SLUSB56B November 2012 – April 2019 TPS53819A
PRODUCTION DATA.
Similar to the output voltage fine adjustment, margin adjustment also cannot change output voltage instantaneously. The soft-slew rate of margin adjustment is also programmed by SST<1:0>. The details are listed in Table 15.
COMMAND | DEFINITION | DESCRIPTION | NVM |
---|---|---|---|
MODE_SOFT_START_CONFIG<3:2> | SST<1:0> | 00: 1 step per 4 µs(1)
01: 1 step per 8 µs 10: 1 step per 16 µs 11: 1 step per 32 µs |
Yes |
Figure 35 shows the timing diagram of the output voltage adjustment via PMBus. After receiving the write command of VOUT_ADJUSTMENT (MFR_SPECIFIC_04), the output voltage starts to be adjusted after tP delay time (about 50 μs). The time duration tDAC for each DAC step change can be controlled by SST bits (MODE_SOFT_START_CONFIG<3:2:> from 4 μs to 32 μs.
The margining function is enabled by setting the OPERATION command, and the margining level is determined by the VOUT_MARGIN (MFR_SPECIFIC_05) command. Figure 36 and Figure 37 illustrate the timing diagrams of the output voltage margining via PMBus. Figure 36 shows setting the margining level first, and then enabling margining by writing OPERATION command. After the OPERATION margin high command enables the margin high setting (VOMH<3:0>), the output voltage starts to be adjusted after tP delay time (about 50 μs). The time duration tDAC for each DAC step change can be controlled by SST bits (MODE_SOFT_START_CONFIG<3:2>) from 4 μs to 32 μs.
As shown in Figure 37, the margining function is enabled first by a write command of OPERATION. The output voltage starts to be adjusted toward the default margin high level after tP delay. Since the margining function has been enabled, the output voltage can be adjusted again by sending a different margin high level with a write command of VOUT_MARGIN. The time duration tDAC for each DAC step change can be also controlled by SST bits (MODE_SOFT_START_CONFIG<3:2>) from 4 μs to 32 μs.