Add a time delay to signal going high to low

I think that one very simple way to do this is with a low cost, low pin count micro controller

I am not familiar with micro controllers.  Can you recommend one that you think would work for my application?

You can check TI's value line of MSP430 microcontrollers. The MSP430G2001  device should be enough for your project. And be sure to check the Launchpad, for less than 5 dollars you have a very nice tool for your first designs programming and testing

Hi Scott,

could you charge up a capacitor with the output? You could use a resistor to vary the charge/discharge time, and the capacitor would keep the output high for a small amount of time after the port switches off.

 You could run some numbers using a website like http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html#c2 to do the calculations for you.

If it works, it would be simpler than even a simple microcontroller. 

mmmm...

The capacitor and resistor affects both edges of the signal, and generally speaking, are too inexact for most applications.

Hello,

I apprecaite the help but the LTC6994 made by Linear tech does exactly what I need and it is very very easy.

Problem solved!