Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
75 words
A protection circuit for protecting a functional circuit from electrostatic discharge, the protection circuit comprising: a first node for being connected to a first higher potential source; a second node for being connected to a second lower potential source; switch means for switchably connecting the first node to the second node in response to a control signal; triggering means connected to the switch means for generating the control signal in response to an electrostatic discharge.
Claim 2
Dependent Claim
41 words
A protection circuit as in claim 1 wherein the switch means comprises: a first transistor connected between an input node of the functional circuit and the first node, and a second transistor connected between the input node and the second node.
Claim 3
Dependent Claim
36 words
A protection circuit as in claim 2 wherein each of the first and second transistors is connected to receive the control signal and in response connect the input node to the corresponding first and second nodes.
Claim 4
Dependent Claim
20 words
A protection circuit as in claim 3 wherein each of the first and second transistors comprises a field effect transistor.
Claim 5
Dependent Claim
28 words
A protection circuit as in claim 1 wherein the triggering means comprises a resistor-capacitor network for triggering the switch means whenever power is applied to the functional circuit.
Claim 6
Dependent Claim
25 words
A protection circuit as in claim 5 wherein the resistor-capacitor network comprises a serially-connected resistor and capacitor between the first node and the second node.
Claim 7
Dependent Claim
27 words
A protection circuit as in claim 6 wherein the resistor-capacitor network is chosen to have a time constant of greater than the duration of the electrostatic discharge.
Claim 8
Dependent Claim
24 words
A protection circuit as in claim 1 wherein the switch means comprises a single transistor connected to the first node and the second node.
Claim 9
Dependent Claim
25 words
A protection circuit as in claim 8 wherein the single transistor comprises a field effect transistor having a control electrode connected to the trigger circuit.
Claim 10
Dependent Claim
46 words
A protection circuit as in claim 1 wherein the triggering circuit comprises: a transistor connected between the first node and the second node and the transistor, whereby an electrostatic discharge on the first node will turn on the transistor to connect the first node to ground.
Claim 11
Dependent Claim
105 words
An integrated circuit protected from electrostatic discharge comprising: a functional circuit having a plurality of connection nodes for performing operations in response to signals supplied to the connection nodes, the functional circuit having at least a first and a second connection node for being connected across a potential source; a plurality of switch means, one connected to each of the corresponding ones of the plurality of connection nodes, each switch means for connecting that connection node to both the first and second connection nodes in response to a control signal; and a triggering circuit for generating the control signal in response to an electrostatic discharge.
Claim 12
Dependent Claim
29 words
An integrated circuit as in claim 11 wherein the triggering circuit also generates the control signal for a short time each time power is applied to the functional circuit.
Claim 13
Dependent Claim
22 words
An integrated circuit as in claim 12 wherein the triggering circuit is also connected between the first and the second connection node.