The AMC1400 offers a differential analog output comprised of the OUTP and OUTN pins. For differential input voltages (V_INP – V_INN) in the range from –250 mV to +250 mV, the device provides a linear response with a nominal gain of 8.2. For example, for a differential input voltage of 250 mV, the differential output voltage (V_OUTP – V_OUTN) is 2.05 V. At zero input (INP shorted to INN), both pins output the same common-mode output voltage V_CMout, as specified in the Section 6.9 table. For absolute differential input voltages greater than 250 mV but less than 320 mV, the differential output voltage continues to increase in magnitude but with reduced linearity performance. The outputs saturate at a differential output voltage of V_CLIPout, as shown in Figure 7-2, if the differential input voltage exceeds the V_Clipping value.

The AMC1400 offers a fail-safe feature that simplifies diagnostics on a system level. Figure 7-2 shows the fail-safe mode, in which the AMC1400 outputs a negative differential output voltage that does not occur under normal operating conditions. The fail-safe output is active in two cases:

• When the high-side supply is missing or below the VDD1_UV threshold
• When the common-mode input voltage, that is V_CM = (V_INP + V_INN) / 2, exceeds the common-mode overvoltage detection level V_CMov

Use the maximum V_FAILSAFE voltage specified in the Section 6.9 table as a reference value for fail-safe detection on a system level.