Ad converter and semiconductor device including the same
AssigneeRenesas Electronics Corporation
InventorMasaaki USUI
Life of this patent
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Abstract
An AD converter includes a plurality of analog input terminals, a reference signal generation circuit that generates an analog reference signal, a sample-and-hold unit that includes a plurality of sample-and-hold circuits sampling the analog reference signal or one of analog input signals from the analog input terminals, a control unit that controls the sample-and-hold unit, and a conversion unit that converts an output signal from the sample-and-hold unit into a digital signal. The control unit controls the sample-and-hold unit to perform the output operation for analog input signal and the sampling operation for the analog reference signal.
Claims16
An AD converter comprising:
- a plurality of analog input terminals;
- a reference signal generation circuit generating an analog reference signal;
- a sample-and-hold unit including a plurality of sample-and-hold circuits, each of the sample-and-hold circuits sampling the analog reference signal or one of analog input signals inputted to the analog input terminals;
- a control unit controlling the sample-and-hold unit, and
- a conversion unit converting an output signal from the sample-and-hold unit into a digital signal,
- wherein the control unit controls the sample-and-hold unit to perform the output operation for the analog input signal and the sampling operation for the analog reference signal in parallel.
An AD converter comprising:
- a plurality of analog input terminals;
- a reference signal generation circuit generating an analog reference signal;
- an input selector connected to the analog input terminals and the reference signal generation circuit, and selecting the analog reference signal and a plurality of analog input signals which are inputted to the analog input terminals in order;
- a sample-and-hold unit sampling an analog signal selected by the input selector;
- and
- a conversion unit converting a sampled analog signal by the sample-and-hold unit into a digital signal,
- wherein the input selector selects next analog input signal after a preceding selected analog input signal is converted by the conversion unit, and selects the analog reference signal while the preceding selected analog input signal is converted by the conversion unit before the input selector selects the next analog input signal,
- wherein the sample-and-hold unit includes a plurality of sample-and-hold circuits, one of the sample-and-hold circuit samples the analog reference signal when the other one of the sample-and-hold circuit outputs a sampled analog input signal.
A semiconductor device comprising:
- a plurality of analog input terminals;
- a reference signal generation circuit generating an analog reference signal;
- an input selector selecting the analog reference signal and the analog input signals inputted to the analog input terminals in a predetermined order;
- a sample-and-hold circuit sampling an analog signal selected by the input selector;
- a conversion unit converting a sampled analog signal by the sample-and-hold unit into a digital signal;
- and
- a control unit controlling the sample-and-holding unit and the input selector,
- wherein the sample-and-hold unit includes a plurality of sample-and-hold circuits,
- wherein the control unit controls the sample-and-hold unit so that the analog signals selected by the input selector are sampled into the sample-and-hold circuits sequentially and the sampled analog signals are outputted to the conversion unit in sampling order, and
- wherein the control unit controls the input selector to select the analog signals and the analog reference signal alternately and select the analog input signals in a predetermined interval.
Dependencies are inferred from the claim text.