Provided is a variable resistance circuit in which the resistance value of the variable resistance circuit can be accurately adjusted, by reducing the error in the change amount of the resistance value of the variable resistance circuit due to the on-resistances of switch circuits even if the switch circuits that each bypass a resistor included in a ladder resistor circuit are switched between an OFF state and an ON state. This variable resistance circuit includes: a ladder resistor circuit including a plurality of resistors; a first switch circuit connected in series to one end of one resistor of the plurality of resistors; and a second switch circuit connected in parallel to a series circuit of the one resistor and the first switch circuit. When one of the first and second switch circuits is turned on, the other of the first and second switch circuits is turned off.

A resistance trimming circuit has a resolution of N=X+Y bits. Included is a first circuit with M resistors, where M=2.sup.X1, with each of the M resistors having a resistance of R*(2.sup.Y)*i, i being an index having a value ranging from 1 to 2.sup.X1. M switches are associated with the M resistors. Each of the M resistors is coupled between a first node and its one of the M switches, and each of the M switches couples its one of the M resistors to a second node. Included is a second circuit with P resistors, where P=2.sup.Y1, with each of the P resistors having a resistance of R*i. P switches are associated with the P resistors. Each of the P resistors is coupled between the second node and its one of the P switches, and each of the P switches selectively couples its one of the P resistors to a third node.

A light adjusting device includes a housing, a light adjusting assembly and a circuit switching mechanism. The circuit switching mechanism is connected to the light adjusting assembly. The light adjusting assembly can be in communication with a first circuit and a second circuit respectively by means of the circuit switching mechanism, so as to control light-emitting elements in the first and second circuits by one light adjusting device.

In a multi-directional input device, an upward convex spherical trapezoidal portion is provided at a lower end of an operation shaft projecting downward of a lower arm, a receiving portion for the upward convex spherical trapezoidal portion is provided in a case, the receiving portion has a receiving surface configured with a spherical surface having a radius of curvature identical to a radius of curvature of a spherical zone of the upward convex spherical trapezoidal portion, the receiving surface against which the spherical zone of the upward convex spherical trapezoidal portion is pressed downward by a compression coil spring, and the operation shaft is supported to be rotatable around the center of curvature of the receiving surface.

In a multi-directional input device, an upward convex spherical trapezoidal portion is provided at a lower end of an operation shaft projecting downward of a lower arm, a receiving portion for the upward convex spherical trapezoidal portion is provided in a case, the receiving portion has a receiving surface configured with a spherical surface having a radius of curvature identical to a radius of curvature of a spherical zone of the upward convex spherical trapezoidal portion, the receiving surface against which the spherical zone of the upward convex spherical trapezoidal portion is pressed downward by a compression coil spring, and the operation shaft is supported to be rotatable around the center of curvature of the receiving surface.

A temperature sensing device includes a resistor string and a control circuitry. The resistor string includes a variable resistor, a first resistor, and a second resistor which are coupled in series with each other. The resistor string is coupled between a sensing end and a reference ground voltage. The first resistor and the second resistor are coupled to a monitoring end to provide a monitoring voltage. The control circuitry compares the monitoring voltage with a plurality of reference voltages to generate sensing temperature information, and generate adjustment information according to the sensing temperature information. The control circuitry adjusts a resistance provided by the variable resistor according to the adjustment information. The first resistor is a polysilicon resistor, and the second resistor is a silicon carbide diffusion resistor.

A temperature sensing device includes a resistor string and a control circuitry. The resistor string includes a variable resistor, a first resistor, and a second resistor which are coupled in series with each other. The resistor string is coupled between a sensing end and a reference ground voltage. The first resistor and the second resistor are coupled to a monitoring end to provide a monitoring voltage. The control circuitry compares the monitoring voltage with a plurality of reference voltages to generate sensing temperature information, and generate adjustment information according to the sensing temperature information. The control circuitry adjusts a resistance provided by the variable resistor according to the adjustment information. The first resistor is a polysilicon resistor, and the second resistor is a silicon carbide diffusion resistor.

A memory device includes a first chip, a second chip and a processor. The second chip is coupled to the first chip at a first node. The second chip includes a first capacitor and a first variable resistor. The first capacitor is coupled to the first node. The first variable resistor is coupled in series with the first capacitor. The processor is coupled to the first node, and is configured to perform a first read operation to the first chip via the first node. A method for operating a memory device is also disclosed herein.

A memory device includes a first chip, a second chip and a processor. The second chip is coupled to the first chip at a first node. The second chip includes a first capacitor and a first variable resistor. The first capacitor is coupled to the first node. The first variable resistor is coupled in series with the first capacitor. The processor is coupled to the first node, and is configured to perform a first read operation to the first chip via the first node. A method for operating a memory device is also disclosed herein.

In an example, there is disclosed a configurable impedance element, having: a first impedance network including a plurality of series impedance elements and providing an initial impedance; a trim impedance network parallel to the first impedance network, including a plurality of corresponding impedance elements to the impedance elements of the first impedance network; and antifuses between the impedance elements of the first impedance network and their corresponding impedance elements of the trim network. There is also disclosed an integrated circuit including the impedance element, and a method of manufacturing and configuring the impedance element.