FX579 Datasheet, PDF (21/23 Pages) CML Microcircuits – HALF DUPLEX GMSK MODEM

Half Duplex GMSK Modem
Characteristic
Transmit Parameters
TXOP output impedance
TXOP output level
Tx output offset (wrt V_BIAS)
Tx data delay (BT = 0.3)
Tx data delay (BT = 0.5)
Receive Parameters
RXIN input impedance
RXIN input level
Rx dc offset from ½ V_DD
Rx time delay
On-Chip Xtal Oscillator
Input impedance
Output impedance
Voltage gain
"High" clock pulse width
"Low" clock pulse width
FX579
Note
3
4, 6, 9
-
5
5
7, 9
9
8
10
10
10
11
11
Min. Typ. Max.
Units
-
100
0.8
1.0
-100
-
-
2.0
-
1.5
-
1.2
+100
2.5
2.0
Ω
Vpk-pk
mV
bit periods
bit periods
3
-
MΩ
0.7
1.0
1.3
Vpk-pk
-
±0.5
-
V
-
-
3
bit periods
10
-
MΩ
-
50
-
kΩ
-
25
-
dB
60
-
-
ns
60
-
-
ns
Notes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Not including any current drawn from the modem pins by external circuitry
For V_IN in the range V_SS to V_DD
Measured by ac coupling an external 1kHz source via suitable resistance to the TXOP pin.
The value specified is the average of values measured in the all "1"s and all "0"s states
Data pattern of "1111000011110000..."
Measured between the rising edge of the Tx DATACLK and the centre of the corresponding bit
at the output of the external RC network connected to TXOP
Measured at the output of the external RC network
For optimum performance, measured at RXIN for a "1111000011110000..." pattern
Measured between the centre of bit at RXIN and corresponding rising edge of the
Rx data clock
Levels are proportional to applied V_DD
Small signal measurement at 100Hz with no load on XTALN output
Timing for an external clock input to the XTAL/CLK pin
© 1996 Consumer Microcircuits Limited
21
D/579/4