STP16CPC26 flash on power up

[GlassPaul]

Hi! I'm using the STP16CPC26 as an LED driver, but have a problem where all the attached LEDs initially flash when powering up. This is a problem since this is a UI with a large-ish number of LEDs and you get hit right in the face with the bright flash.

I've tried delaying /OE until after I've written all zeros, and I've tried delaying applying power (12V) to the LEDs until after all zeros and /OE, but without a complete solution. Delaying the 12V power helps, but there is always a tiny blink regardless of what I do.

Is there some way to ensure that everything is dark on power-up?

Paul

[GlassPaul]

I have found a solution, but it makes me wonder about the part itself.

Background: I do pull up /OE with a resistor to 3.3V, and I would have expected this to prevent any initial flash. It is not sufficient, however.

My system is powered by 12V via an external supply (not automotive.) There is a 3.3V DC-DC switcher powered from this 12V input, as are the anodes of all the LEDs. When powering on, the 12V comes up first (of course), and the 3.3V switcher takes some time to start. During this interval the LEDs have 12V, but the STP16CPC26 does not yet have 3.3V. This appears to result in all of the mosfet drivers turning on, causing the LEDs to all turn on until the 3.3V is up.

Can someone from ST comment on this? I would have expected the part to be better behaved than this.