MT8841
Applications
The circuit shown in Figure 6 illustrates the use of
the MT8841 device in a typical FSK receiver system.
Bellcore Special Report SR-TSV-002476 specifies
that the FSK receiver should be able to receive FSK
signal levels as follows:
Received Signal Level at 1200Hz:
-32dBm to -12dBm
Received Signal Level at 2200Hz:
-36dBm to -12dBm
This condition can be attained by choosing suitable
values of R1 and R2. The MT8841 configured in a
unity gain mode as shown in Fig. 6 meets the above
level requirements.
For applications requiring detection of lower FSK
signal level, the input op amp may be configured to
provide adequate gain.
+5V
C1
R1
IN +
IN -
GS
R2
VRef
CAP
C2
Notes:
R1, R2 = 100 kΩ 1%
R3, R4 = 100 kΩ 10%
C1, C2, C3 = 0.1µF 20%
X-tal = 3.579545 MHz
X-tal
MT8841
VDD
IC2
IC1
PWDN
CD
DR
DATA
DCLK
To
Controller
R3
C3
R4
OSC1
OSC2
VSS
Figure 6 - Application Circuit (Single-Ended Input)
5-15
MITEL [ MITEL NETWORKS CORPORATION ]
