RE: TRF3722: Datasheet Clarifications

Please see responses below.

- We assume that LO output buffer and LO div blocks are activated. Is that correct?

RJH>> Correct.

An abrupt power dissipation (for +3.3V pwr supply)  increase is depicted at figures 110-115 at frequencies approx 3GHz. However as noted in the data sheet , a constant  Txdiv=1, Lo div=1 setup should be used for Fout=2050Mà 4100M. Please clarify.

RJH>> There are four VCOs that cover the fundamental range.  The two higher frequency VCOs start at about 3 GHz.  They are biased a little stronger to maintain good phase noise.  There is also a buffer that is biased harder to maintain signal strength at the higher frequencies.  This is what accounts for the quantum jump.  At divided down frequencies the buffer is not used but you can still see a bit of a jump due to the VCOs.

- figures 111, 113 depict “ +3.3V supply current vs supply, High gain mode”, with graphs labels “+3.3V, 5V”. To which power supply rail the “5V” refers to?

RJH>> The 5V refers to the VCO tank voltage.

Does the total  Icc_3.3V depends on any other power supply rail Icc (ex. Vcc_tk)?

RJH>> No.  3.3V current independent of tank voltage.

- figure 115 depicts “ 5V supply current vs supply, low power mode”. However as specified in the data sheet the typ Icc_Tk=21mA and not >200mA as the graph depicts.

RJH>> This is a typo. It should read 3.3V and not 5V for that graph.

- Figures 119,121,123   depict “ 3.3V Pdiss vs supply” with labels “+3.3V, 5V”. To which power supply rail the “5V” refers to?

RJH>> This again is the VCO tank voltage.