CMX589A View Datasheet(PDF) - CML Microsystems Plc

Part Name

Description

Manufacturer

CMX589A

GMSK Modem

CML Microsystems Plc 

GMSK Modem

3 External Components

CMX589A

Figure 3: Recommended External Components

Component

R1

R2

R3

R4

C1

C2

C3

Notes

1

2

3

1

4

4

Value

1.0MΩ

Tolerance

±5%

±10%

±10%

±10%

±10%

Component

C4

C5

C6

C7

C8

Notes

5

6

6

Value

0.1µF

1.0µF

Tolerance

±20%

±20%

±20%

X1

8

Table 2: Recommended External Components

Recommended External Component Notes:

1. The RC network formed by R1 and C1 is required between the Tx Out pin and the input to the modulator.

This network, which can form part of any DC level shifting and gain adjustment circuitry, forms an important

part of the transmit signal filtering. The ground connection to the capacitor C1 should be positioned to give

maximum attenuation of high-frequency noise into the modulator.

The component values should be chosen so that the product of the resistance and the capacitance is:

For a BT of 0.3 R1C1 = 0.34/bit rate (bps)

For a BT of 0.5 R1C1 = 0.22/bit rate (bps)

© 1998 Consumer Microcircuits Limited

6

D/589A/3

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