FX828D2 CMLMICRO [CML Microcircuits], FX828D2 Datasheet - Page 6

• Manufacturer Part Number: FX828D2
• Description: CTCSS/DCS/SELCALL Processor
• Manufacturer: CMLMICRO [CML Microcircuits]

CTCSS/DCS/SELCALL Processor
1.4
© 2009 CML Microsystems Plc
Notes:
C1
C2
C3
C4
C5
C6
C7
C8
C9
External Components
1. R2, R6, R7 and C3 form the gain components for the Summing Amplifier. R6 and R7
2. R3, R4, C5 and C7 form the gain components for the Rx Input Amplifier. R4 should be
22pF
22pF
100pF
0.1µF
100pF
0.1µF
Note 2
0.1µF
1.0 to 3.3µF
should be chosen as required from the system specification, using the following formula:
chosen as required by the signal level, using the following formula:
C7 x R4 should be chosen so as not to compromise the low frequency performance of this
product.
Tx Sub Audio Gain =
Tx Audio Gain
±20%
±20%
±20%
±20%
±20%
±20%
±20%
±20%
±20%
Figure 2 Recommended External Components
Gain
R1
R2
R3
R4
R5
R6
R7
=
=
1MΩ
100kΩ
100kΩ
Note 2
22kΩ
Note 1
Note 1
−
−
−
6
R2
R6
R2
R7
R3
R4
±5%
±10%
±10%
±10%
±10%
±10%
±10%
X1
4.032MHz
(tolerance depends upon
system requirements)
D/828/4
FX828