ZHCSRW7 march 2023 AFE781H1 , AFE881H1
PRODUCTION DATA
On the AFEx81H1, a HART frequency-shift keyed (FSK) signal can be modulated onto the MOD_OUT pin. Figure 7-23 illustrates the output current versus time operation for a typical HART interface.
DC current = 6 mA |
To enable the HART interface, set the HART_EN bit in the MODEM_CFG register. An external capacitor, placed in series between the RX_IN pin and HART FSK source, is required to ac-couple the HART FSK signal to the RX_IN pin. The recommended capacitance for this external capacitor is 2.2 nF.
If additional filtering is required, the AFEx81H1 also support an external band-pass filter. For this configuration, use the RX_INF pin instead of RX_IN pin.