ELECTROSTATIC BREAKDOWN PROTECTION CIRCUIT AND SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE THEREWITH
First Claim
1. An electrostatic breakdown protection circuit for protecting an open-drain output transistor from electrostatic breakdown, the electrostatic breakdown protection circuit comprising:
- a diode having an anode thereof connected to a signal input terminal leading to the output transistor, and having a cathode thereof connected to a gate of the output transistor;
a first resistor having one end thereof connected to the signal input terminal, and having the other end thereof connected to ground; and
a PNP bipolar transistor or a P-channel field effect transistorhaving an emitter or a source thereof connected to the gate of the output transistor,having a base or a gate thereof connected to the one end of the first resistor andhaving a collector or a drain connected to ground.
1 Assignment
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Accused Products
Abstract
A protection circuit according to the present invention includes: a diode (D1) having an anode thereof connected to a gate signal input terminal and a cathode thereof connected to the gate of an output transistor (N1); a resistor (R1) having one end thereof connected to the gate signal input terminal and the other end thereof connected to ground; a PNP bipolar transistor (Qp1) having the emitter, base and collector thereof connected to the gate of the output transistor (N1), the one end of the resistor (R1) and ground, respectively. With this configuration, it is possible to prevent, without the need for electric power, an open-drain output transistor from erroneously turning on as a result of an electrostatic pulse or the like being applied thereto, and thus to protect the output transistor from electrostatic breakdown.
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Citations
4 Claims
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1. An electrostatic breakdown protection circuit for protecting an open-drain output transistor from electrostatic breakdown, the electrostatic breakdown protection circuit comprising:
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a diode having an anode thereof connected to a signal input terminal leading to the output transistor, and having a cathode thereof connected to a gate of the output transistor; a first resistor having one end thereof connected to the signal input terminal, and having the other end thereof connected to ground; and a PNP bipolar transistor or a P-channel field effect transistor having an emitter or a source thereof connected to the gate of the output transistor, having a base or a gate thereof connected to the one end of the first resistor and having a collector or a drain connected to ground. - View Dependent Claims (2, 3, 4)
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Specification