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TPS25910: TPS25910 Enable threshold voltage limits and bias currents

Part Number: TPS25910

I am trying to understand the limits published in the datasheet for the ENABLE pins Threshold voltage ?  I would like to model this input circuit using external components.

But need better understanding of the circuit.  Yes a 10Meg and a 16.8Meg reisistor divider exist, 

Specifically the bias currents and threshold limits.   Are the negative bias currents  sourcing or sinking ?  for an input of 2.4V, how are these bias currents calculated ?

What is the voltage at Vin for each of the published limits: -1.5uA, -1uA, and 1uA ?  Same question with the  0.2V input at ENA ?  

  • Hi Paulhus,

    When mentioned as 'sinking' and the current value is negative, it indicates that the the current is actually sourced. Similarly, When mentioned as 'sourcing' and the current value is negative, it indicates that the the current is sinked by the IC.
    These bias currents are tested and characterized values. So all the devices you see will have bias currents within the Min and Max values.
    As mentioned on the top of the Electrical Characteristic table, these bias current values are valid for Vin = 3 V - 20 V.
  • I'm afraid your answer does not help me. I need to be able to know the the bias current my design will be seeing on the ENABLE input. If I have 5V on Vin, what will the the min and max bias current be on EN ? What about 10V at Vin? Is there an equation that will allow me to predict these values?
  • Hi Paulhus,

    We do not have any equation to calculate the bias current flowing into the pin. The values of Input bias current parameter in the Electrical Characteristics table are characterized and we guarantee that the bias currents are within the Min and Max values. Also, as highlighted below,  these values are valid for Vin = 3V to 20V. So, you can use the same values for 5V Vin and 10V Vin.

  • What voltage on the ENABLE input causes the bias current to go from "sourcing" to "sinking" and vice versa ? Where is this transition range ?
  • Hi Paulhus,

    The voltage on EN at which the bias currents into the EN pin are mentioned in the EC table itself as highlighted below. 

    These values are actually not dependent on Vin and are dependent on voltage on EN. Regarding your concern on -ve and +ve bias current, you can consider the bias current to be -ve for your analysis.