5

dc2475aafb

DEMO MANUAL

DC2475A-A

QuicK start proceDure

Power over Ethernet (PoE) Input

1. Disconnect auxiliary supply if it is connected to AUX+

and AUX– inputs of the DC2475A-A.

2. Place and connect test equipment (voltmeter, ammeter,

oscilloscope, and electronic load) as shown in Figure 8.

3. Turn down the electronic load to a minimum value and

turn off the electronic load.

4. Connect the output of the IEEE 802.3bt compliant PSE

to the RJ45 connector (J1) of the DC2475A using a

CAT5e or CAT6 Ethernet cable. (See note.)

5. After the LED (D4) on the DC2475A is lit, check the

output voltage using a voltmeter. Output voltage should

be within 12.0V ± 0.2V.

Figure 8. Setup Diagram for PoE Input

6. Turn on the electronic load and increase its load cur-

rent up to 3A. Observe the output voltage regulation,

efficiency, and other parameters.

7. Verify T2P response with an oscilloscope as shown in

Figure8.TheT2PresponsetothetypeofPSEconnected

to the DC2475A-A is provided in Table 1.

Note: An 802.3bt PSE has not yet been released. In

may be used to provide power to the DC2475A-A. The

LTPoE++classificationwillnotbe802.3btcompliant,but

the PSE will provide a compatible detection and power

output. Specifically, the T2P output of the DC2475A-A

is different from the behavior stated in Table 1 and will

indicate connection to a Type 2 PSE. Otherwise PD

behavior will be unaffected.

Table 1. T2P Response vs PSE Type

PSE

T2P RESPONSE

NEGOTIATED PD INPUT POWER

IEEE

Logic High

13W

Logic Low

25.5W

50% Logic High/50% Logic Low, Toggle at 976Hz ±7%

40W

LTPoE++, 52.7W

Logic Low

40W

IEEE 802.3bt

PSE

+

–

DC POWER

SUPPLY

+

–

AMMETER

+

–

VOLTMETER

+

–

ELECTRONIC

LOAD

+

–

OSCILLOSCOPE

+

–

CAT5e

OR CAT6

CABLE

J1