PM8800 STMicroelectronics, PM8800 Datasheet - Page 19

• Manufacturer Part Number: PM8800
• Description: Integrated IEEE 802.3af compliant PoE-PD interface and PWM controller with support of external source
• Manufacturer: STMicroelectronics

PM8800A
inrush current level, which is set by default at 440 mA. Connecting a resistor between VSS
and AUXI_IRL it's possible to adjust this limit to a lower value.
Figure 9.
The maximum inrush current can be set by programming the value of the resistor on the
AUX_IRL pin. Depending on the chosen value there could be 3 steps (when the selected
max current is between 250 and 400 mA), 2 steps (when the selected max current is
between 140 and 250 mA) or a single step.
The formulae to select the desired inrush current is the following:
The PM8800A useful programming range for the inrush current limitation is between
140 mA and 440 mA. Practical resistor value ranges between 25 kΩ and 82 kΩ.
Figure 10. Inrush current limit vs R
R
IRL
[
kΩ
]
=
440
250
140
----------------------- -
I
Relation between the hot-swap drain-source voltage and the default
Inrush current.
IRL
11200
[
mA
]
15V
30V
IRL
VIN-VSS
PD interface
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