WS1111 Datasheet, PDF (11/18 Pages) AVAGO TECHNOLOGIES LIMITED – Good linearity

Calibration
Calibration procedure is shown in Figure 16. Two
calibration tables, high mode and low mode respec-
tively, are required for CoolPAM, which is due to gain
difference in each mode.
For continuous output power at the mode change
points, the input power should be adjusted accord-
ing to gain step during the mode change.
Offset Value
(difference between rising point and falling point)
Offset value, which is the difference between the ris-
ing point (output power where PA mode changes from
low mode to high mode) and falling point (output
power where PA mode changes from high mode to
low mode), should be adopted to prevent system
oscillation. 3 to 5 dB is recommended for Hysteresis.
Average Current and Talk Time
Probability Distribution Function implies that what
is important for longer talk time is the efficiency of
low or medium power range rather than the efficiency
at full power. WS1111 idle current is 22 mA and
operating current at 16 dBm is 65 mA at nominal
condition. These features give extended talk by no
less than 30 minutes compared to conventional PAs.
Average current = ∫(PDF x Current)dp
TX AGC
Low mode
High mode
Min PWR
Falling _Rising
Figure 16. Calibration procedure.
Pout
Max PWR
Gain
Low Mode
High Mode
Falling
Rising
Pout
Figure 17. Setting of offset between rising and falling power.
5.00
4.50
CDG Urban
4.00
CDG Suburban
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
-50
-40
-30
-20
-10
0
10
PA Out (dBm)
Conv PAM
Digitally Controlled PA
700
600
500
400
300
200
100
0
20
30
Cool PAM
Figure 18. CDMA Power Distribution Function.
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