Wide Band frequency fixed current source for BIT and BIA
High frequency bioelectrical impedance analysis devices are mostly used in Bioimpedance tomography and blood analysis. Nowadays 50 - 100 KHz bioelectrical impedance devices are commonly used for body composition analysis. AD8130 or AD 8129 deferential op-amp is used in this paper. These two op-amps...
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| Main Authors: | , , |
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| Format: | Conference or Workshop Item |
| Published: |
2009
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| Subjects: | |
| Online Access: | http://eprints.um.edu.my/9745/ |
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| Summary: | High frequency bioelectrical impedance analysis devices are mostly used in Bioimpedance tomography and blood analysis. Nowadays 50 - 100 KHz bioelectrical impedance devices are commonly used for body composition analysis. AD8130 or AD 8129 deferential op-amp is used in this paper. These two op-amps offer high output impedances at low frequencies because of the amplifiers' good low-frequency CMRR (common-mode-rejection ratios). At higher frequencies, decreasing CMRR, inherent output capacitances, and slew-rate limitations prevent realization of high-quality current sources. 170 mV sine wave signal is used as input voltage considering the current should be no more than 1 mA. Four frequencies of 100 KHz, 1 MHz, 2 MHz and 3.2 MHz are applied to the circuit and by changing the load resistor, the current is measured. The result shows the current stable during the load resistor changing. |
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