Variable Split Band Inverter

6

MX214/224

1998 MX-COM, Inc.

www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054

Doc. # 20480112.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA

All trademarks and service marks are held by their respective companies.

MX214

Pin No.

MX224

Pin No.

Signal Name

Description

J/P

LH

J/P

LH

2

20

20

20

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.

3

21

21

21

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.

4

22

22

22

Tx input

This analog ‘Clear’ audio input for the VSB

Scrambler. This pin is held at a DC ‘bias’ voltage by

a 300k

 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

23

23

23

Lowband Filter

Output

The output of the Input filter of the lowerband limit.

The

Tx

/

Rx

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.

6

24

A single 5.0V supply is required.

10,

11,

12

4, 5, 6,

7, 9

N/C

No Connection

Table 1: Signal List

Tx

Rx/

= 1

Tx

Rx/

= 0

MUTE = 0

POWERSAVE

Rx Path

Enabled

Disabled

Disabled

Disabled

Rx Out Level

Bias

Bias

Bias

High Impedance

Tx Path

Disabled

Enabled

Disabled

Disabled

Tx Out Level

Bias

Bias

Bias

High impedance

Table 2: Functions Influencing Signal Paths