ZHCSNL3A December 2021 – November 2023 TPSM8D6C24
PRODUCTION DATA
| CMD Address | 65h |
| Write Transaction: | Write Word |
| Read Transaction: | Read Word |
| Format: | SLINEAR11 per CAPABILITY |
| Phased: | No |
| NVM Backup: | EEPROM |
| Updates: | On-the-fly |
The TOFF_FALL command sets the time, in milliseconds, from the end of the turn-off delay time until the voltage is commanded to 0. This command can only be used with a device whose output can sink enough current to cause the output voltage to decrease at a controlled rate, which effectively sets the slew rate of the reference DAC during the soft-off period. The fall time is equal to TOFF_FALL regardless of the value of the target output voltage or VOUT_SCALE_LOOP for the purposes of slew rate selection based on the target output voltage.
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
| RW | RW | RW | RW | RW | RW | RW | RW |
| TOFFF_EXP | TOFFF_MAN | ||||||
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| RW | RW | RW | RW | RW | RW | RW | RW |
| TOFFF_MAN | |||||||
| LEGEND: R/W = Read/Write; R = Read only |
|
Bit |
Field |
Access |
Reset |
Description |
|---|---|---|---|---|
|
15:11 |
TOFFF_ EXP |
RW |
11110b |
Linear format two’s complement exponent. Exponent = -2, LSB = 0.25 ms |
|
10:0 |
TOFFF_ MAN |
RW |
NVM |
Linear format two’s complement mantissa |
Attempts to write (65h) TOFF_FALL beyond the supported range are considered invalid or unsupported data and cause the TPSM8D6C24 to respond by flagging the appropriate status bits and notifying the host according to the PMBus 1.3.1 Part II specification section 10.9.3. (65h) TOFF_FALL supports values from 0.5 ms to 31.75 ms in 0.25-ms steps. Values less than 0.5 ms are implemented as 0.5 ms.
Due to hardware limitations in the resolution of the reference DAC slew-rate control, longer TOFF_FALL times with higher (21h) VOUT_COMMAND voltages can result in some quantization error in the programmed TOFF_FALL times with several TOFF_FALL times producing the same VOUT slope and TOFF_FALL time even with different TOFF_FALL settings, or different TOFF_FALL times for the same TOFF_FALL setting and different (21h) VOUT_COMMAND voltages.