SBVS438 April 2024 TPS7B92
PRODUCTION DATA
As illustrated in Figure 7-2, the TPS7B92 contains an adjustable version (the TPS7B9201) that sets the output voltage using an external resistor divider. The output voltage operating range is 1.205V to VIN − VDO, and is calculated using:
where:
Choose resistors R1 and R2 to allow approximately 1.5μA of current through the resistor divider. To ignore the FB pin current error term in the VOUT equation, set the feedback divider current to 15 times the FB pin current listed in the Electrical Characteristics table. Using lower value resistors improves noise performance, but consumes more power. Avoid higher resistor values. Leakage current into or out of FB across R1 / R2 creates an offset voltage proportional to VOUT divided by VREF. Choose R2 = 1MΩ to set the divider current at 1.205μA. Equation 3 calculates R1. Figure 7-2 depicts this configuration.
To understand more about the impact of feedback divider current on the output accuracy, see the IQ vs Accuracy Tradeoff in Designing Resistor Divider application note.