March 9, 2014, 8:12 pm
One way to extend the resolution of a digital-to-analog converter (DAC) is by employing a sigma-delta converter in software. The main disadvantage of such approach is the slow speed. Alternatively, we can use some extra hardware to extend the usable resolution of a DAC. In this post, I will illustrate one such method to extend an 8-bit DAC to 16 bits using a digital potentiometer. Continue reading ‘Extending DAC Resolution Using Digital Potentiometer’ »
January 17, 2013, 9:50 pm
For current measurement in the low micro-amp and nano-amp ranges, a feedback ammeter is usually an excellent choice (see Keithley Application Note 1671). Because of the very high gain of an Op-amp, the burden voltage can usually be ignored when using a feedback ammeter. Thus, the measurement results can be obtained much more accurately compared to using the shunt resistance current measurement method. Also, because of the near zero burden voltage, circuit that is sensitive to power supply voltage changes can be instrumented without affecting its operation. Continue reading ‘Current Adapter for Low Current Measurement Using TS1001’ »
August 14, 2011, 7:08 pm
Most of the multimeters do not offer resistance measurement in the milliohm range. In most meters a typically Ohm range has an accuracy of 0.1 ohm and is too coarse for measuring small resistance. Of course, some of the high-end multimeters have milliohm range and there are also dedicated micro ohmmeters for even more accurate small resistance measurements, but most of them are priced way out of the range for personal use. Continue reading ‘Accurate Milliohm Measurement’ »