To run a 5X7 display you don't need an additional MAX 6952 IC.
It’s designed to limit I/O pins in a micro or to control through serial interface up to 4 digits.
Directly driving from a MICROCONTROLLER will be easy than you expect.
A 18 pin PIC is enough for the job. The circuits are all over the internet.
The MAX6952 has supply pins for the LED anode and sinking pins for the LED catode. I can see who the ULN2803 could be used for the sinking but will it also work for sourcing, or vice versa?
So what can I use for the sourcing side of the LEDs (Anode) ? Will a standard high current BJT work. Should I use NPN or PNP. I never really know when it is appropiate to use NPN or PNP, is there a general rule for this, likewise for N-FET or P-FET.
1. interfacing led's switches with 8051... in this you not will use uln
2. interfacing seven segment with 8051... in this also you will not use uln
3. interfacing stepper motor... in this you shall be using uln...
I can see what your saying but the MAX6952 has multiplexed outputs so the sourcing and the sinking needs to be switched on/off. The ULN2803 is Ok for the sinking part but the sourcing, which will be 24V in my case is not permanently connected, it needs to be switched on and off also, so a sourcing element similar to the ULN2803 does for sinking is needed.
Hi all. I think I may have found a solution to my sourcing problem. I've found a device, UDN2981A which seems to be what I'm looking for. Has anyone any experience of this device? Do you think this will solve my sourcing issue. I can then use the ULN2803 inverted for sinking the current.
I think I should have been searching for "High Side Switching" all along.