ADP1046-100-EVALZ AD [Analog Devices], ADP1046-100-EVALZ Datasheet - Page 61

• Manufacturer Part Number: ADP1046-100-EVALZ
• Description: Digital Controller for Isolated
• Manufacturer: AD [Analog Devices]

Data Sheet
Bits
[1:0]
Table 52. Register 0x34—VS1 Undervoltage Limit (UVP)
Bits
7
[6:0]
Table 53. Register 0x35—Line Impedance Limit
Bits
[7:0]
Table 54. Register 0x36—Load Line Impedance
Bits
7
[6:4]
3
Bit Name
OVP sampling
Bit Name
End of cycle
shutdown
VS1 UVP setting
Bit Name
Line impedance
limit
Bit Name
Load line enable
Slew rate
Reserved
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
The OVP flag is set if the average voltage during the OVP sampling period is greater than the OVP
threshold. This OVP flag sampling period is 80 μs. The number of samples can be increased using
these bits. If the number of samples is increased, the average voltage must be greater than the
OVP threshold for each of those cycles. For example, if this value is set to two cycles, the average
voltage must be greater than the OVP threshold for both cycles.
Bit 1
0
0
1
1
Description
This bit is valid only when the OUTAUX pin is used for regulation. When any flag shuts down the
power supply, the OUTAUX PWM is immediately shut down. This bit specifies when the other PWM
outputs are shut down.
1 = all other PWM outputs are shut down at the end of the switching cycle.
0 = all other PWM outputs are immediately shut down.
These bits set the UVP limit to one of 128 settings. The UVP limit can be programmed from 0% to
158.75% of the nominal VS1 voltage. Each LSB increases the voltage by 158.75%/128 = 1.25%. In
reality, there are 81 usable settings, which program the UVP threshold from 0% to 100% of the
nominal VS1 voltage. The VS1 UVP threshold is calculated as follows:
VS1_UVP_Threshold = [(VS1_UVP_Setting + 1)/128] × 1.6 V − 12.5 mV
For example, if the VS1 UVP setting is 60, then
VS1_UVP_Threshold = [(60 + 1)/128] × 1.6 V − 12.5 mV = 750 mV
Setting these bits to 0 gives a UVP limit of 0% of the nominal VS1 voltage.
Setting these bits to 72 (0x48) gives a UVP limit of 90% of the nominal VS1 voltage.
Setting these bits to 76 (0x4C) gives a UVP limit of 95% of the nominal VS1 voltage.
Setting these bits to 80 (0x50) gives a UVP limit of 100% of the nominal VS1 voltage.
Setting these bits to 127 (0x7F) gives a UVP limit of 158.75% of the nominal VS1 voltage.
Description
This value sets the threshold at which the line impedance flag is enabled. This 8-bit value is
compared with the line impedance value (Register 0x1F). If the line impedance value exceeds this
value, the line impedance flag is set (Register 0x02, Bit 2).
Description
Set this bit to enable the load line.
These bits set the load line slew rate limit, which determines the maximum slew rate for changing
the reference when adjusting the output load line value.
Bit 6
0
0
0
0
1
1
1
1
Reserved.
Bit 0
0
1
0
1
Bit 5
0
0
1
1
0
0
1
1
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Additional Sampling (μs)
0 (one sample sets the OVP flag)
80 (two samples set the OVP flag)
160 (three samples set the OVP flag)
240 (four samples set the OVP flag)
Bit 4
0
1
0
1
0
1
0
1
Maximum Slew Rate Duration
200 mV/ms
100 mV/ms
50 mV/ms
25 mV/ms
12.5 mV/ms
6.25 mV/ms
3.125 mV/ms
1.5625 mV/ms (4 LSB/ms)
ADP1046