CMX7261 Voice Multi-transcoder
CMX7261
4
PCB Layout Guidelines and Power Supply Decoupling
+
C27
C26
Digital Ground Plane
DV
DV
SS
SS
Active low reset from
supervisor IC or RC circuit
DVSS
CLKI
BOOTEN1
BOOTEN2
DVSS
1
2
3
4
5
6
7
8
DVSS
DV
DD
DV
DD
NC
DV
SS
DVDD3V3
DVCORE1
DVSS
DVDD3V3
GPIOA
+
CMX7261Q1
C28
C22
C21
C20
RESETN
GPIOB
GPIOC
DVSS
NC
NC
NC
NC
DV
DV
DV
SS
DV
SS
DV
SS
SS
SS
9
DV
SS
10
AV
DD
AVSS
AVDD
SPKR2
AVDD
11
12
13
14
+
NC
NC
SPKR1VSS
SPKR1P
C24
C23
C25
C30
C29
AV
SS
AV
AV
SS
NC
NC
AV
SS
SPKR1N
SS
15
+
SPKR1VDD
16
17 18 19 20 21
23 24 25
22
SPKR1 V
DD
SPKR1 V
SS
C31
Analogue Ground Plane
AV
AV
SS
SS
C20 10µF
C26 22µF
C27 10nF
C28 10nF
C29 10µF
C30 10nF
C31 100nF
C21 10nF
C22 10nF
C23 10µF
C24 10nF
C25 10nF
Figure 3 CMX7261 Power Supply and De-coupling
Notes:
To achieve good noise performance, VDD and VBIAS decoupling and protection of the receive path from
extraneous in-band signals are very important. It is recommended that the printed circuit board is laid out
with a ground plane in the CMX7261 area to provide a low impedance connection between the VSS pins
and the VDD and VBIAS decoupling capacitors.
2012 CML Microsystems Plc
Page 13
D/7261_FI-1.x/9
CMLMICRO [ CML MICROCIRCUITS ]
