SLUSC70D March 2016 – July 2017 TPS548D22
PRODUCTION DATA.
Optimize the reference voltage by choosing a value for RVSEL. The TPS548D22 device is designed with a wide range of precision reference voltage support from 0.6 V to 1.2 V with an available step change of 50 mV. Program these reference voltages using the VSEL pin strap configurations. See Table 3 for internal reference voltage selections. In addition to providing initial boot voltage value, use the VSEL pin to program hiccup and latch-off mode.
There are two ways to program the output voltage set point. If the output voltage set point is one of the 16 available reference and boot voltage options, no feedback resistors are required for output voltage programming. In the case where feedback resistors are not needed, connect the RSP pin to the positive sensing point of the load. Always connect the RSN pin to the load return sensing point.
In this design example, since the output voltage set point is 1 V, selecting RVSEL(LS) of either 75 kΩ (latch off) or 68.1 kΩ (hiccup) as shown in Table 3. If the output voltage set point is NOT one of the 16 available reference or boot voltage options, feedback resistors are required for output voltage programming. Connect the RSP pin to the mid-point of the resistor divider. Always connect the RSN pin to the load return sensing point as shown in Figure 18 and Figure 19.
The general guideline to select boot and internal reference voltage is to select the reference voltage closest to the output voltage set point. In addition, because the RSP and RSN pins are extremely high-impedance input terminals of the true differential remote sense amplifier, use a feedback resistor divider with values much less than 100 kΩ.