Copyright © 2016 Microsemi Page 1
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
f
Description
PD70211 is an advanced PD Interface IC with
integrated switching (PWM) regulator control for
Powered Devices in PoE applications. It supports
IEEE802.3af, IEEE802at, HDBaseT and general 2/4-pair
configurations.
The PD70211 front-end includes an advanced
classification block that supports 2, 3, 4, and 6 event
classification. Using the SUPP_Sx pins, it also identifies
which of the four pairs of the cable actually receives
power and generates appropriate flags.
The IC features an internal bleeder for discharging the
input capacitor of the DC/DC converter rapidly, so as
to ensure fast re-detection and port power-up in case
of sudden removal and re-insertion of the Ethernet
cable into the RJ-45. The advanced PWM current-
mode section supports synchronous Flyback and Active
clamp Forward topologies, as well as Buck, Boost etc.
.
Features
Supports IEEE802.3af/at, HDBaseT and other 2-
pair/4-pair configurations
Wall-adapter support (Rear Aux method)
PD detection & programmable classification
2,3,4, and 6 event classification
Integrated 0.3Ω isolating (series-pass) FET
Inrush current limiting
Less than 10µA offset current during detection
Advanced PWM section
Lead-free MLPQ-36 (6 × 6 mm) package
Applications
HDBaseT up to 95 Watts
IEEE802.3af and 802.3at
Power Forwarding
Indoor and outdoor PoE
31 VH
32 VAUX_VCC
25 VL
0.1µF/10V
0.1µF/10V
17 SS
0.1µF/10V
VCC
18 RCLP
12 ENABLE
VINS
13
VPP
0.1µF/
25V
10µF/
25V
HYST
14
562k 18.7k
562k
RFREQ
1649.9k
GND
24
PGND
27
VSN
19
SG
26
CSN 28
Si7852ADP
3A/80V
120µH/1.5A
57V/0.6A
PD70211
(PWM SECTION)
Loop compensation
will need to be
tweaked
PG 30
100
1nF
29
CSP
10
BOOST CONVERTER (FOR 0.6A, PoE Applications)
VSP
20
SYNC
15
DAO
22
RDET
36
24.9k 1%
RCLASS
5
RREF
4
30.9k
243k EPAD
(Pin 37)
VPN_IN
8 , 9
VPP
35
VPN_OUT 10 , 11
VAUX_VCC
32 WA_EN 33
SUPP_S1 1
AT_FLAG 7AT_FLAG
SUPP_S2 2
VPN
0.1µF/100V
SMAJ58A
PD70211
(Front-End SECTION)
FB 23
COMP 21
4 x ERJ-1TYJ2R4U
(Four 2.4/1W)
21.5k
4.99k
237k
2nF
100pF
215k330pF
330µF/63V/
Aluminum
STAND-ALONE PD SOLUTION FOR POWER FORWARDING
4P_AT_FLAG 34P_AT_FLAG
HD_FLAG 6HD_FLAG
4P_HD_FLAG 34 4P_HD_FLAG
SUPP_S1
SUPP_S2
SUPP_S1
VPortN1
VPortP1
VPN
VPP
SUPP_S2
VPortN2
VPortP2
VPN
VPP
VPN
Figure 1: Typical Applications Diagram (PD70211)
Copyright © 2016 Microsemi Page 2
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Pin Configuration
VPN_OUT
VPN_OUT
ENABLE
VINS
HYST
SYNC
RFREQ
SS
RCLP
EPAD
(Pin 37)
1
2
3
4
5
6
7
8
SUPP_S1
SUPP_S2
4P_AT_FLAG
RREF
RCLASS
HD_FLAG
AT_FLAG
VPN_IN
9
VPN_IN 19
20
21
22
23
24
25
26
VSN
VSP
COMP
DAO
FB
GND
VL
SG
27 PGND
CSN
CSP
PG
VH
VAUX_VCC
WA_EN
4P_HD_FLAG
VPP
RDET
10 11 12 13 14 15 16 17 18
28293031
32
333435
36
PD70211
(Top view)
Figure 2: Pinout of PD70211 (top view)
Ordering Information
Ambient
Temperature
Type
Ordering
P/N
Package
Note
-40°C to 85°C
RoHS compliant,
Pb-free
PD70211ILQ-
TR
MLPQ-36
(6 mm × 6 mm,
0.5mm pitch)
Copyright © 2016 Microsemi Page 3
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Pin Description (PD70211)
Pin
Number
Designator
Description
1
SUPP_S1
Input pin for sensing the voltage on the diode bridge connected to the data pairs. This pin
along with the SUPP_S2 pin can be used to distinguish between 2-pair and 4-pair operation.
(For PSEs that operate in 4 pairs but do not generate the classification procedure on both
pair but one pair only). Signal is referenced to VPN_IN. Place a 10k resistor in the input of
this pin.
2
SUPP_S2
Input pin for sensing the voltage on the diode bridge connected to the data pairs. This pin
along with the SUPP_S1 pin can be used to distinguish between 2-pair and 4-pair operation.
(For PSEs that operate in 4 pairs but do not generate the classification procedure on both
pair but one pair only) . Signal is referenced to VPN_IN. Place a 10k resistor in the input of
this pin.
3
4P_AT_FLAG
Open Drain Output. The pin gets actively pulled low when a 4-pair version of a (non-
standard) Type 2 PD-PSE mutually identifies each other via classification. There is a
minimum 80 ms delay from the moment that the input capacitor is fully charged to this
signal activity. Signal is referenced to VPN_OUT
4
RREF
Bias current resistor. A 60.4k, 1% resistor is connected between RREF and IC ground
(VPN_IN)
5
RCLASS
Sets the Class of the PD. Connect RCLASS (programming resistor) between this pin and IC
ground (VPN_IN). Allowed values are 133 Ω, 69.8 Ω, 45.3 Ω, and 30.9 Ω for Class 1, 2, 3, and
4 respectively. If RCLASS is not present, the PD will draw up to 3 mA during classification,
thus indicating Class 0 (default Type 1) to the PSE. Signal is referenced to VPN_IN
6
HD_FLAG
Open Drain Output. The pin gets actively pulled low when a 2-pair HDBaseT PD-PSE
mutually identify each other via classification. There is a minimum 80 ms delay from the
moment that the input capacitor is fully charged to this signal activity. Signal is referenced
to VPN_OUT
7
AT_FLAG
Open Drain Output. This pin gets actively pulled low when a Type 2 PD-PSE mutually
identifies each other via classification. There is a minimum 80 ms delay from the moment
that the input capacitor is fully charged to this signal activity. Signal is referenced to
VPN_OUT
8, 9
VPN_IN
Lower rail of the incoming PSE voltage rail from the negative terminal of the two OR-ed
bridge rectifiers (the corresponding upper PoE rail is VPP)
10, 11
VPN_OUT
This is in effect, the switched ground for establishing continuity to the PWM section after
successful detection, classification, and Power-up. It is connected to the Power ground and
PWM controller IC’s ground plane of the DC-DC converter section
Copyright © 2016 Microsemi Page 4
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Pin
Number
Designator
Description
12
ENABLE
A logic-level input to enable the converter. We can pull it constantly up, say with a 100k
resistor to VDD, to forcibly enable the converter. Provided the input supply has exceeded
any applicable UVLO thresholds, of course, as set on the VINS pin or on the VCC pin.
Internally, the ENABLE pin actually goes to the input of an OR-gate, the other input terminal
of which is tied to “POK” a signal provided by the front-end. If the ENABLE pin is forced
high, the output of the OR-gate goes high and the converter is allowed to start (provided all
UVLO’s are past of course). If the ENABLE pin is held low, the internal node “POK” goes
active high when the PD’s front end conducts (power OK), so the OR-gate goes high once
again. In this case the switching converter turns ON naturally and correctly as required by
the PoE standard. However, for supporting wall-adapters, injecting power after the front-
end (at the input of the converter), we can forcefully turn the converter ON without the
front-end signaling PGOOD, by not tying the ENABLE pin low, but by tying it high (to VDD).
That will turn ON the converter irrespective of the state of the front-end (conducting or
not), and whether there is any incoming PoE power or not.
13
VINS
The VINS pin is a programmable UVLO pin. The converter will turn ON provided the voltage
on the VINS pin is above 1.2V (and VCC is not in UVLO, and ENABLE pin is also high
connected to VDD for example). The converter will stop switching (turn OFF) when the
voltage on the VINS pin falls below 1.2V (or if ENABLE is taken low, or if VCC falls outside its
operating range). Thus by connecting a voltage divider between input rail and IC ground, we
can set the UVLO threshold to enable switching. However, to have a smooth startup, it is
advisable to have some hysteresis too, by means of a resistor between VINS and HYST as
explained below.
14
HYST
This is the output of the UVLO comparator as shown in the Block Diagram. We connect a
“hysteresis resistor” from HYST pin to VINS pin to create positive feedback (and hysteresis).
Initially, as the input voltage is rising, the VINS pin voltage is below 1.2V and so the output of
the UVLO comparator is low, and the hysteresis resistor falls in parallel to the lower resistor
of the UVLO divider placed at the VINS pin, assisting it by pulling down the VINS pin voltage
further. As soon as the rising UVLO threshold is exceeded (VINS > 1.2V), the output of the
UVLO comparator suddenly goes high (up to VDD) and the hysteresis resistor, effectively
comes partially across the upper resistor of the UVLO divider, assisting it in the act of pulling
up on the VINS pin. This feedback therefore increases the voltage on the VINS pin. And so,
now the input rail has to fall to a much lower level to allow the VINS pin voltage to fall below
1.2V. That is how hysteresis is created by positive feedback action through the hysteresis
resistor. The exact math is in the applications information of this datasheet. Note that HYST
pin always toggles high or low depending on whether the voltage on the VINS pin is above
or below 1.2V respectively. This can always be used to simultaneously drive an opto, to
indicate when the input rail is above the programmed rising threshold and when it falls
below the programmed falling threshold.
15
SYNC
Used to synchronize the LX7309 to a frequency higher than its default value as set on RFREQ
pin. The synchronizing clock must be 2x the desired sync frequency, with a maximum
synchronizing clock frequency of 1MHz (for 500kHz PWM frequency). The PG pin’s rising
edge will occur at the same instant as the rising edge of the clock being applied on the SYNC
pin.
Copyright © 2016 Microsemi Page 5
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Pin
Number
Designator
Description
16
RFREQ
Connect a programming resistor from this pin to IC ground (pin GND) to set the switching
frequency. A typical value of the programming resistor is 49.9k, and this value will provide a
frequency between 215kHz. Halving it will roughly double the frequency, whereas doubling
it will halve the frequency. Note that the converter is designed to operate from 100 to 500
kHz based on this pin.
Switching Frequency Equation:


where Freq is [Hz] and RFREQ in []
For further information refer to Setting Switching Frequency.
17
SS
This is the soft-start pin. Typically a 0.1µF cap, the “soft-start capacitor”, is connected
between this pin and IC ground (pin GND). The capacitor gets charged up to 1.2V by an
internal resistor, and the voltage on the cap in effect forms the input voltage reference VREF
of the error amplifier. But note that this capacitor serves other functions too; for example,
it controls the rate of hiccupping under overcurrent fault conditions. So even if the internal
reference is not being used (as in isolated topologies with a TL431 on the Secondary side),
the soft-stat cap is always recommended to be in place. The actual capacitor used will be
determined by the application. For further information refer to Setting Soft-Start.
18
RCLP
Low power clamp resistor. We can connect a resistor from this pin to IC ground (pin GND)
to set the exact level at which pulse-skipping mode is entered at light loads. However, the
usual default is to connect this pin directly to IC ground, in which case pulse-skipping mode
is disabled. The method to select the threshold (and RCLP resistor value) is described in the
Applications Information section of this datasheet.
19
VSN
The negative input of the internal differential-sense voltage amplifier. Note that the
common-mode range of the differential voltage amplifier is 3.5V and its gain is 7. We can
use this differential amplifier for implementing topologies where the “system (output)
ground” is different from the IC ground. We can then step-down both output rails (output
rail and its return), by equal amounts, using identical voltage dividers, to bring the voltage
below 3.5V, then use differential sensing, and finally connect the output of the differential
voltage amplifier (pin DAO) to FB pin.
20
VSP
The positive input of the internal differential-sense voltage amplifier. Note that it must
always be connected in such a way that VSP is at a higher voltage than VSN. Also keep in
mind that since the differential voltage amplifier has a gain of 7 and the output of that amp
is connected to the feedback pin which compares that against a 1.2V reference, in effect,
the difference between VSP and VSN stabilizes to 1.2V/7 = 0.171V in steady state. That is
how we design the (identical) voltage dividers present on VSP and VSN.
Copyright © 2016 Microsemi Page 6
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Pin
Number
Designator
Description
21
COMP
This is the output of the internal error amplifier, and the input of the PWM comparator. It is
brought out to support isolated topologies because in such cases, there is an error amplifier
already present on the Secondary side (for example a TL431 or equivalent). Therefore we
want to bypass the error amplifier of the converter section. On the other hand, in non-
isolated topologies, we want to use the error amplifier of the converter. We can do that
directly, or through the differential voltage amplifier stage.
22
DAO
This is the output of the internal differential voltage amplifier (gain = 7). When this
amplifier is used, we connect DAO to the feedback pin (FB). We have part of the
compensation network between the two pins, and this network is typical of any Type 3 error
amplifier input, with or without a differential amplifier present.
23
FB
This is the feedback pin of the IC. It is internally compared to a 1.2V reference. If the
internal error amplifier is not used and the COMP pin is being used to inject the error signal
(as in isolated topologies), the FB pin can be either tied high (to VDD), or connected to
COMP.
24
GND
This is the IC ground. In more detail this is the analog (quiet) ground of the IC. Pin 20 is the
Power ground (PGND). Typically, we can connect the analog ground and PGND together on
a copper island on the component side, and then connect that through several vias very
close to the chip on to a large ground plane which extends up to the lower side of the
current sense resistor. All chip decoupling can then be very simply with respect to the
copper island on the component side.
25
VL
This is created by an internal LDO and basically provides a housekeeping rail for the IC itself,
which is 5V with respect to the IC ground. A 1µF ceramic cap placed close to this pin,
connected to IC ground is recommended for proper decoupling. This pin can also provide
up to 5mA for external circuitry if required, thermal aspects (IC dissipation) being
considered.
26
SG
Secondary Gate driver. We can use this to drive a synchronous FET or an active clamp FET.
It is derived from VCC (~ 12V), and has a 10Ω limiting resistor. So it can be used to drive a
Gate-drive transformer directly. It is usually complementary to the Primary Gate driver pin
(PG). But there is a typical 110ns blanking time between the two to prevent cross-
conduction. SG is held firmly low in pulse-skip mode (if allowed). It is also low during soft-
start. It allows forced PWM (continuous conduction) mode by allowing negative inductor
currents. It does not support diode-emulation mode (discontinuous conduction mode).
However, in pulse-skip mode, since SG stays OFF, the converter automatically lapses into
discontinuous conduction mode through the body-diode of the synchronous FET. We can
leave this pin floating if unused.
27
PGND
Power ground (for internal SG and PG drivers). This is also best for VCC decoupling, and the
Primary-side current sense resistor’s lower terminal. We can also combine GND an PGND
on to a single large ground plane. Note that Power ground plane is firmly connected to
VPN_OUT, which is the Drain side of the PDs low-side pass-FET (it stands for Negative Port
Voltage Out).
Copyright © 2016 Microsemi Page 7
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Pin
Number
Designator
Description
28
CSN
The negative input of the internal current-sense voltage amplifier. Note that the common-
mode range of the differential current-sense amplifier is 2V and its gain is 5. We can use this
for high-side current sensing up to 2V. It is then placed on the (steady) output side of a Buck
inductor, and the max output voltage is 1.8V for using this type of sensing. Ensure that CSN
is at a lower voltage compared to the positive input of the current-sense amplifier (CSP).
Current sensing can also be implemented in a more basic fashion for “low-side” sensing,
with a resistor in the return (ground) of the Buck. In that case CSN is shown connected to IC
ground. However, to avoid noise from ground bounce, it is best to route this on the PCB in
Kelvin manner to the lower end of the sense resistor. This is important because the peak
operating voltage on the sense resistor is only 200mV and PCB-related noise can cause jitter
in the switching waveform in current-mode control.
29
CSP
The positive input of the internal current-sense voltage amplifier. See discussion for Pin 28
(CSN) above. Note that the output of the current-sense amplifier is amplified 5 times. So a
0.2V current-sense voltage translates to a 1V swing at the input of the PWM comparator.
Higher voltages lead to hiccup mode protection.
30
PG
This stands for Primary Gate driver. We can use this to drive the main FET, and it has a 5 or
10Ω limiting drive resistor switched between a voltage close to VCC rail and the IC ground.
For guaranteeing proper shutdown during OFF time, it is necessary to add a 470k resistor
from PG to VINS, as shown in Figure 1.
31
VH
Internal rail of -5V with respect to VCC, brought out only for decoupling purposes. Connect a
0.1µF ceramic cap very close, from this pin to VAUX_VCC pin.
32
VAUX_VCC
Auxiliary voltage rail from front-end to the VCC (supply) input of the PWM section. The
front-end provides a few mA of startup current for the PWM controller (at typically 10.5V).
Signal is referenced to VPN_OUT and is activated once front end power up sequence is end.
After initial startup of PWM section, a bias winding can be connected to this pin through a
diode, to sustain the PWM section.
33
WA_EN
While this input is low (referenced to VPN_IN) the chip work according to internal flow
diagram. When this input is high, it enable wall adapter feature. Place 100nF/10V capacitor
from WA_EN to VPN_IN pins, locate it close to device. When WA_EN is not used, connect it
to VPN_IN. For further information, refer to External source connected to PD device output.
34
4P_HD_FLAG
Open Drain Output. The pin gets actively pulled low when a 4-pair HDBaseT PD-PSE
mutually identify each other via classification. There is a minimum 80 ms delay from the
moment that the input capacitor is fully charged to this signal activity. Signal is referenced
to VPN_OUT
35
VPP
Upper rail of the incoming PSE voltage rail from the positive terminal of the two OR-ed
bridge rectifiers (the corresponding lower PoE rail is VPN_IN)
36
RDET
Internally connects to VPN_IN during detection phase and disengages after it is over. A
25KΩ (or 24.9K), 1% resistor is connected between this pin and VPP
37
EPAD
Connected on PCB plane to VPN_IN
Copyright © 2016 Microsemi Page 8
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Functional Block Diagram
RDET
RCLS
VPP
SUPP_S1
SUPP_S2
VPN_IN
WA_EN
4P_AT_FLAG
HD_FLAG
AT_FLAG
4P_HD_FLAG
VPN_OUT
Enhanced
Classification
Block
Startup/
Inrush control
VAUX_VCC
10.5V
regulator
4.8V
regulator
Vdd
45mA
1.2V
Bandgap
Bleeder
control
Detection
control
RREF
Iclass Class
control
Temp
Temp
+48V
48VRTN
Rsense
RCLASS
RDET
RREF
80ms delay
timer
VPP UVLO
Figure 3: Block Diagram (PD70211 front-end section)
Copyright © 2016 Microsemi Page 9
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
VCC
VCC
Dead time
+
-
Blanking
and
Limiting
offset
+
-
CLK
Clock
SYNC
RFREQ
+
-
offset
+
-
+
-
+
-
× 7
× 5
Differential
Current sense
amplifier
Differential
Voltage sense
amplifier
Pulse skip
Mode
Rskip
RCLP
Soft-start / Logic
Csoftstart
Enable ENABLE
SS
12
17
15
16
18
FB
23
DAO
22
Differential
amp output
Vout_high Vout_low
COMP
21
Rsense
Rupper
Rlower
Rupper
Rlower
PWM
logic
VREF +
-
Vin
UVLO/PFW select
SYNC DAO
VDD
VIN
VIN
Rfreq
VINS 13 HYST 14
VSN
VSP
CSP
CSN
29
28
20
19
SG
PG
26
30
Chip Supply
VAUX_VCC 32
5V drop
“High”
Internal Rail
VH
31
5V LDO
“Low”
Internal Rail
(VDD)
VL
25
VREF
(1.2V)
Decoupling
for VH rail
Decoupling
for VL
(VDD) rail
PD70211 (PWM section)
GND 24 PGND 27
POK
Figure 4: Block Diagram (PD70211 PWM section)
Copyright © 2016 Microsemi Page 10
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Absolute Maximum Ratings
Performance is not necessarily guaranteed over this entire range. These are maximum stress ratings only.
Exceeding these ratings, even momentarily, can cause immediate damage, or negatively impact long-term
operating reliability. Voltages are with respect to IC ground (VPN_IN).
Min
Max
Units
VPP, VPN_OUT, RDET
-0.3
74
V
AT_FLAG, HD_FLAG, 4P_AT_FLAG,
4P_HD_FLAG
-0.3
20
V
SUPP_S1, SUPP_S2
0
VVPP + 1.5
V
RREF, RCLS, WA_EN
-0.3
5
V
VAUX_VCC
-0.3
20
V
PG, SG
-0.3
20
V
VL
-0.3
6
V
VH (with respect to VAUX_VCC)
0.3
-6
V
ENABLE
All other pins
-0.3
VL+0.3
V
Junction Temperature
-40
150
°C
Lead Soldering Temperature (40s, reflow)
260
°C
Storage Temperature, MSL3
-65
150
°C
ESD rating
HBM
±1.5*
kV
MM
±50
V
CDM
±500
V
*Pins VPP, VAUX/VCC , RREF pass ±1kV HBM only.
Operating Ratings (Front-End Section)
Performance is generally guaranteed over this range as further detailed below under Electrical
Characteristics. voltages are with respect to IC ground (VPN_IN).
Min
Max
Units
VPP
0
57
V
Ambient Temperature*
-40
85
°C
Detection Range
1.1
10.1
V
Mark event range
4.9
10.1
V
Class event range
13.7
20.9
V
* Corresponding Max Operating Junction Temperature is 125°C.
Copyright © 2016 Microsemi Page 11
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Operating Ratings (PWM Section)
Performance is generally guaranteed over this range as further detailed below under Electrical
Characteristics. Voltages are with respect to IC ground.
Min
Max
Units
VCC
7.8
20
V
Fsw (adjustable frequency range)
100
500
kHz
Max Duty Cycle
44.5
%
fsw_synch (synchronization frequency range)
200
1000
kHz
Thermal Properties
Thermal Resistance
Min
Typ
Max
Units
θJA
22.3
°C/W
θJP
3
°C/W
θJC
4
°C/W
Note: The Jx numbers assume no forced airflow. Junction Temperature is calculated using TJ = TA + (PD x JA). In particular, θJA is a
function of the PCB construction. The stated number above is for a four-layer board in accordance with JESD-51 (JEDEC).
Electrical Characteristics (Front-End Section)
Unless otherwise specified under conditions, the Min and Max ratings stated below apply over the entire
specified operating ratings of the device. Typ values stated, are either by design or by production testing at
25°C ambient. Voltages are with respect to IC ground (VPN_IN).
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Input Voltage
IIN
IC input current with
ICLASS off
VPP=55V
1
3
mA
Detection phase
VDET
Detection range
1.1
10.1
V
RDET_TH
RDET disconnect
threshold
10.1
12.8
V
RDS_DET_ON
On-resistance of internal
FET during detection
50
Copyright © 2016 Microsemi Page 12
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PD70211
PD Controller with Switching Regulator for
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Symbol
Parameter
Conditions
Min
Typ
Max
Units
RDS_DET_OFF
Off-resistance of internal
FET after detection
2
MΩ
IOFFSET_DET
Input offset current
1.1V ≤ VPP ≤ 10.1V, TJ
85°C
5
μA
VR_DET_ON
RDET reconnection
threshold when VPP goes
low
2.8
3.0
4.85
V
Classification phase
VCLS_ON
Classification sink turn-
on threshold
11.4
13.7
V
VCLS_OFF
Classification sink turn-
off threshold
20.9
23.9
V
VHYS_CLS_ON
Hysteresis of VCLS_ON
threshold
1
V
VMARK_TH
Mark detection
threshold (VPP falling)
10.1
11.4
V
IMARK
Current sink in Mark
event region
0.25
4
mA
ICLASS_CLIM
Current limit of class
current
50
68
80
mA
ICLASS
Classification current
sink
RCLASS = not present (Class
0)
3
mA
RCLASS = 133 Ω (Class 1)
9.5
10.5
11.5
RCLASS = 69.8 Ω (Class 2)
17.5
18.5
19.5
RCLASS = 45.3 Ω (Class 3)
26.5
28.0
29.5
RCLASS = 30.9 Ω (Class 4)
38.0
40.0
42.0
Isolation FET
RDSON
On resistance
Total resistance between
VPN_IN to VPN_OUT;
ILOAD < 600mA, -40oC <TA <
85oC
0.3
ICLIM_INRUSH
Inrush current limit
105
240
325
mA
OCP
Overcurrent protection
2.2
A
Copyright © 2016 Microsemi Page 13
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Symbol
Parameter
Conditions
Min
Typ
Max
Units
ILOAD
Continuous operation
load
2
A
Undervoltage Lockout
UVLOON
Threshold that marks
start of Inrush phase
36
42
V
UVLOOFF
Threshold where pass-
FET turns off as VPP
collapses
30.5
34.5
V
DC-DC Input Cap Discharger
ICAP_DIS
Discharge current
7V ≤ VPP ≤ 30V
22.8
60
mA
tdis
Discharge time
CDC_DC ≤ 264 μF
(by design, not tested)
500
ms
timerdis
Discharge timer
Time for which discharge
circuit is activated
430
ms
References, Rails and Logic
VAUX
Auxiliary voltage
0mA < IAUX < 4mA
9.8
10.5
12.0
V
IAUX
Max continuous current
from VAUX
4
mA
IAUX_CLIM
Aux current limit
10
32
mA
VREF
Bandgap reference
voltage
1.17
1.2
1.23
V
tFLAG_LO
Low level flag
For AT_FLAG, HD_FLAG,
4P_AT_FLAG,
4P_HD_FLAG, IFLAG= 3mA
0.4
V
IFLAG
Flag Current driving
capability
For AT_FLAG, HD_FLAG,
4P_AT_FLAG, 4P_HD_FLAG
5
mA
tFLAG
Delay timer between
start of inrush and flags
declared
For AT_FLAG, HD_FLAG,
4P_AT_FLAG, 4P_HD_FLAG
80
ms
VSUPP_HI
SUPP_Sx high voltage
threshold
For SUPP_S1 and SUPP_S2
25
35
V
Copyright © 2016 Microsemi Page 14
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Wall Adapter
Min
Typ
Max
Units
VIH
Input high logic
2.4
V
VIL
Input low logic
0.8
V
Truth Table for Status of Flags
Number of Fingers “N”
(N-Event classification)
SUPP_S1
SUPP_S2
AT_FLAG
HD_FLAG
4P_AT_FLAG
4P_HD_FLAG
1
X
X
Hi Z
Hi Z
Hi Z
Hi Z
2
H
L
0V
Hi Z
Hi Z
Hi Z
2
L
H
0V
Hi Z
Hi Z
Hi Z
2
H
H
0V
Hi Z
0V
Hi Z
3
L
H
0V
0V
Hi Z
Hi Z
3
H
L
0V
0V
Hi Z
3
H
H
0V
0V
0V
Hi Z
4
X
X
0V
0V
0V
Hi Z
5
RESERVED FOR FUTURE
6
X
X
0V
0V
0V
0V
Electrical Characteristics (PWM Section)
Unless otherwise specified under conditions, the Min and Max ratings stated below apply over the entire
specified operating ratings of the device. Typ values stated, are either by design or by production testing at
25°C ambient. Voltages are with respect to IC ground (VPN_IN).
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Input Voltage Current
VCC_UVLO_UP
UVLO threshold with
input rising
VCC rise time > 0.5 ms
8.85
9.15
9.5
V
VCC_UVLO_DN
UVLO threshold with
input falling
VCC rise time > 0.5 ms
7
7.3
7.6
V
IVCC_SD
IC input current (no
switching)
VENABLE = Low, or VVCC <
VCC_UVLO_UP
1
2000
µA
Copyright © 2016 Microsemi Page 15
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Symbol
Parameter
Conditions
Min
Typ
Max
Units
IVCC_Q
IC input current
(switching, no load on
SG, PG, VDD)
VENABLE = High, and
VVCC > VCC_UVLO_UP, fsw =
500kHz
3
mA
Input UVLO/PFW
VINS_TH
Threshold on VINS pin
Rising or falling
1.171
1.200
1.229
V
VHYST_HIGH
Hysteresis pin high
voltage
IHYST_SOURCING = 1mA
2.8
V
VHYST_LOW
Hysteresis pin low
voltage
IHYST_SINKING = 3mA
0.4
V
LDOs
VL
IVDD_EXT < 5mA (current out
of pin)
4.75
5
5.25
V
VH
VH rail (with respect to
VCC)
-5V
V
Soft Start
ISS_CH
Current out of SS pin
during charging phase
RFREQ=33.3k, VSS=0.5V
32
36
40
µA
ISS_DISCH
Current into SS pin
during discharging
phase
RFREQ=33.3k, VSS=0.5V
10
% of
ISS_CH
VSS_CH
Soft start charge
completed threshold
By design only
90
95
% of
VREF
VSS_DISCH
Soft start discharge
completed threshold
50
mV
RSS_DISCH
Soft-start pin discharge
FET resistance
50
Copyright © 2016 Microsemi Page 16
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Symbol
Parameter
Conditions
Min
Typ
Max
Units
tDISCH
Soft-start discharge FET
on-time
32
Switch
cycles
Switching Frequency and Synchronization
fsw_range
Switching frequency
accuracy
RFREQ=33.2k
285
315
345
kHz
fsync_max
Max synchronization
frequency
1
MHz
VSYNC_HI
SYNC pin high
threshold
2.4
V
VSYNC_LO
SYNC pin low threshold
0.8
V
tsync
Minimum pulse width
of SYNC pulse
100
ns
Dsync_max
Max SYNC pulse duty
cycle
90
%
Error Amplifier
VREF
Reference voltage
1.171
1.200
1.229
V
GainDC_OPL
DC Open-loop gain
Rload=100k
70
100
dB
AVUGBW
Unity Gain Bandwidth
Cload=10pF (By design
only)
2
5
MHz
ICOMP_OUT
Output sourcing
current
0.2V< VCOMP < 1.3V
110
620
µA
ICOMP_IN
Output sinking current
0.2V< VCOMP < 1.3V
145
495
µA
VEA_CMR_MAX
Max of input common-
mode range
2
V
VCLAMP
COMP pin high clamp
1.8
2.1
2.6
V
Copyright © 2016 Microsemi Page 17
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Symbol
Parameter
Conditions
Min
Typ
Max
Units
PWM Comparator
VOFFSET
Inserted offset in
inverted input
200
300
mV
VRCLP
Voltage set on RCLP pin
by external resistor to
GND
0
1
V
Current Sense Amplifier
GainCSA
DC Gain
4.75
5
5.25
V
IAUX
Max continuous
current from VAUX
4
mA
VCSA_CMR_MAX
Max input common-
mode range
2
V
tBLANK
Blanking time
50
100
ns
VILIM
Current limit threshold
on output of current
sense amplifier
Where PWM pulses start
to get truncated
1.1
1.2
1.3
V
VILIMHICCUP
Current Limit threshold
on output of current
sense amplifier
capability
Where PWM pulses start
to get omotted in hiccup
mode
1.7
1.8
1.9
V
Differential Voltage Amplifier
GainDA
DC gain of differential
voltage amp
6.68
7.0
7.14
AVUGBW_DA
Unity Gain Bandwidth
of differential voltage
amp
5
MHz
VDA_CMR_MAX
Max of input common-
mode range
3.5
V
Drivers
RPG_HI
Drive resistance when
PG is high
10
RPG_LO
Drive resistance when
PG is low
5
tPG_MIN
Minimum on-time of
PG
120
ns
DMAX
PG max duty cycle
44.5
50
%
Copyright © 2016 Microsemi Page 18
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Symbol
Parameter
Conditions
Min
Typ
Max
Units
RSG_HI
Drive resistance when
SG is high
10
RSG_LO
Drive resistance when
SG is low
10
tDEAD
Deadtime
PG low to SG high or PG
high to SG low
60
110
190
ns
Logic Levels on VINS and ENABLE
VHI
Input high threshold
2
V
VLO
Input low threshold
0.8
V
Thermal Protection
TSD
Thermal shutdown
(rising)
157
°C
THYST
Thermal shutdown
hysteresis
15
30
°C
Thermal Protection
PD70211 is protected from excessive internal temperatures that may occur during various operating
procedures. Two temperature sensors are located on the chip, monitoring the temperatures of the
following:
Isolating Switch (pass-FET)
Classification Current Sink
Each of the over temperature sensor activates a protection mechanism that will disconnect the Isolation
(pass) FET or the classification circuit respectively. This protects the device from being permanently
damaged or even from long-term degradation.
Copyright © 2016 Microsemi Page 19
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Truth Table for Status of Flags
Number of Fingers “N”
(N-Event Classification)
SUPP_S1
SUPP_S2
AT_FLAG
HD_FLAG
4P_AT_FLAG
4P_HD_FLAG
1
X
X
Hi Z
Hi Z
Hi Z
Hi Z
2
H
L
0V
Hi Z
Hi Z
Hi Z
2
L
H
0V
Hi Z
Hi Z
Hi Z
2
H
H
0V
Hi Z
0V
Hi Z
3
L
H
0V
0V
Hi Z
Hi Z
3
H
L
0V
0V
Hi Z
3
H
H
0V
0V
0V
Hi Z
4
X
X
0V
0V
0V
Hi Z
5
RESERVED FOR FUTURE
6
X
X
0V
0V
0V
0V
Wall Adapter mode
PD70211 support wall adapter functionality, i.e. by setting WA_EN pin high it will give priority to the wall
adapter jack to supply the load.
WA_EN pin is used while connecting a wall-adapter voltage between VPP and VPN_OUT by means of an OR-
ing diode.
While WA_EN, Wall-adapter enable pin, is held low (referenced to VPN_IN), the front-end works as a normal
PD.
When WA_EN is raised high (referenced to VPN_IN) three internal operations are forced:
The Isolation FET is turned OFF.
All output flags AT_FLAG, HD_FLAG, 4P_AT_FLAG and 4P_HD_FLAG are activated (low state).
Vaux output voltage is turned ON.
While activating WA_EN pin, the wall-adapter will supply input voltage for the DC-DC converter.
Having WA_EN at high state does not disable detection and classification modes.
Copyright © 2016 Microsemi Page 20
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PD70211
PD Controller with Switching Regulator for
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Applications Information
Peripheral devices
An 100nF/100V capacitor should be placed between device VPP and VPNI pins, and located as close as
possible to the device.
An 58V TVS should be placed between device VPP and VPNI pins.
An 10K ohm resistor should be placed on SUPP_S1 and SUPP_S2 lines between diode bridge and
PD70211 device.
When WA_EN is used, an 100nF/10V Capacitor should be placed between WA_EN and VPNI pin close to
PD70211 device.
When not used, WA_EN should be connected to VPNI pin.
Setting Switching Frequency
A resistor, RFREQ, is connected from RFREQ pin to IC ground. Based on that, we get the following frequency

  
where Freq is [Hz] and Rfreq in Ω
For example, by setting RFREQ=49900Ω, we get

󰇛 󰇜  
We can set any frequency between 100 to 500 kHz. Note that when synchronizing, the default frequency (as set
by RFREQ) must be lower than the synchronization clock. In case the synchronization breaks, the converter will
lapse back to the default value. When synchronizing, we can increase the frequency to 1MHz.
Copyright © 2016 Microsemi Page 21
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PD70211
PD Controller with Switching Regulator for
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Setting Soft-Start
A capacitor is connected between SS pin and IC ground. The current charging the capacitor is
SS_CHG
1.2V
I (in seconds)
RFREQ
For example, if RFREQ=49.9k, we get
5
SS_CHG 3
1.2V
I (in Amperes) = 2.4 10 24 A
49.9 10
So, charging a 0.1µF ceramic cap on the soft-start pin from 0 to 1.2V will take
3
SS
SS_CHG
C V 0.1 1.2 0.12
t (in seconds) = (in seconds) = (in seconds) = 5 10 (in seconds) 5ms
24 24
I
This is the soft-start time in this case.
Setting Pulse-skip Mode threshold
If a programming resistor RCLP is placed between RCLP pin and IC ground, the clamping voltage level is given by
CLP
0.3 RCLP
V (in Volts)
RFREQ
For example, if RCLP = RFREQ, say both are 49.9k, then the converter will enter pulse skipping when the output
of the current sense amplifier drops to 0.3V. Note that the gain with this current amplifier is 5, so in terms of the
voltage on the sense resistor (input of the current amp), we get 0.3V/5 = 0.06V. Since we usually design the
converter so that its peak is around 0.2V (the peak of Rsense voltage before it starts to current limit), we are
getting a ratio of 0.06V/0.2V = 0.3. In other words, the converter will enter pulse-skipping when the output
current is 30% of the max designed output current.
Setting UVLO/Hysteresis thresholds
Note: A 470k resistor from PG pin to VINS pin is required for guaranteeing proper termination of Gate drive pulse
during UVLO.
Suppose we have a divider connected to input at the VINS pin. Suppose we call the resistors RUPPER and RLOWER.
We also have a hysteresis resistor, RHYST, from the output of the UVLO comparator, which provides positive
feedback on to the VINS pin, as explained in the Pin Description section. So, when the input voltage is rising, in
Copyright © 2016 Microsemi Page 22
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PD70211
PD Controller with Switching Regulator for
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effect the hysteresis resistor is in parallel to the lower resistor RLOWER. When the voltage on the VINS pin rises
above 1.2V, the UVLO comparator flips and the hysteresis resistor appears connected to 5V (output of the UVLO
comparator). The equivalent configurations are shown in Figure 5. After solving the equations, the following
example indicates the set thresholds. The values are as used in Figure 3.

UPPER LOWER HYST
LOWER HYST
LOWER HYST
LOWER _EQUIV
LOWER HYST
R 270k; R 8.66k; R 270k
Part 1: (VINS less than 1.2V)
Equivalent lower resistor is a parallel combination of R and R
RR
8.66k 270k
R 8.391
R R 8.66k 270k
UPPER LOWER _EQUIV
UVLO_ UP
LOWER _EQUIV
k
The rising voltage threshold is
RR 270k 8.391k
V VREF 1.2V 39.8V
R 8.391k
UPPER UPPER
UVLO_ DN
LOWER HYST
Part 2: (VINS greater than 1.2V)
RR
V VREF VDD VREF VREF
RR
270k 270k
1.2V 3.8V 1.2 34.8V
8.66k 270k
So with the selected resistors, we get a rising threshold of 39.8V, and a falling threshold of 34.8V.
VIN
RUPPER
RLOWER RHYST
VVINS < 1.2V
Rising Input
VIN
RUPPER
RLOWER RHYST
VVINS > 1.2V
Falling Input
5V
Figure 5: Equivalent Diagrams for UVLO and Hysteresis
Copyright © 2016 Microsemi Page 23
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Setting the Voltage Divider for Output Rails
Generically, we can state the equation to be

UP LOW
OUT X
LOW
RR
VV R
Where RUP is the name we have given to the upper resistor (connected to output rail) and RLOW is the name we
have given here to the resistor connected to lower rail (usually IC ground). However, there are so many
topologies, we have in effect thress cases in all the typical schematics presented so far.
a) Non-isolated topologies with simple divider connected directly to FB pin. For this use VX = 1.2V.
b) Isolated topologies with divider to another reference (such as TL431 with an internal reference of 2.5V).
For this use VX = 2.5V.
c) Non-isolated topologies with a differential divider connected to differential voltage amplifier of the
LX7309 . Here we use the same divider equation provided above, but using VX = 0.171V (that is 1.2V
divided down by the gain of the diff-amp, i.e. by 7). We need two identical dividers.
Selecting the Sense Resistor
In a Buck topology, the center of the switch current ramp equals the output current. To that we need to add
about 30% for the peak current “IPEAK+” because of the rising ramp caused by the inductor. That is a factor of 1.3.
We also need to include some headroom for proper transient response at max load. Since the peak voltage on
the sense resistor is 0.2V, to leave headroom, we should plan that the switch current peak stays at around 0.18V
max at max load. This means that:

PEAK O
SENSE
OO
I 1.3 I , So
0.18 0.138
R =
1.3 I I
SENSE
O
0.138
R = (Buck)
I
Assuming we have designed the converter to operate up to 44% max duty cycle, we can quickly estimate the
peak current as follows.
Copyright © 2016 Microsemi Page 24
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PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
For example, if we have a Buck application for 5A output, irrespective of the input and output voltage conditions
(as long as they are not violating the min and max duty cycle limits of the converter), and assuming we have
selected inductance appropriately, we should pick a sense resistor of

SENSE
0.138
R =0.028
5A
We may need to put an adjust resistor in parallel (such as the “22Ω” placeholder) we have shown in all the
typical application schematics.
For a Forward converter (Buck with a transformer), instead of the load current IOR in the above equation, use the
reflected load current of IO/n, where n is the turns ratio (number of Primary-side turns divided by number of
Secondary-side turns). You will also need to lower the sense resistance further (by means of the adjust resistor),
to account for the magnetization current component on the switch side. So roughly:

P
SENSE
OS
N
0.138
R (Forward)
IN
For a Boost or Buck-Boost, we have to account for the fact that the peak current is not just 1.3 times max load
current, but is actually

O
PEAK
I
I 1.3 (where D can be as high as 44%)
1D
So we should use the following equation for sense resistor

SENSE
O O O
0.18 1 D 0.101 1
R = =
1.3 I 1.3 I 13 I
SENSE
O
0.077
R (Boost, Buck-Boost)
I
For example, if the max load current is 5A, the sense resistor value to use is

SENSE
0.077
R =0.015
5A
As we can see, this is roughly half of what we got for the Buck (same load current).
For a Flyback topology (Buck-Boost with a transformer), we have to use the reflected output current. So we get:

P
SENSE
OS
N
0.077
R (Flyback)
IN
Copyright © 2016 Microsemi Page 25
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PD70211
PD Controller with Switching Regulator for
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Operation with an External DC Source
PD applications utilizing PD70211 IC may be operated with an external power source (DC wall adaptor). There
are two cases of providing power with an external source, the cases are presented in.
Figure 6 and Figure 7.
External source connected to application’s low voltage supply rails. External source voltage level is
dependent on DCDC output characteristics. Described in
Figure 6
External source connected to PD device output connection toward the application (VPP to VPNOUT).
External source voltage level is dependent on DCDC input requirements. Described in Figure 7
100nF
100V
Primary DC(+)
Bootstrap Winding
controller VCC
Primary DC (-)
Isolated Output
Isolated Output
Isolated DCDC Application
SUPP_S1
SUPP_S2
-
SUPP_S2
IN1B
IN2B OUTN
+
SUPP_S1
OUTP
IN1A
IN2A
Data- from
line XFMR
Data+ from
line XFMR
Spare+ from
line XFMR
Spare- from
line XFMR
TVS
(+) Input
(-) Input
D1
10K
10K PD70211
Vpp
WA_EN
Supp_S1
Rdet
Rcls
VPNI
VPNI
Supp_S2
Rref
VAUX_VCC
VPNo
VPNo
PGND
Figure 6: External Power Input connected to Application supply Rails
100nF
100V
Primary DC(+)
Bootstrap Winding
controller VCC
Primary DC (-)
Isolated Output
Isolated Output
Isolated DCDC Application
SUPP_S1
SUPP_S2
-
SUPP_S2
IN1B
IN2B OUTN
+
SUPP_S1
OUTP
IN1A
IN2A
Data- from
line XFMR
Data+ from
line XFMR
Spare+ from
line XFMR
Spare- from
line XFMR
R1
R4
R3
TVS
R2
(+) Input
(-) Input
D1
Q1
10K
10K 100nF PD70211
Vpp
WA_EN
Supp_S1
Rdet
Rcls
VPNI
VPNI
Supp_S2
Rref
VAUX_VCC
VPNo
VPNo
PGND
Copyright © 2016 Microsemi Page 26
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Figure 7: External Power Input connected to PD70211 Output
External source connected to PD device output (Figure 7)
PD70211 WA_EN pin is used for disabling the isolation switch and thus PSE input power, when an external
adapter is connected.
WA_EN resistors divider depends on the VinH threshold of the PD70211.
Figure 8 is zooming into the resistors to be selected in external adapter connection.
R4
R3
R2
R1
VPNo
VPNin
(-) Input
(+) Input
PD IC EN
Q1
100nF
Figure 8: External Power Input resistors dividers
R1 and R2 sets a rough threshold for Pfet Q1 enable, to detect whether external adapter exists or not. It should
be set to be lower threshold than PD70211 disable levels.
R3 and R4 sets PD70211 disable threshold.
So in case of 36V-57V external adapter. The disable setting can be selected as follows:
Pfet enable threshold = 30V.
R1 and R2 setting should be so that the value of Q1 VGS < 20V at max voltage condition of external adapter.
While external adapter voltage is above 30V, Q1 will be above its VGSth value.
  
 
R1 is selected as 2kΩ.
   

Using R1=2kΩ, Vext_adapter=30V and VGS= maximum VGSth =3.5V. we get R2 value.
 
Copyright © 2016 Microsemi Page 27
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
R3 and R4 are set to the range of few k- 10’s of kΩ using the equation below:
(I)   
󰇛󰇜
Using R3=15kΩ, Vext_adapter=33.7V and from data sheet we use PD70211_WA_EN=2.4V as turn Off min
threshold.
Solving the equation , we get the valid resistors values for an adapter of 36V and above.
 
 
Copyright © 2016 Microsemi Page 28
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
Package Dimensions
LQ
36-Pin QFN 6x6mm
Dim
MILLIMETERS
INCHES
MIN
MAX
MIN
MAX
A
0.80
1.00
0.031
0.039
A1
0.00
0.05
0
0.002
A3
0.20 REF
0.008 REF
e
0.50 BSC
0.019 BSC
L
0.45
0.65
0.018
0.026
b
0.18
0.30
0.007
0.011
D2
4.00
4.25
0.157
0.167
E2
4.00
4.25
0.157
0.167
D
6.00 BSC
0.236 BSC
E
6.00 BSC
0.236 BSC
Note:
1. Dimensions do not include protrusions; these shall not
exceed 0.155mm (.006”) on any side. Lead dimension
shall not include solder coverage.
2. Dimensions are in millimeters, inches for reference only.
e
D
E
A
A1 A3
K
b
1
10 19
28
D2
E2
L
Copyright © 2016 Microsemi Page 29
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
PD70211 Recommended PCB layout
Recommended PCB layout pattern for PD70211 is described in the following figures.
4.2 4.3
0.3
0.5
4.3
4.2
1.0
Figure 9: PD70211 Top layer Copper Recommended PCB Layout (mm)
4.3
0.3
0.5
4.3
1.0
3.9
3.9
1.8
1.8
Solder past
Solder mask
Figure 10: PD70211 Top layer Solder Mask, Solder Paste and Vias Recommended PCB Layout (mm)
1.0
3.9
4.2
1.0
0.6
0.6 3.9 4.2
So ld er PAD
So ld er m ask
So ld er p ast
0.3
Figure 11: PD70211 Bottom layer Copper and Solder Paste Recommended PCB Layout for Thermal Pad Array (mm)
Copyright © 2016 Microsemi Page 30
Rev. 1.4, July 2017 CPG PoE BU
One Enterprise Aliso Viejo, CA 92656 USA
PD70211
PD Controller with Switching Regulator for
AF/AT/UPOE/HDBaseT/4-pair PoE Applications
The information contained in the document (unless it is publicly available on the Web without access restrictions) is
PROPRIETARY AND CONFIDENTIAL information of Microsemi and cannot be copied, published, uploaded, posted,
transmitted, distributed or disclosed or used without the express duly signed written consent of Microsemi. If the recipient of
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apply. This document and the information contained herein may not be modified, by any person other than authorized
personnel of Microsemi. No license under any patent, copyright, trade secret or other intellectual property right is granted
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or otherwise. Any license under such intellectual property rights must be approved by Microsemi in writing signed by an
officer of Microsemi.
Microsemi reserves the right to change the configuration, functionality and performance of its products at anytime without
any notice. This product has been subject to limited testing and should not be used in conjunction with life-support or other
mission-critical equipment or applications. Microsemi assumes no liability whatsoever, and Microsemi disclaims any
express or implied warranty, relating to sale and/or use of Microsemi products including liability or warranties relating to
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Any performance specifications believed to be reliable but are not verified and customer or user must conduct and complete
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Revision History
Revision Level / Date
Para. Affected
Description
0.1 / Feb 2, 2012
-
Initial Release
0.2 / March 2012
-
Class Values Typo’s Editing
0.3 -0.5/ March 2013
-
General update
0.6/ July 2014
-
Reduce flags maximum voltage, Add WA_EN information
1.0/ August 2014
-
Add freq setting information
1.1/ Jan 2015
-
Add PCB footprint recommendation
1.2 / June 2015
-
Updating typo in part marking definition
1.3 / Oct 2015
Page 7
Page 13
Page 31
Fix Vaux pin description.
Add UVLO_ON missing information.
Fidure 9, 10, 11 Typo (cnage PD70224 to PD70211)
1.31 / July 2016
Page 2
Clarified Ordering Information table
Fix typo descibing the IC marking (remove the initial “PD”)
Page 8
Remove the name of the front end die in functional block
diagram (Remove PD70210A)
All Pages
Update Rev number and date in the footer.
1.4 / July 2017
Page 2, 10
Updated marking and MSL3 per PCN 157021
© 2016 Microsemi Corp.
All rights reserved.
For support contact: PoEsupport@microsemi.com
Visit our web site at: www.microsemi.com Catalog Number: DS_PD70211