AK2401 Datasheet, PDF (65/103 Pages) Asahi Kasei Microsystems – Direct Conversion Transceiver

[AK2401]
 AGCKP_MODE[1:0] bit= “01”
In this mode, PGA gain is changed only the timing when the AGC KEEP function is turned OFF.
While the AGC KEEP function is OFF, only signal power detection is executed and the PGA gain is not
changed. When the AGC KEEP function is turned ON, the AK2401 calculates the PGA gain from the
detected value while the AGC KEEP function is OFF and keeps the calculated PGA gain. This value will
be set to the PGA when the AGC KEEP function is turned OFF again. Figure 39 is a timing chart of this
mode.
AGC KEEP
AGC Status
PGA Gain
Wait
Power Detect
calculates the PGA gain
at this time
PGA gain is changed when the
AGC KEEP function is turned OFF
Wait
Power Detect
calculates the PGA gain
at this time
PGA gain is changed when the
AGC KEEP function is turned OFF
Wait
Power Detect
Figure 39. AGC Operation when AGCKP_MODE[1:0] bit= “01”
 AGCKP_MODE[1:0] bit= “1x”
In this mode, the PGA gain is not kept even the AGC KEEP function is ON. The calculation result of
RDOC function can be kept by inter locking with AGC_KEEP function when KEEP_DYOFSC bit = “1”
<Address 0x26>. For example, only the DC offset value can be kept while the AGC operation is ON by
setting AGCKP_MODE[1:0] bits to “1x”. It is not normally used.
AGCKP_MODE
0
0
0
1
1
X
0
0
0
1
1
X
KEEP_RDOC
0
0
0
1
1
1
Description
PGA Gain Keeping
DC Offset Keeping
DO
DO NOT
DO
DO NOT
This setting is not used.
DO
DO
DO
DO
DO NOT
DO
017003093-E-00
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2017/3