AN313 SILABS [Silicon Laboratories], AN313 Datasheet - Page 2

• Manufacturer Part Number: AN313
• Description: USING THE Si3400 AND Si3401 IN HIGH POWER APPLICATIONS
• Manufacturer: SILABS [Silicon Laboratories]

AN313
3. Other BOM Considerations
For 802.3af-compliant applications, the basic BOM
recommendations for the Si3400 and Si3401 are
documented in “AN296: Using the Si3400/01 POE PD
Controller in Isolated and Non-Isolated Designs” and the
Si3400 and Si3401 ISO EVB user's guides.
When using the Si3400 or Si3401 at higher power
levels, the following other BOM changes are required:
1. Pulse transformer:
2. Input Ethernet transformer and jack:
2
A Coilcraft FA2671 (10:3–3.3 V), FA2672 (10:4–5 V),
or FA2732 (1:1–12 V) (transformer with an EP10
core and 40 µH magnetizing inductance is currently
recommended. For the higher-power application, an
EP13 core with the same turns ratio and magnetizing
inductance is used.
Several vendors are now offering Ethernet
transformers for PoE+, but these are more
commonly not integrated in the Ethernet RJ-45 jack.
Notes:
PD Controller
1. EP13 is recommended for short circuit protection.
2. Available output power will depend on minimum PSE voltage and maximum UTP cable resistance.
Si3400
Si3401
Table 1. Recommended Options for Higher Power Applications
On-chip diode bridges
EP10 or EP13 transformer
Diode bridge bypass
EP13 transformer
Circuit Configuration
1
Rev. 0.2
Output Power
Efficiency
4. Recommended Options for Higher
Power Applications
Table 1 lists the recommended options for higher-power,
isolated supply applications.
14–15 W
10 W
80%
82%
Compliant
802.3af
Power
No
Yes
2
Si3400ISO-EVB
Si3400-EVB
Si3401ISO-EVB
Si3401-EVB
Evaluation
Systems