Good day Colleagues,
My customer is asking:
What is the best way to interconnect those
- TRF372017 LO_OUT_N/P pins 33/34
- TRF371109 LO_IN_N/P pins 31/30
in order to reach the best imbalance performance of the TRF371109? Is there any application notes about such a use case?
Frequency band of interest is from 900MHz to 930MHz.
Thank you, Mikhail
Hello Mikahil,
The TRF371109 has the following RF LO connection for 900MHz range
The TRF372017 has the following broadband connection:
It is by default differential output for the LO_OUT_P and LO_OUT_N.
Here are some areas where the customer need to consider:
1. If the connection between the two devices are short (i.e. less than 1 inch or so, rule of thumb). The customer can consider a direct differential connection from the TRF372017 LO_OUTP/N to TRF371109 LO_IN_P/N.
The additional LDB21897M005C-001 balun on the TRF371109 can be directly bypassed and with LO_OUTP/N connect directly, differentially to the LO_INP/N.
TRF372017 -> LO_OUTP/N -> differential 100ohm routing -> LO_INp/n -> TRF371109.
2. If the connection between the two devices are longer with potentially lots of corners and turns to introduce differential in length between positive and negative leg, then I recommend keep the recommend TRF371109 LDB21897M005C-001 balun connection. Use the same LDB21897M005C-001 in reverse on the TRF372017 LO_OUTP/N side so the long trace routing are single-ended 50ohm based.
TRF372017 -> LO_OUTP/N -> LDB21897M005C-001 balun (for diff to single-ended output) -> 50ohm traces -> LDB21897M005C-001 (for single-ended to diff input) -> LO_INp/n -> TRF371109.
-Kang
