I want to use the INA250A3 to sense a max of +/- 1 amp. My Vs will be 3.3 volts.
1. I assume the Vref should be 3.3volts/2. Can I use two 10k resistors in series as a voltage divider to get the 3.3volts/2?
2. Is it OK to simply connect SH+ to VIN+ and SH- to VIN-
Thanks,
Ed K
Hi Ed,
Thanks for considering TI products.
1. Vref could be any voltage between 0V to Vs (in your case, up to 3.3V). Vs/2 is good. Although, it is not a good practice to use a resistor divider into the reference node, it can cause CMRR issues. If you decide to use the resistor divider then make sure you buffer the REF pin. Refer to text from Page 15 of the datasheet:
"As with any difference amplifier, the INA250 common-mode rejection ratio is affected by any impedance present at the REF input. This concern is not a problem when the REF pin is connected directly to a reference or power supply. When using resistive dividers from a power supply or a reference voltage, buffer the REF pin with an op amp."
2. If you don't need to use filters then connect SH+ to VIN+ and SH- to VIN- as shown in the reference circuit on the datasheet.
