Semiconductor device for sensing physical quantity

摘要

A semiconductor device 3 for sensing a physical quantity adjusts the output characteristic of a pressure sensor, for example, based on trimming data stored in an EPROM 34. A comparator 311 compares an input voltage given to a terminal 43 and a predetermined reference voltage, and delivers a write control signal for EPROM 34. When the comparator 311 delivers a Low signal for the EPROM 34, a first gate circuit 312 provided between the terminal 43 and a temperature sensor 32 connects the terminal 43 and the temperature sensor 32. A second gate circuit 313 provided between the terminal 43 and a pull-down resistor 314 disconnects the terminal 43 and the pull-down resistor 314. The operational voltage of the temperature sensor 32 is lower than the reference voltage, and the terminal 43 is used as an output terminal for the temperature sensor 32.

主权项

1. A semiconductor device for sensing a physical quantity, the semiconductor device including a first sensor element generating an electric signal corresponding to a detected value of the physical quantity and a nonvolatile main memory circuit storing a trimming data for adjusting an output characteristic of the first sensor element during a writing operation, and for adjusting the output characteristic of the first sensor element based on the trimming data, wherein the semiconductor device further includes:
an input terminal that receives an input signal at a specified voltage; a second sensor element that generates an electric signal corresponding to a detected temperature; a comparator circuit that compares the specified voltage applied to the input terminal and a predetermined reference voltage, and that delivers a control signal for controlling writing operations into the main memory circuit based on the comparison result; a first switch; and a first changeover circuit that changes-over ON and OFF of the first switch for selectively connecting the input terminal and the second sensor element according to the control signal; wherein the input terminal also serves as an output terminal to deliver externally an electric signal generated by the second sensor element when the first changeover circuit changes the first switch to an ON state and connects the input terminal and the second sensor element.