Digital PMR Radio Processor
CMX7131/CMX7141
4.3
CMX994 Interface
When operating the 7131/7141FI-3.1 in I/Q mode the interface to the CMX994 Direct Conversion Receiver
shown in Figure 6 should be used. Component values are shown in Table 2, where values are not shown
refer to the CMX994 datasheet.
R100
C103
C100
C101
C102
RXIP
RXIN
LNA
LNA IN
T/R
Tx
RXEN
TXEN
I Channel
/6 /4
or /2
VCCRF
AVSS
VCCRXIF
RXQN
RXQP
VCCLO
VCCSYNTH
CSN
RDATA
CMX994
C-BUS
Control
Interface
Q Channel
SCLK
CDATA
VDDIO
/6 /4
/2 /1
PLL
VCO 1
DVDD
DVDD
R101
RESETN
Reference Oscillator
External
Resonator &
Varactors
Alternative
Local
Oscillator
VBIAS
C400
R401
DISCFB
DISC
R400
R402
R403
R202
R203
-
+
U400
CMX7141
CMX7131
+
-
ALT
R404
R405
R406
R407
ALTFB
ADC1
R450
D400
C450
Figure 6 CMX994 Interface
2014 CML Microsystems Plc
Page 16
D/7141_FI-3.x/6
CMLMICRO [ CML MICROCIRCUITS ]
