说明：  AVR单片机SPI的串行ADC接口的设计 SPI（SerialPeripheralInterface---串行外设接口）总线系统是一种同步串行外设接口，允许MCU与各种外围设备以串行方式进行通信、数据交换，广泛应用于各种工业控制领域。 MAX187用采样／保持电路和逐位比较寄存器将输入的模拟信号转换为12位的数字信号，其采样／保持电路不需要外接电容。MAX187有2种操作模式：正常模式和休眠模式，将置为低电平进入休眠模式，这时的电流消耗降到10μA以下。置为高电平或悬空进入正常操作模式。
(AVR single-chip SPI serial ADC interface design SPI (SerialPeripheralInterface--- Serial Peripheral Interface) bus system is a synchronous serial peripheral interface that allows MCU with a variety of peripheral devices to the serial approach to communications , data exchange, widely used in various industrial control. MAX187 with sample/hold circuit and the case-by-bit compare register will be entered into the analog signal is converted to 12-bit digital signal, the sample/hold circuit does not require an external capacitor. MAX187 has two kinds of operating modes: normal mode and sleep mode, will be home to enter the sleep mode for low-level, when the current consumption down to 10μA. Or vacant home for high into the normal operating mode.)