Semiconductor Device

Patent metadata

Field	Value
Publication number	US-2016226508-A1
Application number	US-201614991978-A
Country	US
Kind code	A1
Filing date	Jan 10, 2016
Priority date	Jan 29, 2015
Publication date	Aug 4, 2016
Grant date	—

Abstract

In a semiconductor device, a sine wave signal is input to a first input part and a cosine wave signal is input to a second input part. A multiplexer alternately selects one of the sine wave signal and the cosine wave signal. An analog to digital converter converts the output signal of the multiplexer into a digital value. A switching circuit is coupled between at least one of the first and second input parts and the multiplexer. The switching circuit is configured to be able to invert the input sine wave signal or the input cosine wave signal, in order to reduce the angle detection error due to the non-linearity error of the A/D converter.

First claim

What is claimed is:

1 . A semiconductor device comprising:
a first input part to which a first signal indicating the sine of an angle to be detected is input; a second input part to which a second signal indicating the cosine of the angle is input; a multiplexer for selecting one of the first and second signals; an analog to digital converter for converting the output signal of the multiplexer into a digital value; and a switching circuit coupled between at least one of the first and second input parts and the multiplexer, wherein the switching circuit is configured to be able to invert the input first or second signal.

2 . The semiconductor device according to claim 1 , further comprising:
an angle operation circuit for calculating the angle based on the first and second signals converted into digital values by the analog to digital converter; and a switch control circuit for controlling the switching of the switching circuit based on the angle calculated by the angle operation circuit.

3 . The semiconductor device according to claim 2 ,
wherein the first signal is a signal obtained by modulating an excitation signal, which is input to a resolver, by the sine of the angle, wherein the second signal is a signal obtained by modulating the excitation signal by the cosine of the angle, and wherein the switch control circuit is configured to invert the input first or second signal in such a way that the first and second signals to be input to the analog to digital converter have the same phase.

4 . The semiconductor device according to claim 3 ,
wherein the switch control circuit controls the timing of the switching of the switching circuit so that the first or second signal is inverted at the timing of the zero crossing point of the excitation signal.

5 . The semiconductor device according to claim 3 ,
wherein when it is detected that the first and second signals, which are input to the respective first and second input parts, change from the same phase to the reverse phase or from the reverse phase to the same phase, the switch control circuit switches the switching circuit at the timing when the calculated angle further changes by a predetermined angle, from the time when the same phase and the reverse phase are switched.

6 . The semiconductor device according to claim 3 ,
wherein the switching circuit is coupled between the first input part and the multiplexer but not coupled between the second input part and the multiplexer, and wherein the switch control circuit is configured to invert the first signal by the switching circuit when the calculated angle is 90 degrees or more and 180 degrees or less, or is 270 degrees or more and 360 degrees or less.

7 . The semiconductor device according to claim 3 ,
wherein the switching circuit is coupled between the second input part and the multiplexer but not coupled between the first input part and the multiplexer, and wherein the switch control circuit is configured to invert the second signal by the switching circuit when the calculated angle is 90 degrees or more and 180 degrees or less, or is 270 degrees or more and 360 degrees or less.

8 . The semiconductor device according to claim 3 ,
wherein the semiconductor device comprises, as the switching circuit: a first switching circuit coupled between the first input part and the multiplexer; and a second switching circuit coupled between the second input part and the multiplexer, wherein the switch control circuit is configured to perform the steps of: inverting the first signal by the first switching circuit when the calculated angle is 180 degrees or more and 360 degrees or less; and inverting the second signal by the second switching circuit when the calculated angle is 90 degrees or more and 270 degrees or less.

9 . The semiconductor device according to claim 3 ,
wherein the semiconductor device comprises, as the switching circuit: a first switching circuit coupled between the first input part and the multiplexer; and a second switching circuit coupled between the second input part and the multiplexer, wherein the switch control circuit is configured to perform the steps of: inverting the first signal by the first switching circuit when the calculated angle is 0 degrees or more and 90 degrees or less; and inverting the second signal by the second switching circuit when the calculated angle is 0 degrees or more and 90 degrees or less, or is 270 degrees or more and 360 degrees or less.

10 . The semiconductor device according to claim 1 ,
wherein the first and second signals are differential signals, and wherein the switching circuit is configured to invert the first or second signal by reversing the positive side and negative side signals of the first or second signal to be input.

11 . A semiconductor device comprising:
a first input part to which a first signal is input; a second input part to which a second signal is input; a multiplexer for selecting one of the first and second signals; an analog to digital converter for converting the output signal of the multiplexer into a digital value; an operation circuit for performing arithmetic operations based on the first and second signals that are converted into digital values by the analog to digital converter; and a switching circuit coupled between at least one of the first and second input parts and the multiplexer, wherein the switching circuit is configured to be able to invert the input first or second signal.

12 . A motor control device for controlling the drive of a synchronous motor based on an output signal of a resolver coupled to the synchronous motor,
wherein the resolver outputs a first signal indicating the sine of an angle to be detected as well as a second signal indicating the cosine of the angle, wherein the motor control device comprises: an inverter circuit for generating a motor voltage supplied to the synchronous motor; a resolver to digital converter for calculating the angle based on the first and second signals; and a processor for generating a control signal to control the inverter circuit based on the calculated angle, wherein the resolver to digital converter includes: a first input part to which the first signal is input; a second input part to which the second signal is input; a multiplexer for selecting one of the first and second signals; an analog to digital converter for converting the output signal of the multiplexer into a digital value; and a switching circuit coupled between at least one of the first and second input parts and the multiplexer, wherein the switching circuit is configured to be able to invert the input first or second signal.

Assignees

• Renesas Electronics Corp

Inventors

• Kurooka Kazuaki
• Funato Yoshihiro

Classifications

• H03M1/485 Primary

  for position encoding, e.g. using resolvers or synchros · CPC title

• H03M1/645

  for position encoding, e.g. using resolvers or synchros (H03M1/485 takes precedence) · CPC title

• H03M1/0872

  by disabling changes in the output during the transitions, e.g. by holding or latching · CPC title

• G01B7/30 Primary

  for measuring angles or tapers; for testing the alignment of axes · CPC title