PGA460: How select tuning capacitor?

Asael7

Part Number: PGA460

Hi.

In the application report SLAA732 there's an equation to calculate the value of Ctune (it is shown in the figure below), but the datasheet of the ultrasonic sensor doesn't have the values to calculate the tuning capacitor, only has the paramateter "Capacitance a 1kHz" that is 2000 pF +- 20%, the operating frequency of the sensor is 40 kHz.

So, how can I calculate the tuning capacitor value?

over 6 years ago

0 Bharat Aravamudhan over 6 years ago

TI__Genius 11015 points

Hello Martin,

I have received your question & we will respond to you as early as possible.

0 Bharat Aravamudhan over 6 years ago

TI__Genius 11015 points

Martin,

In the document: www.ti.com/.../slaa732.pdf, please refer to the section: "3.4 Passive Tuning".

First as in the above document, you will have to use the impedence analyser to obtain the resonant frequency of your transducer and an equivalent circuit of the transducer. Most Impedance analyser will provide you with the values of the Rt, Lt, Ct & Cpt. Using these values you could then plug it in the equation above to obtain your Ctune value.

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PGA460: How select tuning capacitor?