Application of ADC GX2245 (LTC2245 compatible) in Handheld Digital Storage Oscilloscopes

Oscilloscopes as electronic measurements in the most commonly used electronic measurement instruments, in the measurement technology occupies an important position, mainly used to measure the period of the electrical signal, amplitude, signal characteristics, and the reduction of signal characteristics. Therefore, the oscilloscope is the electronic circuit design is the most commonly used signal observation and troubleshooting tools, it can be said that the naked eye can not directly see the process of electrical signal changes into people can intuitively see the waveforms to be observed, and through the display to show, to facilitate the observation and analysis of researchers.

Due to the rapid development of measurement technology, compared with traditional analog oscilloscopes, digital storage oscilloscopes have advanced pre-trigger function, able to observe the waveform before the trigger point, but also has the advantage of rapid and automatic measurement of unknown signals, to capture the power supply on, off, or the signal changes such as single transient events, can be quickly and accurately calculated and processed a variety of parameters and other advantages of the characteristics.

Based on the design of the program, the handheld device should meet the requirements of low power consumption, easy to carry, outdoor operation, etc., the program‘s A/D conversion part of the GXS GX2245 high-performance, low-power CMOS ADC, which has an effective bit number of 14 bits, high speed and high precision, the conversion rate of 80MSPS, 65MSPS, 40MSPS, 25MSPS, 10MSPS selectable.

The GX2245 ADC is powered by a 3V analog power supply, a separate output power supply can drive 0.5V to 3.6V logic circuits. Designed to digitize high-frequency, wide dynamic range signals, the GX2245 ADC boasts a signal-to-noise ratio of 72.8dB and a spurious-free dynamic range of 85dB at 80M Hz samples, and can be used for input signals well beyond the Nyquist frequency. DC specifications include ±1LSB INL (typical), ±0.25LSB DNL (typical) and no leakage codes. Reference noise at the input is very low at 0.96 LSBRMS.

The GX2245 (compatible with the LTC2245) is a low-power 3V single-supply ADC for digitizing high-frequency, wide dynamic range signals. Ideally suited for demanding imaging and communications applications, the GX2245‘s AC performance includes a SNR of 73dB and SFDR of 88d with a 575MHz full power bandwidth.