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General => Technical support => Topic started by: cch1955 on October 13, 2016, 10:34:29 AM

Title: Fx2424 analog 5VDC current increase?
Post by: cch1955 on October 13, 2016, 10:34:29 AM

My application is pulling the 10ma 5VDC ref voltage down on the Fx2424. If I add an external 5 volt source, all works well.

I remember one of your boards allowed changing a resistor to increase the current. I don't see that in the Fx2424 manual.

Any way to do this on the Fx2424 so I don't have to add an external supply?


Thanks

Title: Re:Fx2424 analog 5VDC current increase?
Post by: support on October 13, 2016, 10:16:02 PM

On the Fx2424 the 5V is derived from a precision voltage reference IC LM4040-5  and this IC can only source 10mA maximum. It is unfortunately not possible to supply more current from the 5V reference.

A cheap 7805 with a heat sink with 2 capacitors will allow you to step down the 24V DC to 5V and supply maybe 50mA for your requirement.

Otherwise 5V power supply can be obtained from pretty cheap 5V power supply (those USB phone charger).

Title: Re:Fx2424 analog 5VDC current increase?
Post by: cch1955 on October 14, 2016, 06:58:47 AM

I thought that might be the case. I have a small power supply on the way.
Thanks.