CMX868 查看數據表（PDF） - MX-COM Inc
零件编号
产品描述 (功能)
生产厂家
CMX868 Datasheet PDF : 43 Pages
| |||
Low Power V.22bis Modem
5
3 External Components
CMX868 Advance Information
C1
XTAL
C2
X1
XTAL/CLOCK
RDRV
VSS
RD
Ring Detector
See Section 3.1
RT
VDD
VSS
RXAFB
Rx Line Interface
See Section 3.2
RXA
RXA
+
VDD
C5
C4
1
24
2
23
3
22
4
21
5
20
6 CMX868 19
7
18
8
17
9
16
10
15
11
14
12
13
VDD
VDD
R1
IRQ
REPLY DATA
VSS
SERIAL CLOCK
COMMAND DATA
CS
C-BUS
to/from
µC
VSS
VDD
TXA
TXA
VBIAS
C3
Tx Line Interface
See Section 3.2
Figure 2: Recommended External Components for Typical Applciation
R1
100k:
C1, C2 22pF
C5
10uF
X1
11.0592MHz or 12.288MHz
C3, C4 100nF
Resistors r5%, capacitors r20% unless otherwise stated.
Table 2: Recommended External Components for typical Application
Note:
1. This device is capable of detecting and decoding small amplitude signals. To achieve this VDD and VBIAS
should be de-coupled and the receive path protected from extraneous in-band signals. It is
recommended that the printed circuit board be laid out with a VSS ground plane in the CMX868 area to
provide a low impedance connection between the VSS pins and the VDD and VBIAS decoupling capacitors.
The VSS connections to the Xtal oscillator capacitors C1 and C2 should also be low impedance and
preferably be part of the VSS ground plane to ensure reliable start up of the oscillator.
2. For best results, a crystal oscillator design should drive the clock inverter input with signal levels of at
least 40% of VDD, peak to peak. Tuning fork crystals generally cannot meet this requirement. To obtain
crystal oscillator design assistance, please consult your crystal manufacturer.
¤2001 MX-COM, Inc.
www.mxcom.com tel: 800 638 5577 336 744 5050 fax: 336 744 5054
Doc. # 20480205.007
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
All trademarks and service marks are held by their respective companies.
Share Link: 