SLVSHO1A March 2025 – December 2025 TPS1689
PRODUCTION DATA
PSU_VOLTAGE is a manufacturer-specific command for configuring or reading an 8-bit data corresponding to the input power supply voltage for implementing the input cable fault detection feature.
This command uses the PMBus® read or write byte protocol.
Sending a value to the PSU_VOLTAGE register:
Real world value of input power supply voltage in V is converted into a 10-bit binary data through PMBus® DIRECT format conversion using Equation 15 and the 'm', 'b', & 'R' coefficients corresponding to READ_VIN in Table 7-65. Hexadecimal value corresponding to the eight least significant bits from this 10-bit binary data needs to be written in the PSU_VOLTAGE register.
Interpreting the received values from the PSU_VOLTAGE register:
One byte of hexadecimal data read from the PSU_VOLTAGE register needs to be converted into a 10-bit binary data by appending the READ_VIN[9:8] bits to the left side. The hexadecimal value corresponding to this 10-bit binary data needs to be converted to a real world value of input power supply voltage in V through PMBus® DIRECT format conversion using Equation 14 and the 'm', 'b', & 'R' coefficients corresponding to READ_VIN in Table 7-65.
The details of this register are shown in Table 8-67.
| Bit | Name | Description | READ_VIN[9:8] | Minimum Value | Maximum Value | Default Value | Access |
|---|---|---|---|---|---|---|---|
7:0 | PSU_VOLTAGE | Nominal input power supply voltage | 00 | 0x00h (0V) | 0xFFh (21.87V) | 0xA3h (13.98V) | Read/Write |
01 | 0x00h (21.95V) | 0xFFh (43.83V) | 0xA3h (35.94V) | ||||
10 | 0x00h (43.91V) | 0xFFh (65.79V) | 0xA3h (57.89V) | ||||
11 | 0x00h (65.87V) | 0xFFh (19.48V) | 0xA3h (79.85V) |
Programming this register with the nominal PSU voltage is recommended to avoid unnecessary fault assertions
A write command to this register should be preceded by the MFR_WRITE_PROTECT command to unlock the device first to prevent accidental accidental/spurious writes.