NCP1091DBG ON Semiconductor, NCP1091DBG Datasheet - Page 9

• Manufacturer Part Number: NCP1091DBG
• Description: IC INTERFACE CTLR POE-PD 8-TSSOP
• Manufacturer: ON Semiconductor
• Series: HIPO™r

Specifications of NCP1091DBG

• Controller Type: PoE-PD Interface
• Interface: IEEE 802.3af
• Current - Supply: 500mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP
• Output Voltage: 9.8 V
• Output Current: 500 mA
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Number Of Outputs: 8
• Input Voltage: 57V
• Supply Current: 500mA
• Digital Ic Case Style: TSSOP
• No. Of Pins: 8
• Svhc: No SVHC (20-Jun-2011)
• Base Number: 1091
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: NCP1091DBGOS

Auxiliary Supply
networks and minimize the bill of materials, the NCP1093
supports drawing power from an external supply and allows
simplified designs with PoE or auxiliary supply priorities.
pass switch when pulled high. This feature is useful for PD
applications where the auxiliary supply has to be dominant
over the PoE supply. When the auxiliary supply is inserted
on a POE powered application, the pass switch
disconnection will move the current path from the PSE to the
rear auxiliary supply. Since the current delivered by the PSE
will goes below the DC MPS level (specified in IEEE
802.3 af/at standard), the PSE will disconnect the PoE−PD
Spare
Pairs
Pairs
Data
To support application connected to non−PoE enabled
The NCP1092 offers an AUX input pin which turns off the
RJ−45
Rclass
Rdet
Rinrush
DB1
DB2
VPORTP
DET
CLASS
INRUSH
VPORTN
Figure 9. Auxiliary Supply Dominant PD Interface
Figure 8. Power GOOD Implementation
NCP1090
VAUX (+)
VAUX (−)
PGOOD
http://onsemi.com
RTN
Rdet
Rinrush
Rclass
9
between VPORTP and RTN with a serial diode between
VPORTP and VAUX, as shown in Figure 9.
and the application will remain supplied by the auxiliary
supply. The transition will happens without any power
conversion interruption since the PGOOD indicator stays
active (high impedance state).
POE supply is dominant over the VAUX supply. A diode D1
has been added in order to not corrupt the PD detection
signature when the dc−dc converter is supplied by VAUX.
Cpd
In most of the cases, the auxiliary supply is connected
Next Figure 10 depicts an other PD application where the
VPORTP
DET
CLASS
INRUSH
AUX
VPORTN
NCP1092
UVLO
OVLO
DC−DC Converter
Controller
NCP103x
VDD
PGOOD
VSS
RTN
GATE
To DC−DC
Converter