TMP814: IN+ and IN- voltage

Akash S

Intellectual 800 points

Part Number: TMP814

Hi,

Can we drive the IN+ and IN- pin from a microcontroller instead of hall effect sensor.

If yes, what are the voltage thresholds?

over 3 years ago

0 Aaron Barrera over 3 years ago

TI__Mastermind 26046 points

Hi Akash,

These are Hall differential inputs, which means they are low voltage outputs from the Hall element. A microcontroller would produce too high of an input voltage for IN+ and IN-. The datasheet is supposed to say "IN+" instead "H+" and "IN-" instead of "H-" for the Hall element inputs.

Thanks,
Aaron

0 Akash S over 3 years ago in reply to Aaron Barrera

Intellectual 800 points

Hi,

Can you please tell us how to control the direction of motor rotation using IN+ and IN-

If not possible using IN+ and IN-, is there any other option?

0 Aaron Barrera over 3 years ago in reply to Akash S

TI__Mastermind 26046 points

Hi Akash,

Let me check the functionality of these pins with some experts on the team and I'll get back to you by the end of the day.

Thanks,
Aaron

0 Aaron Barrera over 3 years ago in reply to Aaron Barrera

TI__Mastermind 26046 points

Hi Akash,

These pins support a Hall element, which is placed to sense the BEMF of the single phase BLDC motor and detect its position. This is a voltage that is proportional to its BEMF, and typically it is low in amplitude (in the order of mV).

You will need to use a Hall element (not a Hall sensor IC, which outputs digital outputs), which can be biased with the HB voltage and the outputs of the Hall element go to IN+ and IN-.

Examples of Hall elements can be found here: https://www.akm.com/us/en/products/hall-sensor/hall-element/

Thanks,
Aaron

0 Akash S over 3 years ago in reply to Aaron Barrera

Intellectual 800 points

Hi Aaron,

When asked previously over the forum, it was told that TMP814 can be used for brushed DC motor.

If it's right, how to control the direction of rotation.

0 Aaron Barrera over 3 years ago in reply to Akash S

TI__Mastermind 26046 points

Hi Akash,

There was a misunderstanding before, TMP814 supports a single-phase BLDC driver, not a brushed DC motor. I fixed this in the previous thread. https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1086448/tmp814-for-brushed-motors

Thanks,
Aaron

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TMP814: IN+ and IN- voltage