Abstract: A semiconductor device includes a plurality of resistors each of which has a resistance that varies depending on voltage applied between contacts of the resistor. The semiconductor device includes a first resistor including a first resistive layer connected at a first contact to a first input wire and connected at a second contact to a first output wire, the first output wire having a first shielding portion which is connected to the second contact and shields the first resistive layer. A second resistor includes a second resistive layer connected at a third contact to a second input wire and connected at a fourth contact to a second output wire, the second output wire having a second shielding portion which is connected to the fourth contact and shields the second resistive layer.

Abstract: An offset voltage trimming circuit for sending a current from a constant-current source to a trimming resistor and thus obtaining an offset voltage, the offset voltage trimming circuit having a Zener diode with a temperature characteristic of zero, a transistor connected so as to form a diode and connected in series to the Zener diode, a current-mirror circuit connected to the transistor and a second resistor connected in series to the current-mirror circuit and having a temperature characteristic identical to that of the trimming resistor, with the current being supplied to the trimming resistor from the current-mirror circuit in order to prevent changes in the offset voltage due to changes in temperature.

Abstract: A differential amplifier circuit for amplifying and outputting a differential voltage between a pair of input terminals includes a voltage-to-current converting circuit, a current amplifying circuit, and a current-to-voltage converting circuit. In the voltage-to-current converting circuit, each of the input terminals is connected with one end of each of resistances, a potential on the other end of each of the resistances is kept constant by a feedback circuit, and an electric current corresponding to the differential voltage flows into a first differential circuit. In the current amplifying circuit, the electric current corresponding to the differential voltage and flowing into the first differential circuit is amplified and then flows into a second differential circuit. In the current-to-voltage converting circuit, an electric current outputted from the current amplifying circuit is converted to a voltage to be outputted.

Abstract: In a protection circuit for protecting a plurality of chargeable electric cells by detecting overdischarge and overcharge by detection circuits for respective electric cells to control a protection switch upon detection, the detection circuit is a single chip device comprising an overcharge detection circuit and an overdischarge detection circuit to produce first and second detection signals, respectively, first and second terminals to be connected to an electric cell, third and fourth terminals for receiving first and second input signals, respectively, and fifth and sixth terminals for delivering first and second output signals, respectively. The first input signal and the first detection signal are processed by an OR gate to produce a first processed signal which is delivered to the fifth terminal. The second input signal and the second detection signal are processed by AND gate to produce a second processed signal which is delivered to the sixth terminal.

Abstract: An amplifying circuit includes: amplifying device for amplifying an input signal and outputting the amplified signal; feedback device for feeding the output signal from the amplifying device back to an input terminal of the amplifying device so that the output signal may have a predetermined frequency characteristic; and a variable impedance circuit which, included in the feedback device, operates on the basis of a current from a current source, and which has its impedance altered in accordance with the current.