XPR5550 off current drain

[romanrobles]

My XPR5550 draws 24mA when off. I know the radio has a soft on/off instead of a real mechanical switch, but this seems quite high. Is this normal for this model? If it is, what is drawing so much current while waiting for someone to press ON?
Thanks!

 

[Mars]

The 5550 doesn't have a mechanical on/off switch. The CPU needs current so it can monitor the input lines from the power button and ignition sense circuits, to detect power-up.

 

[N4KVE]

While on this topic, does it make a difference if using the ign key/trigger wire to turn the radio on, & off, vs using the on/off switch? Will there still be the same draw when the radio is off ? GARY

 

[triptolemus]

I wouldn't think so. The CPU is still monitoring those inputs for on/off function. The "switch" is software in both cases.

 

[Fatboy]

This is common in newer "fly-by-wire" electronics... This is why many of our customers have moved to Master power disconnects and/or relays to limit the amount of current this crap is drawing when in the "off" state. FB

 

[romanrobles]

As I said in my question, I know it's a soft on/off and not a mechanical switch, but 24mA is a lot more than necessary. Is this typical?

 

[romanrobles]

I was hoping there might be more of an engineering level response to the question. I cannot understand why any modern microcontroller would draw over a quarter of a watt waiting for a contact closure.

I have to put soft on/off switches in my designs at work and I would get laughed out the door if I went into a review with something that drew 0.288 watts for soft on/off. Therefore, I asked if this was normal for the model, and if so, what else is drawing current in the off state?

 

[Mars]

If you find the amount of current objectionable, perhaps calling Motorola and complaining about it would be the proper course of action. We are unable to resolve this issue on the forum.

 

[mss-dave]

24mA? Squelched? Really been a while since I paid attention to current draw on RX but that doesn't seem out of line at all.. 250 mA would be.

 

[N4KVE]

When I was getting ready to install a XPR4550 in my Impala, I too was worried about parasitic draw from the radio when it was off, & the car parked. I was considering using the common 5 pin relay found in so many cars. But under the passenger front carpet was wiring for up to 50 amps, & a small wire specifically meant for an ign trigger wire. I've been using it for a few months now, & I've never had a dead battery. Sometimes I don't use the car for 4 days, & even then, when the car is parked, a small red light flashes every 20 seconds on the Factory Delco Stereo radio. I think all these newer cars have a tiny draw, needed to feed all the computers, even when the car is parked. GARY

 

[tvsjr]

24mA = 0.576Ah/day. Average car battery is ~50Ah. So, over a month and you'd still be at 2/3 battery capacity. If your vehicle is sitting for longer than a month, you should be thinking about ways to maintain battery charge (crank it every week or two, run a (smart) battery maintainer, etc.) I suspect this is what Motorola would classify a "non-issue". Considering they can't make simple things like a day/night display button work in both regular and Con+ modes, I doubt they're horribly concerned with parasitic current draw.