Author Topic: MAX7219 Reverse Voltage  (Read 1925 times)

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Offline MuhKuhTopic starter

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  • Posts: 2
MAX7219 Reverse Voltage
« on: December 01, 2012, 07:18:12 pm »
Hi,

I am confused about the way the MAX7219 works.

According to the datasheet:
- The MAX7219 pulls the digit outputs to V+ when turned off.
- On the MAX7219, when a segment driver is turned off it is pulled to GND.

So when the LED segment and digit is turned off it will have a reverse voltage of 5V. Of course the segment will be off this way but looking at different 7 segment datasheets I see that they all say:

Absolute Maximum Ratings: Reverse Voltage: 5V

Is there something I misunderstand or is the MAX7219 really driving the LEDs at their limits?
 

Offline MuhKuhTopic starter

  • Newbie
  • Posts: 2
Re: MAX7219 Reverse Voltage
« Reply #1 on: December 03, 2012, 11:21:09 pm »
It looks like most LEDs survive higher reverse voltages than specified. Still strange the MAX7219 design runs the LEDs at the specified absolute maximum.
 


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