Not a solution for you ... Just that the function (power driver) and part
number (UDN2595) that you mentioned set off bells here. Just two days ago (what
are the chances?!) I was sorting through a box of very old (1970's) DIP and TO-3
devices when I stopped at a single Sprague UHP 500 in plastic DIP. I used to
know what it is, because I ordered it (from Cramer?) for a project at work a-way
back in '73 when I was a tech., but full-blown CRS set in when I turned 60 and
so ... well, I couldn't remember the d___ed function of this device. By dang!,
a PDF was easy to find on the web (also amazing). POWER DRIVER. Now I remember
that my intended use for this part was to drive small incandescents (panel
indicators). This device is still in its protective white plastic carrier, has
never been removed as far as I know. Wonder if all the electrons leaked out
during the intervening years. Maybe I could sell it on Ebay and retire on the
proceeds!


Oppie wrote:

I was updating a design that used the Allegro UDN2595 non-inverting power
driver. Allegero has discontinued most of their old power drivers and only
has a few that are not serial inputs. Toshiba has a similar part TD62384 but
it is a real pain to obtain. I was having a real problem trying to find
power drivers that would work with a 24V bus. It occurred to me that the old
TTL series 7406 and 7407 are rated for 30V open drain and will sink 40ma.
This will definitely work in the application and they are still showing as
active (Texas Instruments).

If anybody has suggestions on other power drivers - Source or Sink for 24V
and 100 to 300ma please let me know.

The ULN2803 was discontinued by Allegro but is still being sourced by
Toahiba snd TI in dip and soic packages.
A6801 is new from Allegro - Octal latched sink driver with cmos inputs and
darlington outputs. Interesting part.

For most of my new designs- I plan to use the Freescale MC33879 low/high
side switch. Has a SPI input and octal output switches that can be wired to
source or sink from a 5.5 to 26.5V bus. Current limited, protected and load
fault detection-Can detect open load or fault. With a bit of trickery, can
also be used as an input port. Two of the channels have PWM inputs.

For general purpose I/O - found a nice port expander from Microchip MCP23S17
16bit port expander which can have any bits input or output and has built-in
interrupt on change or condition. Available in SPI or I^2C.

Thanks for any input
Oppie