METHOD AND APPARATUS OF PROVIDING 2-STAGE ESD PROTECTION FOR HIGH-SPEED INTERFACES
First Claim
1. An electrostatic discharge protection device that protects another separate protected device from an ESD event pulse by transmitting the ESD event pulse to ground and passes a signal to the separate protected device comprising:
- an integrated semiconductor, the integrated semiconductor including;
an input pad that receives the signal and the ESD event pulse;
an output pad adapted for connection to the separate protection device so that the electrostatic discharge protection device is disposed in series with the separate protected device and provides the signal to the separate protected device; and
an electrostatic discharge circuit connected between the input pad and the output pad, the electrostatic discharge circuit dissipating the ESD event pulse by providing a path to the ground, the electrostatic discharge circuit comprising;
a first stage that contains a first ESD clamp device that provides an electrostatic discharge path to the ground for the ESD event pulse;
a second stage that contains a second ESD clamp device that provides another electrostatic discharge path to the ground for the ESD event pulse, such that the first stage clamps more energy from the ESD event pulse than the second stage; and
a series coupling element that couples the first stage to the second stage, so that during the ESD event, the first stage turns on independently of the second stage.
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Accused Products
Abstract
The present invention relates to a method and apparatus of providing 2-stage ESD protection for high-speed interfaces. An aspect of the present invention is to provide an integrated multi-stage ESD/EOS protection solution for such high-speed applications. In one embodiment, the ESD protection device has multiple ESD stages integrated into a single integrated circuit package and is mounted to a printed circuit board in series with a device under protection. In another embodiment the multiple ESD stages integrated into a single integrated circuit package of the ESD protection device are coupled with a series element that isolates a 2nd stage from a 1st stage during an ESD event, thus ensuring that the 2nd stage turns on before the 1st stage, as well as provides for less current in the 2nd stage.
8 Citations
18 Claims
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1. An electrostatic discharge protection device that protects another separate protected device from an ESD event pulse by transmitting the ESD event pulse to ground and passes a signal to the separate protected device comprising:
an integrated semiconductor, the integrated semiconductor including; an input pad that receives the signal and the ESD event pulse; an output pad adapted for connection to the separate protection device so that the electrostatic discharge protection device is disposed in series with the separate protected device and provides the signal to the separate protected device; and an electrostatic discharge circuit connected between the input pad and the output pad, the electrostatic discharge circuit dissipating the ESD event pulse by providing a path to the ground, the electrostatic discharge circuit comprising; a first stage that contains a first ESD clamp device that provides an electrostatic discharge path to the ground for the ESD event pulse; a second stage that contains a second ESD clamp device that provides another electrostatic discharge path to the ground for the ESD event pulse, such that the first stage clamps more energy from the ESD event pulse than the second stage; and a series coupling element that couples the first stage to the second stage, so that during the ESD event, the first stage turns on independently of the second stage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for transmitting a signal and discharging an ESD event pulse associated with an ESD event to ground comprising:
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a printed circuit board having an input line that transmits the signal; a device under protection mounted on the printed circuit board, the device under protection including an integrated circuit that contains an ESD protected input that receives the signal and a device under protection electrostatic discharge circuit for dissipating the ESD event pulse by providing a device under protection path to the ground, the device under protection electrostatic discharge circuit including a second stage that contains a second ESD clamp device; and an electrostatic discharge protection device mounted on the printed circuit board in series with the device under protection, thereby protecting the device under protection from the ESD event and transmitting the signal to the device under protection, the electrostatic discharge protection device including; an integrated semiconductor, the integrated semiconductor including; an input pad electrically coupled to the input line of the printed circuit board, that receives the signal and the ESD event pulse associated with the ESD event; an output pad electrically coupled to the ESD protected input of the device under protection so that the electrostatic discharge protection device is disposed in series with the device under protection and providing a path for the signal to the ESD protected input; and an electrostatic discharge circuit connected between the input pad and the output pad, the electrostatic discharge circuit dissipating the ESD event pulse by providing a path to the ground, the electrostatic discharge circuit comprising; a first stage that contains a first ESD clamp device that provides an electrostatic discharge path to the ground, such that the first stage clamps more energy from the ESD event pulse than the second stage; and a series coupling element that couples the first stage to the second stage, so that during the ESD event, the first stage turns on independently of the second stage. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification