Features
• Features of the PM8805 PoE-PD interface:
– System in package integrating a double active bridge, a hot-swap MOSFET
and a PoE-PD
– Supports legacy high power, 4-pair applications
– 100 V N-ch MOSFETs with 0.2 Ω total path resistance for each active
bridge
– Identifies which kind of PSE (standard or legacy) is connected to, and
provides successful IEEE802.3 af /at /bt classification indication as
combination of the T0, T1 and T2 signals (open drain)
– Smart operational mode selection through the STBY, FAUX and RAUX
control signals
– QFN 56 8x8mm package with 43 pins and 6 exposed pads
• Features of the PM8804 PWM controller:
– PWM peak current mode controller
– Input operating voltage up to 75 V
– Internal high voltage start up regulator with 20 mA capability
– Programmable fixed frequency up to 1 Mhz
– Soft start up with adjustable time
– Soft turn off (optionally disabled)
– Dual 1 APK, low side complementary gate drivers
– GATE2 optionally turned off for reduced consumption
– 80% maximum duty cycle with internal slope compensation
– QFN 16 3x3mm package with exposed pad
Description
This reference design represents a 3.3 V, 20 converter solution ideal for various
applications including wireless access points, supplied with a PoE-PD interface and a
DC-DC active clamp forward converter.
The PoE-PD interface is based on the PM8805 system in package device with two
active bridges and an IEEE 802.3bt compliant Powered Device (PD) interface. It can
be used in all medium-to-high power 2P and 4P high efficiency PoE and PoE+
applications.
The DC-DC active clamp forward converter is designed around the PM8804 PWM
controller, which is an integrated solution for smart and efficient 48 V converters,
featuring a programmable oscillator for the switching frequency, adjustable slope
compensation, dual complementary low-side drivers with programmable dead time,
programmable soft start, soft turn off and a programmable current sense blanking
time.
Product summary
High power PoE PD, 12 V
up to 8 A active clamp
forward evaluation board
STEVAL-
POE005V1
PWM peak current mode
controller for PoE and
telecom systems
PM8804
IEEE802.3bt PoE-PD
interface with integrated
dual-active bridge
PM8805
12V/8A, active clamp forward converter, Power Over Ethernet (PoE)
IEEE 802.3bt compliant reference design
STEVAL-POE005V1
Data brief
DB3699 - Rev 2 - May 2019
For further information contact your local STMicroelectronics sales office.
www.st.com
1Efficiency
The STEVAL-POE005V1 reference design consists of a PoE interface compliant with the IEEE 802.3bt standard
and a forward active clamp DC-DC converter that receives DC voltage from the PoE interface.
The figure below shows the efficiency of a single forward converter and the overall efficiency including the PoE
interface power losses.
Figure 1. STEVAL-POE005V1 overall and DC-DC forward efficiency
The dotted lines indicate the STEVAL-POE005V1 efficiency at different DC input voltages applied to RJ45
connector J1. The continuous line indicates the DC-DC forward efficiency, which does not include the following
losses associated with the PoE interface section:
• RJ45 connector J1
• PoE data transformer T1
• common chokes T7 and T8 placed on the two power supply pairs
•PM8805 interface that integrates the dual power MOS bridges and a hot swap MOSFET
• Forward converter input filter
This efficiency is measured between output test points TP8/TP9 and input test points TP5/TP6 of the forward
converter.
STEVAL-POE005V1
Efficiency
DB3699 - Rev 2 page 2/7
2STEVAL-POE005V1 schematic diagrams
Figure 2. STEVAL-POE005V1 circuit schematic (1 of 3)
C2
42
0603
R18
TP-Red
T6
NM
C87
10nF-NM
22
C90
10nF-NM
5
U16
EP3
ExPad
Chassis
250V
T2
D4
Wurth 7490220123
U5
SMC
C98
47K
1
75R
4
1KV1210
VB
IN45 36
TP18
R6
SM15T68CA
C5
2.2nF
1812
8
100V
U8
SMC
NM
EP6
ExPad
VDC
1
2
3
4
5
6
7
CLS1
IN12
250V
Chassis
CLS1
Chassis
2
C15
33uF
TP15
C17
100nF
0805
6AGND
IN36
19
J1
1210
U17
NM 0805
SMAJ58A
RV2
Chassis
19
SM15T68CA
C14
10nF
10
C93
1KV
10nF-NM
TP16
CTRL
1
IN78
R20
VOB
GND
14
Coilcraft WA8704-ALD
100V
34
13
3
VOB
17
U10
SMC
1
2
3
4
5
6
7
8
10x10.2
EEEFK2A330P
T1 Mounted
0805
RAUX
GND45
22
2
75R
R475R
100V
IN45
VOB 38
IN36
20
0603
RN102-2-02-1M1
100V
1
C92
10nF-NM
1KV
24
28
VOUT
VOUT 27
10
Orange
Brown
3
3
17
NM 0805
C4
R60
10nF
0805
B88069X9231T203-NM
1KV
1210
CLS2
PGD 25
2
NOTE for Resistors
Where not indicated the body is 0603 and tolerance 5%
NOTE for Capacitors
Where not indicated the body is 0603, the voltage is 100V
material X7R and tolerance 10%
100nF 100V is X7R 10%0805.
Ferrite bead 0805
1
C
0n
C64
94
F-NM
33nF
0805
U1
PM8805
0R0
TP19
GND78
100V
3.9K
24
1
GND78
B88069X9231T203-NM
21
4
C9
1nF-NM
1812
VB
2
40
C6
1nF-NM
EP1 ExPad
4
7
T7
Chassis
TP20
0603
2010
T0
DATA & POWER INPUT
R23
36R5
0805
NC 26
0603
1
250V
R22
51R1
0805
14
R14
26.1K
1%
IN36
2
31
U6
NM
SMC
R59
4
3
3
EP2
ExPad
J2
5
VOB
VCP 32
D3
BAV70
R8
SM15T68CA
Brown
R90R
Green
C10
1nF
1812
2
VOB
TP-Red
250V
2KV
Blue
R375R
2KV
PGD
VOB
FAUX
10
IN78 41
0603
1812
2KV
VB
SM15T68CA
0805
100V
100V
C1
10nF
0805
100V
0603
11
18
C8
1nF-NM
1812
4
NM 0805
10nF
0805
Chassis
ExPad
1KV1210
RN102-2-02-1M1
6
T1
D5
TP-Red
3.9K
0603
C88
10nF-NM
T0
2KV
3.9K
L8
0603
C19
10nF
0805
C91
10nF-NM
R5
U9
NM
SMC
GND12
IN12
12
SM15T68CA
1
QFN56-8X8X1-49PIN
RV1
C62
33nF
0805
2KV
C18
Ferrite bead 0805
0603
1.5nF
TP-Red
16
10nF
0805
FAUX
IN45
T8
T1
TP-Red
R275R
C16
4.7uF
1210
2
T0
7
37
C7
1nF-NM
2KV
1812
1KV
1210
2
20
2
9
18
1210
R57
0603
75R
IN45 33
C3
DET
8
2
R175R
NM 0805
T2
Wurth 7490220123
9
9
R107
100V
R58
C13
100nF
3
SMA
39
IN12
IN36 23
1
C63
33nF
0805
0603
T1
8
EP5
T1
GND36
IN78
L7
Ferrite bead 0805
Chassis
C12
1nF
0805
STBY
GND45
Green
Orange
1IN78
L5
35
100V
Ferrite bead 0805
1
RAUX
1
15
GND12
U19
1KV 1210
10
T2
L6
4
1%
D7
VDD
VOB 29
30
EP4
13
U18
SM15T68CA
D6
STBY
3
75R
SGND
2
43
21
C89
10nF-NM
250V
DATA OUTPUT
250V
R21
NM
IN12
15
9
U21
SMA
NM
11
U7
1KV 1210
SMC
NM
GND36
ExPad
T5
NM
TP-Red
TP17
NOTE for Class1 and Class2 resistors
their final value could be selected from table
based on the output power and Type of the PD.
1
100V
C11
1nF
0805
U11
NM
SMC
R19
U20
SMA
NM
16
23
C97
47K
1%
C61
33nF
0805
Blue
12
R7
STEVAL-POE005V1
STEVAL-POE005V1 schematic diagrams
DB3699 - Rev 2 page 3/7
Figure 3. STEVAL-POE005V1 circuit schematic (2 of 3)
2
SMC
R131
1%
AutoClass
1k
C78
3
0805
4k7
VB
1%
BAT46J
D43
3
NM
TP4
STBY
2
1nF
VDC
12
100K
C84
VB
FOD817AS
R123
C81
SOD323
RAUX
TP2
R119
TP1
4
TP-Red
R130
R75
1k
P1
4k3
U23
SOD323
3
SLEEP/WKUP
R105
GND
4 1
Raux +live PoE
SOD323
OVP
AUX Rear
0805
STPS4S200S
R117
MODE
D45
FAUX
BAT46J
R0805
R76
0R
330R
D52
VOUT
0
C82
D42
R127
1%
470K
BAT46J
GND
D14
PGD
0805
J10
R114
TP-Black
R121
20K
22nF
1%
AUXR
TS431AILT-NM
SOT23-5
5
R122
47K
CLS1
SOT-23
J9
0805
C83
1
2
3
0805
1
2
3
3
R116
D53
STBY High
R67
0R-NM
SOT23
Q14
2N7002
R133
1
RAUX_MAN
D37
3
SHDN
D46
SOD323
STBY
BAT46J
0805
U24
0805
U22
R102
1K
SOD323
R115
D51
BAS70
1
TP-Red
FAUX
D41
NM
R132
AUX Front
4k7
D39
TS2431-AILT
GND
1nF
SOD323
R129
1nF
C86
NM
4
1
2
Q13
2N7002
0R-NM
R104
56K
1%
D20
P2
STBY
BAT46J
STPS4S200S
R118
NM
R101
BAT46J
RAUX
SOT23
C85
20K
SOT-23
OVP
SOT23
R77
SMC
1%
100k
R128
10K
2
AUXF
1%
D40
D47
SOD323
R103
12K
VOB
4
BAT46J
100k
TP-Black
R126
10
1%
SOD323
R120
BAS70-05
TP3
BAS70-05
FAUX_MAN
NM
6K8-NM
0R
SS
SGND
D44
2.2K-NM
R69
100k
STEVAL-POE005V1
STEVAL-POE005V1 schematic diagrams
DB3699 - Rev 2 page 4/7
Figure 4. STEVAL-POE005V1 circuit schematic (3 of 3)
D7
0805
16V
200V
2KV
2KV
SOD323
S2
C59
R54
4K64
1%
C52
SMA
C32
4.7uF
1210
L1
5.6uH
11
VC 12
5
S1D5
0603
C55
100nF
25V
100V
R33
5R6-NM
VSP
7
750370225 Rev 03
TP-Red
STL90N6F7
Chassis
GND
0603
1%
R43130K
TP-Red
D7
Auxiliary voltage
3
Input Filter
TP7
C29
33uF
100V
D49
BAS70
C43
100uF
100nF
Q9
3
NC
0805
NM
0805
Q2
6
100V
C
C38
47uF
1210
SOT23
10K
GSH
S2
1
SOT23
TP6
R125
0805
2
G4
GSH
0603
S3
SS
2
NM
T3
D8
D13
BAS16J
D8
4
PGND
D11
4
PBSS4240T
0R
D16
BAS16J
VOUT Led
D7
R40
C26
1nF
0805
1206
Ex Pad
11
8
SGND
8
2
R62
NM
Q3
C54
2200pF
1812
Q5
G4
CTL
D6
U4
3
R55
5K23
J6
TP11
PGND
D7
POE120PL-xxL_-NM
0R
1
1206
D8
NC
0805
R41NM
R30
NM
D8
NC2 7
GAT1
PGND 10
1206
TP14
VSP
0805
C20NM
1812
AGND
C50
100nF
25V
D5
NC
SGND
C21
2200pF
1812
C35
2200pF-NM
1812
R26
0R
S1
4.7K 1%
R61
10k
VIN 8
C25
100nF
SMAJ58A
2
D6
TP-Red
0805
R4691K
C33
4.7uF
1210
5
R52
20k
1%
SGND
0805
TP-Red
R50
390R
SGND
R24
0R
R34
R17
Q11
C44
100nF
0603
L9
1mH
R25
10K
G4
100V
T4
SGND
C37
47uF
1210
S3
D8
22nF
Power circuit
Feedback circuit
GSL
2
10
9
R37
Q1
4
STL90N6F7-NM
C96
2.2uF
25V
S1
0805
4
1
R16
5R6-NM
Q8
STL90N6F7-NM
MODE
13
0603
10K
SOD323
0603
VSN
D7
BSC190N15NS3
S2
VSN
TP5
C36
47uF
1210
16V
R56
C
C48
47nF
1206
BZX84C10-NM
R48
D2
D15
PBSS5240T-NM
17
2K
Wurth 74439346056
C41
47uF
1210
16V
2
1
4
LPS4018-105ML
D12
BAS70
0603
PBSS5240T-NM
C30
NM
C27
NM
Fairchild FOD817AS
D5
C49
NM
1206
GAT2
15
1210
SOT23-5
SOT23
5
22R
S1
C51
1nF
0805
PGD
1%
25V
PowerFLAT 5x6
1K
D8
2KV
0805
PowerFLAT 5x6
PowerFLAT 5x6
D6
D7
SOT23
220pF
TP12
6
PGD
100V
D50
BAS70
U2
R15
NM
PM8804
C58
S2
S3
50V
10
C56
NM
3
TP-Red
powerFLAT 5x6
TP-Black
TP-Red
L2
0R
2
C24
4.7uF
1210
1
DT
3
C40
47uF
1210
16V
NM
R38
10R
1
AGND
VSP
0805
D48
BAS16J
2
1
C57
22nF
NM
S3
10k
100V
SOT23
22R
D8
SGND
SS
EEEFK2A330P
SGND
16V
PGND
2KV
C60
SOT23
0603
7443631000
Q10
12
A
turret
0805
VOUT
R124
18R
1
0603
G4
D5
C46
1nF
0805
STL90N6F7
0805
C39
1nF NM
D9
BAS16J
6.3x5.8mm
CS
14
1
R28
0R
S2
R53
U12
S3
SGND
S1
powerFLAT 5x6
2
SOD323
R47
2K
2KV
SOT23
1206
TP8
TP-Black
U3
S3
D6
BZX84C10
16V
50V
L4
R27
3M-NM
Q7
R36
10R
R45330K
VSN
C34
2200pF
1812 R35
100V
S1
1K
TS431AILT-NM
0805
C45
100nF
25V
T2
NM
D5
R29
NM
TP13
SOD323
VDC
J4
Synchronous rectifiers
R78
0R
This circuit at the bottom side under
the equivalent circuit of the top side
D6
C47
2.2uF
25V
47K
6
100pF
C95
1nF
1
A
Q4
TP9
2
C22
2200pF-NM
1812
R51
D5
C28
NM
1
GSL
SOD323
MODE
L3
2
turret
G4
FDMC86259P
100V
C75
100pF
0805
MMBT3904LT1-NM
A
C42
47uF
1210
16V
NM
Q12
1210
SOD323
16QFN_3X3X0.75_0.5
AGND
BLK
16
R44
0R05
5
NC1
2
0603
C23
1nF
0805
D1
PGND
SOD323
C31
4.7uF
1210
100V
200V
SOD323
3
D17
BZX84C10
C
R32
10R
SOT23
C53 10nF
PBSS4240T
R108
0R100
4FSW
BAS16J
TP10
D6
G4
2KV
10x10.2
9
R49
0R
S2
R31
NM
C76
100pF
0805
SOT23
TS2431-AILT
2010
1
STEVAL-POE005V1
STEVAL-POE005V1 schematic diagrams
DB3699 - Rev 2 page 5/7
IMPORTANT NOTICE – PLEASE READ CAREFULLY
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© 2019 STMicroelectronics – All rights reserved
STEVAL-POE005V1
DB3699 - Rev 2 page 7/7
