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TS5A26542: Current Consumption Inquiry

Darren (FAE)
Expert 5483 points
Part Number: TS5A26542

I have a customer asking about the current consumption under the following conditions. If possible, I need to provide an estimated max current consumption during such a use-case.

V+ = 5.1V
Vio = 1.8V
IN1, IN2 = MAX 2.3V
NOx & NCx = DC 2.5V common-mode, and then a ±1.5V sine wave signal applied from a function generator

In this setup, IN1 and IN2 can be at a voltage potential larger than VIO, which is only 1.8V.

Are the INx pin ESD diodes connected to VIO or V+?
If VIO, then I suspect if INx voltage goes above VIO + 0.3V or so, a lot of current could flow.

If my understanding about the above is not correct, then what kind of device current draw could be expected in such a case?

Regards,

Darren

  • 0
    Guru 279980 points

    The VI absolute maximum rating shows that the control inputs are overvoltage tolerant, i.e., there are no diodes, and no current.

  • 0
    TI__Mastermind 46687 points

    Hi Darren,

    From the absolute max electrical table you can see that there is two ways that max voltage on a pin is defined. On the I/O pins the abs. max = (V+) + 0.5V this indicates an ESD diode from V+ to the I/O pins. However the max IN pin voltage is 6.5V -> no ESD diode to V+ as Clemens mentioned. There is a clamp but it is connected to ground on the digital pins - so a negative voltage will cause current to come out of the I/O pins and increase power consumption of the device. However supply current won't increase - supply current increases due to current being drawn from VCC to GND through the logic of the IC. This is minimized when the input of the logic is ~ the supply of the logic device.

    To put an apprx. value for the application I'd follow the electrical spec tables definition for a 5V supply:

    Approximate Typical Value @ (25C): 5.5nA

    Approximate Max Value @ (25C): 100nA

    Approximate Max Value @ (Full Temp Range): 750nA

    Also the max ratings may be a bit lower than that since they are measured at a 5.5V supply voltage - at lower supplies you may see a lower max but a slightly higher typical value.

    Please let me know if I can be of any more assistance to you!

    Best,

    Parker Dodson