74HC595N and com anode 7 segment

Is it possible? I don’t think it is but I am not sure. The 595 outputs source voltage and a common anode 7-seg requires a sinking output correct?

74HC595 will source and sink, its not great at either (its a thinkin chip)

if you want bright numbers you need a transistor + 1k resistor in addition to your led resistors...

arduino sends 595 a binary high (+5v), the corresponding output , triggers a transistor and switches that segment to ground

If I were using 595's and led displays, I would prefer to not drive them directly from the chip. I would use some form of driver chip to be safe. Maybe a ULN2803.

However, to answer your question... I think you have it backwards. You would prefer to have a common anode in a situation you describe. I know if I were to design what you describe... I would use a common anode unit. Other opinions might differ, of course. I think these chips prefer to drive loads from the lower transistor collector so they would prefer to feed GND path to load. (A resistor is involved in the emitter feed path.

The TPIC6B595 is an identical circuit only the outputs are open drain FETs. This means they can sink about 150mA each.

The 74HC596 can only sink about 15-20mA, not much but enough for a segment maybe.

74HC595 will source and sink, its not great at either (its a thinkin chip)

if you want bright numbers you need a transistor + 1k resistor in addition to your led resistors...

as i read the datasheet the 745HC595 can source or sink 35ma which seems like lots for a led or segment. Am I reading this wrong? http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf

most are restricted to around 20ma per pin and a total of 70-75ma for the entire chip, the entire chip restriction is the one that usually gets people

so unless you know your going to buy that exact model of nxp 595 I would not use those numbers

for example as listed in this toshiba datasheet for a 595

http://www.toshiba.com/taec/components2/Datasheet_Sync//151/397.pdf

Am I reading this wrong?

Yup: when you see "Absolute maximum ratings", what it means, more or less, is "You're not supposed to push the chip this hard, but, if you accidentally bump up against these limits, non-defective chips won't immediately catch fire".

If you're just tinkering around at home, and willing to accept that you'll occasionally burn out a chip, you can usually get away with pushing the limits some of the time. But sometimes you won't get lucky, and you may find when you re-use the chip for another project, or keep using it in the same project, that it fails mysteriously because it's been over-stressed and damaged.

My suggestion: if you're eager to get something working, set up the 74HC595 with higher-value resistors to limit the current to 5mA or so, and test with a dimmer display while you're waiting for the suitable driver chip(s) that you're going to order to arrive. Or use the HC595 just for logic, and add some external circuitry for power driving.