DocID018560 Rev 2

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PM8801

List of figures

List of figures

Figure 1.

Simplified application schematic for powered devices using PM8801

in forward active clamp configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 2.

Simplified application schematic for powered devices using PM8801

in synchronous flyback configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 3.

PM8801 internal block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 4.

Block diagram of the DC/DC section of the PM8801 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 5.

Pin connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 6.

PM8801: reference schematic of the PoE classification logic. . . . . . . . . . . . . . . . . . . . . . . 20

Figure 7.

T2P signal when connected to PSE supporting 1-event classification . . . . . . . . . . . . . . . . 21

Figure 8.

T2P signal when connected to PSE supporting 2-event classification . . . . . . . . . . . . . . . . 21

Figure 9.

Line transient response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 10.

Sleep mode with pulsed MPS current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 11.

LED enabled at startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 12.

Wakeup sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 13.

PWM frequency vs. RT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 14.

Delay time vs. RDT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 15.

Timing relationship between output drivers as a function of DT . . . . . . . . . . . . . . . . . . . . . 29

Figure 16.

Overload (left) and short-circuit (right) behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 17.

Smooth transition from POE to auxiliary source and vice-versa. . . . . . . . . . . . . . . . . . . . . 32

Figure 18.

HTSSOP24 package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35