Differential signalling to single ended adc

mirza azher

Prodigy 40 points

Other Parts Discussed in Thread: OPA172, OPA316, INA826, INA118

differential receiver signal of anlog front end to single ended adc

over 8 years ago

0 LeonardEllis over 8 years ago

TI__Guru 71526 points

Hello Mirza,

I'll need a little more specific information, such as operating frequency, power supplies available, etc. A block diagram would also be helpful.

~Leonard

0 mirza azher over 8 years ago in reply to LeonardEllis

Prodigy 40 points

I have a analog front end of an ultrasonic sensor of 51.2 KhZ, it has two differential receiver pins.I want to read the received signal using an Arduino. So,before I connect it to Arduino pin, I need to convert the differential signal into a single ended signal

0 LeonardEllis over 8 years ago in reply to mirza azher

TI__Guru 71526 points

So to be clear, the ADC is in the Arduino, you just need the buffer in-between the sensor and the ADC; for that reason, I moved this thread to the Prec Amps Forum. Also, here is an ADC tool to use for the design of the front-end, Op Amp to ADC Circuit Topology Calculator: www.ti.com/tool/adc-input-calc . Voltage levels required would also be helpful.

~Leonard

0 Errol Leon6 over 8 years ago in reply to mirza azher

TI__Expert 5850 points

Hello Mirza,

Could you provide the Ardruino model that you are using? This will help with understanding the ADC on board the Ardruino.

Best,

Errol Leon

Texas Instruments Inc.

Precision Op Amp Applications

0 Collin Wells over 8 years ago in reply to LeonardEllis

TI__Guru 63885 points

Hello,

If the differential to single-ended circuit does not require very high input impedance, then a standard difference (or differential) op amp circuit will work fine. Consider using the OPA316 for <= +5V supplies and the OPA172 for >=4.5V supplies. Here's an example circuit using the OPA316 for a differential 0.5 - 4.5V input. .

If the circuit requires very high input impedance, consider a 3-op amp INA like the INA826.

DifferenceAmp1.TSC

0 mirza azher over 8 years ago in reply to Collin Wells

Prodigy 40 points

I have a INA118P amp,Can I use it too?

0 Pete%20Semig over 8 years ago in reply to mirza azher

TI__Mastermind 25825 points

Hello Mirza,

The INA118 does in fact convert a signal from differential to single-ended. If you decide to use an instrumentation amplifier please be aware of the relationship between input common-mode voltage, power supply voltage, reference voltage, and gain to the output swing. Here is a link that contains a lot of information about these relationships:

e2e.ti.com/.../3373.understanding-instrumentation-amplifier-vcm-vs-vout-plots

If you don't need such a precise amplifier and your source impedance is not high then a straightforward difference amplifier as suggested by Collin should work well for you.

Amplifiers

Amplifiers forum

Differential signalling to single ended adc