ESD protection devices and methods for forming ESD protection devices
View Patent ↗The present disclosure provides a circuit that has an electrostatic discharge (ESD) protection device and a protected circuit in communication with the ESD protection device. The ESD protection device has a first inductor between a signal input terminal and a complimentary power line. The first inductor has a length less than ¼ of a normal operating wavelength of the protected circuit. The ESD protection device also has a first capacitor between the signal input terminal and the protected circuit.
1. A circuit comprising:
an electrostatic discharge (ESD) protection device; and
a protected circuit in communication with the ESD protection device, the protected circuit processing a signal having a wavelength;
wherein the ESD protection device comprises:
a first inductor between a signal input terminal and a complementary power line, the first inductor having a length less than ¼ of the wavelength of the signal;
a second inductor between the protected circuit and the complementary power line, the second inductor forming a transformer with the first inductor; and
a first capacitor between the second inductor and the protected circuit, wherein the transformer and the first capacitor provide matching impedance for the protected circuit, and wherein there is no diode between the signal input terminal and the protected circuit.
2. The circuit of claim 1 in which the protected circuit comprises a Low Noise Amplifier (LNA).
3. The circuit of claim 2 in which the ESD protection device is included in a core design of a matching network for the protected circuit.
4. The circuit of claim 1 in which the first inductor comprises a transmission line.
5. The circuit of claim 1 in which the first inductor comprises a spiral inductor.
6. The circuit of claim 1 in which the ESD protection device further comprises a second capacitor coupled to the complementary power line, and further in which the second capacitor and the first inductor are coupled to opposite terminals of the first capacitor.
7. The circuit of claim 1 in which the ESD protection device further comprises a second inductor in series with the first capacitor.
8. The circuit of claim 1 in which the ESD protection device further comprises a second inductor coupled to the complementary power line, and further in which the first and second inductors are coupled to opposite terminals of the first capacitor.
9. The circuit of claim 1 further comprising a power clamp coupled to the ESD protection circuit.
10. The circuit of claim 1 in which the signal is selected from the list consisting of:
RF signals; and
millimeter wave signals.
11. A circuit comprising:
an electrostatic discharge (ESD) protection device positioned between a protected circuit and a signal input terminal, the signal input terminal receiving a signal with a wavelength, the ESD protection device including:
a first inductor having a length less than ¼ of the wavelength, the first inductor providing an ESD current path from the signal input terminal to the complementary power line;
a second inductor between the protected circuit and the complementary power line, the second inductor forming a transformer with the first inductor; and
a first capacitor between the second inductor and the protected circuit, wherein the ESD protection circuit is part of an impedance matching network for the protected circuit, and wherein there is no diode between the signal input terminal and the protected circuit.
12. The circuit of claim 11 , in which the signal input terminal comprises at least one of a Radio Frequency (RF) pad and a millimeter wave input pad.
13. The circuit of claim 11 in which the protected circuit has an operating frequency greater than 15 GHz.
14. The circuit of claim 11 in which the first inductor includes an item selected from the list consisting of:
a spiral inductor; and
a transmission line inductor.
15. The circuit of claim 11 further comprising at least one of the following:
a second capacitor coupled to the complementary power line, in which the second capacitor and the first inductor are coupled to opposite terminals of the first capacitor;
a second inductor in series with the first capacitor; and
a second inductor coupled to the complementary power line, in which the first and second inductors are coupled to opposite terminals of the first capacitor.
16. A method of fabricating a device, the method comprising:
fabricating a protected device between a power line and a complementary power line; and
fabricating an electrostatic discharge (ESD) protection device between a signal input terminal and the protected device, in which fabricating the ESD protection device comprises:
disposing a first inductor between the signal input terminal and the complementary power line, in which the first inductor has a length less than ¼ of a normal operating wavelength of protected device;
disposing a second inductor between the protected circuit and the complementary power line, the second inductor forming a transformer with the first inductor; and
disposing a first capacitor between the second inductor and the protected device, wherein there is no diode between the signal input terminal and the protected circuit.
17. The method of claim 16 further comprising at least one of the following actions:
coupling a second capacitor to the complementary power line, in which the second capacitor and the first inductor are coupled to opposite terminals of the first capacitor;
disposing a second inductor in series with the first capacitor; and
coupling a second inductor to complementary power line, in which the first and second inductors are coupled to opposite terminals of the first capacitor.
18. The method of claim 16 , in which the ESD protection device is disposed within a matching network for the protected device.