Microcyber HT1200M, Руководство пользователя

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Figure 5 Demodulator Signal Timing
The output of the demodulator is qualified with the carrier detect signal (OCD),
therefore, only IRXA signals large enough to be detected (100 mVp-p typically) by
the carrier detect circuit produce received serial data at ORXD. Maximum
demodulator jitter is 12 percent of one bit given input frequencies within HART
specifications, a clock frequency of 460.8 kHz (1.0 percent) and zero input (IRXA)
asymmetry.
TRANSMIT-SIGNAL SHAPER
The transmit-signal shaper generates a HART compliant FSK modulated signal at
OTXA. Figure 6 and Figure 7 show the transmit-signal forms of the HT1200M.
For IAREF=1.235 V
DC
, OTXA will have a voltage swing from approximately 0.25
to 0.75 V
DC
.
Figure 6 OTXA Waveform (1200 Hz)