DAQ on a Stick:Thermocouple with Intersil precision products and Renesas R5F10JBC

DAQ on a stick with thermocouple K-for temperatures above 0°C. The “DAQ on a Stick, Renesas Thermocouple” is one of a series of reference designs highlighting Intersil’s precision products with different microcontrollers. This reference design is a self contained demo showing a complete signal chain solution using Intersil parts and an Renesas microcontroller. The complete reference design is conveniently housed in a USB stick form factor.

GUI ( Graphical User Interface) measurement screen. From the DAQ Start-up Screen, the user can click on the Instantaneous Temperature button to get a single temperature reading or click the Start button to go to the Measurement display screen

From this screen, the user can stop and start data collection, adjust the minimum and maximum X and Y axis and go back to the set-up screen by clicking on the Show Main button

KEY Components:

ISL28134 5V, Low Noise, Zero-Drift Op Amp an ideal choice for the input amplifier for a thermocouple design. The ISL28134 uses auto-correction circuitry to provide ultra low offset voltage (2.5μV), and low offset temperature drift (15nV/°C). The very low 1/f noise corner <0.1Hz and low input noise voltage (8nV/√Hz @ 100Hz) of the amplifier makes it ideal for low frequency precision applications requiring very high gain and low noise. Other attributes of the ISL28134 are the wide gain bandwidth and rail-to-rail input/output swing

ISL26102 24-bit Low Noise Delta Sigma ADC is a complete analog front-end with dual differential multiplexed inputs for high resolution measurements. The ISL26102 features a third order modulator providing up to 21.4-bit noise-free performance (10Sps). The 24-bit delta-sigma analog-to-digital converter includes a very low-noise amplifier with programmable gain. Although this application demo uses an input buffer amplifier (ISL28134), the high input impedance of the ISL26102 allows direct connection of sensors, such as load cell bridges to ensure the specified measurement accuracy without a buffer amplifier.

ISL21010CFH341 Micropower Precision Bandgap Voltage Reference precision 4.096V, low dropout micropower bandgap voltage reference. It provides a ±0.2% accurate reference. The ISL21010 provides up to 25mA output current sourcing with low 150mV dropout voltage. The low supply current and low dropout voltage combined with high accuracy make the ISL21010 ideal for precision low powered applications.

ISL22317 Precision DCP (Digitally Controlled Potentiometer) features a low end-to-end temperature coefficient of ±10ppm/°C and precise resistance selection. It maintains less than ±1% typical variance from the ideal resistance at each wiper position providing 99% accuracy of selected resistance value. This highly accurate DCP eliminates the need for complex algorithms to guarantee precision. The ISL22317 operates from a single supply between 2.7V to 5.5V.

R5F10JBC Renesas Integrated USB Controller

APPLICATIONS