FX829 Datasheet, PDF (28/34 Pages) CML Microcircuits – Baseband Signal Processor

Baseband Signal Processor
FX829
Notes Min.
FFSK Receiver
Signal Input Dynamic Range (SNR = 50dB) 10, 11 100
Bit Error Rate
(SNR = 12dB at 1200 Baud) 11
-
(SNR = 12dB at 2400 Baud) 11
-
(SNR = 20dB at 1200/2400 Baud) 11
-
Receiver Synchronisation
(SNR = 12dB) 12
Probability of Bit 16 being correct
Carrier Detect
Sensitivity
12, 13
-
Probability of Carrier Detection
- After Bit 16
(SNR = 12dB)
- With 230mVrms Noise
(No Signal)
Miscellaneous Impedances
FILTER OUT
-
Tx Audio Input (MIC) (at 100Hz)
10
Xtal/Clock Input
'High' pulse width
'Low' pulse width
Input Impedance (at 100Hz)
Gain (I/P = 1mVrms at 100Hz)
4
40
4
40
10
20
Typ.
230
2.5
1.5
1.0
0.995
-
0.995
0.05
600
-
Max.
1000
-
-
-
150
-
-
Units
mVrms
10-⁴
10-³
10-⁸
mVrms
Ω
MΩ
ns
ns
MΩ
dB
Notes:
1. At V_DD = 5.0V only. Signal levels are proportional to V_DD.
2. Not including any current drawn from the modem pins by external circuitry.
Powersaved = all functions disabled.
Tx or Rx
= device configured into any half-duplex operating mode.
Currents measured at Tamb = 25°C only.
3. Small signal impedance, at V_DD = 5.0V and Tamb = 25°C. A minimum load resistance of 6kΩ
is suggested.
4. Timing for an external input to the XTAL/CLOCK pin.
5. Between MIC or AMP1 inputs to Modulator and Audio outputs, see Figures 10a and 10b.
6. It is recommended that these output levels are used to produce 60% or 100% deviation in the
transmitter.
7. With the Tx Audio input level 20dB above the level required to produce 0dB at the
Output Drives.
8. With output gains set to 0dB.
9. IRQN pin.
10. See Figure 13 (variation of BER with Input Signal Level).
11. SNR = Signal to Noise Ratio in the Bit Rate Bandwidth.
12. For a "10101010101 ...01" pattern.
13. Measured with a 150mVrms input signal (no noise).
14. dBp represents a psophometrically weighted measurement.
© 1997 Consumer Microcircuits Limited
28
D/829/4