ncp1080 ON Semiconductor, ncp1080 Datasheet
ncp1080
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ncp1080 Summary of contents
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... ON Semiconductor’s unique manufacturing process and design enhancements allow the NCP1080 to deliver regulated power to support PoE applications according to the IEEE802.3af standard. This device leverages the significant cost advantages of PoE− ...
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... INTERNAL THERMAL SUPPLY SHUT & DOWN BANDGAP VPORT MONITOR CONVERTER HOT SWAP SWITCH CONTROL & CURRENT LIMIT BLOCKS Figure 1. NCP1080 Block Diagram http://onsemi.com 2 † Temperature Range −40°C to 85°C −40°C to 85°C VDDH VDDH VDDL VDDL VDDL VDDL ...
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... R2 FB TEST1 ARTN VPORTN1 RTN VPORTN2 Rosc Css Figure 2. Isolated Fly−back Converter VPORTP Rclass CLASS Rinrush INRUSH Rilim1 ILIM1 NCP1080 R1 UVLO TEST2 R2 TEST1 VPORTN1 VPORTN2 Css Rosc Figure 3. Non−Isolated Fly−back Converter http://onsemi.com 3 Cpd D1 T1 Cvddh LD1 Cvddl ...
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... Figure 4 shows the same non−isolated fly−back configuration as Figure 3, but adds auxiliary bias winding on the transformer to provide power to the NCP1080 DC−DC controller via its VDDH pin. This topology shuts off the current flowing from VPORTP to VDDH and therefore reduces the internal power dissipation of the PD, resulting in higher overall power efficiency. RJ− ...
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Table 1. Pin Descriptions Name Pin No. Type VPORTP 1 Supply VPORTN1 6,8 Ground VPORTN2 RTN 7 Ground ARTN 14 Ground VDDH 16 Supply VDDL 17 Supply CLASS 2 Input INRUSH 4 Input ILIM1 5 Input UVLO 3 Input GATE ...
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Table 2. Absolute Maximum Ratings Symbol Parameter VPORTP Input power supply RTN Analog ground supply 2 ARTN VDDH Internal regulator output VDDL Internal regulator output CLASS Analog output INRUSH Analog output ILIM1 Analog output UVLO Analog input OSC Analog output ...
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Recommended Operating Conditions Operating conditions define the limits for functional operation and parametric characteristics of the device. Note that the functionality of the device outside the operating conditions described in this section is not warranted. Operating outside the recommended operating ...
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Table 3. Operating Conditions Symbol Parameter PASS−SWITCH AND CURRENT LIMITS Ron Pass−switch Rds−on I_Rinrush1 Rinrush = 150 kW (Note 7) I_Rinrush2 Rinrush = 57.6 kW (Note 7) I_Rilim1 Rilim1 = 84.5 kW (Note 7) INRUSH AND ILIM1 CURRENT LIMIT TRANSITION ...
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Table 3. Operating Conditions Symbol Parameter ERROR AMPLIFIER Vbg_fb Reference voltage Av_ol DC open loop gain GBW Error amplifier GBW SOFT−START Vss Soft−start voltage range Vss_r Soft−start low threshold (rising edge) Iss Soft−start source current CURRENT LIMIT COMPARATOR CSth CS ...
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... IEEE802.3af defined operating modes: detection signature, current source classification, inrush and operating current limits. In order to give more flexibility to the user and also to keep control of the power dissipation in the NCP1080, both current limits are configurable. The device enters operation once its programmable Vuvlo_on threshold is reached, and operation ceases when the supplied voltage falls below the Vuvlo_off threshold ...
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... When using the external resistor divider, the NCP1080 has an external reference voltage hysteresis of 15 percent typical. Inrush and Operational Current Limitations The inrush current limit and the operational current limit are programmed individually by an external Rinrush and Rilim1 resistors respectively connected between INRUSH and VPORTN Figure 9 ...
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... V output on the VDDH pin. VDDH supplies the internal gate driver circuit which drives the GATE pin and the gate of the external power MOSFET. The NCP1080 gate driver supports an external MOSFET with high Vth and high input gate capacitance. A second LDO regulator steps down the VDDH voltage to a 3.3 V output on VDDL. VDDL powers the analog circuitry of the DC− ...
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... NCP1080 integrates a current slope compensation circuit. The amplitude of the added slope compensation is typically 110 mV over one cycle example, for an operating switching frequency of 250 kHz, the internal slope provided by the NCP1080 is 27.5 mV/ mA typically. DC−DC Controller Oscillator The frequency is configured with the Rosc resistor ...
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... DIM MIN MAX M A --- 1.10 A1 0.05 0.15 A2 0.85 0.95 b 0.19 0.30 b1 0.19 0.25 c 0.09 0.20 c1 0.09 0.16 D 6.40 6.60 E 6.40 BSC L2 E1 4.30 4.50 e 0.65 BSC GAUGE L 0.50 0.70 PLANE L2 0.25 BSC --- 4.20 P1 --- 3.00 C SOLDERING FOOTPRINT* 4.30 3.10 20X 0.65 0.35 PITCH DIMENSIONS: MILLIMETERS ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative NCP1080/D ...