Analog Devices AFDF7021 Application Note page 6

AN-1258
START
WRITE TO REGISTER 1
(DELAY 700µs)
WRITE TO REGISTER 3
SETS DEMOD CLOCK
WRITE TO REGISTER 0
SETS ADF7021 RF
(DELAY 40µs)
WRITE TO REGISTER 4
WRITE TO REGISTER 5
EXECUTES FILTER CALIBRATION
SET GAIN = 15, PHASE = 15
ON Q CHANNEL
(DELAY 40µs)
WRITE TO REGISTER 9
SETS AGC MODE, LNA_CURRENT,
LNA, AND FILTER GAIN
NO
TONE
PRESENT?
YES
END
Figure 4. Internal Tone Setup
INCREASE
IR_CAL_SOURCE_DRIVE_LEVEL
TO HIGH (DECIMAL 3)
TONE
YES
PRESENT?
NO
INCREASE LNA_GAIN
TO HIGH (DECIMAL 2)
TONE
YES
PRESENT?
NO
SET UP REGISTERS WITH
DIFFERENT HARMONICS.
TRY SETTING
IR_CAL_SOURCE ÷ 2
TO DECIMAL 0
Rev. 0 | Page 6 of 12
START
READBACK RSSI
(AVERAGE OVER 10 READBACKS)
NO
RSSI > 60?
YES
END
Figure 5. Procedure for Determining if a Tone is Present
Application Note
SET GAIN AND PHASE
TO 15 ON I CHANNEL
NO
ALREADY
CHECKED
I CHANNEL?
YES
SET GAIN AND PHASE
TO 15 ON Q CHANNEL