Circuit of protection against electrostatic discharges
A circuit for protecting against electrostatic discharges includes two avalanche circuit components having different turn-on delays with respect to a beginning of an electrostatic discharge. The two avalanche circuit components are coupled in parallel. The avalanche circuit component closer to an output node has a turn-on delay on the order of 30 ns, while the avalanche circuit component closer to an input node has a turn-on delay on the order of 1 ns.
1. A circuit for protection against electrostatic discharges, comprising:
a first avalanche circuit component comprising a thyristor having a cathode directly electrically connected to a reference potential node, and having an anode coupled to a first node through a diode;
a second avalanche circuit component;
wherein the first and second avalanche circuit components are coupled in parallel;
wherein the second avalanche circuit component comprises:
an avalanche diode having a cathode coupled to a second node and an anode coupled to the reference potential node; and
a plurality of series connected avalanche diodes, with a first of the plurality of series connected avalanche diodes having an anode coupled to the second node, and with a last of plurality of series connected avalanche diodes having a cathode coupled to the reference potential node; and
wherein the first and second avalanche circuit components have different turn-on delays with respect to a beginning of an electrostatic discharge.
2. The circuit of claim 1 , wherein the reference potential node is at ground.
3. The circuit of claim 1 , further comprising a resistor directly electrically connected between the second node and the first node.
4. The circuit of claim 3 , wherein the resistor has a resistivity of approximately 1.5 ohms.
5. The circuit of claim 1 , wherein the first node is an input node and the second node is an output node.
6. The circuit of claim 1 , wherein the first and second avalanche circuit components have different turn-on delays.
7. The circuit of claim 6 , wherein the different turn-on delays differ by a time in a range of tens of nanoseconds.
8. An electrostatic discharge (ESD) protection discharge circuit, comprising:
an input node;
an output node;
a first avalanche circuit component comprising a thyristor having a cathode directly electrically connected to a reference node, and having an anode coupled to the input node through a first diode; and
a second avalanche circuit component coupled between the output node and the reference node;
wherein the second avalanche circuit component comprises:
an avalanche diode having a cathode coupled to the output node and an anode coupled to the reference node; and
a plurality of series connected avalanche diodes, with a first of the plurality of series connected avalanche diodes having an anode coupled to the output node, and with a last of plurality of series connected avalanche diodes having a cathode coupled to the reference node;
wherein the first avalanche circuit component has a turn-on delay longer than a turn-on delay of the second avalanche circuit component.
9. The ESD protection circuit of claim 8 , wherein the turn-on delay of the first avalanche circuit component is approximately 30 ns greater than the turn-on delay of the second avalanche circuit component.
10. The ESD protection circuit of claim 8 , wherein the first avalanche circuit component comprises:
a second diode having a cathode coupled to the input node and an anode coupled to the reference node.
11. The ESD protection circuit of claim 8 , further comprising an avalanche diode having a cathode coupled to a gate of the thyristor and an anode coupled to the reference node.
12. The ESD protection circuit of claim 8 , wherein the plurality of series connected avalanche diodes comprises first, second, third, and fourth avalanche diodes, and wherein:
an anode of the first avalanche diode is coupled to the output node;
an anode of the second avalanche diode is coupled to a cathode of the first avalanche diode;
an anode of the third avalanche diode is coupled to a cathode of the second avalanche diode;
an anode of the fourth avalanche diode is coupled to a cathode of the third avalanche diode; and
a cathode of the fourth avalanche diode is coupled to the reference node.
13. The ESD protection circuit of claim 8 , further comprising a resistor coupled between the input node and the output node.
14. The ESD protection circuit of claim 8 , wherein the first diode has an anode directly electrically connected to the input node and a cathode directly electrically connected to the anode of said thyristor.
15. The circuit of claim 1 , wherein the diode has an anode directly electrically connected to the first node and a cathode directly electrically connected to the anode of said thyristor.