Concept for a handy Nanovoltmeter, 7.5 Digits

based on the AD7190, 24-Bit delta sigma ADC

• Graphic LCD
• Bargraph
• DC/AC measurements with 0.1, 1 or 10 Updates per second
• Autorange:
  • Gain=1: ±4.096V
  • Gain=8: ±512mV
  • Gain=16: ±256mV
  • Gain=32: ±128mV
  • Gain=64: ±64mV
  • Gain=128: ±32mV
• Manual range with dedicated range-button
• zero-offset
• ratiometric measurements for strain gauges
• Min/Max/Average
• Integration over time (for Coulomb counting)
• Current sensing with possibility to specify a shunt resistance.
• BNC and 4mm banana socket
• battery powered
• USB charging
• USB interface, optically coupled

• AD7190
• 24 bit
• delta sigma
• differential inputs
• external 1-5V reference

• LTC6655
• hermetically sealed LS8 package
• ±250ppm initial accuracy
• ±0.25ppm peak-peak noise (0.1-10Hz)
• 2ppm/°C temperature drift
• 4.096V
• optionally oven controlled @ 45°C
• dead bug mounting (–> more long term stability)

• ILI9341
• 2.2 inch
• SPI
• 240×320
• Backlight
• Colour

• Hold
• AC/DC
• Speed (0.1, 1, 10 S/s)
• Range
• Zero
• Min/Max (implies Average and Integral)
• Voltage/Current
• Cancel
• 2nd
  • Up
  • Down
  • Left
  • Right
  • OK
  • Shunt