[tech] Octal high side driver from STMicro

[Harry]

Harry wrote:
*gah* the earlier ones were low side :-/

The right one:
http://www.st.com/stonline/products/literature/ds/11456/vn808cm-e.htm#

Datasheet:
http://www.st.com/stonline/products/literature/ds/11456.pdf

And DigiKey have them:
http://www.digikey.com/scripts/dksearch/dksus.dll?KeywordSearch&Site=US&Vendor=497&MPart=VN808CM-E

The 74HC595 is _almost_ an appropriate shift register to partner with
the driver to replicate the failed part. The issue is that the gate
signal tristates the outputs (so they could be setup to turn off by
adding eight pull-down resistors) _but_ the data can only propogate from
the shift register to the output latches on a rising RCLK (see data):
http://www.fairchildsemi.com/ds/MM/MM74HC595.pdf

It may be easier to use a 3.3volt regulator and a small Xilinx CPLD like:
http://www.xilinx.com/bvdocs/publications/ds091.pdf
This is overkill but the CPLDs don't get much smaller these days :-/

If I get time, I'll draw a circuit for the solution.
Harry