TPS543C20A: TPS543C20A Vout Accuracy

Mason Liu 

The total VOUT regulation accuracy of the TPS543C20A includes several elements:

1) Reference voltage Accuracy - This is detailed on page 7 under Reference Voltage Accuracy in the Electrical Characteristics (EC) Table at +/- 0.5%

2) Differential Remote Sense Amplifier Accuracy - This is also detailed on page 7 under Differential Remote Sense Amplifier in the EC Table at +/- 1.9mV

3) External Feedback Divider Accuracy, if used.  This is not part of the TPS543C20A and depends on the precision of the resistors used to set the output voltage.  In addition, the closer the output voltage is to the reference voltage, the smaller of an error the divider introduces.

To calculate the total range of the output voltage:

1) Calculate the range of reference voltages:  Vref(nom) & 0.995 to Vref(nom) * 1.005

2) Apply the worst case remote sense amplifier offset. 

Vref(min) = 0.995 x Vref -1.9mV

Vref(max) = 1.005x Vref +1.9mV for maximum.

3) Apply the worst case divider Vref(min) x (1+Rtop(min) / Rbot(max)) and Vref(max) x (1+Rtop(max) / Rbot(min)

Vout(min) = (0.995 x Vref - 1.9mV)  x (1+Rtop(min) / Rbot(max)

Vout(max) = (1.005 x Vref + 1.9mV) x (1+ Rtop(max) / Rbot(min)