TLC59731: EasySet wiring tips&tricks

HS FAE Germany

Part Number: TLC59731
Other Parts Discussed in Thread: TLC5973

Hello,
cusotmer want to use our TLC59731 and evaluated it. He had problems with the sing-wire and measured data pulses witha length of only 100ns. He has some questions how to improve the cabeling (max length, shielding, twisting, ...). May be the drive capability in the data interface can be improved.
Are there other LED driver with the EasySet interface?

Regards, Holger

over 6 years ago

0 Kenneth Du over 6 years ago

TI__Genius 14295 points

Holger,

Proper engineer has been assigned to take a look at this.

We'll reply you next week.

0 Shawn Ding over 6 years ago

TI__Expert 3190 points

Hi Holger,

We only have two devices TLC5973/TLC59731 with Easyset interface, as for the customer's questions, could you supply some test waveform?

Regards,
Shawn.

0 HS FAE Germany over 6 years ago in reply to Shawn Ding

TI__Mastermind 32220 points

Hello,
the failure happens with communication in BURST mode, capacitive coupling +/-500V and +/-1000V. This is recoverable but annoying. Please find measurings attached.

Notice:
- 4 TLC59731 in a row
- CH2 (green): DI of the 1st IC
- CH1 (yelow): DO of the 1st IC

Oscillograms:
StreamA: complet data paket
StreamA_zoom1: first bits (5 bits of 0x3A: 0011 1...) of the 32bit data streams
StreamA_zoom2: first bit: periode = 16 µs; DI impulslength: ca. 2,5 µs
StreamA_zoom3: a impuls at DO: impulslength ca150 ns

- Why is the impuls shorten?
- Is this behaviour different in the TLC5973?

Regards, Holger

~$reenshots.docx

0 Shawn Ding over 6 years ago in reply to HS FAE Germany

TI__Expert 3190 points

Hi Holger,

I can see the waveform, would you please upload it?

Regards,

Shawn

0 HS FAE Germany over 6 years ago in reply to Shawn Ding

TI__Mastermind 32220 points

the screenshots are in the doc file:7776.screenshots.docx

0 Shawn Ding over 6 years ago in reply to HS FAE Germany

TI__Expert 3190 points

Hi Holger,

I cannot point out the problem from the waveform, could you send the schematic?

Regards,
Shawn

0 Kenneth Du over 6 years ago in reply to Shawn Ding

TI__Genius 14295 points

I'll close this thread due to inactivity and if you have more questions please reply to it directly and it will open again.

0 Shawn Ding over 6 years ago

TI__Expert 3190 points

Hi Holger,

We only have two device with Easyset, TLC5973/TLC59731.

Regards,

Shawn.

0 HS FAE Germany over 6 years ago in reply to Shawn Ding

TI__Mastermind 32220 points

Hello Shawn,

here is the schematics. It is his own HW. The seriel data line is 1m long.

Regards, Holger

0 Shawn Ding over 6 years ago in reply to HS FAE Germany

TI__Expert 3190 points

Hi Holger,

It maybe the line is too long, so the slew rate of the data will be very slow at the terminal. For 100ns pulse, it maybe filtered.

I will suggest to test the waveform at the terminal to see if the hypothesis is right.

Regards,

Shawn

0 Stefan Schulz over 6 years ago in reply to Shawn Ding

Prodigy 10 points

Hello Shawn,

I am the customer who has this request regarding the shorten 100ns pulse.

While I was explaining my request more in detail, I found the answer in the datasheet - the value for T_wo (Shift data output one pulse duration). The time is always app. 125 ns, independent of input pulse duration. So I have to take this behavior into account.

Thanks and regards,

Stefan

0 Shawn Ding over 6 years ago in reply to Stefan Schulz

TI__Expert 3190 points

Hi Stefan,

Sounds good, thanks to let us know.

Regards

Shawn.

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TLC59731: EasySet wiring tips&tricks