ncp1082 ON Semiconductor, ncp1082 Datasheet
ncp1082
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ncp1082 Summary of contents
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... ON Semiconductor’s unique manufacturing process and design enhancements allow the NCP1082 to deliver regulated power to support PoE applications according to the IEEE 802.3af standard. This device leverages the significant cost advantages of PoE− ...
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... Tape & Reel (Pb−Free) INTERNAL THERMAL SUPPLY SHUT & DOWN BANDGAP VPORT MONITOR CONVERTER CONTROL HOT SWAP SWITCH CONTROL & CURRENT LIMIT BLOCKS Figure 1. NCP1082 Block Diagram http://onsemi.com 2 PIN DIAGRAM COMP VDDL Exposed VDDH Pad GATE ARTN NC CS ...
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... GATE CS AUX FB TEST ARTN VPORTN1 RTN R2 VPORTN2 SS OSC COMP Rosc Css VPORTP Rclass VDDH CLASS Cline Rinrush R1 INRUSH VDDL Rilim1 ILIM1 NCP1082 UVLO GATE CS AUX TEST FB VPORTN1 ARTN R2 VPORTN2 RTN SS OSC COMP Rosc Css http://onsemi.com 3 Cpd D1 Voutput T1 Cvddh Cload LD1 ...
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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 NCP1082 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 ...
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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 AUXILIARY SUPPLY OPERATION – AUX PIN AUX_threshold AUX pin internal threshold AUX_bias_min Minimum Voltage required on the AUX pin for low auxiliary supply operation AUX_bias_max Maximum Voltage allowed on the AUX pin AUX_res_ladder Resistor ...
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Table 3. Operating Conditions Symbol Parameter VDDH REGULATOR VDDH_reg Regulator output voltage (Notes 10 and 11) VDDH_Off Regulator turn−off voltage VDDH_lim VDDH regulator current limit (Notes 10 and 11) VDDH_Por_R VDDH POR level (rising) VDDH_Por_F VDDH POR level (falling) VDDH_ovlo ...
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Table 3. Operating Conditions Symbol Parameter OSCILLATOR DutyC Maximum duty cycle Frange Oscillator frequency range F_acc Oscillator frequency accuracy CURRENT CONSUMPTION IvportP VPORTP internal current consumption 1 (Note 12) IvportP VPORTP internal current consumption 2 (Note 13) THERMAL SHUTDOWN TSD ...
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... Rdet external resistor. For some types of diodes (especially Schottky diodes), it may be necessary to adjust this external resistor. When the Detection_Off level is detected (typically 11 VPORTP, the NCP1082 turns on its internal 3.3 V regulator and biasing circuitry in anticipation of the classification phase as the next step. Classification Once the PSE device has detected the PD device, the classification process begins ...
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... VPORTN1,2 to VPORTN1,2 (Front AUX Configuration RTN (Rear AUX Configuration) Vdp = 0.5 V the forward voltage drop of the NCP1082 internal diode, and Vt is the desired voltage at the AUX pin. Note that as soon the auxiliary supply is connected the PoE interface (detection and classification) is disabled and does not allow the PD device to be powered from the Ethernet until the auxiliary supply is removed ...
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... VDDH and VDDL regulators • CLASS regulator When the TSD error disappears and if the input line voltage is still above the UVLO level, the NCP1082 automatically restarts with the current limit set in the inrush state, the DC−DC controller is disabled and the Css is 1,2 (soft− ...
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... DC−DC Converter Controller The NCP1082 implements a current mode DC−DC converter controller which is illustrated in Figure 14. VDDL 1 COMP Current Slope Compensation 11 kW Blanking CS time VDDL Soft−start Internal VDDH and VDDL Regulators and Gate Driver An internal linear regulator steps down the VPORTP voltage output on the VDDH pin ...
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... NCP1082 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 NCP1082 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 NCP1082/D ...