SLVSFU1C April 2023 – October 2024 TPS62874-Q1 , TPS62875-Q1 , TPS62876-Q1 , TPS62877-Q1
PRODMIX
Together with the selected range, the VSET[7:0] bits in the VSET register control the output voltage setpoint of the device (see Table 8-4).
VRANGE[1:0] | Output Voltage Setpoint |
---|---|
0b00 | 0.4V + VSET[7:0] × 1.25mV |
0b01 | 0.4V + VSET[7:0] × 2.5mV |
0b10 (default) | 0.4V + VSET[7:0] × 5mV |
0b11 | 0.4V + VSET[7:0] × 5mV |
During initialization, the device reads the state of the VSEL pin and selects the default output voltage according to Table 8-5. Note that the VSEL pin also selects the I2C target address of the device (see below). Please see the DEVICE OPTIONS table for the complete list of device versions and their Output Voltage Setpoint.
VSEL Pin(1) | VSET[7:0] | I2C Device Address | Output Voltage Setpoint |
---|---|---|---|
6.2kΩ to GND | 0x50 | 0x44 | 800mV |
Short-Circuit to GND | 0x46 | 0x45 | 750mV |
Short-Circuit to VIN | 0x5F | 0x46 | 875mV |
47kΩ to VIN | 0x24 | 0x47 | 580mV |
If you program new output voltage setpoint (VOUT[7:0]), output voltage range (VRANGE[1:0]), or soft-start time (SSTIME[1:0]) settings when the device has already begun the soft-start sequence, the device ignores the new values until the soft-start sequence is complete. For example, if you change the value of VSET[7:0] during soft-start, the device first ramps to the value that VSET[7:0] had when the soft-start sequence began and then, when soft-start is complete, ramps up or down to the new value.
If you change VOUT[7:0], VRAMP[1:0], or SSTIME[1:0] while EN is low, the device uses the new values the next time you enable it.
During start-up the output voltage ramps up to the target value set by the VSEL pin before ramping up or down to any new value programmed to the device over the I2C interface.
For reliable voltage setting, make sure that there is no stray current path connected to the VSEL pin and that the parasitic capacitance between the VSEL pin and GND is less than 30pF.