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INA2191: Use for Solenoid and Valve Controls

Anders Larsson
Prodigy 10 points
Part Number: INA2191
Other Parts Discussed in Thread: INA253, INA240

Can "INA2191A1" be used for a solenoid and valve control application? Do we then need to add any additional protection to the component?

If it can't be used, can you suggest a component that we can use which is currently available in high volumes with these requirements:

Supply voltage: 3.3V.

Gain: about 20V/V.

Common-mode range: from below zero to at least 40V.

Preferable: Small package and low price.

  • 0
    TI__Mastermind 34960 points

    Hi,

    Depending on the selected current sense topology, the INA2191 may or may not be appropriate. The topology is in reference to the relative positions of the switch, the solenoid and the current sense amplifier.

    If the current sense amplifier is placed so that one of its input terminals is connected directly to the power supply (high side) or ground (low side), then yes, INA2191 can possibly be used. However, other parameters including speed, need further evaluation against the specific operating condition of the design.

    For topologies other than above mentioned, you may want to evaluate and select from one of these: INA240, INA253(same as INA240 with integrated shunt), INA241 and INA296. The last two are new to market and available for sampling.

    You could refer to this blog post for a more in-depth discussion of current sensing in solenoid drive.

    Regards, Guang

  • 0
    Guru 140200 points

    Hi Anders,

    a schematic would be helpful.

    Kai

  • 0 in reply to Guang Zhou
    Prodigy 10 points

    Yes, the current sense amplifier is placed so that one of its input terminals is connected directly to the power supply (high side) or ground (low side), and a PWM-signal can be created.

    Unfortunately INA240 is not available to buy for some months, INA253 is to large to fit our current layout. We need the component in volume immediately so sampling is not enough.

    The "INA2191A1" has two channels, can both channels be enabled and used at the same time? It seems like that as the enable pins can be connected to VS, do I understand that correct?

    Maybe this component needs some more transient protection than the other components you suggested. We are thinking of TVS-diode protection similar to datasheet image, does this look like a good way?

  • 0 in reply to Anders Larsson
    TI__Mastermind 34960 points

    Hi,

    Yes you can enable both channels of INA2191 at the same time, this is not an issue.

    The problems is that in general INA2191 can not be used in the configuration where the shunt resistor is placed between the driver stage and the coil. I understand the supply chain shortage, but the number of choices is small to begin with when it comes to current sense amplifiers for this position.

    It depends on the actual design implementation, but the CSA would need to be able to withstand -1V common mode input voltage at least. INA2191 is rated for -0.3V, and adding TVS diodes is not going to help. Adding a pair of large input resistors will mitigate the over voltage issue, but I think we may see undesirable output transients. It will become a performance issue. For mass production, I would nor recommend this approach.

    If you must use INA2191, the compromise is to adopt high side or low side topology, where the shunt resistance is placed between the 24V supply and the driver stage, or between the coil and ground.

    Regards, Guang