Semiconductor integrated circuit and semiconductor physical quantity sensor device

摘要

In aspects of the invention, an auxiliary memory circuit includes a shift register wherein a plurality of flip-flops are cascade-connected and a plurality of inversion circuits that invert and output outputs of each D flip-flop. A main memory circuit includes a switch, which acts in accordance with a signal from the auxiliary memory circuit, and an EPROM connected in series to the switch and driven by a writing voltage. A variable resistance circuit includes a switch, which acts in accordance with a signal from the auxiliary memory circuit, and a resistor connected in series to the switch. With aspects of the invention, it is possible for terminals of the writing voltage and a writing voltage to be commonized. Also, it is possible to provide a low-cost semiconductor physical quantity sensor device that can carry out electrical trimming with the voltage when writing into the EPROM kept constant.

主权项

1. A semiconductor integrated circuit, comprising:
a data input terminal that inputs serial digital data; a ground terminal that supplies ground potential; a power source terminal that supplies power source voltage; an auxiliary memory circuit that temporarily stores trimming data input from the data input terminal; a programmable read only main memory circuit that stores trimming data stored in the auxiliary memory circuit using an electrical rewrite action; a writing terminal that inputs an external clock, or that supplies a first writing voltage, equal to or higher than the power source voltage, for writing data into the main memory circuit; a constant resistance circuit that, based on the first writing voltage input from the writing terminal, generates a second writing voltage, which is equal to or higher than the power source voltage and wherein the first writing voltage is divided by resistance of the main memory circuit, for writing data into the main memory circuit, and supplies the second writing voltage to the main memory circuit; and a signal distinguishing means that determines whether voltage applied to the writing terminal is an external clock, or whether it is the first writing voltage, supplies the external clock to the auxiliary memory circuit, and supplies the first writing voltage to the main memory circuit, wherein the auxiliary memory circuit is configured of a shift register wherein a plurality of flip-flops are cascade connected, the main memory circuit includes a first series circuit, corresponding to each flip-flop, formed of a first switch and an EPROM connected in series to the first switch and driven by the first writing voltage, and a second series circuit, corresponding to each flip-flop, formed of a second switch and a resistor connected in series to the second switch, a plurality of the first series circuits and a plurality of the second series circuits are connected in parallel, a plurality of the first series circuits and plurality of the second series circuits and the constant resistance circuit are connected in series, and when the first writing voltage is applied, the first series circuit and second series circuit corresponding to the same flip-flop are such that when the first switch is turned on, the second switch is turned off, while when the first switch is turned off, the second switch is turned on.