I want to drive lots of LEDs in a spinning persistence-of-vision (POV) device.
I need one output pin per LED, because matrix techniques don't work right in spinning POV devices.
A serial-input, parallel-output (SIPO) chip is the best way to independently control lots of output pins using only a few pins on my microcontroller, right?
Which SIPO chip should I choose?
TPIC6595 used in ... (a POV device I can't find the link to right now)
... or perhaps something I'm overlooking?
Does one SIPO chip clearly have more capabilities or easier to use than another, or are they all more-or-less equivalent functionality?
They all can be connected in the "daisy-chain SPI" configuration, right?
If I only have room for one kind of SIPO chip in my box of
"electronics components I always have on hand",
which one should it be?
I'm working on a LED POV project, and I'm using TI's TLC5925. It's pretty much a latched shift register with constant current sinking outputs. They have more advanced chips as well; some with digital brightness control and even PWM settings for each channel. It also has 16 output channels. Non-SMT versions are also available.
I hadn't looked at the 74HC4094, having always used the 74HC595, but the 74HC4094 looks like it has a couple of interesting differences:
The load signal is level-sensitive, rather than edge sensitive, allowing the device to be used in a "transparent" mode, where bits from the input are immediately shown on the output.
It has a cascading output which triggers on the same clock edge as the input, as well as a cascading output which is delayed by half a clock. Use of this latter output will greatly improve sample and hold margins when feeding the output of the device into another one; the former may be useful in some situations when feeding a device which is known to receive the clock before the data.
The 74HC4094 does not have the asynchronous clear function of the 74HC595. There have been times I would have used the 74HC595's asynchronous clear if the load signal was level-sensitive (so that asserting clear and load simultaneously would clear the outputs), and times I would have used a synchronous clear (wire the cascade output to synchronous clear and synchronous load signals, and reduce communications requirement to two wires), but I don't think the signal will be missed on the 74HC4094.
Read the datasheets. TPIC6595 is for when you need more output current. HC595 is very cheap & widely available, and would be the 'default' choice - I think the HC4094 similar but may be some small differences - I've only used the old CMOS 4094 ages ago.