AK2401 Datasheet, PDF (61/103 Pages) Asahi Kasei Microsystems – Direct Conversion Transceiver

[AK2401]
START
■Parameters iin flowchart
T_W ： Wait time after gain switching
Set with AGCTRW bit
AGCOFF
No
T_P ： signal power calculation/detection time
Set with AGCTIM bit
Upper Limit, Lower Limit ：
Hysteresis width with respect to signal power
Yes
convergence level
Set with AGCHYS bit
AGC_KEEP pin="L" or
No
AGC_KEEPR bit="0"
Yes
Wait ： T_W
AGC RESET
END
G_MAX ： Maximum permissible gain variation
in one cycle of AGC operation
Set with AGCMAX bit
G_C ： Currently set gain
G_N ： Gain to be set next as a result of calculation
G_CORR : Correction gain (see text)
G_TGTH, G_TGTL： Target value of LNA gain switching
Power Detect ：T_P
■G_UP, G_DOWN are calculated by the following formula
G_UP = ROUND(P_TGT - P_DET)
G_DOWN = ROUND(P_DET - P_TGT)
P_TGT ： Convergence target value set with AGCTGT bit
P_DET ： Detected power
P_DET > Upper Limit
No
Yes
AGC calculated the amount of
lowering of gain, G_DOWN
P_DET < Lower Limit
No
Yes
AGC calculates the amount of
raising of gain, G_UP
G_DOWN > G_MAX
Yes
G_N = G_C - G_MAX
No
G_N = G_C - G_DOWN
YGe_Us_P > G_MAX
Yes
G_N = G_C + G_MAX
No
G_N = G_C + G_UP
LNA_AGCOFF bit="0"
No
Yes
LNA_LGMODE bit="0"
No
Yes
G_CORR ≤ G_TGTL or
G_N = Minimum Gain
No
Yes
R_LNA_LGMODE bit="1"
G_CORR ≥ G_TGTH
No
Yes
R_LNA_LGMODE bit="0"
Figure 36. AGC Flow Chart
017003093-E-00
61
2017/3