TLC59116: Parallel output channels

Mars Huang1

Part Number: TLC59116

Hi,

Excuse me, the maximum output of each channel of TLD59116 is 120mA. If the circuit diagram is as follows, can each LED get a current of 120mA*4=480mA?

How to set REXT if each channel wants to get 120mA? Is it directly grounded?

Thank you.

over 4 years ago

0 Monet Xu over 4 years ago

TI__Genius 9255 points

Hi Mars,

the REXT setting can refer to the following table. Register IREF Bit7 needs to be set to 1.

in addition, the attached pic can't be display successfully, could you please provide it again?

Best Regard

Monet Xu

0 Mars Huang1 over 4 years ago in reply to Monet Xu

Prodigy 120 points

Hi Monet,

Sorry,I have re-updated the pic.

I have seen how REXT is calculated, but I don't know very well.

If 120mA is used per channel, how should REXT be calculated?

thanks.

0 Monet Xu over 4 years ago in reply to Mars Huang1

TI__Genius 9255 points

Hi Mars,

Refer to the formula:

Iout,target = 1.26V/Rext * VG * 15 * 3^(CM-1)

setting IREF Bit7 to 1(High current multiplier) and Bit6 to 1(High-Voltage subband), CC[0:5] = 111111. Therefore, Rext = 1.26 * 127/128 * 15 * 1 / 120mA = 156Ω.

Best Regard

Monet Xu

0 Mars Huang1 over 4 years ago in reply to Monet Xu

Prodigy 120 points

Hi Monet,

Is the schematic is ok? Can each LED get 480mA drive current?

Should the application choose TLC59116 or TLC59116F?

Any suggestions? Thank you.

0 Monet Xu over 4 years ago in reply to Mars Huang1

TI__Genius 9255 points

Hi Mars,

it will be OK. The different between TLC59116 and TLC59116F is the REXT pin and each device is suitable for your application. But TLC59116 can help reduce the cost from remove the outside resister.

Best Regard

Monet Xu

0 Mars Huang1 over 4 years ago in reply to Monet Xu

Prodigy 120 points

Hi Monet,

Understand, thank you for your quick reply!

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TLC59116: Parallel output channels