SI3402ISO-EVB Silicon Laboratories Inc, SI3402ISO-EVB Datasheet - Page 13

• Manufacturer Part Number: SI3402ISO-EVB
• Description: BOARD EVAL POE ISOL FOR SI3402
• Manufacturer: Silicon Laboratories Inc
• Type: PWM Controllersr

Specifications of SI3402ISO-EVB

• Main Purpose: Special Purpose DC/DC, Power Over Ethernet
• Outputs And Type: 1, Isolated
• Voltage - Output: 5V
• Voltage - Input: 44 ~ 57V
• Regulator Topology: Flyback
• Frequency - Switching: 350kHz
• Board Type: Fully Populated
• Utilized Ic / Part: Si3402
• Input Voltage: 5 V
• Output Voltage: 3.3 V
• Interface Type: Ethernet
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Product: Power Management Modules
• For Use With/related Products: Si3402
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1828

e. If you are using the “Non-isolated” worksheet:
f.
If you are using either of the “Isolated” worksheets, enter in the input values to determine if your design
will be operating in the “continuous” mode or the “discontinuous mode”:
i. If using appropriate, select on-chip “diode bypass” option in cell B9 in the Excel spreadsheet utility.
ii. Enter V
iii. Enter your design’s desired output current, I
iv. Enter your design’s desired output voltage, V
v. Enter your design’s maximum ambient operating temperature in °C into cell B13.
i. The feedback resistor network values (R5 and R6) for your design are calculated and displayed in
ii. To use the default diode and inductor components used in the Si3402-EVB non-isolated
iii. To ensure your design is operating within the acceptable operating ranges for all the external
iv. Carefully review the calculated values in the Summary section (cells B29 through B33).
i. Check the value of the current calculated in cell H11.
ii. The feedback resistor network values (R5 and R6) for your design are calculated and displayed in
iii. Select transformer turns ratio: use 3.3, 2.5 or 1 as standard choices for 3.3, 5, and 12 V output,
iv. To use the default transformer, snubber and diode components used in the Si3402 ISO-EVB
v. To ensure your design is operating within the acceptable operating ranges for all the external
By entering a “1” in this cell, the Si3402’s on chip diodes are assumed to be bypassed with
external diode bridges in your schematic. A “0” in this cell means the Si3402’s on-chip diode
bridges will be used.
3 V less than the PSE input voltage, or typically 46 V.
cells G13 and G12, respectively. Use these resistor values to update your schematic.
schematic, Silicon Labs strongly recommends leaving each default values “as-is” in cells B15
through B18.
components you use in your schematic, carefully review the calculated values found in cells B20
through B27.
cells E12 and E13, respectively. Use these resistor values to update your schematic.
respectively. Leave the rest of the options as defaults. If you have different output voltage, then
contact Silicon Labs for recommendations.
isolated schematic, Silicon Labs strongly recommends leaving each default values “as-is” in cells
B15 through B23. Always select the EP13 core if you require short circuit protection.
components you use in your schematic, carefully review the calculated values found in cells B25
through B35.
1. Cell B29: PSE input voltage. Make sure the PSE input voltage is compatible with the PSE
2. Cell B30: PSE input power. If the power is >12.95 W (more than the IEEE 802.3af limits),
3. Cell B33: If the calculated junction temperature is >140 °C, then this cell is shaded in light
1. If your desired output current (B11) is less than the value shown in cell H11, then use the
2. If your desired output current (B11) is greater than the value shown in cell H11, then use
intended to power your PD.
then this cell is shaded in light RED and your PSE must be capable of sourcing the power
level shown in cell B30.
red. Consider bypassing the on-chip diodes to lower the effective junction temperature, or
reducing the output current (if possible). Other inputs in cells B9 through B13 may also need
to be adjusted to lower the calculated junction temperature.
“Isolated Discontinuous” worksheet.
the “Isolated Continuous” worksheet.
IN
into cell B10. This voltage is the input voltage at the diode bridge output, which is 2 to
Rev. 1.1
O
O
in Amperes, into cell B11.
in Volts, in cell B12.
Si3402 ISO-EVB
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