MTK ADC校准问题

linhf

最近在调试MTK平台时，出现ADC校准失败，主要是电流差值变化较大，参数设定：
[ADC table]　　　　　　　　　　　//ADC参数列表
ADC_V1 = 3400　　　　　　　　　　　　
ADC_V2 = 4200
NORMAL_VOLTAGE = 3800
MAX_BATTERY_ADC_SLOPE = 5550.0
MIN_BATTERY_ADC_SLOPE = 5250.0
MAX_BATTERY_ADC_OFFSET = 1000000
MIN_BATTERY_ADC_OFFSET = -1000000
BATTERY_CHANNEL = 5
CHARGER_CHANNEL = 4
ADC_RESISTANCE = 0.1
MAX_VOLTAGE_DIFFERENCE = 0.04
MAX_CURRENT_DIFFERENCE = 0.04
ADC_MEASUREMENT_COUNT = 1000

测试结果：

ADC Calibration Battery Slope Ok  ;
ADC Calibration Battery Channel Offset Ok
ADC Calibration current difference fail（此电流差值变化大，有一定概率超出限定值0.04）
ADC Calibration voltage difference Ok

大家有遇到这种情况吗？请帮忙分析一下是什么原因造成的？谢谢

lengdong03

记得之前遇到过这样的问题，具体是什么原因忘记了，跟楼主一起等高手解答。[em06]

jyudyw

[ADC table]
; ADC_RESISTANCE: resistance between Vbat and Isense
ADC_V1 = 3400
ADC_V2 = 4200
ADC_CHECK_VOLTAGE = 3600
NORMAL_VOLTAGE = 3800
CURRENT_LIMIT = 3000[/COLOR]
MAX_BATTERY_ADC_SLOPE = 5650
MIN_BATTERY_ADC_SLOPE = 5250
MAX_BATTERY_ADC_OFFSET = 1000000
MIN_BATTERY_ADC_OFFSET = -1000000
BATTERY_CHANNEL = 0
CHARGER_CHANNEL = 1
ADC_RESISTANCE = 0.4
MAX_VOLTAGE_DIFFERENCE = 0.04
MAX_CURRENT_DIFFERENCE = 0.04
ADC_MEASUREMENT_COUNT = 1000