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US 12,009,834 B2Granted
Control circuit and method for calibrating signal converter, and signal conversion system using the same
AssigneeNuvoton Technology Corporation
InventorYun Kai Lai
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Abstract
A control circuit and a method of calibrating a signal converter (such as DAC) are disclosed. The control circuit can be an existing control circuit, so no additional calibration circuit is required and the circuit area can be reduced. The control circuit can be an embedded microcontroller or other type of microcontroller. In general, the microcontroller includes an analog comparator and an arithmetic unit. With the combination of using the arithmetic unit to execute firmware program codes and using of the analog comparator, the control circuit is able to calibrate the signal converter.
Claims18
A control circuit for calibrating a signal converter, comprising,
- a switch, wherein an input terminal of the switch is electrically connected to an output terminal of the signal converter and configured to receive an analog signal, which is outputted by the signal converter by converting a digital signal, an output terminal of the switch is selectively conducted to the input terminal based on an event trigger signal, and an initial value of the digital signal corresponds to an analog reference signal;
- an analog comparator, wherein a first input terminal of the analog comparator receives the analog reference signal, and a second input terminal of the analog comparator is electrically connected to an output terminal of the switch;
- a signal converter control unit electrically connected to an output terminal of the analog comparator and an input terminal of the signal converter, wherein the signal converter control unit is selectively enabled to transmit the digital signal to the input terminal of the signal converter based on the event trigger signal;
- wherein when the signal converter control unit determines that a comparison signal outputted from the analog comparator has no transition, the signal converter control unit increases or decreases a value of the digital signal based on an comparison signal, when the signal converter control unit determines that the comparison signal outputted from the analog comparator has transition, the signal converter control unit records the value of the digital signal after transition or before transition, so as to obtain an offset of the signal converter;
- and,
- a filter and control circuit electrically connected between the output terminal of the signal converter and the signal converter control unit, wherein based on an event trigger signal, the filter and control circuit is enabled based on an event trigger signal, to perform noise filtering on the comparison signal outputted from the analog comparator, and output the noise-filtered comparison signal to the signal converter control unit.
3 more elements
A signal conversion system, comprising:
- a signal converter;
- a control circuit calibrating the signal converter, and comprising:
- a switch, wherein an input terminal of the switch is electrically connected to an output terminal of the signal converter, the switch receives an analog signal, which is outputted by the signal converter by converting a digital signal, an output terminal and the input terminal of the switch are conducted to each other based on an event trigger signal, and an initial value of the digital signal corresponds to an analog reference signal;
- an analog comparator, wherein a first input terminal of the analog comparator receives the analog reference signal, and a second input terminal of the analog comparator is electrically connected to an output terminal of the switch;
- and
- a signal converter control unit electrically connected to an output terminal of the analog comparator and an input terminal of the signal converter, wherein the signal converter control unit is enabled to transmit the digital signal to the input terminal of the signal converter, based on an event trigger signal;
- wherein when the signal converter control unit determines that a comparison signal outputted from the analog comparator has no transition, the signal converter control unit increases or decreases a value of the digital signal based on a comparison signal, and when the signal converter control unit determines that the comparison signal outputted from the analog comparator has transition, the signal converter control unit records the value of the digital signal after transition or before transition, so as to obtain an offset of the signal converter;
- and,
- a filter and control circuit electrically connected between the output terminal of the signal converter and the signal converter control unit, wherein the filter and control circuit is enabled based on an event trigger signal to perform noise filtering on the comparison signal outputted from the analog comparator and output the noise-filtered comparison signal to the signal converter control unit.
6 more elements
A method for calibrating a signal converter, wherein the method is executed in an arithmetic circuit in an automatic calibration mode, the arithmetic circuit comprises an analog comparator, and the method comprises:
- obtaining an initial value of the digital signal, wherein the signal converter converts the digital signal to generate the analog signal;
- obtaining the analog signal, outputted from the signal converter by converting the digital signal, and using the analog comparator to compare the analog signal with an analog reference signal, wherein an initial value of the digital signal corresponds to an analog reference signal;
- adjusting a value of the digital signal to update the digital signal, based on n comparison signal;
- outputting the updated digital signal to the signal converter;
- obtaining the comparison signal corresponding to the updated digital signal, to determine whether the comparison signal has a transition;
- when the comparison signal has no transition, continuously increasing or decreasing the value of the digital signal based on the comparison signal;
- and
- when the comparison signal has a transition, storing the digital signal of the comparison signal before the transition or after the transition, to obtain an offset of the signal converter;
- wherein a filter and control circuit are electrically connected between the output terminal of the signal converter and the signal converter control unit, the filter and control circuit are activated by an event trigger signal to conduct noise filtering on the comparison signal outputted from the analog comparator, and the noise-filtered comparison signal is then transmitted to the signal converter control unit.
6 more elements
Dependencies are inferred from the claim text.