MPXY8020A6T1

MPXY8020A6T1 DETAILED DESCRIPTION

The block diagram of the MPXY8000 series sensor is shown in Figure 1. Thepressure sensor is a capacitive transducer constructed using surfacemicromachining, the temperature sensor is constructed using a diffused resistor,and the interface circuit is integrated onto the same die as the sensors using astandard silicon CMOS process.The conditioning of the pressure signal begins with a capacitance to voltageconversion (C to V) followed by a switched capacitor amplifier. This amplifier hasadjustable offset and gain trimming. The offset and gain are factory calibrated,with calibration values stored in the EEPROM trim register. This amplifier alsohas temperature compensation circuits for both sensitivity and offset, which alsoare factory adjusted using the EEPROM trim register.The pressure is monitored by a voltage comparator, which compares themeasured value against an 8-bit threshold adjusted by a serial input. By adjustingthe threshold and monitoring the state of the OUT pin the external device cancheck whether a low-pressure threshold has been crossed, or perform up to8-bit A/D conversions.The temperature is measured by a diffused resistor with a positivetemperature coefficient driven by a current source, thereby creating a voltage.The room temperature value of this voltage is factory calibrated using theEEPROM trim register. A two-channel multiplexer can route either the pressureor temperature signal to a sampling capacitor that is monitored by a voltagecomparator with variable threshold adjust, providing a digital output fortemperature.An internal low frequency, low power 5.4 kHz oscillator with a 14-stage dividerprovides a periodic pulse to the OUT pin (divide by 16384 for 3 seconds). Thispulse can be used to wake up an external MCU to begin an interface with thedevice. An additional 10-stage divider will provide a pulse every 52 minuteswhich can be used to reset an external MCU.The power consumption can be controlled by several operational modesselected by external pins.