ACPM-7821-TR1 AVAGO [AVAGO TECHNOLOGIES LIMITED], ACPM-7821-TR1 Datasheet - Page 9

• Manufacturer Part Number: ACPM-7821-TR1
• Description: 4 x 4 Power Amplifier Module for J-CDMA (898 - 925 MHz)
• Manufacturer: AVAGO [AVAGO TECHNOLOGIES LIMITED]

9
Calibration
Calibration procedure is shown in Figure 11. 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
TX AGC
Figure 11. Calibration procedure.
Min PWR
Low mode
Falling
Rising
5.00
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
-50
High mode
Conv PAM
-40
Max PWR
CDG Urban
CDG Suburban
Figure 13. CDMA Power Distribution Function.
Pout
-30
-20
PA Out (dBm)
Digitally Controlled PA
-10
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. ACPM-7821 idle current is 14 mA and
operating current at 17 dBm is 68 mA at nominal
condition. This PA with low current consumption pro-
longs talk time by no less than 30 minutes compared
to other PAs.
Average current = ∫(PDF x Current)dp
Gain
Figure 12. Setting of offset between rising and falling power.
Low Mode
0
Falling
10
20
Cool PAM
Rising
High Mode
30
100
300
700
600
500
400
200
0
Pout