Does a MOSFET H-bridge need a flyback diode to drive a relay?

[Professor_Chaos]

I am using a TB6612 H-bridge module (here) to drive a 12v relay that has a 400-ohm coil.

Do I need to add a flyback diode across the relay coil, or can I rely on the body diodes of the MOSFETs in the H-bridge?

[The reason I am using the TB6612 is because I designed a board with several TB6612s, and was thinking I would employ an unused output of the board rather than build a separate transistor driver.]

[hmeijdam]

I would add the flyback across the coil, assuming you use one half of the H-bridge in series with the coil.

[jremington]

@Professor_Chaos

or can I rely on the body diodes of the MOSFETs in the H-bridge?

Most people do.

[LarryD]

@Professor_Chaos

Do I need to add a flyback diode across the relay coil, or can I rely on the body diodes of the MOSFETs in the H-bridge?

The internal diodes suffice.

Compare to a relay controlled motor circuit.

[DrDiettrich]

@LarryD

The internal diodes suffice.

These diodes are the internal body diodes of each MOSFET.

[LarryD]

@DrDiettrich

These diodes are the internal body diodes of each MOSFET.

Yes

[Professor_Chaos]

Thanks for the answers!