JAJSIO4A February 2020 – September 2020 TPS546A24A
PRODUCTION DATA
| CMD Address | 62h |
| Write Transaction: | Write Word |
| Read Transaction: | Read Word |
| Format: | SLINEAR11 per CAPABILITY |
| Phased: | No |
| NVM Back-up: | EEPROM |
| Updates: | On-the-fly |
The TON_MAX_FAULT_LIMIT command sets an upper limit, in milliseconds, on how long the unit can attempt to power up the output without reaching the target voltage.
The TON_MAX time is defined as the maximum allowable amount of time from the end of TON_DELAY, until the output voltage reaches 85% of the programmed output voltage, as sensed by the READ_VOUT telemetry at VOSNS - GOSNS.
Note that for the TPS546A24A, the undervoltage fault limit is enabled at the end of TON_RISE. As a consequence, unless VOUT_UV_FAULT_RESPONSE is set to ignore, in the case of a “real” TON_MAX fault (for example, output voltage did not rise quickly enough), UV faults / associated response will always precede TON_MAX.
The converter response to a TON_MAX fault event is described in TON_MAX_FAULT_RESPONSE.
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
| RW | RW | RW | RW | RW | RW | RW | RW |
| TONMAXF_EXP | TONMAXF_MAN | ||||||
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| RW | RW | RW | RW | RW | RW | RW | RW |
| TONMAXF_MAN | |||||||
| LEGEND: R/W = Read/Write; R = Read only |
Bit | Field | Access | Reset | Description |
|---|---|---|---|---|
15:11 | TONMAXF_ EXP | RW | 11111b | Linear format two’s complement exponent |
10:0 | TONMAXF_ MAN | RW | NVM | Linear format two’s complement mantissa |
Attempts to write (62h) TON_MAX_FAULT_LIMIT beyond its supported range will be considered invalid/unsupported data and cause the TPS546A24A 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. TON_MAX_FAULT_LIMIT supports values from 0 ms to 127 ms in 0.5-ms steps.
TON_MAX_FAULT_LIMIT compares the last VOUT telemetry value recorded prior to the TON_MAX_FAULT_LIMIT timer expiring to 87.5% of VOUT_COMMAND to determine a TON_MAX_FAULT. Due to delay in VOUT telemetry, a TON_MAX_FAULT can be declared if VOUT was less than 87.5% of VOUT_COMMAND up to 2ms prior to TON_MAX_FAULT_LIMIT.
*Note: programming TON_MAX_FAULT to 0ms disables the TON_MAX functionality.