hello,
I have one question about the TPS92633 IREF PIN,I checked the DATASHEET and found that
The TPS92633-Q1 device has IREF pin to generate a high accuracy and low temperature shift current
reference.
i would like to ask what is this mean ? what is the function of the Reference Current? please help explain it for me.
Thank you
best regards
Hello Qinlei,
The reference current is used to calculate the set maximum output current. In actuality, it is better to think of the IREF pin as a voltage source that provides a constant 1.235V. Seen described in the equation below:
The user can then select a desired resistor value to then set IREF current to any desired value. Inside the driver, the current of IREF is measured and then amplified by 10x. This 10x amplified current is then pushed out of the ICTRL pin. By selecting an appropriate resistor then the user can choose the RICTRL pin such that the voltage generated matches the necessary value. This is represented in the following equation:
The reason that setting OUTx_TOT is not just a simple matter of I_out= VIREF/SNS is that the IREF circuitry is also used for thermal de-rating as well as SLS threshold setting circuitry.
For more information, I would strongly suggest reading through section 7 of the datasheet as it goes into great detail about how to set current and the relationships between RSNS, RICTRL, RIREF, and current setting.
Best,
Pedro Arango Ramirez
