MSP430F42x單芯片電子稱(chēng)

　　When designing applications for weight， force， torque， and pressure measurement， resistive full-bridge

　　sensors are widely used. Most of the bridge sensors require a high excitation voltage （typically in the 10-V

　　range）， while still outputting a rather low， full-scale differential voltage in the range of 2-mV/V excitation

　　voltage. The output from the sensor is typically amplified by an instrumentation amplifier. After signal

　　conditioning， the signal is digitized by a high resolution analog-to-digital converter （ADC）。 Typically， such

　　high resolution ADCs are not integrated in conventional microcontrollers （MCUs）。 A general purpose MCU

　　is then used for further processing and display.

　　The conventional approach of using a bridge sensor excitation voltage of 10 V and an Instrumentation

　　amplifier to achieve a full-scale ADC input voltage increases chip count and complexity of powe

　　management with high power consumption. An energy-efficient and cost-effective solution is to use a

　　microcontroller with an integrated high-resolution ADC and integrated programmable gain amplifier （PGA）。

　　The entire application can then be powered from a 3-V battery. The MSP430F42x has integrated 16-bit

　　sigma delta ADCs with differential inputs and PGA with gain up to 32. This device offers a single chip

　　solution for this application with not only high resolution ADCs with PGA， but also LCD driver and

　　brownout protection.