I've got a TLC5923 wired up on a board to drive a couple of UV LEDs. I have multiple channels, all of which work except for channel zero. The wiring between channels is identical, The SPI mode I'm using (I believe) is correct, and I've adhered to all the AC timing characteristics called out in the data sheet (I'm communicating with the device at an extremely slow rate, so the nanosecond setup times that are required for everything are more than satisfied)
Has anyone had a similar experience with this chip? The behavior persists across several boards, so I don't think I've fried a channel. Not sure what's up here.
Incidentally, I've read out the LOD register for the part. I'm only using 12 of the channels, the remaining 4 are left open circuit. The LOD correctly reports the top four channel as open, but reports channel zero as OK (no open circuit) even though I get no light from my LED.
Due to the fact that this behavior is seen on several boards, is it possible that this is caused by either the board layout or the soldering? If not, it would be helpful to get the schematic and layout to understand the issue a little more in detail.
In reply to Ryan Sturmer:
You should program the outputs you do not need to off mode. It should reduce the quiescent current when you do so. In addition normally you should no longer get a LOD warning on these channels.
My name is Narisawa and I'm in charge of LED driver and in development group.
When you input doc correction data and on/off data and then TLC5923 can controlled each channels except channel zero.
If it's so, data communication is no problem.
To check channel zero issue whether IC or other, could you please check below thing?
When input "on" data for all channels and then channel zero pin is connected other worked channel.
If LED which is connected channel zero is turned on, in this case channels zero is problem and wire is no problem.
And if LED of other channel is turned on and taht brightness is increased, in this case, channel zero is no problem and wire connection of channel zero is problem.
Thank you for your cooperation.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.