The Cleverscope CS448, an isolated high common-mode rejection
ratio four-channel 200MHz 14-bit oscilloscope, has been designed to measure high voltages--now up to 1,600V--for fast slew-rate signals such as those in a full or three-phase power electronics switching bridge.
has announced improvements to the Cleverscope CS448 - a unique isolated high common-mode rejection
ratio (CMRR) four-channel 200MHz 14-bit oscilloscope.
The requirements for instrumentation amplifiers are expressed in terms of high input impedance, low input-referred noise, low offset voltage, high differential gain, high common-mode rejection
ratio (CMRR) and high power supply rejection ratio (PSRR) [3, 10].
MACOM's MAOM-005311 and MAOM-005411 feature differential inputs to provide common-mode rejection
while the single-ended output voltage can be adjusted up to 1.8Vpp.
The device's fully differential input structure features high common-mode rejection
ratio (CMRR) of more than 100 dB and a high impedance of more than 500 MOhms, which results in improved low common-to-differential mode conversion.
Lidgey, "Common-mode rejection
in current-mode instrumentation amplifiers", Int.
8, the measured common-mode rejection
ratios of all types of the corresponding transfer functions are shown.
This results in tight tolerances for electrical parameters such as leakage inductance and winding capacitance, and precise specifications for common-mode rejection
or resonant frequency.
Martin, "Dual-band differential filter using broadband common-mode rejection
artificial transmission line," Progress In Electromagnetics Research, Vol.
Since this common-mode level can lead to undesired radiation and EMI problems that degrades the performance of high-speed circuitry, a lot of effort has been devoted to the design of differential devices with high common-mode rejection
To provide a simple figure-of-merit for characterizing the implement differential filter, the common-mode rejection
ratio (CMRR) can be defined by
The AD8429 has a 90-dB CMRR (common-mode rejection
ratio) when operating in dc mode and an 80-dB CMRR in ac mode, which prevents unwanted signals from corrupting smaller signal acquisition.