BQ24090: TS Pin Control Clarification

Adam Housley

Prodigy 40 points

Part Number: BQ24090

C6 - 1uF

R7 - 536Ohm

R8 - 2.2kOhm

R9 - 5.6kOhm

R10 - 2.7kOhm

CHARGE_EN - 1.892v-1.352v or GND controlled by OR Gate (SN74AUP1G32DCKR)

I just wanted to check my schematic because the datasheet regarding the TS pin could be more clear. Using R9 and R10 as a voltage divider when the OR Gate is high should provide the TS pin with .62V-.44V which should be within range of normal operation, and when low provide 1.82kOhm (5.6kOhm and 2.7kOhm in parallel) of resistance to GND which would disable the chip based (equivalent to 75-80 degrees C) on the 10k NTC thermistor as mentioned in the datasheet. Am I missing something or is this correct operation. Thanks in advance!

over 4 years ago

0 Adam Housley over 4 years ago

Prodigy 40 points

This may be more clear for your assistance. Thanks in advance.

0 Bill Johns over 4 years ago in reply to Adam Housley

TI__Guru 68886 points

Thanks for your Post

Due to holiday reply may be delayed.

0 Adam Housley over 4 years ago in reply to Bill Johns

Prodigy 40 points

No worries. Thanks for the update.

0 Manuel Diaz Corrada over 4 years ago in reply to Adam Housley

TI__Prodigy 460 points

Thank you for your patience. Yes, if you were to have this implementation it would would work. It seems like you are trying to create a charge enable feature through the TS pin. Why not just use one single 10k resistor instead of the or gate? If you do not need the Jeita profile you can use "a fixed 10k can be placed between TS and VSS to allow normal operation. This may be done if the host is monitoring the thermistor and then the host would determine when to pull the TS pin low to disable charge." as noted on page 22 of the datasheet.

Please let me know if we can help in any other way.

0 Adam Housley over 4 years ago in reply to Manuel Diaz Corrada

Prodigy 40 points

No worries, I hope you had a good Christmas!

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BQ24090: TS Pin Control Clarification