tlc5944: maximum output current allowable on outn pin

Marcin Madeja

Part Number: TLC5944
Other Parts Discussed in Thread: TLC5945,

Dear All,

In datasheet there is maximum output current 70mA. Can this device can handle with current up to 70mA if i put reference resistor about 750 ohm Iref pin ( estimated current on outn pin is about 65mA max.)

Best Regards,

Martin

over 8 years ago

0 Kenneth Du over 8 years ago

TI__Genius 14295 points

Hi, Martin,

According to datasheet, RIREF must be between 810 Ω (typ) and 24.3 kΩ (typ) in order to keep IOLCMax between 2 mA and 60 mA. So it may cause thermal shutdown if you set output current beyond 60mA.
Considering TLC5945 is an 80 mA device, is it possible for you to use this?

Regards,
Kenneth

0 Marcin Madeja over 8 years ago in reply to Kenneth Du

Prodigy 30 points

Hello Kenneth,

After long time we made test in thermal chamber within current up to 70ma. It seemed that thermal event did not appear. I think that is appropriate layout with a lot of polygon and heatspreader. After counting power dissipation everything looks good.

By the way tlc5945 does not have all features as tlc5944.

Thanks and Best REgards,

Martin

0 Kenneth Du over 8 years ago in reply to Marcin Madeja

TI__Genius 14295 points

Hi, Martin,

Glad to hear that and thanks for your information.

Regards,
Kenneth

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tlc5944: maximum output current allowable on outn pin