TRF370417EVM: Do BBIP, BBIN, BBQP and BBQN require a 50 ohm resistor to ground?

Cherry Zhou

Part Number: TRF370417EVM

Hi team,

The BBIP, BBIN, and BBQP, BBQN on the TRF370417EVM reference board schematic do not have an external 50 ohm resistor to ground.

In use, if the IQ baseband output of the RhodSMW200A signal source is connected to the baseband input of the reference board, the RhodSMW200A signal source output IQ baseband signal is a current signal. The baseband input of the reference board has no resistance to ground. Could you please share how does current translate into a voltage signal? Thanks.

Best Regards,

Cherry

over 2 years ago

0 Kang Hsia over 2 years ago

TI__Guru* 78654 points

Hi Cherry

Please refer the customer to the following documents for details on the interfacing network

https://www.ti.com/lit/ug/slua647a/slua647a.pdf

Please ask the user to post detail information on SMW200a output and we can review and comment further

0 Cherry Zhou over 2 years ago in reply to Kang Hsia

TI__Mastermind 22235 points

Hi Kang,

Thank you for the support.

Kang Hsia said:
Please ask the user to post detail information on SMW200a output and we can review and comment further

The differential impedance of the IQ signal at the SMW200A output is 100 ohms. The output is a voltage signal that can be configured to bias from 0V to 4V. The single-ended voltage signal swings from 0.01 V to 1 V.

If the BBIP, BBIN, BBQP and BBQN pins supplied to the TRF370417EVM reference board are voltage signals, are the BBIP, BBIN, BBQP and BBQN pins of the reference board not require a pulldown resistor to ground?

Thanks and regards,

Cherry

0 Kang Hsia over 2 years ago in reply to Cherry Zhou

TI__Guru* 78654 points

Hi Cherry,

Cherry Zhou said:
If the BBIP, BBIN, BBQP and BBQN pins supplied to the TRF370417EVM reference board are voltage signals, are the BBIP, BBIN, BBQP and BBQN pins of the reference board not require a pulldown resistor to ground?

No, it is not required.

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TRF370417EVM: Do BBIP, BBIN, BBQP and BBQN require a 50 ohm resistor to ground?