POEPHYTEREV-I National Semiconductor, POEPHYTEREV-I Datasheet - Page 37

• Manufacturer Part Number: POEPHYTEREV-I
• Description: BOARD EVAL LM5072, DP83848I
• Manufacturer: National Semiconductor
• Series: PHYTER®r

Specifications of POEPHYTEREV-I

• Main Purpose: Special Purpose DC/DC, Power Over Ethernet
• Outputs And Type: 1, Isolated
• Power - Output: 24W
• Voltage - Output: 3.3V
• Current - Output: 7.3A
• Voltage - Input: 39 ~ 57V
• Regulator Topology: Flyback
• Frequency - Switching: 250kHz
• Board Type: Fully Populated
• Utilized Ic / Part: DP83848, LM5072
• Lead Free Status / RoHS Status: Not applicable / Not applicable

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6.0 Reset Operation
The DP83848I includes an internal power-on reset (POR)
function and does not need to be explicitly reset for normal
operation after power up. If required during normal opera-
tion, the device can be reset by a hardware or software
reset.
6.1 Hardware Reset
A hardware reset is accomplished by applying a low pulse
(TTL level), with a duration of at least 1
RESET_N. This will reset the device such that all registers
will be reinitialized to default values and the hardware con-
s, to the
37
figuration values will be re-latched into the device (similar
to the power-up/reset operation).
6.2 Software Reset
A software reset is accomplished by setting the reset bit
(bit 15) of the Basic Mode Control Register (BMCR). The
period from the point in time when the reset bit is set to the
point in time when software reset has concluded is approx-
imately 1 s.
The software reset will reset the device such that all regis-
ters will be reset to default values and the hardware config-
uration values will be maintained. Software driver code
must wait 3 s following a software reset before allowing
further serial MII operations with the DP83848I.