Diode chain with a guard-band

1. An Electrostatic Discharge (ESD) protection device comprising:

at least one diode in a first well of a first conductivity type formed directly in a second well of a second conductivity type; and

a guard-band of the first conductivity type bordering at least a portion of the at least one diode, wherein the guard-band is formed completely within the second well.

2. The ESD protection device of claim 1 wherein the first conductivity type comprises an N-type doping region and the second conductivity type comprises a P-type doping region.

3. An Electrostatic Discharge (ESD) protection device comprising:

at least one diode in a first well of a first conductivity type formed directly in a second well of a second conductivity type; and

a guard-band of the first conductivity type bordering at least a portion of the at least one diode;

wherein the first conductivity type comprises an N-type doping region and the second conductivity type comprises a P-type doping region;

and wherein an NPN transistor is formed by the first well of the first conductivity type, the second well of the second conductivity type and the guard-band of the first conductivity type.

4. The ESD protection device of claim 3 wherein the guard-band is coupled to a low voltage, wherein the low voltage is less than a voltage of an anode of the at least one diode.

5. The ESD protection device of claim 4 wherein the guard-band is coupled to a cathode of the at least one diode.

6. The ESD protection device of claim 2 wherein a PNP transistor is formed by a PN junction of the at least one diode and the second well of the second conductivity type.

7. The ESD protection device of claim 1 wherein the first conductivity type comprises a P-type doping region and the second conductivity type comprises an N-type doping region.

8. An Electrostatic Discharge (ESD) protection device comprising:

at least one diode in a first well of a first conductivity type formed directly in a second well of a second conductivity type; and

a guard-band of the first conductivity type bordering at least a portion of the at least one diode;

wherein the first conductivity type comprises a P-type doping region and the second conductivity type comprises an N-type doping region;

and wherein a PNP transistor is formed by the first well of the first conductivity type, the second well of the second conductivity type, and the guard-band of the first conductivity type.

9. The ESD protection device of claim 7 wherein the guard-band is coupled to a high voltage, wherein the high voltage is higher than a voltage of a cathode of the at least one diode.

10. The ESD protection device of claim 9 wherein the guard-band is coupled to an anode of the at least one diode.

11. The ESD protection device of claim 1 wherein the guard-band is coupled to ground.

12. The ESD protection device of claim 1 wherein the guard-band is coupled to a power line.

13. The ESD protection device of claim 1 wherein the at least one diode comprises at least one of a Shallow Trench Isolation (STI) diode, a gated diode or a NO-STI diode.

14. The ESD protection device of claim 1 wherein the at least one diode comprises a PN junction diode.

15. The ESD device of claim 14 wherein an NPN transistor is formed by a PN junction of the at least one diode and the second well.

16. The ESD device of claim 2 further comprising a triggering circuit connected to the guard-band.

17. The ESD device of claim 16 wherein the triggering circuit connects the guard-band to a low potential during an ESD event.

18. The ESD device of claim 16 wherein the triggering circuit connects the guard-band to a high potential during normal operation.

19. The ESD device of claim 8 further comprising a triggering circuit connected to the guard-band.

20. The ESD device of claim 19 wherein the triggering circuit connects the guard-band to a high potential during an ESD event.

21. The ESD device of claim 19 wherein the triggering circuit connects the guard-band to a low potential during normal operation.

22. The ESD protection device of claim 2 wherein the guard-band comprises an N-well region.

23. The ESD protection device of claim 8 wherein the guard-band comprises a P-well region.

24. The ESD protection device of claim 1 wherein the guard-band completely surrounds the at least one diode.

25. The ESD protection device of claim 1 wherein a highly doped region of the second conductivity type is formed between at least a first diode and a second diode.