FX128 参数 Datasheet PDF下载

Cordless Telephone Scrambler

FX128

1.5

Application

BASE

RF

AMP

IF

AMP

FM

DETECTOR

RXIN

.1uF

100k

CODE

DETECT

120pF

12

RXOUT

13

100k

11

100k

.1uF

DE-EMP

AF AMP

150pF

DTMF

Generation

HYBRID

TRANSFORMER

µ

P

RF AMP

MODULATOR

FX128

5

4

6

120pF

PRE-

EMP

CODE

ENCODE

100k 100k

.1uF

AF

AMP

TELEPHONE

LINE

150pF

100k .1uF

TXOUT

TXIN

PORTABLE

RF

AMP

IF

AMP

FM

DETECTOR

RXIN

.1uF

100k

CODE

DETECT

120pF

12

RXOUT

13

11

100k

100k

.1uF

DE-EMP AF AMP

SPKR

150pF

KEYPAD

P

CODE

ENCODE

FX128

5

120pF

PRE-

EMP

AF

AMP

MIC.

RF AMP

MODULATOR

.1uF

4

6

100k 100k

.1uF

150pF

100k

TXOUT

Note: Components shown set a gain of 0dB

TXIN

Figure 3 Block Diagram of a Typical Application of the FX128 (Cordless Phone)

1.6

Application Notes

Formulae for calculating the carrier frequency, upper cutoff frequency and lower cutoff frequency with clock

select pin high are as follows:

Carrier Frequency

Upper Cutoff Frequency

Lower Cutoff Frequency

=

=

=

(3.2995kHz / 10.24MHz) * XTAL frequency

(2.800kHz / 10.24MHz) * XTAL frequency

(400Hz / 10.24MHz) * XTAL frequency

Formulae for calculating the carrier frequency, upper cutoff frequency and lower cutoff frequency with clock

select pin low are as follows:

Carrier Frequency

Upper Cutoff Frequency

Lower Cutoff Frequency

=

=

=

(3.2995kHz / 3.415MHz) * XTAL frequency

(2.800kHz / 3.415MHz) * XTAL frequency

(400Hz / 3.415MHz) * XTAL frequency

6