MT88E43B
Data Sheet
Crystal Oscillator
The MT88E43 requires a 3.579545MHz crystal oscillator as the master timing source.
MT88E43
MT88E43
MT88E43
OSC1 OSC2
OSC1 OSC2
OSC1 OSC2
to the
next MT88E43
3.579545 MHz
Figure 8 - Common Crystal Connection
The crystal specification is as follows:
Frequency:
3.579545 MHz
±0.1%(-40oC+85oC)
Parallel
18 pF
Frequency tolerance:
Resonance mode:
Load capacitance:
Maximum series resistance: 150 ohms
Maximum drive level (mW): 2 mW
e.g., CTS MP036S
Any number of MT88E43 devices can be connected as shown in Figure 8 such that only one crystal is required.
The connection between OSC2 and OSC1
can be D.C. coupled as shown, or the OSC1 input on all devices can be driven from a CMOS buffer (dc coupled)
with the OSC2 outputs left unconnected.
To meet BT and Bellcore requirements for proper tone detection the crystal must have a frequency tolerance of
0.1%.
VRef and CAP Inputs
VRef is the output of a low impedance voltage source equal to VDD/2 and is used to bias the input opamp. A 0.1µF
capacitor is required between CAP and VSS to eliminate noise on VRef.
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Zarlink Semiconductor Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
