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PSoC 4200L drive current on GPIO pins | Cypress Semiconductor

PSoC 4200L drive current on GPIO pins

Summary: 7 Replies, Latest post by vsrs on 13 Nov 2016 09:41 PM PST
Verified Answers: 2
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user_466193552's picture
User
12 posts

Hello,

 

I am using a CY8C4248LTI-L485 chip to drive an LC circuit to generate a magnetic field. I would like to know the max current I can pull from on these GPIO pins, as there's a lot of confusion in the info I am receiving.

On the datasheet, the absolute max current is 25mA, and in the PSoC creator software, the source current on the pin configuration window is only 4mA. However, I have measured more than 55mA on a single pin.

Please let me know what is the actual current on rating on these, and if I need to short 4 GPIO pins together to drive higher currents.

 

Thanks!

user_1377889's picture
User
9596 posts

Exceeding the max of 25mA may destroy the pin.

At 4mA the logical levels of the pin are maintained, When needing higher currents than 25mA you should combine more pins, but do not exceed the maximum power dissipation of the chip.

 

Bob

user_466193552's picture
User
12 posts

Sorry to ask again, but can you elaborate on the 4mA setting? What exactly does it do?

user_342122993's picture
User
580 posts

Eirrol,
PSoC 4: The maximum total source and sink current for all GPIO pins is 200 mA.
PSoC 5
Total source+sink current should not exceed 100 mA for
any VDDIO quadrant (or VDDIO pair for the 48-pin packages)
See p.3 of the attached AN

user_466193552's picture
User
12 posts

Thanks for your reply! However I don't think this applies to the 68 pin 4200L. What I really want to know is if I connect one pin to a load that draws more current than rated, would there be a current limiter built in to protect the circuit?

user_342122993's picture
User
580 posts

No. The pin will be destroyed. Use external FET. What current/frequency you need?

user_466193552's picture
User
12 posts

In order to generate a magnetic field strong enough I would use as much current as possible, at least 100mA, at 500 kHz. 

vsrs's picture
Cypress Employee
23 posts

Hi Eirrol,

Drawing more current than the spec may destroy the pin. As per datasheet Maximum Total Source or Sink Chip Current is 200mA. But you have to gang more pins to achieve this. Follow section 6.11 of this AppNote to know how to gang pins for more sink or source current : http://www.cypress.com/file/127101/download

Best Regards,
VSRS

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