PM8800ATR STMicroelectronics, PM8800ATR Datasheet

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... PoE powered device appliances ■ High power (>12.95 W) powered devices Table 1. Device summary Order codes PM8800A PM8800ATR February 2008 HTSSOP16 Description The PM8800A integrates a standard power over Ethernet (PoE) interface and a current mode PWM controller to simplify the design of the power supply sections of all powered devices. ...

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Contents Contents 1 Typical application circuit and block diagram . . . . . . . . . . . . . . . . . . . . 4 1.1 Application circuits . . . . . . . ...

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PM8800A 7 Auxiliary sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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Typical application circuit and block diagram 1 Typical application circuit and block diagram 1.1 Application circuits Figure 1. Simplified application schematic for powered devicesing PM8800A in isolated configuration Figure 2. Simplified application schematic for powered device using PM8800A in non-isolated ...

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PM8800A 1.2 Block diagram Figure 3. Block diagram of the PoE PD interface VIN RCLASS AUXI_IRL DCCL VSS Figure 4. Block diagram of the current mode PWM controller AGND COMP 1.25V FB 3.3V 10µ charge ...

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Pins description and connection diagrams 2 Pins description and connection diagrams Figure 5. Pins connection (top view) AUXI_IRL 2.1 Pin descriptions Table 2. Pin description Pin# Name AUXII 4 VIN 5 RCLASS 6 AUXI_IRL 6/35 ...

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PM8800A Table 2. Pin description (continued) Pin# Name 7 DCCL 8 VSS 9 GND VCC 12 nPGD COMP 15 VFB 16 AGND EP Pins description and connection diagrams DC current limit. A resistor between ...

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Pins description and connection diagrams 2.2 Thermal data Table 3. Thermal data Symbol R Max thermal resistance junction to ambient thJA T Maximum junction temperature MAX T Storage temperature range STG T Junction temperature range J T Operative temperature range ...

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PM8800A 3 Electrical specifications 3.1 Absolute maximum ratings Table 4. Absolute maximum ratings VIN, GND to VSS AUXI_IRL to VSS DCCL, RCLASS to VSS AUXII to AGND COMP AGND VFB, RT AGND VCC AGND ...

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Electrical specifications 3.2 Electrical characteristic Table 5. Electrical characteristics - interface section ( VCC = open °C unless otherwise specified Symbol Parameter Detection and classification Signature enable Signature resistance Signature disable classification ...

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PM8800A Table 5. Electrical characteristics - interface section (continued VCC = open °C unless otherwise specified Symbol Parameter Power good indication Hot-swap V DS Hysteresis Hot-swap V required GS for power ...

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Electrical specifications Table 6. Electrical characteristics - SMPS section ( = 48 V, VCC = open °C unless otherwise specified Symbol Parameter Oscillator Free running f Frequency osc programmability Ext. synch threshold Error amplifier ...

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PM8800A Table 6. Electrical characteristics - SMPS section ( = 48 V, VCC = open °C unless otherwise specified Symbol Parameter Peak sink current Thermal shutdown Shutdown temp. Th. shutdown Hyst. VCC regulation Internal ...

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Device description and operation 4 Device description and operation The PM8800A is a monolithic device embedding an IEEE 802.3af compliant PD interface together with a current mode pulse width modulator to be used in all power over Ethernet powered devices. ...

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PM8800A PM8800A can work with power either from PoE networks or from auxiliary sources - like AC adapters -. Alternative sources are present in PoE appliances where devices can work also outside the context of the PoE networks or to ...

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PD interface 5 PD interface 5.1 Detection In power over Ethernet systems, the PSE senses the connection to detect whether an IEEE 802.3af compatible device is plugged to the cable termination by applying a small voltage (2 ...

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PM8800A 5.2 Classification Classification process in the IEEE 802.3af standard is optional for the powered device. This feature allows PSE to plan and allocate the available power to the appliances connected to the PoE network. IEEE 802.3af specification groups the ...

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PD interface Table 7. value of the external classification resistor for the different PD class of power CLASS 5.3 Under voltage lock-out After the classification is completed, the PSE raises the voltage to provide the ...

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PM8800A inrush current level, which is set by default at 440 mA. Connecting a resistor between VSS and AUXI_IRL it's possible to adjust this limit to a lower value. Figure 9. Relation between the hot-swap drain-source voltage and the default ...

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PD interface In the following picture a typical start sequence that can be observed in real circuits. Figure 11. Typical start up sequence Ch1 = 5 Vout, Ch2 = VSS - GND, Ch3 = Vcc, Ch4 = I input Depending ...

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PM8800A Figure 12. DC current vs R 900 800 700 600 500 400 300 200 100 0 10 This limitation is active after nPGD set and when the PD is supplied through the PoE or in the Front connection (see ...

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PD interface 5.7 Power good indication The PM8800A embeds a power good circuit that is used to indicate that PWM input capacitors are fully charged and that the switching regulator can start operation. The power good circuit monitors the status ...

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PM8800A 6 PWM section 6.1 Error amplifier and loop compensation The PM8800A addresses both isolated and non-isolated configuration by embedding a wide band high gain error amplifier. In non-isolated topology, the voltage to be regulated is connected to the FB ...

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PWM section When a shunt regulator is used for output voltage regulation, the output voltage is set by the ratio of resistors R1 and R2, see following equation: ⎛ ⋅ ⎝ out REF where V ...

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PM8800A The PM8800A can work also with a clock reference provided by an external source whose frequency is higher than the one programmed by the R external resistor is mandatory also when the reference is provided from outside the IC. ...

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PWM section 6.4 PWM comparator / slope compensation In typical isolated operation, current is sensed on a sense resistor Rs put between the source of the primary side MOSFET and GND pin, while for non-isolated topology it is often sensed ...

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PM8800A Figure 17. Short circuit on the output Ch1 = 5Vout, Ch2 = SoftStart, Ch3 = VSS - GND, Ch4 = I input When a severe over current occurs, like a short circuit of an internal power component, and 0.7 ...

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PWM section Figure 18. Internal short circuit Ch1 = 5 Vout, Ch2 = SoftStart, Ch4= I input 6.6 Leading edge blanking The sense current waveform often observes large spikes on the leading edge. This is due to rectifier recovery and/or ...

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PM8800A 7 Auxiliary sources The majority of powered devices is designed to work with power from either PoE network or auxiliary sources. Even though having both sources simultaneously connected is not the normal operating case, the presence of an auxiliary ...

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Auxiliary sources The minimum external voltage to be used in this configuration is about 16 V. Option I connection is activated when the voltage at the relevant pin is higher than 2 V and a higher than 70 µA is ...

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PM8800A If the current forced into AUXII pin is lower than 60 µA, the internal under voltage lock out threshold will be lowered but AUXII connection will be not prevalent to the PoE; in this case power to the DC/DC ...

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Package mechanical data 8 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a lead-free second level interconnect. The category of second Level Interconnect is marked on the package and ...

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PM8800A 8.1 HTSSOP16 mechanical data Figure 21. HTSSOP16 mechanical data and package dimensions mm DIM. min typ 0.80 1.0 b 0.19 c 0.09 D 4.90 5.00 D1 3.00 E 6.20 6.40 E1 4.30 4.40 E2 3.00 e ...

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Revision history 9 Revision history Table 8. Document revision history Date 17-Sep-2007 20-Feb-2008 34/35 Revision 1 Initial release 2 Content reworked in order to improve readability PM8800A Changes ...

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... PM8800A Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...