INA200: INA200AIDGKR

Hello Hemi,

Thanks for considering to use Texas Instruments.  Yes you should have a pull-up resistor.  According to our application report "Choosing an Appropriate Pull-up/Pull-down Resistor for Open Drain Outputs" (slva485), we can calculate a range of resistances that we could use for the pull-up.  The equations in this report are posted below.  In equation 2 which determines the largest acceptable resistance, we utilize the leakage currents associated with the pins connected to the pull-up.  These currents are 1ua for both the INA200 and SN74LVC1G123.  Collective these currents sum to 2uA.  Assuming you used a supply of 5V, the largest resistance (or weakest pull-up) you could use is  2.5Megohms.  As noted, this is your weakest pullup with the slowest rise/fall time based on the pull-up and any parasitic or intentional capacitance on your pins.  The lowest resistance value can be calculated by using the maximum input current that the INA200 closed drain can accept.  According to the absolute max ratings, no pin should exceed 5mA.  Based off this current rating and the previous supply condition of 5V, your smallest pullup resistance should be 5V/.005A = 1kohm.  This will provide the fastest fall and rise time.  The downside to this will then be power consumption.  Higher resistances will lower your average power draw.  So likely you will want to choose some resistance in the middle of these bounds that provides relatively low power consumption with a quick transition.