RF6886 Datasheet, PDF (9/16 Pages) RF Micro Devices – 3.6V, 100MHz TO 1000MHz LINEAR POWER AMPLIFIER

RF6886
One key consideration will be output side isolated port 50 termination resistance. In the case where output VSWR deviates
significantly from 50, reflected power will be absorbed in the isolated port. This will require placement of resistor bank capa-
ble of handling power dissipation while fault condition exists.
Finally, consider the maximum allowable operating device voltage, listed at 4.0V in the table on page 2. Operating with
V_CC=4.0 V enables higher compression point, which becomes attractive in two types of applications:
1. High power, high efficiency
2. Linear, requiring specification compliance at higher power level
Viewing curves in the graph section, it can be seen that device junction temperature stays below 150°C (85°C ambient) up to
rated power levels. Junction temperature becomes a more critical specification with higher operating voltage. It should be
stressed again here that a properly matched output load impedance is required to provide high efficiency. Load impedance
has been measured on both standard evaluation boards. The table below contains that data:
Freq
MHz
865
900
928
955
Standard Evaluation
Board Load Impedance
A + jB 
1.983+j 0.157
1.983+j 0.579
1.953+j 0.789
1.969+j 0.914
Freq
MHz
433
450
470
Standard Evaluation
Board Load Impedance
A + jB 
1.997-j 0.941
1.866-j 0.251
1.778-j 0.268
In any application where greater than 3.6V operation is being considered, use of an isolator at RF6886 output is recom-
mended. This, of course, excludes the balanced configuration already discussed. The recommendation would also hold for
V_CC 3.6V, in cases where potential output VSWR conditions exceed those outlined previously in this section.
DS100817
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at ([phone] or [e-mail].
9 of 16