NCP1096GEVB NCP1096 Evaluation Board User s Manual IEEE 802.3bt PoE-PD Interface Controller Board www.onsemi.com EVAL BOARD USERS MANUAL General Quick Start Guide The NCP1096GEVB board allows easy implementation Step 1: Connect the power connections available on and evaluation of a Power-over-Ethernet powered connector J2 (labeled GND and VPP) to the DC/DC equipment that is able to operate with an assigned power converter on the system that needs to be powered (cf. black level up to 90 W. The evaluation board is based on the PoE and red wires in the picture on the left). The DC/DC PD Controller NCP1096 (U2) that uses an internal converter behind the NCP1096 EVB should be operational pass-switch and sense resistor. The board can also facilitate over a 34 V to 57 V voltage range. the design of proprietary 100 W+ applications. Step 2: Connect the control connection to the DC/DC converter It is important that the DC/DC converter or any significant load is kept off when the pass-switch is charging the input capacitance. For a DCDC converter with an undervoltage (UV or UVLO) or an active high enable (EN or SHND), the PG signal on connector J2 could be used (cf. green wire in the picture on the left). The PG signal will be clamped to 18 V by a zener when the board is powered up. For some DCDC converter boards an additional diode in series with the control connection might be required (cathode connected to NCP1096 and anode connected to the DCDC converter). For a DCDC converter with an active low enable (EN or SHDN or ON/OFF), the nPG signal on P1 could be used. The nPG signal will be pulled up to VPP during the inrush phase. Always check the voltage rating of the enable, Figure 1. Operational NCP1096GEVB Showing shutdown or undervoltage pin of the DCDC converter. Basic Interconnections Step 3: Insert the Ethernet cable (cf. blue cable in the picture on the left) coming from the PSE in the Ethernet connector The NCP1096GEVB board is designed as a PoE splitter: J3 labeled PoE IN. having a PoE-enabled Ethernet port (labeled PoE IN) as If the PSE powers up the system the green PGOOD LED input and offering the power to a separate connector (J2) should be ON. while passing through the data to another Ethernet port The status of the remaining LEDs depends on the PSE (labeled E OUT). being used. Semiconductor Components Industries, LLC, 2019 1 Publication Order Number: July, 2019 Rev. 1 EVBUM2645/DNCP1096GEVB Assigned Power System Startup The NCP1096GEVB will request Class 8 during Physical A PD can be underpowered and assigned to Class 3 only. Layer classification. PDs need to take into account that they Therefore the DC/DC converter behind NCP1096GEVB can be underpowered and eventually be assigned to Class 3, should not draw more than 13 W during start-up. Eventually 4 or 6. the soft-start setting of the DC/DC converter might need to The state of the NCM and NCL outputs provides be adapted to accomplish this. information about the power level that the PSE has assigned Requested Power to the NCP1096GEVB during classification. See Table 1 to As mentioned before, the NCP1096GEVB will request determine the assigned power based on the status of the Class 8 during Physical Layer classification. If a lower Class orange NCM and NCL leds. or power level is preferred, resistor R8 labeled CLB and/or resistor R7 labeled CLA should be changed. See Table 1. CLASSIFICATION RESULT the NCP1096 datasheet for the nominal resistance values. NCM NCL Assigned Assigned The Class the PD is actually assigned to is always limited Led Led Class Power to the requested Class. off off 3 13 W Autoclass off on 4 25.5 W The NCP1096GEVB will by default not request on off 6 51 W Autoclass during Physical Layer classification. If the PD should request Autoclass, remove 0E resistor R9 labeled on on 8 71.390 W acs. Maintain Power Signature (MPS) PDs assigned to Class 8 may consume greater than 71.3 W A PD should draw a minimum amount of current in order as long as they guarantee not to exceed the 90 W power limit to prevent the PSE from removing power. The load resistor at the PSE power interface. Operation beyond 71.3 W is, R15 was added on the bottom side of the board to make sure however, only possible if additional information is available the load current is always sufficient and the NCP1096GEVB to the PD regarding the actual link section DC resistance remains powered. between the PSE and the PD. Depending on the minimum current the system may draw, The application should always operate at or below the the resistance value of R15 should be increased for the final assigned power limit. Failure to do so will result in the PSE design in order not to waste power unnecessarily. disconnecting the PD For some systems, the load resistor can even be omitted. PSE Categorization The state of the LCF output provides information (retrieved during classification) about the type of PSE the NCP1096GEVB is connected to. See Table 2 to determine the PSE Type based on the status of the red LCF led. Table 2. PSE TYPE LCF Led PSE Categorization off The PSE is categorized according to 802.3af/at (PSE Type 1 or Type 2) on The PSE is categorized according to 802.3bt (PSE Type 3 or Type 4) The PSE Type determines the MPS timing. It also indicates to a PD requesting Autoclass whether it makes sense to go to the maximum power state according to its assigned Class. www.onsemi.com 2