模数转换器和数模转换器
利用这些示例了解如何设计微控制器和物理系统之间的接口，以及如何转换模拟信号和数字信号。
精选示例
具有 GPIO、ADC 和 DAC 连接的微控制器
此示例展示了如何对微控制器单元 (MCU) 和物理系统之间的接口进行建模。此处使用微控制器的 GPIO、ADC 和 DAC 连接来控制一个角度行程有限的 DC 电机及连接负载。通过电位计传感器测量负载角度。此测量的校准方法是首先逐步调整转子位置，直到光电二极管检测到来自 LED 的零角度光脉冲。校准完成后，MCU 会发出一个频率为 0.1 Hz、振幅为 45 度的正弦波指令。
Delta Sigma ADC with Noise
A simple implementation of a sigma delta analog-to-digital converter. An input in the range 0 to Vref (=1V) is integrated until it causes the integrator to reset. The time to reset is proportional to the input value. Demodulation of the pulses is performed by a low-pass filter. The Asynchronous Sample & Hold block behaves like an edge-triggered D-type flip-flop, passing input U to output Y only on a rising edge of the clock. This model can be used to explore and understand the effect of op-amp impairments such as equivalent input noise on converter accuracy. To turn off the noise, open block Vn and select 'Disabled' for the noise mode.
Switched Capacitor Analog to Digital Converter
How a sigma-delta ADC (analog to digital converter) uses sigma-delta modulation to convert an analog input signal into a digital output signal. The analog input to the sigma-delta ADC controls an oscillator that produces pulses of fixed voltage and duration, but with period between pulses being inversely proportional to the analog input. The oscillator pulses are integrated over a fixed time interval to give a digital representation of the analog input signal.
