® INA106 INA 106 INA 106 Precision Gain = 10 DIFFERENTIAL AMPLIFIER FEATURES APPLICATIONS ● ACCURATE GAIN: ±0.025% max ● HIGH COMMON-MODE REJECTION: 86dB min ● NONLINEARITY: 0.001% max ● EASY TO USE ● PLASTIC 8-PIN DIP, SO-8 SOIC PACKAGES ● ● ● ● ● G = 10 DIFFERENTIAL AMPLIFIER G = +10 AMPLIFIER G = –10 AMPLIFIER G = +11 AMPLIFIER INSTRUMENTATION AMPLIFIER DESCRIPTION The INA106 is a monolithic Gain = 10 differential amplifier consisting of a precision op amp and on-chip metal film resistors. The resistors are laser trimmed for accurate gain and high common-mode rejection. Excellent TCR tracking of the resistors maintains gain accuracy and common-mode rejection over temperature. The differential amplifier is the foundation of many commonly used circuits. The INA106 provides this precision circuit function without using an expensive resistor network. The INA106 is available in 8-pin plastic DIP and SO-8 surface-mount packages. –In 2 R1 10kΩ R2 100kΩ 5 7 6 4 +In 3 R3 10kΩ R4 100kΩ 1 Sense V+ Output V– Reference International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111 Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 © 1987 Burr-Brown Corporation PDS-729F Printed in U.S.A. August, 1998 SPECIFICATIONS ELECTRICAL At +25°C, VS = ±15V, unless otherwise specified. INA106KP, U PARAMETER CONDITIONS MIN GAIN Initial(1) Error vs Temperature Nonlinearity(2) TYP 10 0.01 –4 0.0002 OUTPUT Related Voltage Rated Current Impedance Current Limit Capacitive Load IO = +20mA, –5mA VO = 10V 10 +20, –5 Voltage Range Common-Mode Rejection(3) OFFSET VOLTAGE Initial vs Temperature vs Supply vs Time NOISE VOLTAGE fB = 0.01Hz to 10Hz fO = 10kHz DYNAMIC RESPONSE Small Signal Full Power BW Slew Rate Settling Time: 0.1% 0.01% 0.01% POWER SUPPLY Rated Voltage Range Quiescent Current 0.025 0.001 12 Differential Common-Mode Differential Common-Mode TA = TMIN to TMAX 10 110 ±1 ±11 86 UNITS V/V % ppm/°C % V mA Ω mA pF 0.01 +40/–10 1000 To Common Stable Operation INPUT Impedance MAX kΩ kΩ V V dB 100 RTI(4) 50 0.2 1 10 ±VS = 6V to 18V 200 10 µV µV/°C µV/V µV/mo RTI(5) –3dB VO = 20Vp-p 30 2 VO = 10V Step VO = 10V Step VCM = 10V Step, VDIFF = 0V ±5 Derated Performance VO = 0V TEMPERATURE RANGE Specification Operation Storage 0 –40 –65 1 30 µVp-p nV/√Hz 5 50 3 5 10 5 MHz kHz V/µs µs µs µs ±15 ±1.5 ±18 ±2 V V mA +70 +85 +150 °C °C °C NOTES: (1) Connected as difference amplifier (see Figure 1). (2) Nonlinearity is the maximum peak deviation from the best-fit straight line as a percent of full-scale peakto-peak output. (3) With zero source impedance (see “Maintaining CMR” section). (4) Includes effects of amplifiers’s input bias and offset currents. (5) Includes effect of amplifier’s input current noise and thermal noise contribution of resistor network. ® INA106 2 ELECTROSTATIC DISCHARGE SENSITIVITY PIN CONFIGURATION Top View DIP/SOIC • (1) Ref 1 –In 2 +In 3 V– 4 10kΩ 8 NC 7 V+ 6 Output 5 Sense This integral circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. 100kΩ 10kΩ 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 published specifications. 100kΩ INA106 NOTE: (1) Pin 1 indentifier for SO-8 package. Model number identification may be abbreviated on SO-8 package due to limited available space. PACKAGE/ORDERING INFORMATION ABSOLUTE MAXIMUM RATINGS Power Supply Voltage ...................................................................... ±18V Input Voltage Range ............................................................................ ±VS Operating Temperature Range: P, U ................................ –40°C to +85°C Storage Temperature Range ............................................ –40°C to +85°C Lead Temperature (soldering, 10s): P .......................................... +300°C Wave Soldering (3s, max) U .......................................................... +260°C Output Short Circuit to Common .............................................. Continuous PRODUCT PACKAGE PACKAGE DRAWING NUMBER(1) INA106KP INA106U 8-Pin Plastic DIP SO-8 Surface Mount 006 182 TEMPERATURE RANGE 0°C to +70°C 0°C to +70°C NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. 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. ® 3 INA106 TYPICAL PERFORMANCE CURVES At TA = +25°C, VS = ±15V, unless otherwise noted. SMALL SIGNAL RESPONSE (No Load) STEP RESPONSE Output Voltage (mV) 50 0 –50 2µs/div 2µs/div TOTAL HARMONIC DISTORTION AND NOISE vs FREQUENCY SMALL SIGNAL RESPONSE (RLOAD = ∞, CLOAD = 100pF) 1 A = 20dB, 3Vrms, 10kΩ load THD + N (%) Output Voltage (mV) 50 0 0.1 Inverting Noninverting 0.01 –50 30kHz low-pass filtered 0.001 1k 2µs/div 10k 100k Frequency (Hz) MAXIMUM VOUT vs IOUT (Negative Swing) MAXIMUM VOUT vs IOUT (Positive Swing) –17.5 17.5 VS = ±18V –15 15 VS = ±15V –10 VS = ±12V 12.5 VOUT (V) VOUT (V) VS = ±18V –12.5 –7.5 –5 VS = ±15V 10 VS = ±12V 7.5 5 VS = ±5V –2.5 2.5 0 VS = ±5V 0 –2 0 –4 –6 –8 –10 –12 0 –IOUT (mA) 12 18 IOUT (mA) ® INA106 6 4 24 30 36 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, VS = ±15V, unless otherwise noted. POWER SUPPLY REJECTION vs FREQUENCY 110 140 100 120 PSRR (dB) CMR (dB) CMR vs FREQUENCY 90 80 70 100 V– 80 60 V+ 60 40 10 100 1k 10k 100k 1 10 Frequency (Hz) 100 1k 10k 100k Frequency (Hz) APPLICATIONS INFORMATION Figure 1 shows the basic connections required for operation of the INA106. Power supply bypass capacitors should be connected close to the device pins as shown. V– Ref terminal will be summed with the output signal. The source impedance of a signal applied to the Ref terminal should be less than 10Ω to maintain good common-mode rejection. V+ 1µF Figure 2 shows a voltage applied to pin 1 to trim the offset voltage of the INA106. The known 100Ω source impedance of the trim circuit is compensated by the 10Ω resistor in series with pin 3 to maintain good CMR. 1µF 4 7 INA106 V2 2 R2 100kΩ R1 10kΩ 5 INA106 R2 R1 V3 3 R3 10kΩ 2 V2 6 + – 5 VOUT = 10(V3 –V2) 10Ω R4 100kΩ V3 1 3 6 R3 Compensates for some impedance at pin 1. See text. R4 +15V 1 499kΩ VO = V2 – V3 Offset Adjustment Range = ±3mV FIGURE 1. Basic Power Supply and Signal Connections. VO 100kΩ 100Ω The differential input signal is connected to pins 2 and 3 as shown. The source impedance connected to the inputs must be equal to assure good common-mode rejection. A 5Ω mismatch in source impedance will degrade the commonmode rejection of a typical device to approximately 86dB. If the source has a known source impedance mismatch, an additional resistor in series with one input can be used to preserve good common-mode rejection. –15V FIGURE 2. Offset Adjustment. Referring to Figure 1, the CMR depends upon the match of the internal R4/R3 ratio to the R1/R2 ratio. A CMR of 106dB requires resistor matching of 0.005%. To maintain high CMR over temperature, the resistor TCR tracking must be better than 2ppm/°C. These accuracies are difficult and expensive to reliably achieve with discrete components. The output is referred to the output reference terminal (pin 1) which is normally grounded. A voltage applied to the ® 5 INA106 INA106 V1 10Ω 10kΩ 2 E1 –In 100kΩ 5 A1 E0 6 2 R2 Gain Adjust 200Ω INA106 5 6 R1 E0 Output R2 V2 10Ω 10kΩ 3 100kΩ 1 3 CMR Adjust 200Ω A2 To eliminate adjustment interactions, first adjust gain with V2 grounded. To make a high performance high gain instrumentation amplifier, the INA106 can be combined with state-of-the-art op amps. For low source impedance applications, OPA37s will give the best noise, offset, and temperature drift. At source impedances above about 10kΩ, the bias current noise of the OPA37 reacting with input impedance degrades noise. For these applications, use an OPA111 or a dual OPA2111 FET input op amp for lower noise. For an electrometer grade IA, use the OPA128—see table below. INA106 10kΩ 100kΩ 2 E0 = 10(1 + 2R2 /R1) (E2 – E1) E2 +In FIGURE 3. Difference Amplifier with Gain and CMR Adjust. V2 5 6 Using the INA106 for the difference amplifier also extends the input commonmode range of the instrumentation amplifier to ±10V. A conventional IA with a unity-gain difference amplifier has an input common-mode range limited to ±5V for an output swing of ±10V. This is because a unity-gain difference amp needs ±5V at the input for 10V at the output, allowing only 5V additional for common-mode. VO VO = –10V2 10kΩ 100kΩ 3 1 1 A1, A2 R1 (Ω) R2 (kΩ) GAIN (V/V) CMRR (dB) Ib (pA) NOISE AT 1kHz (nV/ √Hz) OPA37A OPA111B OPA128LM 50.5 202 202 2.5 10 10 1000 1000 1000 128 110 118 40000 1 0.075 4 10 38 FIGURE 6. Precision Instrumentation Amplifier. Gain Error = 0.01% maximum Nonlinearity = 0.001% maximum Gain Drift = 2.ppm/°C INA106 FIGURE 4. Precision G = –10 Inverting Amplifier. 2 INA106 2 R2 100kΩ R1 10kΩ V1 1 R4 100kΩ 1 5 V0 6 V0 = V1 + 10 V3 6 R3 10kΩ 3 VO FIGURE 7. Precision Summing Amplifier. VO = VIN ±100V Safe Input R2 100kΩ R4 100kΩ 5 V3 VIN R1 10kΩ R3 10kΩ INA106 2 3 5 This circuit follows an 11/1 divider with a gain of 11 for an overall gain of unity. With an 11/1 divider, the input signal can exceed 100V without damage. 6 FIGURE 5. Voltage Follower with Input Protection. 1 VIN VO = 11VIN 3 FIGURE 8. Precision G = 11 Buffer. ® INA106 6 VO Gain Error = 0.01% maximum