ZHCSHP3 February 2018 DAC8771
PRODUCTION DATA.
The DAC8771 features an internal resistor to convert a 500-mVpp HART FSK signal sourced by an external HART modem. These resistors are ratiometrically matched to the gain-setting resistors for the current output signal chain to ensure that a 500-mVpp input at the HART_IN pin is delivered as a 1-mApp signal at the IOUT pin regardless of which gain mode is selected.
An external capacitor, placed in series between the HART_IN pin and HART FSK source, is required to AC couple the HART FSK signal to the HART_IN pin. The recommended capacitance for this external capacitor is from 10 nF to 22 nF.