SLVSER5A December 2018 – May 2021 TPS73801-SEP
PRODUCTION DATA
The TPS73801-SEP has an adjustable output voltage range of 1.21 V to 20 V. The output voltage is set by the ratio of two external resistors as shown in Figure 7-1. The device maintains the voltage at the FB pin at 1.21 V referenced to ground. The current in R1 is then equal to (1.21 V / R1), and the current in R2 is the current in R1 plus the FB pin bias current. The FB pin bias current, 3 µA at 25°C, flows through R2 into the FB pin. The output voltage can be calculated using the formula shown in Equation 1. The value of R1 should be less than 4.17 kΩ to minimize errors in the output voltage caused by the FB pin bias current. Note that in shutdown the output is turned off, and the divider current is zero.
The output voltage can be set using the following equations: