Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.

Method and apparatus for output driver calibration

Abstract: An output driver calibration circuit determines calibration values for configuring adjustable impedance output drivers. Output drivers are calibrated by generating a first variable count in response to comparing a reference voltage to a first voltage at a calibration terminal when an external load is connected. A first pull-up impedance circuit is varied in response to a first variable count and varying an impedance in a second variable pull-up impedance circuit in response to the first variable count. A second variable count is generated responsive to comparing the reference voltage to a second voltage at a reference node between the second variable pull-up impedance circuit and a serially connected to a variable pull-down impedance circuit. The impedance to the variable pull-down impedance circuit is varied in response to the second variable count. The first and second variable counts for configuring the output drivers are output when a steady state is achieved.

Zeta converter for power factor correction and voltage regulation

Abstract: This paper proposes a power factor correction using an intermediate zeta converter. Average current mode control technique is used in the closed loop, which will force the input source current to be almost in phase with the supply voltage. Further, this control loop also ensures that tight regulation of load voltage against line and load disturbances. Input current is almost smooth and exhibits low ripple current thus results in lower EMI. To verify the proposed control principle a zeta converter is designed to handle a power 250 W and the total system is simulated in PSIM environment. The power factor obtained through simulation is in compliance with the standards.

Four-state I/O control circuit

Abstract: An I/O control circuit is provided which is of the type that receives two inputs such that four sets of input conditions to the circuit are defined. A first set of input conditions establishes a low impedance path from the circuit output to the positive supply. A second set of input conditions establishes a low impedance path from the output to the negative supply, or ground. A third set of input conditions establishes a high impedance path from the output to both the positive and the negative supply. And, in accordance with the present invention, "pull-up" means is connected to the output such that the fourth set of input conditions establishes a path to the positive supply, the path having an impedance which is intermediate that of the low impedance and the high impedance. Alternatively, "pull-down down" means is connected to the output such that the fourth set of input conditions establishes an intermediate impedance path to the negative supply.

ZVS Combined Three-Level Converter—A Topology Suitable for High Input Voltage With Wide Range Applications

Abstract: A novel zero-voltage-switching (ZVS) combined three-level (TL) converter is proposed in this paper. It is essentially a hybrid combination of a half-bridge TL section and a full-bridge section. The main advantages of the proposed converter are given as follows: the voltage stress of all the switches is ensured to be only half of the input voltage; the secondary rectified voltage is very close to the output voltage, so the high-frequency content is very low, leading to a reduced output filter requirement; the voltage stress of the rectifier diodes is also reduced; and the switches can achieve ZVS with the use of the leakage inductances of the transformers and the intrinsic capacitors of the switches. This paper describes the operating principles and design procedures for the proposed converter. Experimental results from a 1080 W prototype converter operating at 100 kHz are presented to validate the theoretical analysis and demonstrate the performance of the proposed converter