CS1237采集结果与温度的关系

使用电池作为标准电压，用CS1237对电池电压进行采集。
发现温度对ADC的采集值是有影响的。现在是使用5V作为VREF，提供的是500mV的输入电压。取18位有效精度。电压计算为：
V=26232/2^17*2.5V=500.3357mV。与实际情况是相对应的。但是，在不同温度情况下，这个ADC的输出值是有变化的。具体如下：
[17:39:50.250] Tmep=32.1
[17:39:51.659] DAT=26222.0
[17:39:56.249] Tmep=28.6
[17:39:57.656] DAT=26232.0
[17:40:02.246] Tmep=27.3
[17:40:03.654] DAT=26240.0
[17:40:08.243] Tmep=26.4
[17:40:09.650] DAT=26247.0
[17:40:14.259] Tmep=25.7
[17:40:15.648] DAT=26252.0
[17:40:20.254] Tmep=25.1
[17:40:21.645] DAT=26256.0
[17:40:26.251] Tmep=24.6
[17:40:27.658] DAT=26260.0
[17:40:32.249] Tmep=24.1
[17:40:33.656] DAT=26263.0
[17:40:38.245] Tmep=23.7
[17:40:39.653] DAT=26266.0
[17:40:44.244] Tmep=23.5
[17:40:45.653] DAT=26270.0
[17:40:50.256] Tmep=23.2
[17:40:51.647] DAT=26271.0
[17:40:56.253] Tmep=22.9
[17:40:57.646] DAT=26273.0
[17:41:02.251] Tmep=22.6
[17:41:03.643] DAT=26274.0
[17:41:08.249] Tmep=22.5
[17:41:09.656] DAT=26275.0
[17:41:14.247] Tmep=22.2
[17:41:15.654] DAT=26277.0
[17:41:20.243] Tmep=22.0
[17:41:21.651] DAT=26278.0
[17:41:26.256] Tmep=21.9
[17:41:27.648] DAT=26279.0
[17:41:32.254] Tmep=21.8
[17:41:33.646] DAT=26281.0
[17:41:38.252] Tmep=21.7
[17:41:39.643] DAT=26282.0
[17:41:44.249] Tmep=21.5
[17:41:45.656] DAT=26282.0
[17:41:50.249] Tmep=21.3
[17:41:51.654] DAT=26283.0
[17:41:56.243] Tmep=21.1
[17:41:57.650] DAT=26285.0
[17:42:02.241] Tmep=20.9
[17:42:03.649] DAT=26286.0
[17:42:08.254] Tmep=20.8
[17:42:09.646] DAT=26287.0
[17:42:14.253] Tmep=20.8
[17:42:15.643] DAT=26288.0
[17:42:20.250] Tmep=20.8
[17:42:21.656] DAT=26288.0
[17:42:26.252] Tmep=20.7
[17:42:27.654] DAT=26289.0
[17:42:32.244] Tmep=20.7
[17:42:33.652] DAT=26289.0
[17:42:38.241] Tmep=20.6
[17:42:39.648] DAT=26289.0
[17:42:44.254] Tmep=20.6
[17:42:45.646] DAT=26289.0
[17:42:50.251] Tmep=20.6
[17:42:51.643] DAT=26289.0
[17:42:56.249] Tmep=20.5
[17:42:57.656] DAT=26290.0
[17:43:02.246] Tmep=20.4
[17:43:03.656] DAT=26290.0
[17:43:08.249] Tmep=20.4
[17:43:09.651] DAT=26291.0
[17:43:14.241] Tmep=20.3
[17:43:15.649] DAT=26291.0
[17:43:20.255] Tmep=20.3
[17:43:21.645] DAT=26291.0
[17:43:26.252] Tmep=20.2
[17:43:27.643] DAT=26291.0
温度是使用的CS1237的内部温度采集的。这个ADC的结果与温度还不是线性关系。