19-4593; Rev 3; 3/12
High-Power, Quad, Monolithic, PSE Controllers
for Power over Ethernet
General Description
The MAX5965A/MAX5965B are quad, monolithic, -48V
power controllers designed for use in IEEE
®
802.3af-com-
pliant/IEEE 802.3at-compatible power-sourcing equipment
(PSE). These devices provide powered device (PD) dis-
covery, classification, current limit, DC and AC load discon-
nect detections in compliance with the IEEE 802.3af
standard. The MAX5965A/MAX5965B are pin compatible
with the MAX5952/MAX5945/LTC4258/LTC4259A PSE
controllers and provide additional features.
The MAX5965A/MAX5965B feature a high-power mode
that provides up to 45W per port. The MAX5965A/
MAX5965B provide new Class 5 and 2-event classifica-
tion (Class 6) for detection and classification of high-
power PDs. The MAX5965A/MAX5965B provide
instantaneous readout of each port current through the
I
2
C interface. The MAX5965A/MAX5965B also provide
high-capacitance detection for legacy PDs.
These devices feature an I
2
C-compatible, 3-wire serial inter-
face, and are fully software configurable and programmable.
The class-overcurrent detection function enables system
power management to detect if a PD draws more than the
allowable current. The MAX5965A/MAX5965B’s extensive
programmability enhances system flexibility, enables field
diagnosis, and allows for uses in other applications.
The MAX5965A/MAX5965B provide four operating modes
to suit different system requirements. Auto mode allows
the devices to operate automatically without any software
supervision. Semi-automatic mode automatically detects
and classifies a device connected to a port after initial
software activation, but does not power up that port until
instructed to by software. Manual mode allows total soft-
ware control of the device and is useful for system diag-
nostics. Shutdown mode terminates all activities and
securely turns off power to the ports.
The MAX5965A/MAX5965B provide input undervoltage
lockout (UVLO), input undervoltage detection, a load-
stability safety check during detection, input overvolt-
age lockout, overtemperature detection, output voltage
slew-rate limit during startup, power-good status, and
fault status. The MAX5965A/MAX5965B’s programma-
bility includes startup timeout, overcurrent timeout, and
load-disconnect detection timeout.
The MAX5965A/MAX5965B are available in a 36-pin SSOP
package and are rated for both extended (-40°C to +85°C)
and upper commercial (0°C to +85°C) temperature ranges.
Features
o
IEEE 802.3af Compliant/IEEE 802.3at Compatible
o
Instantaneous Readout of Port Current Through
I
2
C Interface
o
High-Power Mode Enables Up to 45W Per Port
o
High-Capacitance Detection for Legacy Devices
o
Pin Compatible with MAX5952/MAX5945/
LTC4258/LTC4259A
o
Four Independent Power-Switch Controllers
o
PD Detection and Classification (Including 2-
Event Classification)
o
Selectable Load-Stability Safety Check During
Detection
o
Supports Both DC and AC Load Removal
Detections
o
I
2
C-Compatible, 3-Wire Serial Interface
o
Current Foldback and Duty-Cycle-Controlled
Current Limit
o
Open-Drain
INT
Signal
o
Direct Fast Shutdown Control Capability
o
Special Class 5 Classification
MAX5965A/MAX5965B
Ordering Information
PART
MAX5965AEAX+
MAX5965AUAX+*
MAX5965BEAX+
MAX5965BUAX+*
TEMP RANGE
-40°C to +85°C
0°C to +85°C
-40°C to +85°C
0°C to +85°C
PIN-PACKAGE
36 SSOP
36 SSOP
36 SSOP
36 SSOP
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*Future
product—contact factory for availability.
Selector Guide
PART
MAX5965AEAX+
MAX5965AUAX+
MAX5965BEAX+
MAX5965BUAX+
PIN-PACKAGE
36 SSOP
36 SSOP
36 SSOP
36 SSOP
AC DISCONNECT
FEATURE
No
No
Yes
Yes
Applications
Power-Sourcing Equipment (PSE)
Switches/Routers
Midspan Power Injectors
Pin Configuration appears at end of data sheet.
IEEE is a registered service mark of the Institute of Electrical and Electronics Engineers, Inc.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
High-Power, Quad, Monolithic, PSE Controllers
for Power over Ethernet
MAX5965A/MAX5965B
ABSOLUTE MAXIMUM RATINGS
(Voltages referenced to V
EE
, unless otherwise noted.)
AGND, DGND, DET_, V
DD
,
RESET,
A3–A0,
SHD_,
OSC,
SCL, SDAIN, AUTO .............................................-0.3V to +80V
OUT_........................................................-12V to (AGND + 0.3V)
GATE_ (internally clamped) (Note 1) ..................-0.3V to +11.4V
SENSE_ ..................................................................-0.3V to +24V
V
DD
,
RESET,
MIDSPAN, A3–A0,
SHD_,
OSC, SCL,
SDAIN and AUTO to DGND ..................................-0.3V to +7V
INT
and SDAOUT to DGND....................................-0.3V to +12V
Maximum Current into
INT,
SDAOUT, DET_ .......................80mA
Maximum Power Dissipation (T
A
= +70°C)
36-Pin SSOP (derate 17.4mW/°C above +70°C) .....1388.9mW
Operating Temperature Ranges:
MAX5965A/MAX5965B_EAX ...…………………-40°C to +85°C
MAX5965A/MAX5965B_UAX ...............................0°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Note 1:
GATE_ is internally clamped to 11.4V above V
EE
. Driving GATE_ higher than 11.4V above V
EE
may damage the device.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
AGND
= 32V to 60V, V
EE
= 0V, V
DD
to V
DGND
= +3.3V, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
= +48V, V
DGND
= +48V, V
DD
= (V
DGND
+ 3.3V), T
A
= +25°C. Currents are positive when entering the pin and negative other-
wise.) (Note 2)
PARAMETER
POWER SUPPLIES
V
AGND
Operating Voltage Range
V
DGND
V
DD
V
DD
to V
DGND
, V
DGND
= V
AGND
V
DD
to V
DGND
, V
DGND
= V
EE
V
OUT_
= V
EE
, V
SENSE
_ = V
EE
, DET
_
= AGND,
all logic inputs open, SCL = SDAIN = V
DD
.
INT
and SDAOUT unconnected. Measured at
AGND in power mode after GATE_ pullup
All logic inputs high, measured at V
DD
Power mode, gate drive on, V
GATE_
= V
EE
(Note 3)
SHD_
= DGND, V
GATE_
= V
EE
+ 10V
V
SENSE_
= 600mV, V
GATE_
= V
EE
+ 2V
V
GATE_
- V
EE
, power mode, gate drive on,
I
PU
= 1µA
9
V
AGND
- V
EE
32
0
2.4
3.0
60
60
3.6
3.6
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Currents
I
EE
4.8
6.8
mA
I
DIG
GATE DRIVER AND CLAMPING
GATE_ Pullup Current
Weak GATE_ Pulldown Current
Maximum Pulldown Current
External Gate Drive
I
PU
I
PDW
I
PDS
V
GS
0.2
0.4
-40
-50
42
100
10
-65
µA
µA
mA
11.5
V
2
_______________________________________________________________________________________
High-Power, Quad, Monolithic, PSE Controllers
for Power over Ethernet
ELECTRICAL CHARACTERISTICS (continued)
(V
AGND
= 32V to 60V, V
EE
= 0V, V
DD
to V
DGND
= +3.3V, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
= +48V, V
DGND
= +48V, V
DD
= (V
DGND
+ 3.3V), T
A
= +25°C. Currents are positive when entering the pin and negative other-
wise.) (Note 2)
PARAMETER
CURRENT LIMIT
IVEE = 00
Maximum V
SENSE_
allowed
during current limit, V
OUT_
= 0V
(ICUT = 000) (Note 4)
IVEE = 01
IVEE = 10
IVEE = 11
ICUT = 000
(Class 0/3)
ICUT = 110
(Class 1)
Overcurrent Threshold After
Startup
Overcurrent V
SENSE_
threshold
allowed for t
≤
t
FAULT
after
startup; V
OUT_
= 0V (IVEE = 00)
ICUT = 111
(Class 2)
ICUT = 001
ICUT = 010
ICUT = 011
ICUT = 100
ICUT = 101
ICUT = 000,
ICUT = 110,
ICUT = 111
ICUT =
001…101
202
192
186
170
177
47
86
265
310
355
398
443
212
202
190
180
186
55
94
280
327
374
419
466
32
V
13
220
212
mV
200
190
196
64
101
mV
295
345
395
440
488
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5965A/MAX5965B
Current-Limit Clamp Voltage
V
SU_LIM
V
FLT_LIM
Foldback Initial OUT_ Voltage
V
FLBK_ST
V
OUT_
- V
EE
, above which the
current-limit trip voltage starts
folding back, IVEE = 00
Foldback Final OUT_ Voltage
Minimum Foldback
Current-Limit Threshold
SENSE_ Input Bias Current
IVEE = 00, ICUT = 000, V
OUT_
- V
EE
above
V
FLBK_END
which the current-limit trip voltage reaches
V
TH_FB
V
TH_FB
V
OUT_
= AGND = 60V, IVEE = 00, ICUT = 000
V
SENSE_
= V
EE
-5
50
V
64
+5
mV
µA
_______________________________________________________________________________________
3
High-Power, Quad, Monolithic, PSE Controllers
for Power over Ethernet
MAX5965A/MAX5965B
ELECTRICAL CHARACTERISTICS (continued)
(V
AGND
= 32V to 60V, V
EE
= 0V, V
DD
to V
DGND
= +3.3V, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
= +48V, V
DGND
= +48V, V
DD
= (V
DGND
+ 3.3V), T
A
= +25°C. Currents are positive when entering the pin and negative other-
wise.) (Note 2)
PARAMETER
SUPPLY MONITORS
V
EE
Undervoltage Lockout
V
EE
Undervoltage Lockout
Hysteresis
V
EE
Overvoltage Lockout
V
EE
Overvoltage Lockout
Hysteresis
V
EE
Undervoltage
V
DD
Overvoltage
V
DD
Undervoltage
V
DD
Undervoltage Lockout
V
DD
Undervoltage Lockout
Hysteresis
Thermal Shutdown Threshold
V
EEUVLO
V
EEUVLOH
V
EE_OV
V
OVH
V
EE_UV
V
DD_OV
V
DD_UV
V
DDUVLO
V
DDHYS
Ports shut down and device resets if its
junction temperature exceeds this limit,
temperature increasing (Note 5)
Thermal hysteresis, temperature decreasing
(Note 5)
V
OUT_
= V
AGND
, all modes
OUT_ discharge current, detection and
classification off, port shutdown, V
OUT_
=
AGND - 2.8V
V
OUT_
- V
EE
, V
OUT_
decreasing
Minimum time PGOOD has to be high to set
bit in register 10h
200
1.5
2.0
220
3
V
EE_UV
event bit is set if V
AGND
- V
EE
<
V
EE_UV
, V
EE
increasing
V
DD_OV
event bit is set if V
DD
- V
DGND
>
V
DD_OV
; V
DD
increasing
V
DD_UV
is set if V
DD
- V
DGND
< V
DD_UV
,
V
DD
decreasing
Device operates when V
DD
- V
DGND
>
V
DDUVLO
, V
DD
increasing
V
AGND
- V
EE
, V
AGND
- V
EE
increasing
Ports shut down if V
AGND
- V
EE
< V
UVLO
-
V
EEUVLOH
V
EE_OV
event bit sets and ports shut down if
V
AGND
- V
EE
> V
EE_OV
, V
AGND
increasing
28.5
3
62.5
1
40
3.82
2.7
2
120
V
V
V
V
V
V
V
V
mV
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
T
SHD
+150
°C
Thermal Shutdown Hysteresis
OUTPUT MONITOR
OUT_ Input Current
Idle Pullup Current at OUT_
PGOOD High Threshold
PGOOD Hysteresis
PGOOD Low-to-High Glitch
Filter
T
SHDH
20
°C
I
BOUT
I
DIS
PG
TH
PG
HYS
t
PGOOD
2
265
2.5
µA
µA
V
mV
ms
4
_______________________________________________________________________________________
High-Power, Quad, Monolithic, PSE Controllers
for Power over Ethernet
ELECTRICAL CHARACTERISTICS (continued)
(V
AGND
= 32V to 60V, V
EE
= 0V, V
DD
to V
DGND
= +3.3V, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
= +48V, V
DGND
= +48V, V
DD
= (V
DGND
+ 3.3V), T
A
= +25°C. Currents are positive when entering the pin and negative other-
wise.) (Note 2)
PARAMETER
LOAD DISCONNECT
DC Load Disconnect
Threshold
AC Load Disconnect
Threshold
Oscillator Buffer Gain
OSC Fail Threshold
OSC Input Impedance
Load Disconnect Timer
DETECTION
Detection Probe Voltage
(First Phase)
Detection Probe Voltage
(Second Phase)
Current-Limit Protection
V
DPH1
V
DPH2
I
DLIM
V
AGND
- V
DET_
during the first detection
phase
V
AGND
- V
DET_
during the second detection
phase
V
DET_
= V
AGND
, during detection, measure
current through DET_
If V
AGND
- V
OUT_
< V
DCP
after the first
detection phase a short circuit to AGND is
detected
First point measurement current threshold for
open condition
(Note 9)
Detection rejects lower values
Detection rejects higher values
32
19.0
3.8
9.0
1.5
4
9.3
1.8
4.2
9.6
2.2
V
V
mA
V
DCTH
Minimum V
SENSE_
allowed before disconnect
(DC disconnect active), V
OUT_
= 0V
Current into DET_, for I < I
ACTH
the port
powers off, ACD_EN_ bit = H; V
OSC
= 2.2V,
MAX5965B (Note 6)
V
DET_
/V
OSC
, ACD_EN_ bit = H, MAX5965B
Port does not power on if V
OSC
< V
OSC_FAIL
and ACD_EN_ bit is high, MAX5965B (Note 7)
OSC input impedance when all the ACD_EN_
are active, MAX5965B
Time from V
SENSE_
< V
DCTH
to gate shutdown
(Note 8)
2.5
3.75
5.0
mV
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5965A/MAX5965B
I
ACTH
A
OSC
V
OSC_FAIL
Z
OSC
t
DISC
285
2.9
1.8
100
300
320
3.0
360
3.1
2.2
µA
V/V
V
kΩ
400
ms
Short-Circuit Threshold
V
DCP
1
V
Open-Circuit Threshold
Resistor Detection Window
Resistor Rejection Window
I
D_OPEN
R
DOK
R
DBAD
12.5
26.5
15.2
µA
kΩ
kΩ
_______________________________________________________________________________________
5
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