PM8803 STMicroelectronics, PM8803 Datasheet - Page 9

• Manufacturer Part Number: PM8803
• Description: High efficiency integrated IEEE 802.3at PoE-PD interface and PWM controller type 2 PSE indicator, plus support for forward active clamp topology
• Manufacturer: STMicroelectronics

PM8803
2
Pin descriptions and connection diagrams
Figure 5.
Table 2.
Pin#
1
2
3
4
5
6
7
8
Name
ARTN
RTN1
GAT1
GAT2
Pin connections (top view)
CTL
Pin descriptions
VB
CS
VC
Input of the Pulse Width Modulator.
CTL pull-up to VB is provided by an external resistor which may be used to
bias an opto-coupler transistor.
5 V, up to 10 mA Bias Rail.
This reference voltage can be used to bias an opto-coupler transistor.
Current sense input for current mode control and overcurrent protection.
Current sensing is accomplished using a dedicated current sense compara-
tor. If the CS pin voltage exceeds 0.5 V, the GAT1 pin switches low for cycle-
by-cycle current limiting. CS is internally held low for 60 ns after GAT1
switches high to blank leading edge current spikes.
Power ground for the GAT1 driver.
This pin must be connected to RTN2 and ARTN.
Main gate driver output of the PWM controller.
DC-DC converter gate driver output with 1 A peak sink-source current capa-
bility. (5 ohm typ MOSFETs).
Output of the internal high-voltage regulator.
When the auxiliary transformer winding (if used) raises the voltage on this
pin above the 8 V typ. regulation set point, the internal regulator will shut-
down, reducing the internal power dissipation. Filter this pin with a 1µF typ.
connected to ground.
Secondary gate driver output.
AUX gate driver output for active clamp or synchronous rectification
designs. 1 A peak sink-source current capability (5 ohm typ. MOSFETs).
Analog PWM supply ground.
RTN for sensitive analog circuitry including the SMPS current limit amplifier.
ARTN
RTN1
RTN2
GAT1
GAT2
VSS
CTL
CS
VC
VB
Doc ID 018559 Rev 1
10
1
2
3
4
5
6
7
8
9
Pin descriptions and connection diagrams
Function
20
19
18
17
16
15
14
13
12
11
T2P
FRS
DT
SA
DCCL
CLS
SP
DET
VDD
VDD
AM045095v1
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