TPS65235-1: Only Use Tone Detection

Hi Kato,

Do you want to use TPS65235-1 only as a tone signal detector? Yes, I think you can do this.

Maybe you can also use a comparator to detect the 22kHz signal. What you need to do is bias both of the comparator inputs at reasonable voltage. Then use a capacitor to isolate the high DC voltage on VLNB power bus , coupling the tone signals to one input of the comparator. If tone signal is presenting on the power bus, you will get a PWM signal on the comparator output. 

Thanks!

Regards,

Hao

Hi Hao-san,

Thank you for your quick response.

Could you please share the recommended referece schematic with comparater for the tone detector if possible ?

Best regards,
Kato

Hi Kato,

It's just a idea appear in my mind. I don't have schematic at hand. Do you fully understand my idea?

Regards,

Hao

Hi Hao-san,

The detection signal which I would expect is not the PWM output, but a detector that operates as follows.

I will return to the first question, Please tell me the minimum required external components when disabling the boost converter.

Best regards,
Kato

Hi Hao-san,

Thank you for the information.

I have additional quesitons as follows.

Q1. Hardware Control
I would like to confirm just in case, does the tone detection work if EN pin is pull to high ?

Q2. Software Control
Does the tone detection work even if LNB output disables via I2C ?

Best regards,
Kato

Hi Hao-san,

Thank you for the explanation.

I have an additional question as follows.

I found in TPS65235-1 data sheet that in non-I2C mode(hardware control mode), SCL, SDA and ADDR pins can be floating. So, can the pins of EXTM and VCTRL be floating ?

Best regards,
Kato

Hi Hao-san,

Thank you for confirming.

I understood and will contact you if I get addtional questions from our customer.

Best regards,
Kato