US 4,937,579 A · Method of converting analog signals into digital signals and system for carrying out the method

Abstract

The same analog signal is inputted to an 8-bit AD converter and to a 4-bit AD converter to obtain an 8-bit digital data and a 4-bit digital data for the same sample value of the analog signal. Values of the 8-bit digital data and 4-bit digital data are compared with each other. The 8-bit digital data is outputted as a digital signal for the sample value of the analog signal when a difference between these values is not greater than one-half the quantity that corresponds to the least significant bit of the 4-bit digital data, and the 4-bit digital data is outputted as a digital signal for the sample value of the analog signal in other cases. There is realized AD conversion which operates apparently at high speeds maintaining high accuracy.

Claims14

Dependent claims

A method of converting analog signals into digital signals, comprising the steps of:

supplying an analog signal to first and second analog-to-digital converters to convert the analog signal into a first digital signal consisting of m bits and a second digital signal consisting of n bits, respectively, where m and n are positive integers, and m>n;
determining whether the difference between the value of said first digital signal and the value of said second digital signal is greater than a predetermined value;
and
when said difference is not greater than said predetermined value, outputting said first digital signal, and when said difference is greater than said predetermined value, outputting said second digital signal.

1 more element

A method of converting analog signals into digital signals, comprising the steps of:

supplying an analog signal to first, second and third analog-to-digital converters to convert the analog signal into, respectively, a first digital signal consisting of m bits, a second digital signal consisting of n bits, and a third digital signal consisting of p bits, where m, n and p are positive integers, and m>n>p;
determining whether the difference between the value of said second digital signal and the value of said third digital signal is greater than a first predetermined value;
when said difference between the value of said second digital signal and the value of said third digital signal is greater than said first predetermined value, outputting said third digital signal;
and
when said difference between the value of said second digital signal and the value of said third digital signal is not greater than said first predetermined value, determining whether the difference between the value of said first digital signal and the value of said second digital signal is greater than a second predetermined value, and when said difference between the value of said first digital signal and the value of said second digital signal is not greater than said second predetermined value, outputting said first digital signal, and when said difference between the value of said first digital signal and the value of said second digital signal is greater than said second predetermined value, outputting said second digital signal.

2 more elements

An analog-to-digital conversion system comprising:

first and second analog-to-digital converters for receiving a single analog signal to produce a first digital signal of m bits and a second digital signal of n bits, respectively, where m and n are positive integers, and m>n;
means for determining whether the difference between the value of said first digital signal and the value of said second digital signal is greater than a predetermined value;
and
means responsive to said difference not being greater than said predetermined value for providing said first digital signal as an output signal and responsive to said difference being greater than said predetermined value for providing said second digital signal as an output signal.

1 more element

Dependencies are inferred from the claim text.

Method of converting analog signals into digital signals and system for carrying out the method

Life of this patent

Method of converting analog signals into digital signals and system for carrying out the method

Life of this patent

Abstract

Claims14