AD22050

AD22050 data sheet

Document overview

• Manufacturer or author: Marie
• PDF pages: 8

Technical content

IN– +VS OFS A1 A2 A1 A2 REV. C 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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. a Single-Supply Sensor Interface Amplifier AD22050 GENERAL DESCRIPTION The AD22050 is a single-supply difference amplifier for ampli- fying and low-pass filtering small differential voltages (typically 100 mV FS at a gain of 40) from sources having a large common- mode voltage. Supply voltages from +3.0 V to +36 V can be used. The input common-mode range extends from below ground to +24 V using

FEATURES

Gain of 320. Alterable from 31 to 3160 Input CMR from Below Ground to 6 3 (VS – 1 V) Output Span 20 mV to (V S – 0.2) V 1-, 2-, 3-Pole Low-Pass Filtering Available Accurate Midscale Offset Capability Differential Input Resistance 400 k V Drives 1 k V Load to +4 V Using V S = +5 V Supply Voltage: +3.0 V to +36 V Transient Spike Protection and RFI Filters Included Peak Input Voltage (40 ms): 60 V Reversed Supply Protection: –34 V Operating Temperature Range: –40 8C to +125 8C

APPLICATIONS

Interface for Pressure Transducers, Position Indicators, Strain Gages, and Other Low Level Signal Sources a +5 V supply with excellent rejection of this common-mode voltage. This is achieved by the use of a special resistive attenua- tor at the input, laser trimmed to a very high differential balance. Provisions are included for optional low-pass filtering and gain adjustment. An accurate midscale offset feature allows bipolar signals to be amplified. AD22050 SINGLE-POLE LOW-PASS FILTERING, GAIN: 40 POWER DARLINGTON 100m V 200kV C +5V ANALOG OUTPUT 4V PER AMP CORNER FREQUENCY = 0.796Hz-mF ANALOG GROUND SOLENOID LOAD +VS (CAR BATTERY) CMOS DRIVER CHASSIS Figure 1. Typical Application Circuit for a Current Sensor Interface

Model Temperature Range Package Descriptions Package Options AD22050N –40 °C to +125°C Plastic DIP N-8 AD22050R –40 °C to +125°C Plastic SOIC SO-8 AD22050R-Reel –40 °C to +125°C Tape and Reel SO-8* *Quantities must be in increments of 2,500 pieces each. AD22050–SPECIFICATIONS REV. C–2– (TA = +258C, VS = +5 V, and VCM = 0, RL = 10 kV unless otherwise noted) Parameter Test Conditions Min Typ Max Units INPUTS (Pins 1 and 8) +CMR Positive Common-Mode Range T A = TMIN to TMAX +24 V –CMR Negative Common-Mode Range T A = TMIN to +85°C –1.0 V CMRRLF Common-Mode Rejection Ratio f £ 10 Hz 80 90 dB CMRRHF Common-Mode Rejection Ratio f = 10 kHz 60 75 dB RINCM Common-Mode Input Resistances Pin 1 or Pin 8 to Pin 2 180 240 300 k W RMATCH Matching of Resistances – 0.5 % RINDIFF Differential Input Resistance Pin 1 to Pin 8 280 400 k W PREAMPLIFIER GCL Closed-Loop Gain1 9.7 10.0 10.3 VO Output Voltage Range (Pin 3) +0.01 +4.8 V RO Output Resistance2 97 100 103 kW OUTPUT BUFFER GCL Closed-Loop Gain1 RLOAD ‡ 10 kW 1.94 2.0 2.06 VO Output Voltage Range 3 TA = TMIN to TMAX +0.02 +4.8 V RO Output Resistance (Pin 5) V O ‡ 0.1 V dc, IO < 1 mA 2.0 W OVERALL SYSTEM G Gain 1 VO ‡ 0.1 V dc 19.9 20.0 20.1 Over Temperature T A = TMIN to TMAX 19.8 20.2 VOS Input Offset Voltage4 –1 0.03 1 mV Over Temperature T A = TMIN to TMAX –3 3 mV OFS Midscale Offset (Pin 7) Scaling 0.49 0.50 0.51 V/V Input Resistance Pin 7 to Pin 2 2.5 3.0 k W IOSC Short-Circuit Output Current T A = TMIN to TMAX 7 1 12 5m A BW–3 dB –3 dB Bandwidth V O = +1 V dc 30 kHz SR Slew Rate 0.2 V/ ms NSD Noise Spectral Density 3 f = 100 Hz to 10 kHz 0.2 mV/ÖHz POWER SUPPLY VS Operating Range T A = TMIN to TMAX 3.0 5 36 V IS Quiescent Supply Current 5 TA = +25°C, VS = +5 V 200 500 mA TEMPERATURE RANGE TOP Operating Temperature Range –40 +125 °C NOTES 1Specified for default mode, i.e., with no external components. The overall gain is trimmed to 0.5%, while the individual gains of A1 and A2 may be subject to a maximum – 3% tolerance. Note that the actual gain in a particular application can be modified by the use of external resistor networks. 2The actual output resistance of A1 is only a few ohms, but access to this output, via Pin 3, is always through the resistor R12 (see Figure 16) which is 100 k W , trimmed to – 3%. 3For VCM £ 20 V. For VCM > 20 V, V OL @ 1 mV/V · VCM. 4Referred to the input (Pins 1 and 8). 5With VDM = 0 V. Differential mode signals are referred to as V DM, while V CM refers to common-mode voltages—see the section Product Description and Figure 3. All min and max specifications are guaranteed, although only those marked in boldface are tested on all production units at final test. Specifications subject to change without notice.

sufficient headroom to allow at least a 10% overrange (to +4.4 V). tance is less than half that needed for the single-pole filter. Figure 11. Illustration of Two-Pole Low-Pass Filtering Figure 12. Typical Connections for a Strain Gage Interface voltage on Pin 7 and the output. act as a pull-down for the output stage. Figure 13. Detailed Schematic of Output Amplifier A2 shown, the output swing toward ground can be extended.

2 VOFS

*This 20 k W resistor is internal to the AD22050 and can vary by – 30%.