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HI Fabio,
The AD8129 is a differential receiver amplifier with 270-MHz high-bandwidth amplifier (high-speed).
I will need to refer your question to the High-Speed amplifiers product line.
Thank you and Best Regards,
Luis
Hi Luis, on my application I need only up to 20Mhz.
Can you forward the question, or I need to open a new topic?
Thank you.
HI Fabio,
You can achieve differential to single-ended conversion with an op-amp configured as a difference amplifier using discrete resistors. If you have strict accuracy, CMRR requirements, you could consider using a matched resistor network such as RES11A00 or other match resistor networks depending on the voltage or gain requirements. If you have a 20MHz bandwidth requirement, you will need to choose an op-amp with higher BW than 20MHz.
https://www.ti.com/lit/ds/symlink/res11a.pdf
Difference amplifier Application Note:
https://www.ti.com/lit/an/sboa274a/sboa274a.pdf
Beyond the 20MHz BW requirement, do you have any specific supply requirements? what is the input common-mode voltage range and differential voltage range requirement? What is the output voltage range and/or gain requirement? Any strict accuracy requirements? do you have any strict input impedance requirements?
Thank you and Regards,
Luis
HI Fabio,
The INA849 is an instrumentation amplifier with relative high bandwidth. If you require high-input impedance, depending on your input common-mode range and voltage supply requirement, the INA849 could work for you offering a BW of 28-MHz at G=1. Leaving RG unpopulated will set the device to a G=1
However, we would need to check the input-common mode range and supply requirements, and confirm/verify if the INA849 meets the supply, input voltage range and output voltage range requirements.
Beyond this, if you don't require a very high input impedance, the OPA211 (or other amplifier with GBW > 20-MHz, depending on accuracy and voltage supply requirements) configured in a difference amplifier configuration, with discrete resistors (or a matched resistor network) could work as well.
Thank you and Kind Regards,
Luis
Thank you Luis, INA849 seems to be a good alternative.
I have available +-5V, and the input is a current sensor that provide a Wheatstone bridge with +-60mV range also feeded in the same power supply.
The ref input will be useful to compensate any offset from the Wheatstone bridge.
Thank you Fabio,
Provided that the INA849 is configured with Gain=1, the device will meet the small-signal bandwidth requirement. Below is the gain vs bandwidth specification for the INA849.
If the INA849 powered with ±5V supplies, and the Wheatstone bridge is powered with the same supplies, with a ±60mV signal centered at 0V common-mode, this will work well within its linear range.
Below is a snap shot of the Vcm vs Vout Instrumentation Amplifier calculator, showing the device is in range.
Many Thanks,
Kind Regards,
Luis