Power over ethernet electrostatic discharge protection circuit

Abstract

A Power over Ethernet electrostatic discharge protection circuit has a diode with an anode coupled to an Ethernet port and a cathode coupled to a non-collapsible clamp. The non-collapsible clamp is coupled to the cathode and ground. A transistor can be added, with the transistor drain coupled to the diode anode and the transistor source is coupled to ground.

1 . A Power over Ethernet (PoE) electrostatic discharge (ESD) protection circuit, comprising:
 an Ethernet port;   a diode including:
 a cathode; and 
 an anode coupled to said Ethernet port; and 
   a non-collapsible clamp coupled between said cathode and ground.   
     
     
         2 . The circuit of  claim 1 , further comprising a transistor including:
 a drain coupled to said anode; and   a source coupled to ground.   
     
     
         3 . The circuit of  claim 1 , further comprising a capacitor coupled between said cathode and ground. 
     
     
         4 . The circuit of  claim 1 , wherein at least a part of the ESD protection circuit is deposited on a substrate. 
     
     
         5 . The circuit of  claim 4 , further including a port coupled to said cathode. 
     
     
         6 . The circuit of  claim 1 , further comprising a control circuit coupled to the PoE ESD protection circuit. 
     
     
         7 . The circuit of  claim 1 , wherein the Ethernet port is a port associated with at least one of 10/100 Ethernet, 1 Gigabit Ethernet, and 10 Gigabit Ethernet. 
     
     
         8 . The circuit of  claim 1 , further comprising:
 a second Ethernet port;   a second diode including:
 a second cathode; and 
 a second anode coupled to the second Ethernet port; 
   wherein the non-collapsible clamp is coupled between the second cathode and the ground.   
     
     
         9 . The circuit of  claim 8 , further comprising:
 a second transistor having a second drain and a second source, wherein the second drain is coupled to the second anode, and the second source is coupled to the ground.   
     
     
         10 . The circuit of  claim 8 , wherein at least a part of the ESD protection circuit is deposited on a substrate. 
     
     
         11 . The circuit of  claim 8 , further comprising:
 a control circuit coupled to the non-collapsible clamp.   
     
     
         12 . A Power over Ethernet (PoE) electrostatic discharge (ESD) protection circuit, comprising:
 a plurality of Ethernet ports;   a plurality of diodes, wherein each one of the plurality of diodes is associated with one of the plurality of Ethernet ports, wherein each one of the plurality of diodes comprises a cathode and an anode, and wherein each anode is coupled to its associated Ethernet port;   a bus connected to the cathode of each one of the plurality of diodes; and   a non-collapsible clamp coupled between the bus and a ground.   
     
     
         13 . The circuit of  claim 12 , wherein each of the plurality of Ethernet ports is a port associated with at least one of 10/100 Ethernet, 1 Gigabit Ethernet, and 10 Gigabit Ethernet. 
     
     
         14 . The circuit of  claim 12 , further comprising:
 a capacitor coupled to the bus and the ground.   
     
     
         15 . The circuit of  claim 14 , wherein the plurality of diodes, the bus and the non-collapsible clamp are deposited on a substrate. 
     
     
         16 . The circuit of  claim 12 , further comprising:
 a plurality of transistors, wherein each one of the plurality of transistors is associated with one of the plurality of diodes and its associated one of the plurality of Ethernet ports, wherein each one of the plurality of transistors comprises a drain and a source, and wherein each drain of the plurality of transistors is coupled to the anode of its associated one of the plurality diodes and each drain of the plurality of transistors is coupled to the ground.   
     
     
         17 . The circuit of  claim 16 , further comprising:
 a capacitor coupled to the bus and the ground.   
     
     
         18 . The circuit of  claim 17 , wherein the plurality of diodes, the plurality of transistors, the bus and the non-collapsible clamp are deposited on a substrate. 
     
     
         19 . A method comprising:
 receiving an electrostatic discharge from an Ethernet port;   coupling the electrostatic discharge through a diode to a capacitor via a bus; and   limiting, by a non-collapsible clamp, a voltage on the capacitor.   
     
     
         20 . The method of  claim 19 , farther comprising:
 preventing, by a second diode, the electrostatic discharge from being coupled to a second Ethernet port, wherein an anode of the second diode is coupled to the second Ethernet port and a cathode of the second diode is coupled to the bus.