INA208: RESET pin LOW level range

Hello Joyce,

1.1V would be the typical upper bound for the CMP 1 Reset Pin.  If a voltage at this pin is above this voltage value, comparator 1 will most likely remain latched when the comparator threshold voltage is crossed.  The figure below illustrates this idea.

One thing I noticed with your schematic, is your customer appears to be using he 10 pin package.  I suspect they confused CMP1 RESET with CMP2 Delay, which can be found on the the 14 pin package.  Comparator 2 functions a bit differently than comparator 1 such that it does not latch and its delay can be changed through an external cap, which appears to be what you have on the reset pin.  For your reset pin, your customer probably should have some sort of switch in the form of a transistor or microcontroller GPIO that is able to pull that pin high or low.  CMP1 RESET has an internal pull-down that would naturally pull it to ground if it were left open.  However, your customer has a pull-up resistor which forms a voltage divider with this internal resistor.  So I would expect that once VCC is applied, the Reset pin will always see (6V-0.7V)*(2Mohms/(2Mohms +4.53kohmms)= 5.29V.  The capacitor on this pin would only remove transients coming from the VCC line.

 Hi Patrick,

Thanks very much for your reply. So 1.1V is typical value for reset high voltage. so what is the range of high voltage for RESET pin?

for eg, >800mV will be treated high, <400mV will treated low. Do we have this data?

Thanks a lot for your reply,

Joyce

Hi Patrick,

See below datasheet from AMC7836 datasheet, this is GPIO pin high and low level definition. 

For high level signal, it will list min value; for low level signal, it will list max value. 

We want to know this data for RESET pin. thanks a lot!

Joyce

Hello Joyce,

For this part we do not specify a min or a max.  We provide a typical value (1.1V) above which the internal comparator typically triggers.  However, I will try to dig up some information from our characterization team on the minimum and maximum values they observed when testing batches of these parts.