beautypg.com

Electrical characteristics (continued) – Rainbow Electronics MAX5965B User Manual

Page 5

background image

MAX5965A/MAX5965B

High-Power, Quad, Monolithic, PSE Controllers

for Power over Ethernet

_______________________________________________________________________________________

5

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

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

LOAD DISCONNECT

DC Load Disconnect
Threshold

V

DCTH

Minimum V

SENSE

allowed before disconnect

(DC disconnect active), V

OUT_

= 0V

2.5

3.75

5.0

mV

AC Load Disconnect
Threshold

I

ACTH

Current into DET_, for I < I

ACTH

the port

powers off, ACD_EN_ bit = H; V

OSC_IN

=

2.2V, MAX5965B (Note 6)

285

320

360

µA

Oscillator Buffer Gain

A

OSC

V

DET_

/V

OSC

, ACD_EN_ bit = H, MAX5965B

2.9

3.0

3.1

V/V

OSC Fail Threshold

V

OSC_FAIL

Port does not power on if V

OSC

< V

OSC_FAIL

and ACD_EN_ bit is high, MAX5965B (Note 7)

1.8

2.2

V

OSC Input Impedance

Z

OSC

OSC input impedance when all the ACD_EN_
are active, MAX5965B

100

k

Ω

Load Disconnect Timer

t

DISC

Time from V

SENSE

< V

DCTH

to gate shutdown

(Note 8)

300

400

ms

DETECTION

Detection Probe Voltage
(First Phase)

V

DPH1

AGND - V

DET_

during the first detection

phase

3.8

4

4.2

V

Detection Probe Voltage
(Second Phase)

V

DPH2

AGND - V

DET_

during the second detection

phase

9.0

9.3

9.6

V

Current-Limit Protection

I

DLIM

V

DET_

= AGND, during detection, measure

current through DET_

1.5

1.8

2.2

mA

Short-Circuit Threshold

V

DCP

If AGND - V

OUT

< V

DCP

after the first

detection phase a short circuit to AGND is
detected

1

V

Open-Circuit Threshold

I

D_OPEN

First point measurement current threshold for
open condition

12.5

µA

Resistor Detection Window

R

DOK

(Note 9)

19.0

26.5

k

Ω

Detection rejects lower values

15.2

Resistor Rejection Window

R

DBAD

Detection rejects higher values

32

k

Ω

CLASSIFICATION

Classification Probe Voltage

V

CL

V

AGND

- V

DET_

during classification

16

20

V

Current-Limit Protection

I

CILIM

DET_ = AGND, during classification

68

80

mA

Class 0, Class 1

5.5

6.5

7.5

Class 1, Class 2

13

14.5

16

Class 2, Class 3

21

23

25

Class 3, Class 4

31

33

35

Classification Current
Thresholds

I

CL

Classification current
thresholds between
classes

Class 4, Class 5

45

48

51

mA