RALCWI Vocoder
CMX608/CMX618/CMX638
4.
External Components
CBUS
IOVDD
C9
C5
VDD
Vss
Vss
Vss
R2
IOVDD
48
47
46
45
44
43
42
41
40
39
38
37
1
2
IOVDD
Vss
NC
36
35
IOVDD
C7
IOVDD
Vss
C8
Vss
Vss
Vss
ENABXTAL
NC
Vss
NC
NC
3
4
34
33
32
XTALSEL3
XTALSEL2
5
IOVDD
XTALSEL1
RESETN
IOVDD
IOVDD
6
31
D1
IOVDD
C12
R1
IOVDD
Vss
7
30
29
28
27
26
25
CMX608
C4
C3
Vss
8
Vss
Vss
Vss
Vss
Vss
NC
XTAL out
XTAL in
9
XTAL
10
11
12
C2
C1
NC
Vss
IOVDD
Vss
SYNC
Vss
Vss
IOVDD
C10
13
14
15
16
17
18
19
20
21
22
23
24
VDD
Vss
IOVDD
C11
C6
Vss
Vss
Vss
CODEC PORT
C1
C2
C3
C4
C5
C6
C7
C8
22pF
22pF
C9
100nF
100nF
1.0µF
100nF
C10
C11
C12
1.0µF
100nF
1.0µF
100nF
100nF
100nF
R1
R2
D1
470k
100k
small signal diode
Notes: 1. On CMX608/CMX618/CMX638 devices, the crystal selection pins (XTALSEL1, XTALSEL2
and XTALSEL3) must be permanently tied to either IOVDD or VSS and not driven from a logic
level output of the host µController (see Table 1 for a list of crystal frequencies). For 9.6MHz
and 12.0MHz operation, either a crystal or a clock can be used. For all other frequencies, a
clock must be injected into the XTALIN pin and the XTALOUT pin must be left unconnected.
2. To use the CMX608/CMX618/CMX638, tie the ENABXTAL pin to IOVDD. If the ENABXTAL pin
is connected to VSS it will force the device into a deep powersave mode, where the C-BUS
interface and clock input (XTALIN) are disabled and the crystal oscillator is powered down.
3. A single 10µF electrolytic capacitor may be fitted in place of C5 and C11, providing the two
VDD pins are connected together on the pcb with an adequate width power supply trace.
Figure 2 CMX608 Recommended External Components
2014 CML Microsystems Plc
9
D/608_18_38/11
CMLMICRO [ CML MICROCIRCUITS ]
