Voltage Attenuator

  • Rajkumar Sharma
  • 42 Views
  • moderate
  • Tested
  • SKU: EL143578
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The project shown here converts bipolar +/-10V (Dual 10V) signal and provides a single-ended 0 to 5V signal. The circuit attenuates a +/-10V, 10Khz bandwidth bipolar signal converts to a single-ended signal, and also filters it by a 3rd-order Butterworth filter to drive a single-ended analog-to-digital converter (ADC). The project was built using OPA2206 OPAMP which protects the input signal from overvoltage up to 40V beyond either supply. The board can be used for applications such as programable logic controllers (PLCs), low-power data acquisition systems (DAQs), and field instruments where high precision, low power, and signal fault protection are needed. OPA2206 is ideal for this application because of the high supply range, high DC precision (4-uV offset and 0.08-uV/C offset drift), and low power consumption (220uA quiescent current) that minimizes the thermal dissipation requirements. Because of the internal OVP topology, the device provides better DC and AC accuracy under normal operating conditions compared to passive external protection and results in a smaller system solution.

The first stage of the signal chain is an attenuator and level shifter. The input signal to this stage is bipolar ±10 V that is attenuated to ±2.5 V, then is level-shifted so that the output is a single-ended, 0V to 5V signal. The feedback and gain resistors were selected as 20 kΩ and 80 kΩ, respectively. Thus, the combined impedance is 100 kΩ, which lowers the input current to the signal chain and minimizes errors resulting from higher output impedance sensors. The second stage of the signal chain uses the second channel of the OPA2206 to create a 3rd-order Butterworth filter with a –3-dB response of 20 kHz. For more information on filter design, please refer to the datasheet.

PR1: Set a voltage of 2V at pin 3 of the chip using trimmer potentiometer PR1.

Features

  • Power Supply +/-12V DC (Dual 12V DC)
  • Input signal range: ±10 V
  • Input signal frequency: up to 10 kHz
  • 3rd-order Butterworth filter -3-dB frequency: 20 kHz
  • Output voltage: 0 V to 5 V
  • Trimmer Potentiometer to Adjust the Offset Voltage
  • Input protection: up to ±52 V
  • PCB Dimensions 22.38 x 18.26 mm

Connections

  • CN1: Pin 1= Signal Output 0 to 5V, Pin 2 = GND
  • CN2: Pin 1 = VC +12V, Pin 2 = GND, Pin 3 = -VE -12V, Pin 4 = +/-10V Signal Input, Pin 5 = GND
  • D1: Power LED

Schematic

Parts List

NO.QNTY.REF.DESC.MANUFACTURERSUPPLIERSUPPLIER PART NO
11CN12 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5315-ND
21CN25 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5318-ND
32C1,C310uF/25V CERAMIC SMD SIZE 1206YAGEO/MURATADIGIKEY
42C2,C4100nF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
52C5,C72.2nF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
61C6330PF/50V CERAMIC SMD SIZE 0805YAGEO/MURATADIGIKEY
71D1LED RED SMD SIZE 0805LITE ON INCDIGIKEY160-1427-1-ND
81PR110K TIMMER POTENTIOMETER SMD 3.65X3MMTT ELECTRONICSDIGIKEY987-1694-1-ND
91R12.2K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
101R239K 5% SMD SIZE 0805YAGEO/MURATADIGIKEY
111R33.74K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
121R411.8K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
131R56.65K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
141R680K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
151R720K 1% SMD SIZE 0805YAGEO/MURATADIGIKEY
161R80E SMD SIZE 0805YAGEO/MURATADIGIKEY
171U1OPA2260 VSOPTIDIGIKEY296-OPA2206ADGKTCT-ND

Connections

Input – Output Diagrams

Gerber View

Photos

Video

OPA2206 Datasheet

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