Pseudo-differential amplifier and analog-to-digital converter using the same
AssigneeSemiconductor Technology Academic Research Center
InventorsShoji Kawahito, Daisuke Miyazaki
Life of this patent
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Abstract
A pseudo-differential amplifier circuit 1 is constructed from two equivalent amplifiers 2 and 3 that amplify a pair of input signals without using a differential pair. This pseudo-differential amplifier circuit 1 is used in an arithmetic unit in each of the A-D converter circuits AD1 through ADm in a parallel pipeline A-D converter 10.
Claims10
A pseudo-differential amplifier circuit comprising:
- a first amplifier that amplifies a first input signal and
- a second amplifier that amplifies a second input signal that has the opposite signal level of said first input signal,
- said first and second amplifiers being of the same circuit configuration and having the same characteristics, and capable of performing pseudo differential amplification for said input first and second signals to output the obtained signals.
In an A-D converter having a sampling and hold circuit that samples and holds a pair of analog signals having mutually opposite voltage levels and a plurality of A-D converter circuits, each of which A-D converts a pair of output signals output from said sampling and hold circuit and performs arithmetic operations in a predetermined way for the A-D converted signals to output as a pair of input voltages for the proceeding A-D converter circuit, each of said A-D converter circuits comprising:
- a sub-A-D converter that A-D converts a pair of input voltages,
- a sub-D-A converter that D-A converts the data A-D converted in said sub-A-D converter,
- an arithmetic unit that performs predetermined arithmetic operations for the pair of said input voltages using the voltages D-A converted by said sub-D-A converter, and
- a pseudo-differential amplifier circuit that comprises a pair of amplifiers and performs pseudo differential amplification for each voltage obtained in said arithmetic unit, said amplifiers being of the same circuit configuration and having the same characteristics.
In an A-D converter having a sampling and hold circuit that samples and holds a pair of analog signals having mutually opposite voltage levels and a plurality of A-D converter circuits, each of which A-D converts a pair of output signals output from said sampling and hold circuit and performs arithmetic operations in a predetermined way for the A-D converted signals to output as a pair of input voltages for the proceeding A-D converter circuit, at least one of said A-D converter circuits comprising:
- a sub-A-D converter that A-D converts a pair of input voltages,
- a sub-D-A converter that D-A converts the data A-D converted in said sub-A-D converter,
- an arithmetic unit that performs predetermined arithmetic operations for said pair of input voltages using the voltages D-A converted by said sub-D-A converter, and
- a pseudo-differential amplifier circuit that comprises a pair of amplifiers and performs pseudo differential amplification for each voltage obtained in said arithmetic unit, said amplifiers being of the same circuit configuration and having the same characteristics.
Dependencies are inferred from the claim text.