Please Help me. I have two question (ASAP)
1rd Question
We checked and strange symptom was found
1) Current sensor, output voltage at oscillocope is 0.259mV~0.260mV : about 1mV drift. (ADC input signal)
2) but current sensing value was read in AMC 7812 using TI GUI SW with 'AUTO Read' mode : 0.259mV~0.280mV, about 20mV variation.
3) When we push 'Read ADC Channels' button continously on AMC7812EVM GUI, one by one reading : about 1mA variation(0.259~0.260mV)
4) The root cause of this problem is by H/W issue or S/W issue? Is there a difference in the way we use and the GUI "Auto Read" mode?
------------------------------------------------------
2rd Question
If set the value of the registor as item#2 below, the above phenmenon does not exit. I wonder it's correct solution or not. Could you let me know it?
If we use the register below (Item#2) through the MCU, this phenomenon does not occur in the ADC shaking.
Is there a difference between a set of GUI (Auto Read mode) and below (Item#2) register. ?
1. AMC7812B Configulation & Resistor setting Value
- Power
: AVCC 5V, AVDD/DVDD 5V, IO VDD 3.3V, Ref ext 2.5V
- ADC, DAC Used
: ADC (Ch9, 10,11,12,13,14 => 6ea)
: DAC (CH0~12 => 12EA)
2. Register Value
a. Initial setting
=> Power_DOWN (0x6B) : Write(0x7FFE)
=> ADC_Channel_0_Setting(0x50) : Write(0x000F)
=> ADC_Channel_1_Settign(0x51): Write(0x6000)
b. ADC Read (conntinous Setting)
=> AMC_CONFIG_0_SETTING(0x4C) : Write (0x3C00)
=> ADC_9_DATA ~ ADC_14_DATA => continuous Reading
c. DAC Write
=> DAC_0_DATA(0x33) ~ DAC_11_DATA (0x3E) => During DAC write control, it is used.
