INA166 INA 166 www.ti.com Low-Noise, Low-Distortion, G = 2000 INSTRUMENTATION AMPLIFIER APPLICATIONS FEATURES ● ● ● ● ● ● ● LOW NOISE: 1.3nV/√Hz at 1kHz LOW THD+N: 0.09% at 1kHz WIDE BANDWIDTH: 450kHz WIDE SUPPLY RANGE: ±4.5V to ±18V HIGH CMR: > 100dB GAIN SET WITH EXTERNAL RESISTOR SO-14 SURFACE-MOUNT PACKAGE ● MOVING-COIL TRANSDUCER AMPLIFIERS ● DIFFERENTIAL RECEIVERS ● BRIDGE TRANSDUCER AMPLIFIERS ● MICROPHONE AND HYDROPHONE PREAMPS DESCRIPTION Unique distortion cancellation circuitry reduces distortion to extremely low levels, even in high gain. The INA166 provides near-theoretical noise performance for 200Ω source impedance. Its differential input, low noise, and low distortion provide superior performance as a low-level signal amplifier. The INA166 is available in a space-saving SO-14 surface-mount package, specified for operation over the –40°C to +85°C temperature range. The INA166 is a very low-noise, low-distortion, monolithic instrumentation amplifier. Its current-feedback circuitry achieves very wide bandwidth and excellent dynamic response over a wide range of gain. It is ideal for low-level signals such as microphones or hydrophones. Many industrial, instrumentation, and medical applications also benefit from its low noise and wide bandwidth. VO1 1 INA166 – VIN 4 3 6kΩ 60kΩ A1 Sense 8 3kΩ 30.3Ω A3 9 VO 3kΩ G = 2000 12 + VIN 5 6kΩ A2 Ref 10 14 V O2 Copyright © 2000, Texas Instruments Incorporated 60kΩ SBOS178 11 V+ 6 V– Printed in U.S.A. December, 2000 SPECIFICATIONS: VS = ±5V TA = +25°C and at rated supplies, VS = ±5V, RL = 2kΩ connected to ground, G = 2000, unless otherwise noted. INA166UA PARAMETER CONDITIONS MIN GAIN Gain Error Gain Temp Drift Coefficient Nonlinearity INPUT REFERRED NOISE Voltage Noise fO = 1kHz fO = 100Hz fO = 10Hz Current Noise fO = 1kHz INPUT OFFSET VOLTAGE Input Offset Voltage vs Temperature vs Power Supply INPUT VOLTAGE RANGE Common-Mode Voltage Range Common-Mode Rejection TYP MAX UNITS ±0.3 ±10 ±0.005 ±1 % ppm/°C % of FS RSOURCE = 0Ω nV/√Hz nV/√Hz nV/√Hz 0.8 pA/√Hz ±50 ±2.5 ±1 VCM = VOUT = 0V TA = TMIN to TMAX VS = ±4.5V to ±18V + – VIN – VIN = 0V + – – VIN = 0V VIN VCM = ±1V, RSRC = 0Ω 1.3 1.6 2 (V+) – 4 (V–) + 4 100 INPUT BIAS CURRENT Initial Bias Current vs Temperature Initial Offset Current vs Temperature ±250 ±3 (V+) – 3 (V–) + 3 120 2.5 15 0.1 0.5 µV µV/°C µV/V V V dB 12 1 µA nA/°C µA nA/°C INPUT IMPEDANCE DYNAMIC RESPONSE Bandwidth, Small Signal, –3dB Slew Rate THD+Noise, f = 1kHz Settling Time, 0.1% 0.01% Overload Recovery OUTPUT Voltage Load Capacitance Stability Short-Circuit Current POWER SUPPLY Rated Voltage Voltage Range Current, Quiescent TEMPERATURE RANGE Specification Operating Thermal Resistance, θJA 2 Differential Common-Mode 60 2 60 2 MΩ pF MΩ pF 5V Step 5V Step 50% Overdrive 450 15 0.09 2.5 3.5 1 kHz V/µs % µs µs µs (V+) – 1.8 (V–) + 1.8 1000 ±60 V V pF mA RL = 2kΩ to Ground (V+) – 2 (V–) + 2 Continuous-to-Common ±4.5 IO = 0mA ±5 ±10 –40 –40 ±18 ±12 +85 +125 100 V V mA °C °C °C/W INA166 SBOS178 ELECTROSTATIC DISCHARGE SENSITIVITY PIN CONFIGURATION Top View This integrated 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. VO1 1 14 VO2 NC 2 13 NC GS1 3 12 GS2 – VIN 4 11 V+ + VIN 5 10 Ref V– 6 9 VO NC 7 8 Sense 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. ABSOLUTE MAXIMUM RATINGS(1) Power Supply Voltage ....................................................................... ±18V Signal Input Terminals, Voltage(2) .................. (V–) – 0.5V to (V+) + 0.5V Current(2) .................................................... 10mA Output Short-Circuit to Ground ............................................... Continuous Operating Temperature .................................................. –55°C to +125°C Storage Temperature ..................................................... –55°C to +125°C Junction Temperature .................................................................... +150°C Lead Temperature (soldering, 10s) ............................................... +300°C SO-14 NC = No Internal Connection 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. (2) Input terminals are diode-clamped to the power-supply rails. Input signals that can swing more than 0.5V beyond the supply rails should be current limited to 10mA or less. PACKAGE/ORDERING INFORMATION PRODUCT PACKAGE PACKAGE DRAWING NUMBER INA166UA SO-14 Surface Mount 235 INA166UA " " " " PACKAGE MARKING ORDERING NUMBER(1) TRANSPORT MEDIA INA166UA INA166UA/2K5 Rails Tape and Reel NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500 pieces of “INA166UA/2K5” will get a single 2500-piece Tape and Reel. INA166 SBOS178 3 TYPICAL PERFORMANCE CURVES At TA = +25°C, VS = ±5V, RL = 2kΩ, CL = 50pF, G = 2000, unless otherwise noted. GAIN vs FREQUENCY THD+N vs FREQUENCY 70 1 VO = 5Vrms RL = 10kΩ 60 THD+N (%) Gain (dB) 50 40 30 0.1 20 10 0 0.01 10k 100k 1M 10M 100 1k Frequency (Hz) NOISE VOLTAGE (RTI) vs FREQUENCY CURRENT NOISE SPECTRAL DENSITY Current Noise Density (pA/√Hz) 10 1 0.1 1 10 100 1k 10k 1 10 100 10k POWER-SUPPLY REJECTION vs FREQUENCY CMR vs FREQUENCY 140 140 120 120 Power-Supply Rejection (dB) Input Referred CMR (dB) 1k Frequency (Hz) Frequency (Hz) 100 80 60 40 20 100 80 60 40 20 0 0 10 100 1k 10k Frequency (Hz) 4 100k 10.0 100 Noise (RTI) (nV/√Hz) 10k Frequency (Hz) 100k 1M 1 10 100 1k 10k 100k 1M Frequency (Hz) INA166 SBOS178 TYPICAL PERFORMANCE CURVES (Cont.) At TA = +25°C, VS = ±5V, RL = 2kΩ, CL = 50pF, G = 2000, unless otherwise noted. SMALL-SIGNAL RESPONSE OUTPUT VOLTAGE SWING vs OUTPUT CURRENT V+ (V+)–4 500mV/div Output Voltage to Rail (V) (V+)–2 (V+)–6 (V–)+6 (V–)+4 (V–)+2 V– 0 10 20 30 40 50 60 2.5µs/div Output Current (mA) 5V/div LARGE-SIGNAL RESPONSE 2.5µs/div INA166 SBOS178 5 APPLICATIONS INFORMATION Figure 1 shows the basic connections required for operation. Power supplies should be bypassed with 0.1µF tantalum capacitors near the device pins. The output Sense (pin 8) and output Reference (pin 10) should be low-impedance connections. Resistance of greater than 5Ω in series with these connections will degrade the common-mode rejection of the INA166. The input stage design used to achieve this low noise, results in relatively high input bias current and input bias current noise. As a result, the INA166 may not provide the best noise performance with a source impedance greater than 10kΩ. For source impedance greater than 10kΩ, other instrumentation amplifiers may provide improved noise performance. INPUT CONSIDERATIONS GAIN Gain of the INA166 is internally set for G = 2000. Input stage (A1, A2) gain is 200 and the output stage gain (A3) is 10. Internal resistor values are laser trimmed for accurate ratios to achieve excellent gain accuracy and common-mode rejection, but absolute resistor values are approximately ±20%. Nominal resistor values are shown. Although the INA166 is primarily intended for fixed-gain applications, the gain can be increased by connecting a gainset resistor, RG, between pin 3 and pin 12 The nominal gain will be: G = 2000 + Very low source impedance (less than 10Ω) can cause the INA166 to oscillate. This depends on circuit layout, signal source, and input cable characteristics. An input network consisting of a small inductor and resistor, as shown in Figure 2, can greatly reduce any tendency to oscillate. This is especially useful if a variety of input sources are to be connected to the INA166. Although not shown in other figures, this network can be used as needed with all applications shown. 60000 RG V+ 47Ω Accuracy of the 60000 term in this equation is approximately ±20%. The stability and temperature drift of RG contributes to the overall gain accuracy and these effects can be inferred from this gain equation. 4 3 11 – VIN 1.2µH 12 5 1.2µH + VIN 11 8 9 INA166 VO 10 6 6 47Ω NOISE PERFORMANCE V– The INA166 provides very low-noise with low-source impedance. Its 1.3nV/√Hz voltage noise delivers near-theoretical noise performance with a source impedance of 200Ω. FIGURE 2. Input Stabilization Network. V+ 0.1µF 1 11 INA166 – VIN 4 3 6kΩ 60kΩ A1 Sense V+ 8 Sometimes Shown in Simplified Form: 3kΩ 30.3Ω RG A3 9 VO 3kΩ INA166 VO G = 2000 12 + VIN 5 6kΩ 60kΩ A2 Ref 10 14 V– 6 0.1µF NOTE: Gain is internally set to G = 2000. RG can be used to increase gain. See text. V– FIGURE 1. Basic Circuit Connections. 6 INA166 SBOS178 OFFSET VOLTAGE TRIM OUTPUT SENSE A variable voltage applied to pin 10, as shown in Figure 3, can be used to adjust the output offset voltage. A voltage applied to pin 10 is summed with the output signal. An op amp connected as a buffer is used to provide a low impedance at pin 10 to assure good common-mode rejection. An output sense terminal allows greater gain accuracy in driving the load. By connecting the sense connection at the load, I • R voltage loss to the load is included inside the feedback loop. Current drive can be increased by connecting a buffer amp inside the feedback loop, as shown in Figure 4. V+ 4 3 12 5 11 8 V+ 9 INA166 VO 10 100µA 6 V– 150Ω OPA237 10kΩ 150Ω 100µA V– FIGURE 3. Offset Voltage Adjustment Circuit. +15V Sense 4 3 12 5 ±250mA Output Drive 11 8 9 INA166 10 VO BUF634 BW 6 BUF634 connected for wide bandwidth. –15V FIGURE 4. Buffer for Increase Output Current. INA166 SBOS178 7 PACKAGE OPTION ADDENDUM www.ti.com 3-Oct-2003 PACKAGING INFORMATION ORDERABLE DEVICE STATUS(1) PACKAGE TYPE PACKAGE DRAWING PINS PACKAGE QTY INA166UA ACTIVE SOIC D 14 58 INA166UA/2K5 ACTIVE SOIC D 14 2500 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Amplifiers Applications amplifier.ti.com Audio www.ti.com/audio Data Converters dataconverter.ti.com Automotive www.ti.com/automotive DSP dsp.ti.com Broadband www.ti.com/broadband Interface interface.ti.com Digital Control www.ti.com/digitalcontrol Logic logic.ti.com Military www.ti.com/military Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork Microcontrollers microcontroller.ti.com Security www.ti.com/security Telephony www.ti.com/telephony Video & Imaging www.ti.com/video Wireless www.ti.com/wireless Mailing Address: Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright 2003, Texas Instruments Incorporated