JAJSQT1 July 2024 TPS546E25
ADVANCE INFORMATION
| CMD Address | D5h |
| Write Transaction: | Write Word |
| Read Transaction: | Read Word |
| Format: | Unsigned Binary (2 bytes) |
| NVM Back-up: | EEPROM |
| Updates: | On-the-fly |
This command contains bits for setting the boot-up voltage VBOOT.
Return to Supported PMBus Commands.
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
| R/W | R/W | R | R | R | R | R | R |
| SPARE_NVM | 0 | 0 | 0 | 0 | 0 | 0 | |
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| R | R | R | R/W | R/W | R/W | R/W | R/W |
| 0 | 0 | 0 | VBOOT_1 | ||||
| LEGEND: R/W = Read/Write; R = Read only |
| Bit | Field | Access | Reset | Description |
|---|---|---|---|---|
| 15:14 | SPARE_NVM | R/W | NVM | Spare NVM. |
| 13:5 | 0 | R | 0b | Not supported and always 0. |
| 4:0 | VBOOT_1 | R/W | NVM | These bits contains VBOOT setting that is used for the the VREF DAC target code
for soft-start purposes (as against directly specifying the initial VOUT voltage).
The user must choose the appropriate VOUT_SCALE_LOOP to achieve the desired output
voltage VOUT. Setting the DAC target code directly multiplies the number of
available VBOOT voltages by the number of internal gain options settings. Note: The effective boot-up voltage is determined by a combination of VBOOT, VOUT_SCALE_LOOP, VOUT_MARGIN_HIGH, VOUT_MARGIN_LOW, and VOUT_TRIM, as described in the tables under the description of VOUT_COMMAND. The appropriate VOUT is from pinstrap or from NVM of VOUT_SCALE_LOOP. There is nothing preventing the VBOOT value from being updated in any state. If the active VBOOT is updated while in the SoftStart state, the output voltage will slew to the updated VBOOT setting. The VBOOT values are programmed through VBOOT_1. |
Attempts to change the read-only bits [13:5] will be considered invalid/unsupported data. The device will NACK the unsupported data and the received value will be ignored. The ’cml’ bit in the STATUS_BYTE and the ‘ivd’ bit in the STATUS_CML registers will be set.
| VBOOT_1 [4:0] (b) | VDAC_BOOT (V) |
|---|---|
| 00000 | 0 |
| 00001 | 0.299804688 |
| 00010 | 0.3125 |
| 00011 | 0.325195313 |
| 00100 | 0.337890625 |
| 00101 | 0.3501 |
| 00110 | 0.362304688 |
| 00111 | 0.375 |
| 01000 | 0.387695313 |
| 01001 | 0.3999 |
| 01010 | 0.412597656 |
| 01011 | 0.424804688 |
| 01100 | 0.4375 |
| 01101 | 0.450195313 |
| 01110 | 0.462890625 |
| 01111 | 0.4751 |
| 10000 | 0.487304688 |
| 10001 | 0.5 |
| 10010 | 0.512695313 |
| 10011 | 0.5249 |
| 10100 | 0.537109375 |
| 10101 | 0.549804688 |
| 10110 | 0.5625 |
| 10111 | 0.575195313 |
| 11000 | 0.587890625 |
| 11001 | 0.599609375 |
| 11010 | 0.625 |
| 11011 | 0.6499 |
| 11100 | 0.674804688 |
| 11101 | 0.700195313 |
| 11110 | 0.724609375 |
| 11111 | 0.75 |