20150028892 | DIGITAL MULTI-METER WITH LCR FUNCTION - A Data acquisition apparatus for measuring purpose can be used as a Digital Multi-Meter (DMM) as well as a LCR meter, and this apparatus can be implemented in semiconductor chip adopted in a handheld case, it includes a DMM and a LCR meter. The LCR meter includes a LCR measuring circuit implemented with integrated circuit. The LCR measuring circuit includes an impedance measuring circuit and an auto-zero amplifier which bias the input offset voltage and amplify the input signal that has passed a big resistor (PTC) to make the signal have a predetermined SNR suitable for the process by the LCR measuring circuit. | 01-29-2015 |