Variable Split Band Inverter
6
MX214/224
MX214
Pin No.
MX224
Pin No.
J/P LH
Signal Name
Description
J/P
LH
2
3
4
20
21
22
20
21
22
20
21
22
Highband Balanced
Modulator Input
The input to the Balanced Modulator of the
Upperband limit. This input must be connected to
the Highband Filter Output via capacitor C5. See
Figure 2 and Figure 3.
Lowband Balanced
Modulator Input
The input to the Balanced Modulator of the
Lowerband limit. This input must be connected to
the Lowband Filter Output via capacitor C6. See
Figure 2 and Figure 3.
Tx input
This analog ‘Clear’ audio input for the VSB
Scrambler. This pin is held at a DC ‘bias’ voltage by
a 300kꢂ on-chip bias resistor, which is selected for
all functions except powersave. In must be
connected to external circuitry by capacitor C4. See
Figure 2 and Figure 3. This input, in Tx mode, is
connected to Upper and Lowerband input filters.
Signal paths and bias levels are detailed in Table 2
and Figure 6.
5
6
23
24
23
24
23
24
Lowband Filter
Output
The output of the Input filter of the lowerband limit.
The Rx/Tx function determines which filter is used
(Filter 1 or 2). See Figure 6 and Figure 7. This
output must be connected to the Lowband balanced
modulator input via capacitor C6. See Figure 7.
V
DD
A single 5.0V supply is required.
No Connection
10,
11,
12
4, 5, 6, N/C
7, 9
Table 1: Signal List
MUTE = 0
Disabled
Bias
POWERSAVE
Disabled
Rx/Tx = 1
Enabled
Bias
Rx/Tx = 0
Disabled
Bias
Rx Path
Rx Out Level
Tx Path
High Impedance
Disabled
Disabled
Bias
Enabled
Bias
Disabled
Bias
Tx Out Level
High impedance
Table 2: Functions Influencing Signal Paths
ꢀ1998 MX-COM, Inc.
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
Doc. # 20480112.002
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