AK2401 Datasheet, PDF (34/103 Pages) Asahi Kasei Microsystems – Direct Conversion Transceiver

[AK2401]
13.5.3. Output Path Selection of Analog Baseband Signal
The signal path of the AAF output is controlled with IQ_SEL, ANA_PATH and MAIN_PATH bits
<Address0x14>. Normally, the path between AAF and ADC is shorten by setting MAIN PATH bit = “1” and
the paths between AAF and the AOUT_P pin, and AAF and the AOUT_N pin are open by setting
ANA_PATH bit = “0”. In this case, the AOUT_P pin and the AOUT_N pin must be opened.
Receiving analog baseband signal can be output in differential format by setting ANA_PATH bit = “1”
shortening the paths between AAF and the AOUT_P pin, and AAF and the AOUT_N pin. In this case,
IQ_SEL bit selects the output channel from Ich and Qch. Connect AC coupling capacitors to the AOUT_P
and AOUT_N pins since these pins are internally DC biased. Connect them to an external device and
they will output Hi-z signals.
33. AOUT_P
Hi-Z
External
Hi-Z Device
34. AOUT_N
ANA_PATH bit
AAF
AAF
IQ_SEL bit
I⁺
24-bit
ΔΣ ADC
I^-
MAIN_PATH bit
Q⁺
24-bit
ΔΣ ADC
Q^-
Figure 21. Output Path Selection of Analog Baseband Signal
017003093-E-00
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2017/3