ADL5502: maximum input and output

Document created by analog-archivist Employee on Feb 23, 2016Last modified by analog-archivist Employee on Aug 10, 2016
Version 2Show Document
  • View in full screen mode

In the section of SPECIFICATIONS, the maximum output voltage is specified as
below, please see figure 1. According to the figures in TYPICAL PERFORMANCE
CHARACTERISTICS, the VRMS is less than 2V. The customer wonders in what
condition VRMS output reaches 2.4V. I check with ADL5502 datasheet. It is said
that At 900 MHz, the VRMS output voltage is nominally 1.89 times the input rms
voltage (a conversion gain of 1.89 V/V rms). Similarly, the PEAK output voltage
is nominally 1.27 times the input rms voltage (a conversion gain of 1.27 V/V
rms). The rms output voltage swings from near ground to 2.4 V on a 3.0 V
supply. I think the output is 2.7V when getting the Absolute Maximum Ratings.
1.25Vrms * 1.89V/Vrms=2.36V, please see figure 2. To be honest, I am not sure
about it and need your confirmation. Could you please help give some comments
on it?

 

I think the confusion is because the figures stop at an input of +13 dBm when
the part can handle +15 dBm.  There was a limit on the test equipment output
ability and the plots where cut off two dB short (arbitrarily). If you where to
plot to the full +15 dBm limit, then you would see the full 2.4 V range. I made
an Excel sheet of the way the plot would look.  I hope this will help clear it
up (red stops at 13 dBm, blue stops at 15 dBm), please see figures 3 and 4.

Outcomes