AD8277BRZ-RL

Low Power, Wide Supply Range, Low Cost Unity-Gain Difference Amplifiers AD8276/AD8277 FEATURES Wide input range beyond supplies Rugged input overvoltage protection Low supply current: 200 μA maximum per channel Low power dissipation: 0.5 mW at VS = 2.5 V Bandwidth: 550 kHz CMRR: 86 dB minimum, dc to 10 kHz Low offset voltage drift: ±2 μV/°C maximum (B Grade) Low gain drift: 1 ppm/°C maximum (B Grade) Enhanced slew rate: 1.1 V/μs Wide power supply range: Single supply: 2 V to 36 V Dual supplies: ±2 V to ±18 V FUNCTIONAL BLOCK DIAGRAM +VS 7 AD8276 –IN 2 40kΩ 40kΩ 5 SENSE 6 OUT +IN 3 40kΩ 40kΩ 1 REF 07692-001 4 –VS Figure 1. AD8276 +VS 11 APPLICATIONS Voltage measurement and monitoring Current measurement and monitoring Differential output instrumentation amplifier Portable, battery-powered equipment Test and measurement –INA 2 40kΩ AD8277 40kΩ 12 SENSEA 13 OUTA +INA 3 40kΩ 40kΩ 14 REFA GENERAL DESCRIPTION The AD8276/AD8277 are general-purpose, unity-gain difference amplifiers intended for precision signal conditioning in power critical applications that require both high performance and low power. They provide exceptional common-mode rejection ratio (86 dB) and high bandwidth while amplifying signals well beyond the supply rails. The on-chip resistors are laser-trimmed for excellent gain accuracy and high CMRR. They also have extremely low gain drift vs. temperature. The common-mode range of the amplifiers extends to almost double the supply voltage, making these amplifiers ideal for singlesupply applications that require a high common-mode voltage range. The internal resistors and ESD circuitry at the inputs also provide overvoltage protection to the op amps. The AD8276/AD8277 are unity-gain stable. While they are optimized for use as difference amplifiers, they can also be connected in high precision, single-ended configurations with G = −1, +1, +2. The AD8276/AD8277 provide an integrated precision solution that has smaller size, lower cost, and better performance than a discrete alternative. The AD8276/AD8277 operate on single supplies (2.0 V to 36 V) or dual supplies (±2 V to ±18 V). The maximum quiescent supply current is 200 μA per channel, which is ideal for batteryoperated and portable systems. –INB 6 40kΩ 40kΩ 10 SENSEB 9 OUTB +INB 5 40kΩ 40kΩ 8 REFB 07692-052 4 –VS Figure 2. AD8277 Table 1. Difference Amplifiers by Category Low Distortion AD8270 AD8271 AD8273 AD8274 AMP03 1 High Voltage AD628 AD629 Current Sensing1 AD8202 (U) AD8203 (U) AD8205 (B) AD8206 (B) AD8216 (B) Low Power AD8276 AD8277 AD8278 U = unidirectional, B = bidirectional. The AD8276 is available in the space-saving 8-lead MSOP and SOIC packages, and the AD8277 is offered in a 14-lead SOIC package. Both are specified for performance over the industrial temperature range of −40°C to +85°C and are fully RoHS compliant. Rev. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. 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All rights reserved. AD8276/AD8277 TABLE OF CONTENTS Features .............................................................................................. 1  Applications ....................................................................................... 1  General Description ......................................................................... 1  Functional Block Diagram .............................................................. 1  Revision History ............................................................................... 2  Specifications..................................................................................... 3  Absolute Maximum Ratings............................................................ 5  Thermal Resistance ...................................................................... 5  Maximum Power Dissipation ..................................................... 5  Short-Circuit Current .................................................................. 5  ESD Caution .................................................................................. 5  Pin Configurations and Function Descriptions ........................... 6  Typical Performance Characteristics ............................................. 8  Theory of Operation ...................................................................... 14  Circuit Information.................................................................... 14  Driving the AD8276/AD8277 .................................................. 14  Input Voltage Range ................................................................... 14  Power Supplies ............................................................................ 15  Applications Information .............................................................. 16  Configurations ............................................................................ 16  Differential Output .................................................................... 16  Current Source............................................................................ 17  Voltage and Current Monitoring.............................................. 17  Instrumentation Amplifier........................................................ 18  RTD .............................................................................................. 18  Outline Dimensions ....................................................................... 19  Ordering Guide .......................................................................... 20  REVISION HISTORY 7/09—Rev. 0 to Rev. A Added AD8277 ................................................................... Universal Changes to Features Section............................................................ 1 Changes to General Description Section ...................................... 1 Added Figure 2; Renumbered Sequentially .................................. 1 Changes to Specifications Section .................................................. 3 Changes to Figure 3 and Table 5 ..................................................... 5 Added Figure 5 and Table 7; Renumbered Sequentially ............. 7 Changes to Figure 10 ........................................................................ 8 Changes to Figure 34 ...................................................................... 12 Added Figure 36.............................................................................. 13 Changes to Input Voltage Range Section .................................... 14 Changes to Power Supplies Section and Added Figure 40........ 15 Added to Figure 40 ......................................................................... 15 Changes to Differential Output Section ...................................... 16 Added Figure 47 and Changes to Current Source Section ....... 17 Added Voltage and Current Monitoring Section and Figure 49..... 17 Moved Instrumentation Amplifier Section and Added RTD Section ........................................................................................................ 18 Changes to Ordering Guide .......................................................... 20 5/09—Revision 0: Initial Version Rev. A | Page 2 of 20 AD8276/AD8277 SPECIFICATIONS VS = ±5 V to ±15 V, VREF = 0 V, TA = 25°C, RL = 10 kΩ connected to ground, G = 1 difference amplifier configuration, unless otherwise noted. Table 2. G=1 Parameter INPUT CHARACTERISTICS System Offset 1 vs. Temperature Average Temperature Coefficient vs. Power Supply Common-Mode Rejection Ratio (RTI) Input Voltage Range 2 Impedance 3 Differential Common Mode DYNAMIC PERFORMANCE Bandwidth Slew Rate Settling Time to 0.01% Settling Time to 0.001% Channel Separation GAIN Gain Error Gain Drift Gain Nonlinearity OUTPUT CHARACTERISTICS Output Voltage Swing 4 Short-Circuit Current Limit Capacitive Load Drive NOISE 5 Output Voltage Noise POWER SUPPLY Supply Current 6 vs. Temperature Operating Voltage Range 7 TEMPERATURE RANGE Operating Range 1 2 Conditions Min Grade B Typ Max 100 200 200 2 5 Min Grade A Typ Max 100 500 500 5 10 Unit μV μV μV/°C μV/V dB V kΩ kΩ kHz V/μs TA = −40°C to +85°C TA = −40°C to +85°C VS = ±5 V to ±18 V VS = ±15 V, VCM = ±27 V, RS = 0 Ω 0.5 2 86 −2(VS + 0.1) 80 40 550 1.1 +2(VS − 1.5) 80 −2(VS + 0.1) 80 40 550 1.1 +2(VS − 1.5) 0.9 10 V step on output, CL = 100 pF f = 1 kHz 0.9 15 16 15 16 130 130 0.005 0.02 1 5 μs μs dB % ppm/°C ppm 0.01 TA = −40°C to +85°C VOUT = 20 V p-p VS = ±15 V, RL = 10 kΩ, TA = −40°C to +85°C 0.05 5 10 −VS + 0.2 ±15 200 +VS − 0.2 −VS + 0.2 ±15 200 2 65 +VS − 0.2 V mA pF μV p-p nV/√Hz μA μA V °C f = 0.1 Hz to 10 Hz f = 1 kHz 2 65 70 200 250 ±18 +125 70 200 250 ±18 +125 TA = −40°C to +85°C ±2 −40 ±2 −40 Includes input bias and offset current errors, RTO (referred to output). The input voltage range may also be limited by absolute maximum input voltage or by the output swing. See the Input Voltage Range section in the Theory of Operation section for details. 3 Internal resistors are trimmed to be ratio matched and have ±20% absolute accuracy. 4 Output voltage swing varies with supply voltage and temperature. See Figure 18 through Figure 21 for details. 5 Includes amplifier voltage and current noise, as well as noise from internal resistors. 6 Supply current varies with supply voltage and temperature. See Figure 22 and Figure 24 for details. 7 Unbalanced dual supplies can be used, such as −VS = −0.5 V and +VS = +2 V. The positive supply rail must be at least 2 V above the negative supply and reference voltage. Rev. A | Page 3 of 20 AD8276/AD8277 VS = +2.7 V to