Method and apparatus to ensure functionality and timing robustness in SOI circuits

• US 6,608,785 B2
• Filed: 01/07/2002
• Issued: 08/19/2003
• Est. Priority Date: 01/07/2002
• Status: Expired due to Fees

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Chuang, Ching-Te Kent, Kuang, Jente Benedict, Saccamango, Mary Joseph
• Primary Examiner(s): Dinh, Son T.
• Application Number:
  US10/041,231
• Publication Number:
  US 20030128606A1
• Time in Patent Office: 589 Days
• Field of Search: 365/201, 365/154, 361/56, 361/91.1, 361/111, 361/118
• US Class Current: 365/201
• CPC Class Codes: G11C 2029/5002 Characteristic
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 29/50 Marginal testing, e.g. race, voltage or current testing
• CPC Class Codes: G11C 29/50012 of timing

Abstract

Methods and apparatus are provided to ensure functionality and timing robustness in silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuits. A select signal for the SOI CMOS circuit is received. A floating body charge monitoring circuit is coupled to the SOI CMOS circuit for monitoring excess body charges in at least one predefined SOI device and providing an output control signal. A select signal adjusting circuit is coupled to the floating body charge monitoring circuit receiving the output control signal and the select signal and providing a conditionally adjusted select signal responsive to the output control signal of the floating body charge monitor circuit. The conditionally adjusted select signal is applied to the SOI CMOS circuit. The conditionally adjusted select signal provided by the select signal adjusting circuit responsive to the output control signal of the floating body charge monitor circuit includes a predefined delay at the trailing edge of the select signal extending the select signal pulse width. The conditionally adjusted select signal includes a shortened select signal pulse having a predefined delay at the rising edge of the select signal. The conditionally adjusted select signal includes a substantially unchanged select signal pulse width with a predefined delay of the rising edge of the select signal.

Claims

1. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit comprising:

a select signal for the SOI CMOS circuit;

a floating body charge monitoring circuit coupled to the SOI CMOS circuit for monitoring excess body charges in at least one predefined SOI device and providing an output control signal;

a select signal adjusting circuit receiving said select signal and coupled to said floating body charge monitoring circuit receiving said output control signal and providing a conditionally adjusted select signal responsive to said output control signal of said floating body charge monitor circuit;

said conditionally adjusted select signal applied to the SOI CMOS circuit.

2. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said conditionally adjusted select signal provided by said select signal adjusting circuit responsive to said output control signal of said floating body charge monitor circuit includes a predefined delay at the trailing edge of the select signal extending the select signal pulse width.

3. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said conditionally adjusted select signal provided by said select signal adjusting circuit responsive to said output control signal of said floating body charge monitor circuit includes a shortened select signal pulse having a predefined delay at the rising edge of the select signal.

4. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said conditionally adjusted select signal provided by said select signal adjusting circuit responsive to said output control signal of said floating body charge monitor circuit includes a substantially unchanged select signal pulse width with a predefined delay of the rising edge of the select signal.

5. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said select signal adjusting circuit includes a plurality of inverter stages and wherein said conditionally adjusted select signal provided by said select signal adjusting circuit responsive to said output control signal of said floating body charge monitor circuit includes a predefined delay defined by said plurality of inverter stages.

6. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said floating body charge monitoring circuit includes a monitor core circuit, a current mirroring multiplier and a latch providing said output control signal.

7. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said floating body charge monitoring circuit detects excess body charges in said predefined SOI devices resulting from transient parasitic bipolar current and provides said output control signal to set said select signal adjusting circuit to provide said conditionally adjusted select signal.

8. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said select signal adjusting circuit includes a first two-input NAND gate receiving said select signal and said output control signal;

a plurality of series connected inverter stages connected to said first two-input NAND gate;

an inverter receiving said select signal;

a second two-input NAND gate receiving respective outputs of said series connected inverter stages and said inverter;

said second two-input NAND gate providing said conditionally adjusted select signal output having an extension of a trailing edge of said select signal when triggered by said output control signal of said floating body charge monitor circuit.

9. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 8 wherein said plurality of series connected inverter stages connected to said first two-input NAND gate provide an even number of inversions.

10. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said select signal adjusting circuit includes a first two-input NAND gate receiving said select signal and said output control signal;

a plurality of series connected inverter stages connected to said first two-input NAND gate;

a first inverter receiving said select signal;

a second two-input NAND gate receiving respective outputs of said series connected inverter stages and said first inverter;

a second inverter connected to said second two-input NAND gate;

said second inverter providing said conditionally adjusted select signal output having a delayed rising edge of said select signal when triggered by said output control signal of said floating body charge monitor circuit.

11. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 10 wherein said plurality of series connected inverter stages connected to said first two-input NAND gate provide an even number of inversions.

12. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 1 wherein said select signal adjusting circuit includes a plurality of inverters and a pair of tri-state inverters;

said tri-state inverters having a control input;

a first inverter receiving said select signal;

a plurality of series connected inverter stages connected to said first inverter;

a first one of said pair of tri-state inverters connected to said first inverter;

a second one of said pair of tri-state inverters connected to said plurality of series connected inverter stages;

said output control signal applied to said control input of said first one of said pair of tri-state inverters; and

said output control signal being inverted applied to said control input of said second one of said pair of tri-state inverters;

said pair of tri-state inverters providing said conditionally adjusted select signal output having a substantially unchanged pulse width and a delayed rising edge of said select signal when triggered by said output control signal of said floating body charge monitor circuit.

13. Apparatus to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 12 wherein said first one and said second one of said pair of tri-state inverters are respectively set to a high-impedance state and an inversion state responsive to said output control signal.

14. A method to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit utilizing a charge monitoring circuit coupled to the SOI CMOS circuit and a select signal adjusting circuit comprising the steps of:

utilizing said charge monitoring circuit coupled to the SOI CMOS circuit, monitoring excess body charges in at least one predefined SOI device and providing an output control signal;

applying a select signal for the SOI CMOS circuit and said output control signal to said select signal adjusting circuit;

utilizing said select signal adjusting circuit, providing a conditionally adjusted select signal responsive to said output control signal of said floating body charge monitor circuit; and

applying said conditionally adjusted select signal to the SOI CMOS circuit.

15. A method to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 14 wherein the step of utilizing said select signal adjusting circuit, providing a conditionally adjusted select signal responsive to said output control signal of said floating body charge monitor circuit includes the step of:

providing said conditionally adjusted select signal with a predefined delay at the trailing edge of said select signal for extending a select signal pulse width.

16. A method to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 14 wherein the step of utilizing said select signal adjusting circuit, providing a conditionally adjusted select signal responsive to said output control signal of said floating body charge monitor circuit includes the step of:

providing said conditionally adjusted select signal output having a delayed rising edge of said select signal when triggered by said output control signal of said floating body charge monitor circuit.

17. A method to ensure functionality and timing robustness in a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) circuit as recited in claim 14 wherein the step of utilizing said select signal adjusting circuit, providing a conditionally adjusted select signal responsive to said output control signal of said floating body charge monitor circuit includes the steps of:

providing said conditionally adjusted select signal output having a substantially unchanged pulse width and a delayed rising edge of said select signal when triggered by said output control signal of said floating body charge monitor circuit.