RFID Reader output specification - help needed

[juaneduardodelgado]

Datasheet dude

Im working with a reader of RFID technology.
In datasheet we can read that the output is a FET that it is used as a switch.
The FET switch between V+ and V- what are inputs of the external circuit (external supply). The datasheets describes as follows:

For the GPIO outputs to function, an external user supply must be connected between V+, and V-.

Output high voltage can be V+ if there is a 10k pullup.
Output low voltage can be (V-)+0.5V if there is a 100mA load.


I dont have the internal circuit of the FET switch. That is all the information that I have.

I know what is a 10k pullup. I dont know the internal circuit, but I assume that the resistance garantee the high voltage.

What is a 100mA load? Can anybody help me to understand this?

Im trying to understand this because I design a current amplifier with a TIP31C, and in low voltage in the output of the gpio of the reader, my amplifier turn on its charge (a light).

Thanks

 

[karesz]

Datasheet dude

Hi,
If you have an output current of 100 mA to GND!
It has then an output stauration of max. 0.5V...
K.

 

[juaneduardodelgado]

Re: Datasheet dude

Hi,

I found the problem. It was a connection problem and it wasnt related to the low voltage offset or the current.

But, I have a question yet with the condition of the 100mA in the load.

High voltage output: V+ if a 10k pullup
Low voltage output: V- if a 100mA in load
I can modify the charge to get a current if I know the low voltage in the output. But it defines a resistance, and this condition doesnt allow a 10k pullup resistance.

Am I wrong?

Thanks