Rainbow Electronics MAX5969B User Manual

19-5008; Rev 0; 12/09

EVALUATION KIT

AVAILABLE

IEEE 802.3af/at-Compliant, Powered Device Interface

Controllers with Integrated Power MOSFET

General Description

The MAX5969A/MAX5969B provide a complete interface
for a powered device (PD) to comply with the IEEE®

802.3af/at standard in a power-over-Ethernet (PoE) sys­tem. The MAX5969A/MAX5969B provide the PD with a
detection signature, classification signature, and an inte­grated isolation power switch with inrush current control.
During the inrush period, the MAX5969A/MAX5969B limit
the current to less than 180mA before switching to the
higher current limit (720mA to 880mA) when the isolation
power MOSFET is fully enhanced. The devices feature
an input UVLO with wide hysteresis and long deglitch
time to compensate for twisted-pair cable resistive drop
and to assure glitch-free transition during power-on/-off
conditions. The MAX5969A/MAX5969B can withstand up
to 100V at the input.

The MAX5969A/MAX5969B support a 2-event classifica­tion method as specified in the IEEE 802.3at standard
and provide a signal to indicate when probed by Type 2
power-sourcing equipment (PSE). The devices detect
the presence of a wall adapter power-source connec­tion and allow a smooth switchover from the PoE power
source to the wall power adapter.

The MAX5969A/MAX5969B also provide a power-good
(PG) signal, two-step current limit and foldback, over­temperature protection, and di/dt limit.

The MAX5969A/MAX5969B are available in a space-sav­ing, 10-pin, 3mm x 3mm, TDFN power package. These
devices are rated over the -40NC to +85NC extended
temperature range.

Features

S IEEE 802.3af/at Compliant
S 2-Event Classification
S Simplified Wall Adapter Interface
S PoE Classification 0 to 5
S 100V Input Absolute Maximum Rating
S Inrush Current Limit of 180mA Maximum
S Current Limit During Normal Operation Between

720mA and 880mA

S Current Limit and Foldback
S Legacy UVLO at 36V (MAX5969A)
S IEEE 802.3af/at-Compliant, 40V UVLO (MAX5969B)
S Overtemperature Protection
S Thermally Enhanced, 3mm x 3mm, 10-Pin TDFN

Ordering Information

PART TEMP RANGE

MAX5969AETB+

MAX5969BETB+

+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.

-40NC to +85NC

-40NC to +85NC

PIN-

PACKAGE

10 TDFN-EP* 35.4

10 TDFN-EP* 38.6

UVLO

THRESHOLD

(V)

Pin Configuration

MAX5969A/MAX5969B

Applications

TOP VIEW

IEEE 802.3af/at Powered Devices

IP Phones, Wireless Access Nodes, IP Security
Cameras

WiMAXK Base Station

IEEE is a registered service mark of the Institute of Electrical
and Electronics Engineers, Inc.

WiMAX is a trademark of WiMAX Forum.

_______________________________________________________________ Maxim Integrated Products 1

_______________________________________________________________ Maxim Integrated Products 1

V

DD

N.C.

I.C.

SS

*EP = EXPOSED PAD. CONNECT TO V

+

1

2 9

3

4

5 6

MAX5969A
MAX5969B

EP*

TDFN

(3mm × 3mm)

SS

.

CLS

10

2ECDET

PG

8

WAD

7

RTNV

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.

IEEE 802.3af/at-Compliant, Powered Device Interface
Controllers with Integrated Power MOSFET

ABSOLUTE MAXIMUM RATINGS

VDD to VSS ..........................................................-0.3V to +100V

DET, RTN, WAD, PG, 2EC to V

CLS to VSS ..............................................................-0.3V to +6V

Maximum Current on CLS (100ms maximum) .................100mA

Continuous Power Dissipation (TA = +70NC) (Note 1)
10-Pin TDFN (derate 24.4mW/NC above +70NC)

Multilayer Board ........................................................1951mW

Note 1: Maximum power dissipation is obtained using JEDEC JESD51-5 and JESD51-7 specifications.
Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-

layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.

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.

SS .......................

-0.3V to +100V

ELECTRICAL CHARACTERISTICS

(VIN = (VDD - VSS) = 48V, R
unless otherwise noted. TA = TJ = -40NC to +85NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3)

= 24.9kω, R

DET

= 615ω. RTN, WAD, PG, and 2EC unconnected, all voltages are referenced to V

CLS

Package Thermal Resistance (Note 2)

BJA .................................................................................4NC/W

BJC ................................................................................9NC/W

Operating Temperature Range .......................... -40NC to +85NC

Maximum Junction Temperature .....................................+150NC

Storage Temperature Range ............................ -65NC to +150NC

Soldering Temperature (reflow) .................................... +260NC

SS,

MAX5969A/MAX5969B

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DETECTION MODE

Input Offset Current I

Effective Differential Input
Resistance

CLASSIFICATION MODE

Classification Disable
Threshold

Classification Stability Time 0.2 ms

Classification Current I

TYPE 2 (802.3at) CLASSIFICATION MODE

Mark Event Threshold V

Hysteresis on Mark Event
Threshold

Mark Event Current I

Reset Event Threshold V

POWER MODE

VIN Supply Voltage Range 60 V
VIN Supply Current I

OFFSET

dR

V

TH,CLS

CLASS

THM

MARK

THR

Q

VIN = 1.4V to 10.1V (Note 4) 10

VIN = 1.4V up to 10.1V with 1V step,
V

= RTN = WAD = PG = 2EC (Note 5)

DD

V

rising (Note 6) 22.0 22.8 23.6 V

IN

Class 0, R

=

Class 1, R
Class 2, R
Class 3, R
Class 4, R
Class 5, R

DD

VIN = 12.5V to

20.5V, V
RTN = WAD =
PG = 2EC

VIN falling 10.1 10.7 11.6 V

VIN falling to enter mark event, 5.2V P V

P 10.1V

VIN falling 2.8 4 5.2 V

Measured at V

DD

CLS

CLS

CLS

CLS

CLS

CLS

= 619I
= 117I
= 66.5I
= 43.7I
= 30.9I
= 21.3I

23.95 25.00 25.5

0 3.96

9.12 11.88

17.2 19.8

26.3 29.7

36.4 43.6

52.7 63.3

0.84 V

IN

0.25 0.85 mA

0.27 0.55 mA

FA

kI

mA

2 ______________________________________________________________________________________

IEEE 802.3af/at-Compliant, Powered Device Interface

Controllers with Integrated Power MOSFET

ELECTRICAL CHARACTERISTICS (continued)

(VIN = (VDD - VSS) = 48V, R
unless otherwise noted. TA = TJ = -40NC to +85NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

VIN Turn-On Voltage V

VIN Turn-Off Voltage V

VIN Turn-On/-Off Hysteresis
(Note 7)

VIN Deglitch Time t

Inrush to Operating Mode
Delay

Isolation Power MOSFET
On-Resistance

RTN Leakage Current I

CURRENT LIMIT

Inrush Current Limit I

Current Limit During Normal
Operation

Foldback Threshold V

LOGIC

WAD Detection Threshold V

WAD Detection Threshold
Hysteresis

WAD Input Current I

2EC Sink Current

2EC Off-Leakage Current

PG Sink Current

PG Off-Leakage Current VPG = 48V 1

THERMAL SHUTDOWN

Thermal-Shutdown Threshold T
Thermal-Shutdown Hysteresis TJ falling 28

= 24.9kω, R

DET

V

CLS

ON

OFF

HYST_UVLO

OFF_DLY

t

DELAY

R

ON_ISO

RTN_LKG

INRUSH

I

LIM

WAD-REF

WAD-LKG

SD

= 615ω. RTN, WAD, PG, and 2EC unconnected, all voltages are referenced to V

VIN rising

VIN falling 30 V
MAX5969A 4.2
MAX5969B 7.3
VIN falling from 40V to 20V (Note 8) 30 120

t

= minimum PG current pulse width

DELAY

after entering into power mode

I

= 600mA

RTN

V

= 12.5V to 30V 10

RTN

During initial turn-on period,
V

= 1.5V

RTN

After inrush completed,
V

= 1V

RTN

(Note 9) 13 16.5 V

RTN

V

rising, VIN = 14V to 48V (referenced

WAD

to RTN)

V

falling, V

WAD

unconnected

V

= 10V (referenced to RTN) 3.5

WAD

V

= 3.5V (referenced to RTN), VSS

2EC

unconnected

V

= 48V

2EC

V

= 1.5V, V

RTN

period

TJ rising +140

MAX5969A 34.3 35.4 36.6

MAX5969B 37.2 38.6 40

80 96 112 ms

TJ = +25NC

TJ = +125NC

90 135 180 mA

720 800 880 mA

8 9 10

= 0V, VSS

RTN

1 1.5 2.25 mA

= 0.8V, during inrush

PG

125 230 375

0.5 0.7

0.65 1

0.8

0.725

V

V

Fs

ITJ = +85NC

FA

V

FA

1

FA

FA

FA

NC
NC

MAX5969A/MAX5969B

SS,

_______________________________________________________________________________________ 3

IEEE 802.3af/at-Compliant, Powered Device Interface
Controllers with Integrated Power MOSFET

ELECTRICAL CHARACTERISTICS (continued)

(VIN = (VDD - VSS) = 48V, R
unless otherwise noted. TA = TJ = -40NC to +85NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3)

Note 3: All devices are 100% production tested at TA = +25NC. Limits over temperature are guaranteed by design.
Note 4: The input offset current is illustrated in Figure 1.
Note 5: Effective differential input resistance is defined as the differential resistance between VDD and VSS. See Figure 1.
Note 6: Classification current is turned off whenever the device is in power mode.
Note 7: UVLO hysteresis is guaranteed by design, not production tested.
Note 8: A 20V glitch on input voltage that takes VDD below VON shorter than or equal to t

MAX5969B to exit power-on mode.

Note 9: In power mode, current-limit foldback is used to reduce the power dissipation in the isolation MOSFET during an overload

condition across VDD and RTN.

I

IN

(V

INi + 1

dRi x

(I

INi + 1

I

x I

OFFSET

MAX5969A/MAX5969B

I

INi + 1

I

INi

INi

V

INi

­dR

= 24.9kω, R

DET

- V

)

INi

= 1V

- I

)

(I

INi

i

INi + 1

= 615ω. RTN, WAD, PG, and 2EC unconnected, all voltages are referenced to V

CLS

OFF_DLY

- I

)

INi

dR

i

does not cause the MAX5969A/

SS,

I

OFFSET

1VV

INi

V

INi + 1

V

IN

Figure 1. Effective Differential Input Resistance/Offset Current

4 ______________________________________________________________________________________

IEEE 802.3af/at-Compliant, Powered Device Interface

Controllers with Integrated Power MOSFET

Typical Operating Characteristics

(VIN = (VDD - VSS) = 54V, R

= 24.9kω, R

DET

= 615ω. RTN, WAD, PG, and 2EC unconnected; all voltages are referenced to V

CLS

SS.

MAX5969A/MAX5969B

)

DETECTION CURRENT

vs. INPUT VOLTAGE

0.5
IIN = I

+ I

VDD

DET

= 24.9kI

DET

DD

VIN (V)

R
RTN = 2EC = PG = WAD = V

0.4

-40°C P TA P +85NC

0.3

(mA)

IN

I

0.2

0.1

0

0 10

CLASSIFICATION CURRENT vs.

INPUT VOLTAGE

70

V

CLASS 5

CLASS 4

CLASS 3

CLASS 2

CLASS 1

CLASS 0

(V)

60

50

40

(mA)

IN

I

30

20

10

0

0 30

SIGNATURE RESISTANCE

vs. INPUT VOLTAGE

26.0
IIN = I

+ I

VDD

R

MAX5969A toc01

8642

MAX5969A toc04

252015105

RTN = 2EC = PG = WAD = V

25.5

(kI)

25.0

SIGNATURE

TA = +25NC

R

24.5

24.0

0 10

DET

= 24.9kI

DET

CLASSIFICATION SETTLING TIME

TA = -40NC

TA = +85NC

VIN (V)

100µs/div

DD

8642

MAX5969A toc05

= 30.9I

R

CLS

MAX5969A toc02

V

IN

10V/div

I

IN

0A

200mA/div

V

CLS

1V/div

0V

4

2

0

-2

INPUT OFFSET CURRENT (µA)

-4

2.0

1.6

1.2

(mA)

2EC

I

0.8

0.4

0

INPUT OFFSET CURRENT

vs. INPUT VOLTAGE

TA = -40NC

TA = +25NC

0 10

TA = +85NC

8642

VIN (V)

2EC SINK CURRENT vs. 2EC VOLTAGE

TA = -40NC

VSS UNCONNECTED
V
V

0 60

TA = +25NC

TA = +85NC

REFERENCED TO RTN

2EC

= 14V

WAD

V

(V)

2EC

5040302010

MAX5969A toc03

MAX5969A toc06

PG SINK CURRENT vs. PG VOLTAGE

300

TA = -40NC

250

200

(µA)

PG

I

150

100

50

0 60

TA = +25NC

VPG (V)

_______________________________________________________________________________________ 5

TA = +85NC

5040302010

150

130

MAX5969A toc07

110

90

INRUSH CURRENT LIMIT (mA)

70

50

0 60

INRUSH CURRENT LIMIT

vs. RTN VOLTAGE

V

(V)

RTN

NORMAL OPERATION CURRENT LIMIT

vs. RTN VOLTAGE

900

800

MAX5969A toc08

5040302010

700

600

500

400

CURRENT LIMIT (mA)

300

200

100

0 60

V

(V)

RTN

MAX5969A toc09

504010 20 30