Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

Wenhui Qin

Shaoyu Ma

Xin Yang

Baoxing Chen

Fang Liu

Tianting Zhao

Yuanyuan Zhao

Yue Zhuo

Yingjie Guo

Micro-scale planar-coil transformers including one or more shields are disclosed. The one or more shields can block most common-mode current from crossing from one side to another side of a transformer. Reduction of common-mode current crossing the transformer results in reduction of dipole radiation, which is the main component of electromagnetic interference (EMI) in some transformers.

Micro-scale planar-coil transformer with shield

Isolated circuit systems are provided. The systems include a primary side circuit and a secondary circuit, electrically isolated from each other. The primary side and secondary side circuits each utilize a direct current (DC) reference signal. The primary side circuit may use the DC reference signal in a modulation operation. The secondary side circuit may use the DC reference signal in a demodulation operation. The DC reference signal may be sent from the primary side circuit to the secondary side circuit, or from the secondary side circuit to the primary side circuit.

Isolation amplifier with reference signal transfer

Power isolators for providing electrical isolation between an input port and an output port that exhibit low electromagnetic interference (EMI) are described. The low EMI may be achieved by, for example, canceling out a common mode current across a transformer in the power isolator that may be converted into EMI. The power isolator may include at least one oscillator circuit that is configured to apply a first signal to a first transformer and a second, different signal to a second transformer. The first and second signals may be configured such that the common mode current generated in each of the first and second transformers has an opposite direction. Thus, the common mode currents in the first and second transformers may at least partially cancel out. As a result, the EMI exhibited by the power isolator may be reduced.

Power isolator exhibiting low electromagnetic interference

Power isolators with multiple selectable feedback modes are described. The power isolators may transfer a power signal from a primary side to a second side. A feedback signal may be provided from the secondary side to the primary side to control generation of the power signal on the primary side. In this manner, the power signal provided to the secondary side may be maintained within desired levels. The feedback signal may be generated by feedback circuitry configurable to operate in different modes, such that the feedback signal may be of differing types depending on which feedback mode is implemented.

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Shanghai, China

Wenhui Qin