wfang
Newbie level 4
![Newbie level 4](/styles/images/ranks/blevel1.gif)
Anyone has done or has any idea on how to design a current sense circuit to fit below requirements:
1. DC high side current sense and always online (no current break during messurement).
2. DC input range 3~5V (sense circuit works on 5V)
3. Current input range: DC 1mA ~ 2A, 5% resolution at full range
4. Whole circuit voltage drop shall less than 100mV at full rage (1mA ~ 2A)
5. Sensor Op Amp Voltage output 0~5V, can be multiple output for different current range. (e.g. Op amp 1 for 0~100mA, op amp 2 for 100mA~2A range)
6. Output Shall support ADC sample rate at least 1s/s
7. Shall auto switch range in less than 0.1ms if multiple range measurement applied.
I have implemented high site current sense circuit work fine at 100mA~2A range with 5% resolution. but couldn't tune it to get same resolution at 1mA~100mA range.
Any suggestions would be appreciated.
Wei
1. DC high side current sense and always online (no current break during messurement).
2. DC input range 3~5V (sense circuit works on 5V)
3. Current input range: DC 1mA ~ 2A, 5% resolution at full range
4. Whole circuit voltage drop shall less than 100mV at full rage (1mA ~ 2A)
5. Sensor Op Amp Voltage output 0~5V, can be multiple output for different current range. (e.g. Op amp 1 for 0~100mA, op amp 2 for 100mA~2A range)
6. Output Shall support ADC sample rate at least 1s/s
7. Shall auto switch range in less than 0.1ms if multiple range measurement applied.
I have implemented high site current sense circuit work fine at 100mA~2A range with 5% resolution. but couldn't tune it to get same resolution at 1mA~100mA range.
Any suggestions would be appreciated.
Wei