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INA199: Asking for the INA199 design

SHH
Mastermind 31446 points
Part Number: INA199
Other Parts Discussed in Thread: INA300, INA301

Hi Team,
Customer would like to evaluate INA199 for the following case.

1. Can customer uses 1ohm as Rsense and INA199X1, the output voltage of protect current is 33mA*1ohm*50=1.65V. If not ok for this, would you please suggest the proper way for Rsense?
2. Can customer use INA300 for this case? What i the recommended Rsense and Rlimit recommendation?


design requirement:
1. Power path voltage: 10V
2. Typical operating current: 26.67mA
3. Protect current:33mA

BR,
SHH

  • 0
    TI__Mastermind 32395 points
    Hey SHH,

    The end engineer can easily use a 1 Ohm shunt resistor with INA199A1.

    The engineer can also easily use the INA300 as a simple over-current protection comparator with adjustable threshold voltage. If their shunt resistor is 1 Ohm, the RLIMIT needs to be 1.525kOhm for device to trip at 33mA. This was calculated assuming a 10us delay and thus incorporating the NAF term in RLIMIT equation (Table 2) described in Section 7.3.2.1 in datasheet. This means INA300 is tripping at a input voltage of 33mV. The full-scale input dynamic range of INA300 is 250mV so customer could increase their shunt resistor here.

    Additionally, the end system could just use the INA301, which would provide the internal comparator similar to INA300, but also provide an analog output pin to measure the gained up sense voltage similar to the INA199.

    Hope this helps!

    Best,
    Peter Iliya
    Current Sensing Applications