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TLC5929: LED Driver Recommendation

JDJ
Expert 3791 points
Part Number: TLC5929
Other Parts Discussed in Thread: TLC5922, , , TLC5923, TLC5921, TLC5941, TLC5940, TLC5943, TLC5927, TLC5926, TLC5944, TLC5924, TLC59116

Hello, 

I’m looking for an LED driver that meets these basic requirements:

  • Serial (SPI type) interface
  • 16 individual LED drivers
  • Up to 50mA sink current per driver

It appears that TLC5922 is the only device that meets the above specification. 

Do you have an additional part recommendation with price and longevity the top concerns? 

Also, I have noticed TLC5929 TLC59291 are serial-bus data interface but not specifically SPI. Have you seen anyone use any of these type of LED driver chips successfully use SPI instead of serial bus data interface? 

Thanks!

  • 0
    TI__Genius 12915 points

    Hi JDJ,

    For 16 channel and 50mA on/off output, TLC592x (TLC5921 / TLC5922 / TLC5923 TLC5924 / TLC5926 / TLC5927 / TLC5929 / TLC59291) could meet the requirement. Here are also some PWM output device TLC5940 / TLC5941 / TLC5943 / TLC5944 could also support it.

    Some customer used SPI to control other similar serial interface device but not TLC592x. I think it is OK to use SPI to control these deice but need to do some modify. Here is some points need to be noted: 1) Use the mode with rising edge active and SCLK = 0 when free; 2) Addition GPIO to LAT pin latching the data to device. Timing of LAT need to be met the requirement in datasheet. 3) Since data of SPI need to be whole bytes but some device need unregular length like 17 bits. In this situation I think the active data need to be filled into LSB, since there are shift register inside the IC. 4) SPI read command is not easily performed.

  • 0 in reply to Hardy Wu
    TI__Expert 3791 points

    Thanks for the detailed reply! 

    Would the TLC59291 work in a similar way as well? I have noticed this package is significantly smaller in size. 

    Another concern is having LEDs blinking or otherwise changing state while the internal registers are updated.  Do some of the controllers have an independent control pin that allows turning off all LEDs while registers are updated?

    Lastly, it appears that I2C is a more common interface, do we have any recommended devices that have the above requirements but with I2C interface? Would I2C interface be as difficult as SPI interface if using the TLC5921? 

    Another small note, this would be for an LED display. 

    Regards, 

    JDJ

  • 0 in reply to JDJ
    TI__Genius 12915 points

    Hi JDJ,

    Yes TLC59291 is the same device with TLC5929 but a QFN package. Pulling high BLANK pin of TLC5929 can control all channels off. 

    How many LEDs do you need to control? If you do not need to cascade much LED drivers, TLC59116 with I2C interface, 16 channels and 120mA max output is recommended.

  • 0 in reply to Hardy Wu
    TI__Expert 3791 points

    I potentially need to drive 30 LEDs.  They would actually be 15 Bi-Color Red/Green LEDs.

    For the TLC59116, would you recommend pulling the RESET pin high to control all pins off similarly to the blank pin of the TLC5929 device? 

    I appreciate all of the support!

  • 0 in reply to JDJ
    TI__Genius 12915 points

    Hi JDJ,

    Both of them would turn off all channels when pulling low. But they are little different after pulling high. For TLC59116, registers and I 2C state machine are held in their default states when pulling RESET low. After releasing RESET, all register are still in default value so you need to write all registers to turn on LEDs again.