TLC6983: TLC6983

Parvin Sherakar

Part Number: TLC6983

Hi,
Project requirements:
1. LED matrix driving (NO RGB,all same color LED)
2. VCC-3.3V
3. SPI Interface in daisy chain
4. LED current- 40mA
5. LED Open/short detection
6. PWM dimming
7. Auto scanning
I checked TLC6983 IC datasheet for our application. It fits all our requirements except the current sourcing capacity. (20mA)
Is there any way we can use external transistors to drive LEDs up 40mA each current? If yes then how the Dimming will work.

8. The datasheet of TLC6983 Says connecting two ICs in daisy chain.

9. Can I connect 10 of TLC6983 In daisy chain, does it support this?

10. When I connect 10 in daisy chain, does it support 10MHz clock speed?

11. If I connect transistors amplifier to support 40mA, I can not use brightness control function. So is PWM control is the way to control the LED brightness?

Thanks

Parvin

over 4 years ago

0 Shawn Ding over 4 years ago

TI__Expert 3190 points

HI Parvin,

It seems you want to drive about 480 LEDs with 10pcs TLC6983s, right?

And you want 40mA /channel current capacity, may I know what is the application, what kind of product you are designing?

For your questions, Below are my suggestion,

1. You can parallel two channels to achieve 40mA current.

2. the device support up to 32 devices in a daisy chain with maximum 25MHz dual-edge transmission

3. For the (7) Auto scanning item, I guess you want to use the scanning structure, how many scans you want to use? please kind in mind that the average current = peak current/scan lines. so the higher scan numbers, the higher peak current. TLC6983 only can support up to 20MHz peak current.

Regards,

Shawn

0 Parvin Sherakar over 4 years ago in reply to Shawn Ding

Prodigy 50 points

Hi Shawn,

Thank you for your response.

I want to drive LED Matrix. I am planning to drive 32 x16 = 512 LEDs using single TLC6983. I will have total 10 LED Matrix in the design.

The application is LED Matrix passenger Information Displays for Railways.

1. So still can I use 2 channels to drive one row / column in the matrix to achieve 40mA?

2. Is it possible to control these 2 channels at a time to control the brightness of the LEDs?

3.I think scanning is not an issue for our application, In current design we only use 10MHz max clock, 600Hz scan rate

Other options if possible:

1. Can I use an external current amplifier to drive LEDs in the Matrix with 40mA?

2. In this case, is Brightness control possible?

Thanks

Parvin

0 Frank Qiu over 4 years ago in reply to Parvin Sherakar

TI__Genius 15776 points

Hi Parvin, our expert is on business trip, he will return to office and reply on next Monday.

0 Parvin Sherakar over 4 years ago in reply to Frank Qiu

Prodigy 50 points

Thanks Frank, I will wait for Monday.

0 Shawn Ding over 4 years ago in reply to Parvin Sherakar

TI__Expert 3190 points

Hi Parvin,

1. Yes

2. Yes

3. I would suggest to cut scanning half, and the current should be half to 20mA. Then you can use whole 48 channels to drive 48 LEDs per scanning.

Since this device is complex, It is not easy to explain clearly at here, I will suggest you contact TI FAE to get more support.

Regards,

Shawn

0 Parvin Sherakar over 4 years ago in reply to Shawn Ding

Prodigy 50 points

Thanks, Shawn,

How can I contact FAE? Would you please suggest?

thanks

Parvin

0 Frank Qiu over 4 years ago in reply to Parvin Sherakar

TI__Genius 15776 points

Please connect with your local Arrow agent for help.

+1 Parvin Sherakar over 4 years ago in reply to Frank Qiu

Prodigy 50 points

thank you

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TLC6983: TLC6983