| Popis: |
This paper describes and compares three amplifiers for ECG recording, namely a four-transistor stage band-pass amplifier, a DDA-based fully differential CMOS instrumentation amplifier and an OTA amplifier using current reuse. The performance metrics of the three amplifiers are listed, their respective advantages are compared, what factors limit their disadvantages are analyzed, the current state of the art and the direction of development of the ECG amplifier are indicated, and suggestions are given for further enhancement of the ECG amp. These amplifier circuits are designed in 0.35 µm CMOS and are verified by layout followed by simulation simulations. The results show that running at 2V dc supply, the quad-transistor stage amplifier and the DDA fully differential amplifier consume 672nW, obtain at least 2uVrms of input reference noise, and obtain greater common mode rejection ratios of 86dB and 83dB, while the OTA amplifier consumes less 320nW, obtains the most 2.05uVrms of input reference noise, and obtains a smaller common-mode rejection ratio of 65dB. |
