TPA6138A2: Unused channel treatment

Kelvin Tee

Genius 10035 points

Part Number: TPA6138A2

Customer has following questions

1. What is the treatment of unused channel (Rch is unused)?

For Pin 1, 2 and 3, is that ok to short directly to GND ?

If answer is no, AC ground is not preferred due to capacitor shortage. What about adding series resisitor to GND ?

2. Does this device recommend to use non-inverting input ? In the datasheet only promotes inverting input circuit.

Rgds
Kelvin

over 3 years ago

0 Ivan Salazar over 3 years ago

TI__Guru** 100965 points

Hi Kelvin,

You may check on the model or EVM is it's safe to either short to GND with resistor or leave it floating; it could be the device increasing idle current consumption, but would need to be tested.

Using any inverting or non-inverting input is OK, although it is always best to use differential input signals when possible.

Best regards,
-Ivan Salazar
Applications Engineer

0 Kelvin Tee over 3 years ago in reply to Ivan Salazar

TI__Genius 10035 points

Hi Ivan

Thanks for the comments

I saw the apps note https://www.ti.com/lit/an/sboa204a/sboa204a.pdf

Fig 3 illustrates unused OpAmp treatment for split supply. Do you think we can follow this method ?

TPA6138A2 Pin2 & 3 shorted and pin 1 short to GND.

What is your take on the best approach?
Customer needs CAD out by this week hope to hear from you soon.

Rgds
Kelvin

+1 Ivan Salazar over 3 years ago in reply to Kelvin Tee

TI__Guru** 100965 points

Hi Kelvin,

This approach should be OK for TPA6138A2 as well.

Best regards,
-Ivan Salazar
Applications Engineer

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TPA6138A2: Unused channel treatment