AK2400 Datasheet, PDF (43/52 Pages) Asahi Kasei Microsystems – High integrated receiver for PMR-LMR

[AK2400]
•Impedance matching network for IF Output pin
IF output port with impedance matching network (lowpass filter and balun) is shown as below.
IFOUTP and IFOUTN pins need power feeding via center tap of balun. Typical evaluation board
component values in 50 interface are shown as below.
Figure 26 IF output port with impedance matching network
IF Output Frequency [MHz]
29.25
46.35
50.85
58.05
Rload [k]
2.2
2.2
2.2
2.2
L3/L4 [nH]
1800
1000
1000
1000
C4 [pF]
6
3.3
2.4
1.6
C5 [pF]
-
-
-
-
•Impedance matching network with LC
Figure 27 Impedance matching network with LC
Impedance matching network with LC is shown. AK2400 1st Mixer has open drain outputs, so RL1 +
RL2 is output load resistance. C11and L11 compose lowpass filter. C12 and L12 are for highpass filter.
C13 is DC blocking capacitor and L13 is RF choke. OUTP and OUTN pins need power feeding via L11,
L12 and L13.
The differential voltage from IFOUTP/N can be converted to a single-ended by L11, L12, C11 and C12
properly. The differential impedance (RL1 + RL2) is converted to single-ended output terminating
impedance Ro.
014008989-E-01
43
2015/4