学习KEA之ADC之一：基本介绍

墨蓝 2023-02-20 07:27 6阅读 0赞

> 作者：曾Jerry 或 大橙员, 250359225@qq.com

[学习KEA之ADC之一：基本介绍][KEA_ADC]  
[学习KEA之ADC之二：查询方式][KEA_ADC 1]  
[学习KEA之ADC之三：中断方式][KEA_ADC 2]  
[学习KEA之ADC之四：FIFO][KEA_ADC_FIFO]

我们以KEA64系列来学习ADC， 其中KEA64系列包括：

*  SKEAZN16AMLC®
 *  SKEAZN32AMLC®
 *  SKEAZN64AMLC®
 *  SKEAZN32AMLH®
 *  SKEAZN64AMLH®

其它系列的和KEA64类似，但也有点不同，具体要看各自的参考手册。

## ADC特点 ##

*  Linear Successive Approximation algorithm with 8-, 10-, or **12-bit** resolution
 *  Up to **16** external analog inputs（ADC0\_SE0 ~ ADC0\_SE15）, external pin inputs, and 5 internal analog inputs, including **internal bandgap**(AD22), **temperature sensor** (AD23), and references
 *  Output formatted in 8-, 10-, or 12-bit right-justified unsigned format
 *  Single or **Continuous Conversion** (automatic return to idle after single conversion)
 *  Support up to eight result FIFO with selectable FIFO depth
 *  Configurable sample time and conversion speed/power
 *  Conversion complete flag and interrupt
 *  Input clock selectable from up to four sources
 *  Operation in Wait or Stop modes for lower noise operation
 *  Asynchronous clock source for lower noise operation
 *  Selectable asynchronous hardware conversion trigger
 *  Automatic compare with interrupt for less-than, or greater-than or equal-to,  
    programmable value

## ADC框图 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70]  
**ADC时钟，由ADC\_SC3 \[ADICLK\]选定：**

*  Bus clock
 *  Bus clock divided by 2
 *  Alternate clock (ALTCLK)
 *  Asynchronous clock (ADACK)

## ADC寄存器 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70 1]

## ADC的基本使用 ##

KEA64的ADC是逐次逼近型ADC，最多具有16个外部模拟输入（ADC0\_SE0 ~ ADC0\_SE15）和5个内部模拟输入（包括温度传感器 (AD22)、内部带隙(AD23)和参考）。

ADC可以在任何可选通道上执行模数转换，可以转换成12位，10位或8位数字结果。转换完成后，结果将放置在数据寄存器（ADC\_R）中，并设置转换完成标志ADC\_SC1\[COCO\] = 1。如果使能了转换完成中断，则会产生一个中断ADC\_SC1 \[AIEN\] = 1。

当在休眠期间或当ADC\_SC1 \[ADCH\]位都为高电平时，ADC模块被禁用。

ADC的转换模式有：Single 或 **Continuous Conversion** (automatic return to idle after single conversion)

## 注意事项 ##

It is recommended that the pin control register bit always be set  
when using a pin as an analog input

*  There is a 0.1 µF low-ESR capacitor from VREFH to VREFL.
 *  There is a 0.1 µF low-ESR capacitor from VDDA to VSSA.
 *  If inductive isolation is used from the primary supply, an additional 1 µF capacitor is placed from VDDA to VSSA.
 *  VSSA (and VREFL, if connected) is connected to VSS at a quiet point in the ground
 *  There is no I/O switching, input or output, on the MCU during the conversion
 *  Bandgap（可作为其它ADC通道的参考源）
    
     *  电压最小1.14 V, 典型1.16 V，最大 1.18 V
 *  Temp sensor voltage  
    ![在这里插入图片描述][20200701203838388.png]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70 2]

[KEA_ADC]: https://blog.csdn.net/feimeng116/article/details/106949471
[KEA_ADC 1]: https://blog.csdn.net/feimeng116/article/details/106998567
[KEA_ADC 2]: https://blog.csdn.net/feimeng116/article/details/107003190
[KEA_ADC_FIFO]: https://blog.csdn.net/feimeng116/article/details/107037460
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200624190548877.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200624192853437.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY=,size_16,color_FFFFFF,t_70
[20200701203838388.png]: https://img-blog.csdnimg.cn/20200701203838388.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200702205236938.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW1lbmcxMTY=,size_16,color_FFFFFF,t_70