temperature are of importance to the user. Two basic methods of specifying voltage reference drift versus temperature are in common usage in the industry—the “butterfly method” and the “box method”. Neither of these methods is entirely satisfactory in cases where the drift versus temperature is relatively nonlinear as is the case with most voltage references. The REF101 is specified with the more commonly used box method. The “box” is formed by the high and low specification temperatures and a diagonal, the slope of which is equal to the maximum specified drift. BASIC CIRCUIT CONNECTION Figure 2 shows the proper connection of the REF101. To achieve the specified performance, pay careful attention to layout. A low resistance star configuration will reduce voltage errors, noise pickup, and noise coupled from the power supply. Commons should be connected as indicated being sure to minimize interconnection resistances. (1) 7 For the REF101, each J and K unit is tested at temperatures of 0°C, +25°C, +50°C, and +70°C, and each R and S unit is tested at –55°C, –25°C, 0°C, +25°C, +50°C, +75°C, +100°C and +125°C. The minimum and maximum test voltages must meet this condition. THIGH – TLOW V2 700µV Worst-case > VOUT for REF101KM l M na 1K go 10 Dia REF for °C m/ +9.9993 DISCUSSION OF PERFORMANCE (VOUT MAX – VOUT MIN)/10V +10.0000 6 Feedback VCC + REF101 (2) (3) 5 VOUT (1) 1µF Tantalum RL1 4 x 106 ≤ drift specification RL2 RL3 (3) (1) This assures the user that the variations of output voltage that occur as the temperature changes within the specification range TLOW to THIGH will be contained within a box whose diagonal has a slope equal to the maximum specified drift. Since the shape of the actual drift curve is not known, the vertical position of the box is not exactly known either. It is, however, bounded by VUPPER BOUND and VLOWER BOUND (see Figure 1). NOTES: (1) Lead resistance here of up to a few Ωs have negligible effect on performance. (2) A relatively constant current of approximately 2mA at 50ppm/°C flows in this lead. 1Ω in this lead would introduce about 2mV error (adjustable to zero) with about 0.1ppm/°C drift at the output. (3) A resistance of 0.1Ω in series with these leads will cause a 1mV error when the load current is at its maximum of 10mA. This results in a 0.01% error of 10V. FIGURE 2. REF101 Basic Circuit Connection. Figure 1 uses the REF101KM as an example. It has a drift specification of 1ppm/°C maximum and a specification ® 5 REF101 APPLICATION INFORMATION OPTIONAL OUTPUT VOLTAGE ADJUSTMENT Optional output voltage adjustment circuits are shown in Figures 3 and 4. Trimming the output voltage will change the voltage drift by approximately 0.01 ppm/°C per mV of trimmed voltage. In the circuit in Figure 3, any mismatch in TCR between the two sections of the potentiometer will also affect drift, but the effect of the ∆TCR is reduced by a factor of 40 by the internal resistor divider. A high quality potentiometer, with good mechanical stability, such as a cermet, should be used. The circuit in Figure 3 has a range of approximately +250mV to –100mV. The circuit in Figure 4 has less range but provides higher resolution. The mismatch in TCR between RS and the internal resistors can introduce some slight drift. This effect is minimized if RS is kept significantly larger than the 165kΩ internal resistor. A TCR of 100ppm/°C is normally sufficient. High accuracy, extremely-low drift, and small size make the REF101 ideal for demanding instrumentation and system voltage reference applications. Since no heater is required, low power supply current designs are readily achievable. Also the REF101 has lower output noise and much faster warm-up times (1ms to 0.1%) than heated references, permitting high precision without extra power from additional supplies. It should be considered that operating any integrated circuit at an elevated temperature will reduce its MTTF. A variety of application circuits are shown in Figures 5 through 19. +VCC +VCC + 7 OPA27 6 1µF Tantalum REF101 7 R 1kΩ 5 VOUT = +10V C 6 Feedback 5 REF101 100µF VOUT fCO = 4 20kΩ Output Voltage Adjust 2 VTRIM 4 +10V 1 =1.6Hz 2π RC FIGURE 5. Precision Reference with Filtering. Maximum range (+2.5%, –1%) and minimal degradation of drift. +15V FIGURE 3. REF101 Optional Output Voltage Adjustment. OPA128 +VCC VOUT 1 = –10V The TCR of RS can effect VOUT drift if RS is made small. + 1µF Tantalum +VCC = 15V –15V 7 6 Feedback REF101 5 VOUT 1 (1) RS 2 4 8 VTRIM 20kΩ Output Voltage Adjust 20kΩ 7 20kΩ +10V REF101 6 5 VOUT 2 = +10V 4 NOTE: (1) RS typically 4MΩ. Higher resolution, reduced range. See information in Typical Performance Curves. FIGURE 6. ±10V Reference. FIGURE 4. REF101 Optional Output Voltage Fine Adjust. The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems. ® REF101 6 +15V DG187 OPA128 VOUT 1 = +10V or –10V OPA128 VOUT 1 = +5V CMOS Switch +VCC = 15V +VCC = 15V 8 1 7 20kΩ 20kΩ 1 20kΩ 20kΩ 6 6 Logic VOUT 0 1 +10V –10V 5 REF101 REF101 Logic Input 7 8 +10V Auxiliary Output 5 VOUT 2 = +10V 4 4 FIGURE 9. Digitally-Controlled Bipolar Precision Reference. FIGURE 7. +10V and +5V Reference. +VCC = 55V to 80V +VCC = 15V to 35V 7 6 7 2 6 REF101 REF101 5 47Ω 2N6551 5 2N3904 VOUT 5 = +50V 7 4 3.3Ω 6 4 REF101 IOUT = 0 to +100mA Optional Trim 5 VOUT 4 = +40V 7 VOUT = +10V 20kΩ 6 4 REF101 5 FIGURE 10. +10V Reference with Boosted Output Current to 100mA. VOUT 3 = +30V 7 6 4 REF101 5 VOUT 2 = +20V 7 6 16kΩ +VCC = 48V (Range of 32V to 64V) 4 REF101 2N6591 5 VOUT 1 = +10V 0.1µF 5.6V 7 4 6 VOUT = +10V REF101 5 FIGURE 8. Stacked References. 4 FIGURE 11. +10V Reference with Input Voltage Boost for 48V Operation. ® 7 REF101 +VCC = 15V 7 +30V 8 2 7 R1 R2 20kΩ 20kΩ 1 6 REF101 Ladder resistor tolerances: All 10kΩ 0.02% All 10Ω 1% 5 6 5 REF101 4 4MΩ 100kΩ 10V 4 10Ω +15V 25kΩ 10kΩ 5V 50Ω OPA111 IOUT IOUT = 10V/R where R = R1||R2. 10Ω 10kΩ –15V 10kΩ 2V 20Ω IOUT may be raised up to 10mA by using external resistors. 10Ω 20kΩ 10kΩ 1V FIGURE 12. Positive Precision 1mA Current Source. 50Ω 10Ω 25kΩ R1 5kΩ VIN 0 to 10V Zero Adjust 2 0.5V IOUT 4mA to 20mA Siliconex +15V +15V 10kΩ 50Ω 7 OPA111 10Ω 3 VN89AB 10kΩ OPA111 20Ω 1 10Ω 100kΩ 20kΩ 10kΩ 0.1V +VCC = 15V 8 1 20kΩ 7 20kΩ 50Ω R2 416.7Ω Span Adjust 10Ω 50kΩ 25kΩ 10kΩ 0.05V 6 50Ω REF101 5 –15V 10Ω +10V 10kΩ 10kΩ 0.02kΩ 4 20Ω 10Ω 10kΩ 10kΩ 0.01V FIGURE 13. 4mA to 20mA Precision Current Transmitter. 20Ω FIGURE 14. Precision Voltage Calibrator. ® REF101 8 VOUT 4 5 10kΩ 0.2V –15V 6 –15V NOTE: Tie all commons to one point. +15V +VCC = 24V 7 8 7 820Ω 6 1 OPA111 6 5 REF101 +5V Out 5 REF101 +10V 4 600Ω 600Ω 4 –5V Out ∆V 600Ω FIGURE 17. ±5V Reference. 600Ω +30V 7 8 At 10.00V, the 600Ω bridge requires 16.7mA. An 820Ω resistor connected directly from the bridge to the positive supply provides the bulk of the bridge current. The REF101 need only supply an error current to keep the bridge at 10.00V. Since the REF101 can sink or source up to 10mA, the circuit shown can tolerate supply variations of up to 24V, ±8V, or bridge resistance drift from 400Ω to 1400Ω. 1 6 FIGURE 15. +10V Reference with Output Current Boost Using a Resistor to Drive a 600Ω Bridge. +20V 4 +10 OPA111 R R + ∆R 5 REF101 FIGURE 18. +10V and +20V Reference. RG 0.01µF +15V 8 1 +VCC 1 20kΩ 20kΩ REF101 6 VOUT = 2kΩ 13 7 8 10 VOUT 11 ∆R X RG 2000R VFC320 7 30kΩ 14 Gain Adjust 5 5 4 +0 to 10kHz Output 3300pF +15V –15V 8 7 4 1 ±10V Input NOTE: “Tame Transducer Bridge Errors with Op Amp Feedback Control”, EDN, May 26, 1982, Jerald Graeme. 6 REF101 5 FIGURE 16. Linear Bridge Circuit Using Internal Precision Resistors of the REF101 as the Bridge Completion Network. 4 FIGURE 19. Bipolar Input Voltage-to-Frequency Converter. ® 9 REF101