Re: [EE] Looking for serial high-side relay driver

I've also had good luck using stepper motor "h" drivers for this. Some of
the models will allow you to control each of the fets individually.

- Forrest

On Thu, May 15, 2025, 6:38 PM Brent Brown <[email protected]> wrote:

> Hi Dwayne,
>
> Seems I'm regularly looking for something like this too, and similarly
> have employed
> the TPIC6A595 with 8 x low side outputs.
>
> There are not too many choices for multi channel high side smart drivers
> with a
> serial interface. TI has some interesting 4 x channel devices worth
> looking at. But
> one I've just noticed is the  Infineon TLE75080 with 8 x channels, nominal
> 330mA
> per channel, high side, SPI for control and diagnostics, reasonable price.
>
> Brent
>
> On 15 May 2025 at 14:21, Dwayne Reid wrote:
>
> > Good day to all.
> >
> > I'm retrofitting an existing product that uses lots of 12 dc or 24 Vdc
> > relays.  These relays all have one side of the coils grounded and take
> > incoming battery supply to activate.  We are adding a pair of cards that
> > allows the relays to be controlled over a 4-wire interface (Gnd, Vbatt,
> > data, data).  I have not yet decided whether to implement a simple SPI
> > interface or RS-485, based on what options the customer wants.
> >
> > My old standby relay drivers (TPIC6595 or TPIC6C595) are not suitable
> > because they are low-side switching.  My question is: is there a modern
> > equivalent that does hi-side switching?
> >
> > Another option is to float several 74HC595 shift registers from the
> > incoming battery supply line and use a whole whack of 2N4403 transistors
> /w
> > clamp diodes to drive the relay coils.  I would then probably use
> > opto-isolators to get the signals into the chips.  I will do this if that
> > is my only option.
> >
> > Suggestions greatly appreciated!
> >
> > Many thanks!
> >
> > dwayne
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