PCA9306: Please review the schematic

Chase Jeong

Genius 5780 points

Part Number: PCA9306

Dear TI experts,

My customer drew their own schematic with PCA9306. Could you review this schematic?

Best regards,

Chase

10 months ago

0 Jack Guan 10 months ago

TI__Mastermind 27771 points

Hey Chase,

The pullups R36 and R37 may need to be sized stronger in order to support the required I2C system data rate. To find the right value, it will depend on the rise time required/ given at the outputs as shown in this app note: I2C Bus Pull-Up Resistor Calculation. The filter cap. (C56) may also be sized larger (recommended value ~0.1uF) for a stable supply.

Aside from that, the schematic looks OK.

Regards,

Jack

0 Clemens Ladisch 10 months ago in reply to Jack Guan

Guru 284750 points

When powering up, C56 must be charged through R38. With 0.1 µF, the resulting time constant of 20 ms might be too long.

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PCA9306: Please review the schematic