IWR1443: Some TX and RX pins are not used in my design. Can them be connected to GND?

Zhenhua Yue

Intellectual 295 points

Part Number: IWR1443

Hello,

Some TX and RX pins are not used in my design. Can them be connected to GND?

I use 1 TX and 1 RX.

over 7 years ago

0 Charles Oladimeji over 7 years ago

TI__Mastermind 33805 points

Hi,

What application are you implementing that requires single TX and RX?

Regards,

Charles O

0 Zhenhua Yue over 7 years ago in reply to Charles Oladimeji

Intellectual 295 points

Thank you for reply.

It is used to measure distance.

Single TX and RX are enough.

How to handle the rest of the TX and RX pins？

0 LAXMI KANT TIWARI over 7 years ago in reply to Zhenhua Yue

Genius 3345 points

Antenna Rx and Tx pins should be terminated with 50-ohm impedance. In the RF circuit, pins terminated with 50-ohm impedance have lowest loss and reflection. Moreover, with 50-ohm termination, you can connect with the ground to save current hence power.

0 Charles Oladimeji over 7 years ago in reply to LAXMI KANT TIWARI

TI__Mastermind 33805 points

Hi.

You can use a 50ohm termination but that gets a bit tricky to determine at 77Ghz. If you are absolutely sure you will not be using the other TX and RX terminals you should connect the pads to ground.

Regards,
Charles O

0 Zhenhua Yue over 7 years ago in reply to Charles Oladimeji

Intellectual 295 points

Hi，

As show in picture I use TX1 and RX4, coupling to single antenna.

I am sure i will not using the other TX and RX pins. I am not sure how to deal with the other TX and RX pins.

Picture1, the rest TX and RX pins connect to 50ohm resistor, the other pad of the 50ohm resistor connect to GND.

Picture2, the rest TX and RX pins connect to 50ohm resistor, the other pad of the 50ohm resistor is floating, coupling to GND through PCB.

Picture3, the rest TX and RX pins connect to GND directly.

Which one is best?

0 Zhenhua Yue over 7 years ago in reply to LAXMI KANT TIWARI

Intellectual 295 points

Thank you for reply.

Please see my furture ask.

0 Charles Oladimeji over 7 years ago in reply to Zhenhua Yue

TI__Mastermind 33805 points

Hi,

The recommendation is to leave the pins to ground (Picture 3).
You will also need separate TX and RX antennas, a TX antenna and an RX antenna.

Regards,
Charles O

0 Zhenhua Yue over 7 years ago in reply to Charles Oladimeji

Intellectual 295 points

Thank you.

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IWR1443: Some TX and RX pins are not used in my design. Can them be connected to GND?