Data processing system

摘要

The present invention provides a data processing system which can increase resolution and which has excellent tracking with respect to the switching of a conversion range and is small in conversion error. The data processing system, which obtains an A/D conversion result after an n (where n: positive integer)-bit extension made to the resolution of an A/D converter, divides the input range of the A/D converter by m (2n≦m), determines to which divided range the A/D conversion result by the A/D converter belongs with respect to an analog signal to be measured, amplifies an amp offset which defines the range of the determined divided range as a voltage range for the input range of the A/D converter by applying the amp offset to a programmable gain amplifier, converts the amplified signal by the A/D converter, and adds a corresponding digital offset to a result of execution of a lower side bit extension to the conversion result and a division thereof by actually measured gain of the programmable gain amplifier, whereby an A/D conversion result with a bit precision being n-bit extended is obtained.

主权项

1. In a data processing system comprising:
an AD converter; a programmable gain amplifier; and a control circuit, a method for obtaining an AD conversion result in which a bit precision has been n-bit extended, the method comprising: determining whether an analog signal to be measured belongs to any of divided ranges obtained by dividing an input range of the AD converter by m (where m: positive integer) by the control circuit; setting an amp offset and target gain 2n (where n: positive integer and 2n≦m) for expanding a voltage range for the determined divided range to a voltage range for the input range of the AD converter to the programmable gain amplifier by the control circuit; converting an amplified signal of the measured analog signal by the programmable gain by the AD converter, performing a bit extension of n bits for the converted data and a division of the extended data by actually measured gain of the programmable gain amplifier by the control circuit; and adding digital offset data of the divided range to a result of division thereof by the control circuit, thereby obtaining the AD conversion result in which the bit precision has been n-bit extended.