List of figures

PM8803

4/34

Doc ID 018559 Rev 2

List of figures

Figure 1.

Simplified application schematic for powered devices using PM8803

in forward active clamp configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2.

Simplified application schematic for powered devices using PM8803

in synchronous flyback configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3.

PM8803 internal block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4.

Block diagram of the DC/DC section of the PM8803 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 5.

Pin connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 6.

PM8803: reference schematic of the PoE classification logic. . . . . . . . . . . . . . . . . . . . . . . 19

Figure 7.

T2P signal when connected to PSE supporting 1-event classification . . . . . . . . . . . . . . . . 20

Figure 8.

T2P signal when connected to PSE supporting 2-event classification . . . . . . . . . . . . . . . 20

Figure 9.

Line transient response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 10.

DC current vs. RDC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 11.

PWM frequency vs. RT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 12.

Delay time vs. RDT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 13.

Timing relationship between output drivers as a function of DT . . . . . . . . . . . . . . . . . . . . . 26

Figure 14.

Overload (left) and short-circuit (right) behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 15.

Smooth transition from POE to auxiliary source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 16.

HTSSOP20 mechanical drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32