A new, low cost, precise measurement card for testing of ultra-low power analog ASICs

The paper presents a new, precise, 16-channel measuring system for testing low energy, analog ASICs (Application Specific Integrated Circuits). The proposed system allows simultaneous testing of circuits working both in the voltage mode (in the range from -4V to 4V) and the current mode (from 1 nA to 20 mA) with resolution up to 20 bits, with a maximum frequency of one channel up to 2 kHz. Each of the inputs can serve simultaneously as an `ideal´ adjustable voltage or the current source, while measuring both the voltage and the current at each of the 16 channels (regardless of the mode) is made on a constant basis. The advantage of the proposed system, in contrast to existing solutions of this tape offered on the market, is its low price, high precision and the ability to operate simultaneously in two modes on each channel (i.e., as a reference signal or as the measuring channel). This feature is is very important, as during the tests we have to work with many different excitations and at the same time perform measurements on all of the channels. The system consists, among others, from signal converters, ADC and DAC blocks, multiplexers, operational amplifiers, STM32 microcontroller with the ARM Cortex-M3 core and the AVR microcontroller. The realized system features high stability and robustness against the noise.