US6147511A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overvoltage-tolerant interface for integrated circuits
Assignee: Altera Corp
•
Filing: 1997-05-27
•
Granted: 2000-11-14
•
Expires: 2017-05-27
Abstract
Abstract An input/output driver for interfacing directly with a voltage at a pad (820) which is above a supply voltage (817) for the input/output driver. This may be referred to as an "overvoltage condition. " For example, if the supply voltage is 3.3 volts, a 5-volt signal may be provided at the pad of the input/output driver. The input/output driver will tolerate this voltage level and prevent leakage current paths. This will improve the performance, reliability, and longevity of the integrated circuit. The input/output driver includes a well-bias generator (1002) for preventing leakage current paths.
Inventors
- 👤 Rakesh H. Patel
- 👤 John E. Turner
- 👤 Wilson Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:55
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/0175; H03K19/0185; H03K19/018585; H03K19/0021; H03K19/0027; H03K19/003; H03K19/00315; H03K19/018507; H03K19/018521
Claims Analysis
Total Claims: 67
Claim 1
Independent Claim
165 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node, not directly connected to the voltage bias node; a second clamping device coupled between the I/O pad and the first node; and a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 2
Dependent Claim
165 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node, not directly connected to the voltage bias node; a second clamping device coupled between the I/O pad and the first node; and a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 3
Dependent Claim
32 words
The circuit of claim 1 wherein a second body electrode of the first bias device and a third body electrode of the second bias device are coupled to the voltage bias node.
Claim 4
Dependent Claim
37 words
The circuit of claim 1 wherein the body bias generator further comprises: a voltage clamp circuit coupled to clamp the voltage bias node to a voltage at or above about a level of the first supply voltage.
Claim 5
Dependent Claim
29 words
The circuit of claim 1 further comprising: a predriver to drive the pull-up device; and an isolation device between the predriver and the control electrode of the pull-up device.
Claim 6
Dependent Claim
30 words
The circuit of claim 1 further comprising: a resistive device coupled between the I/O pad and the first bias device and between the I/O pad and the second bias device.
Claim 7
Dependent Claim
28 words
The circuit of claim 1 further comprising: an input buffer comprising a thick oxide transistor with a control electrode coupled to receive a signal at the I/O pad.
Claim 8
Dependent Claim
18 words
The circuit of claim 1 wherein the first bias device and second bias device are thick oxide transistors.
Claim 9
Dependent Claim
33 words
The circuit of claim 1 wherein the voltage bias node is coupled to body electrodes of the first bias device, second bias device, third bias device, first clamping device, and second clamping device.
Claim 10
Dependent Claim
172 words
An integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node; a second clamping device coupled between the I/O pad and the first node; a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state; and a voltage clamp device coupled to clamp the voltage bias node to about a voltage level at the I/O pad.
Claim 11
Dependent Claim
172 words
An integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node; a second clamping device coupled between the I/O pad and the first node; a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state; and a voltage clamp device coupled to clamp the voltage bias node to about a voltage level at the I/O pad.
Claim 12
Dependent Claim
131 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; and; a third bias device to couple the voltage bias node to a control electrode of the pull-up device whenever the pull-up device is in a nonconducting state.
Claim 13
Dependent Claim
131 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; and; a third bias device to couple the voltage bias node to a control electrode of the pull-up device whenever the pull-up device is in a nonconducting state.
Claim 14
Dependent Claim
32 words
The circuit of claim 10 wherein a second body electrode of the first bias device and a third body electrode of the second bias device are coupled to the voltage bias node.
Claim 15
Dependent Claim
37 words
The circuit of claim 10 wherein the body bias generator further comprises: a voltage clamp circuit coupled to clamp the voltage bias node to a voltage at or above about a level of the first supply voltage.
Claim 16
Dependent Claim
32 words
The circuit of claim 10 wherein the body bias generator further comprises: a voltage clamp device coupled to clamp the voltage bias node to about a voltage level at the I/O pad.
Claim 17
Dependent Claim
29 words
The circuit of claim 10 further comprising: a predriver to drive the pull-up device; and an isolation device between the predriver and the control electrode of the pull-up device.
Claim 18
Dependent Claim
30 words
The circuit of claim 10 further comprising: a resistive device coupled between the I/O pad and the first bias device and between the I/O pad and the second bias device.
Claim 19
Dependent Claim
28 words
The circuit of claim 10 further comprising: an input buffer comprising a thick oxide transistor with a control electrode coupled to receive a signal at the I/O pad.
Claim 20
Dependent Claim
23 words
The circuit of claim 14 wherein the isolation device is a pass transistor having a control electrode coupled to the first supply voltage.
Claim 21
Dependent Claim
18 words
The circuit of claim 10 wherein the first bias device and second bias device are thick oxide transistors.
Claim 22
Dependent Claim
27 words
The circuit of claim 10 wherein the voltage bias node is coupled to body electrodes of the first bias device, second bias device, and third bias device.
Claim 23
Dependent Claim
40 words
The circuit of claim 10 further comprising: a first pass device coupled between the I/O pad and the control electrode of the pull-up device, wherein a control electrode of the first pass device is coupled to the first supply voltage.
Claim 24
Dependent Claim
21 words
The circuit of claim 20 wherein a body electrode of the first pass device is coupled to the voltage bias node.
Claim 25
Dependent Claim
40 words
The circuit of claim 20 further comprising: a second pass device coupled between a predriver output node and the control electrode of the pull-up device, wherein a control electrode of the second pass device is coupled to the I/O pad.
Claim 26
Dependent Claim
21 words
The circuit of claim 20 wherein a body electrode of the second pass device is coupled to the voltage bias node.
Claim 27
Dependent Claim
192 words
An intergrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a predriver to drive the pull-up device; and an isolation device between the predriver and the control electrode of the pull-up device, wherein the isolation device is a pass transistor having a control electrode coupled to the first supply voltage; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node; a second clamping device coupled between the I/O pad and the first node; and a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 28
Dependent Claim
192 words
An intergrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a predriver to drive the pull-up device; and an isolation device between the predriver and the control electrode of the pull-up device, wherein the isolation device is a pass transistor having a control electrode coupled to the first supply voltage; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node; a second clamping device coupled between the I/O pad and the first node; and a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 29
Dependent Claim
185 words
An integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a first pass device coupled between the I/O pad and the control electrode of the pull-up device, wherein a control electrode of the first pass device is coupled to the first supply voltage; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node; a second clamping device coupled between the I/O pad and the first node; and a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 30
Dependent Claim
185 words
An integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a first pass device coupled between the I/O pad and the control electrode of the pull-up device, wherein a control electrode of the first pass device is coupled to the first supply voltage; and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; a first clamping device coupled between the first supply voltage and a first node; a second clamping device coupled between the I/O pad and the first node; and a third bias device to couple the first node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 31
Dependent Claim
21 words
The circuit of claim 25 wherein a body electrode of the first pass device is coupled to the voltage bias node.
Claim 32
Dependent Claim
40 words
The circuit of claim 25 further comprising: a second pass device coupled between a predriver output node and the control electrode of the pull-up device, wherein a control electrode of the second pass device is coupled to the I/O pad.
Claim 33
Dependent Claim
21 words
The circuit of claim 25 wherein a body electrode of the second pass device is coupled to the voltage bias node.
Claim 34
Dependent Claim
176 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a predriver to drive the pull-up device; and an isolation device between the predriver and the control electrode of the pull-up device, wherein the isolation device is a pass transistor having a control electrode coupled to the first supply voltage, and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; and a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage, wherein the first bias device and the second bias device have a first gate oxide thickness that is thicker than a second gate oxide thickness of transistors used to implement the predriver.
Claim 35
Dependent Claim
176 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a predriver to drive the pull-up device; and an isolation device between the predriver and the control electrode of the pull-up device, wherein the isolation device is a pass transistor having a control electrode coupled to the first supply voltage, and a body bias generator having a voltage bias node coupled to a first body electrode of the pull-up device comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; and a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage, wherein the first bias device and the second bias device have a first gate oxide thickness that is thicker than a second gate oxide thickness of transistors used to implement the predriver.
Claim 36
Dependent Claim
15 words
The circuit of claim 29 wherein the isolation device has the first gate oxide thickness.
Claim 37
Dependent Claim
32 words
The circuit of claim 29 wherein a second body electrode of the first bias device and a third body electrode of the second bias device are coupled to the voltage bias node.
Claim 38
Dependent Claim
37 words
The circuit of claim 29 wherein the body bias generator further comprises: a voltage clamp circuit coupled to clamp the voltage bias node to a voltage at or above about a level of the first supply voltage.
Claim 39
Dependent Claim
16 words
The circuit of claim 32 wherein the voltage clamp circuit has the first gate oxide thickness.
Claim 40
Dependent Claim
32 words
The circuit of claim 29 wherein the body bias generator further comprises: a voltage clamp device coupled to clamp the voltage bias node to about a voltage level at the I/O pad.
Claim 41
Dependent Claim
16 words
The circuit of claim 34 wherein the voltage clamp device has the first gate oxide thickness.
Claim 42
Dependent Claim
39 words
The circuit of claim 29 wherein the body bias generator further comprises: a third bias device to couple the voltage bias node to a control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 43
Dependent Claim
16 words
The circuit of claim 36 wherein the third bias device has the first gate oxide thickness.
Claim 44
Dependent Claim
30 words
The circuit of claim 29 further comprising: a resistive device coupled between the I/O pad and the first bias device and between the I/O pad and the second bias device.
Claim 45
Dependent Claim
31 words
The circuit of claim 29 further comprising: an input buffer comprising a transistor with the first oxide thickness and a control electrode coupled to receive a signal at the I/O pad.
Claim 46
Dependent Claim
66 words
The circuit of claim 29 wherein the body bias generator further comprises: a first clamping device coupled between the first voltage source and a first node; a second clamping device coupled between the I/O pad and the first node; and a third bias device to couple the first node to the control electrode of the pull-up device when the pull-up device is in a nonconducting state.
Claim 47
Dependent Claim
20 words
The circuit of claim 40 wherein the first clamping device and third bias device have the first gate oxide thickness.
Claim 48
Dependent Claim
33 words
The circuit of claim 41 wherein the voltage bias node is coupled to body electrodes of the first bias device, second bias device, third bias device, first clamping device, and second clamping device.
Claim 49
Dependent Claim
15 words
The circuit of claim 29 wherein the pull-up device has the first gate oxide thickness.
Claim 50
Dependent Claim
40 words
The circuit of claim 29 further comprising: a first pass device coupled between the I/O pad and the control electrode of the pull-up device, wherein a control electrode of the first pass device is coupled to the first supply voltage.
Claim 51
Dependent Claim
21 words
The circuit of claim 44 wherein a body electrode of the first pass device is coupled to the voltage bias node.
Claim 52
Dependent Claim
40 words
The circuit of claim 44 further comprising: a second pass device coupled between a predriver output node and the control electrode of the pull-up device, wherein a control electrode of the second pass device is coupled to the I/O pad.
Claim 53
Dependent Claim
21 words
The circuit of claim 44 wherein a body electrode of the second pass device is coupled to the voltage bias node.
Claim 54
Dependent Claim
156 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a predriver to drive a control electrode of the pull-up device with a pull-up signal; and a body bias generator, having a voltage bias node coupled to a first body electrode of the pull-up device, comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; and a third bias device, coupled between the voltage bias node and the control electrode of the pull-up device, wherein a control electrode of the third bias device is coupled to an inverted version of the pull-up signal.
Claim 55
Dependent Claim
156 words
A circuit to implement an overvoltage-tolerant integrated circuit comprising: a pull-up device coupled between a first supply voltage and an I/O pad; a predriver to drive a control electrode of the pull-up device with a pull-up signal; and a body bias generator, having a voltage bias node coupled to a first body electrode of the pull-up device, comprising: a first bias device coupled between the first supply voltage and the voltage bias node, wherein a control electrode of the first bias device is coupled to the I/O pad; a second bias device coupled between the I/O pad and the voltage bias node, wherein a control electrode of the second bias device is coupled to the first supply voltage; and a third bias device, coupled between the voltage bias node and the control electrode of the pull-up device, wherein a control electrode of the third bias device is coupled to an inverted version of the pull-up signal.
Claim 56
Dependent Claim
22 words
The circuit of claim 48 further comprising: an isolation device coupled between the predriver and the control electrode of the pull-up device.
Claim 57
Dependent Claim
37 words
The circuit of claim 48 wherein the body bias generator further comprises: a voltage clamp circuit coupled to clamp the voltage bias node to a voltage at or above about a level of the first supply voltage.
Claim 58
Dependent Claim
32 words
The circuit of claim 48 wherein the body bias generator further comprises: a voltage clamp device coupled to clamp the voltage bias node to about a voltage level at the I/O pad.
Claim 59
Dependent Claim
30 words
The circuit of claim 48 further comprising: a resistive device coupled between the I/O pad and the first bias device and between the I/O pad and the second bias device.
Claim 60
Dependent Claim
28 words
The circuit of claim 48 further comprising: an input buffer comprising a thick oxide transistor with a control electrode coupled to receive a signal at the I/O pad.
Claim 61
Dependent Claim
19 words
The circuit of claim 49 wherein the isolation device has a control electrode coupled to the first supply voltage.
Claim 62
Dependent Claim
18 words
The circuit of claim 48 wherein the first bias device and second bias device are thick oxide transistors.
Claim 63
Dependent Claim
27 words
The circuit of claim 48 wherein the voltage bias node is coupled to body electrodes of the first bias device, second bias device, and third bias device.
Claim 64
Dependent Claim
40 words
The circuit of claim 48 further comprising: a first pass device coupled between the I/O pad and the control electrode of the pull-up device, wherein a control electrode of the first pass device is coupled to the first supply voltage.
Claim 65
Dependent Claim
21 words
The circuit of claim 57 wherein a body electrode of the first pass device is coupled to the voltage bias node.
Claim 66
Dependent Claim
40 words
The circuit of claim 57 further comprising: a second pass device coupled between a predriver output node and the control electrode of the pull-up device, wherein a control electrode of the second pass device is coupled to the I/O pad.
Claim 67
Dependent Claim
21 words
The circuit of claim 57 wherein a body electrode of the second pass device is coupled to the voltage bias node.
References Cited (Backward Citations)
US4090236A
Cited
US4361873A
Cited
US4317181A
Cited
US4503494A
Cited
US4837460A
Cited
US4617479B1
Cited
US4617479A
Cited
US4609986A
Cited
US4677318A
Cited
US4713792A
Cited
US5272393A
Cited
US5402375A
Cited
US5528548A
Cited
US4901283A
Cited
US4871930A
Cited
US4912342A
Cited
US4899067A
Cited
US5004936A
Cited
US5041964A
Cited
US5032742A
Cited
US5066873A
Cited
US5222044A
Cited
US5132555A
Cited
US5045772A
Cited
US5151619A
Cited
US5121006A
Cited
US5241224A
Cited
US5144167A
Cited
US5160855A
Cited
US5260610A
Cited
US5260611A
Cited
US5309399A
Cited
US5331219A
Cited
US5162680A
Cited
US5336986A
Cited
US5416661A
Cited
US5274828A
Cited
US5315172A
Cited
US5442277A
Cited
US5417476A
Cited
US5350954A
Cited
US5359243A
Cited
US5604453A
Cited
US5432467A
Cited
US5414312A
Cited
US5508653A
Cited
US5451889A
Cited
US5589783A
Cited
US5576635A
Cited
US5880602A
Cited
US5748010A
Cited
WO1996037958A1
Cited
US5543733A
Cited
US5661685A
Cited
US5726589A
Cited
WO1997021273A1
Cited
US5646550A
Cited
US5825206A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-11-14 | 2004-05-15 | 2004-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-11-14 | 2008-05-15 | 2008-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-11-14 | 2012-05-15 | 2012-11-14 | $7700.00 | Window Closed / Lapsed |