link to page 9 MLX90821 Relative Pressure Sensor IC A broken wire detection block allows actively driving the output to one of the rails in case of a broken supply or ground connection. Extensive protection of the supply lines allows the MLX90821 to handle extreme overvoltage conditions and is immune to severe external disturbances. Several diagnostic functions (over - voltage, under-voltage, overpressure, under pressure detections) have been implemented on the 90821 and can be enabled by programming EEPROM settings. Figure 3 describes MLX90821 block diagram. DSP Overvoltage & Vsupply reverse voltage Sensor bias Divided bridge protection 6/7 VDDA current Off chip temperature IV conversion Voltage regulator sensor current output Gain & Offset POR Temperature On chip temperature Compensation sensor Piezoresistive sensing element Vbrg Pressure Linearization PGA Vana DAC Analog Gain InP M Programmable Filter 12 bits Output U ADC OPA X 16 bits Rom SENT InN InP, InN, VEXT Output EEPROM Test NTC External NTC Test interface Input Oscillator Ram Gnd Figure 3: MLX90821 block diagram REV 002 – 17 OCT 2019 Page 9 of 39 3901090821
