ON-CHIP RANDOMNESS GENERATION

• US 20140197865A1
• Filed: 01/11/2013
• Published: 07/17/2014
• Est. Priority Date: 01/11/2013
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Feng, Kai D., Wang, Ping-Chuan, Yang, Zhijian, Yashchin, Emmanuel
• Application Number:
  US13/739,151
• Publication Number:
  US 20140197865A1
• Time in Patent Office: Days
• US Class Current: 327/100
• CPC Class Codes: H03K 3/012 Modifications of generator to improve response time or to decrease power consumption
• CPC Class Codes: H03K 3/313 by the use, as active elements, of semiconductor devices with two electrodes, one or two potential barriers, and exhibiting a negative resistance characteristic
• CPC Class Codes: H03K 3/84 Generating pulses having a predetermined statistical distribution of a parameter, e.g. random pulse generators
• CPC Class Codes: H03K 5/01 Shaping pulses discrimination against noise or interference H03K5/125

Abstract

An on-chip true noise generator including an embedded noise source with a low-voltage, high-noise zener diode(s), and an in-situ close-loop zener diode power control circuit. The present invention proposes the use of heavily doped polysilicon and silicon p-n diode(s) structures to minimize the breakdown voltage, increasing noise level and improving reliability. The present invention also proposes an in-situ close-loop zener diode control circuit to safe-guard the zener diode from catastrophic burn-out.

Claims

1. An apparatus comprising:

a zener diode located on a substrate;

a voltage source located on the substrate to provide a supply voltage to the zener diode; and

a current monitor located on the substrate to monitor the current through the zener diode and adjust the supply voltage provide by the voltage source to maintain the zener diode in the avalanche zone close to the breakdown condition, wherein the zener diode provides a random noise output.

2. The apparatus of claim 1 further comprising a current probe, wherein the current probe receives the supply voltage and provides a voltage to the zener diode, the current probe providing a current mirroring the current through the zener diode to the current monitor.

3. The apparatus of claim 1, wherein the zener diode is a heavily doped pn junction zener diode.

4. The apparatus of claim 1, wherein voltage source comprises a counter and a digital to analog converter wherein the digital to analog converter provides a threshold voltage to an amplifier, the amplifier providing the supply voltage.

5. The apparatus of claim 3, wherein the zener diode comprises a multi-finger structure.

6. The apparatus of claim 1, wherein the avalanche zone is around 1.5 volts.

7. The apparatus of claim 2, wherein the current monitor comprises a trans-impedance amplifier to monitor the current from the current probe and provide an output voltage, wherein the current monitor provides a increment signal to the voltage source when the output voltage is below a first threshold, and a decrement signal to the voltage source when the output voltage is above a second threshold.

8. The apparatus of claim 4, wherein a noise signal is provided to amplifier in the voltage source.

9. An apparatus comprising:

a first and a second noise generating unit; and

a single-stage differential stochastic amplifier, wherein the first noise generating unit is input into a negative input of the amplifier, and the second noise generating unit is input into the positive input of the amplifier.

10. The apparatus of claim 9, wherein each of the noise generating unit comprises:

a zener diode located on a substrate;

a voltage source located on the substrate to provide a supply voltage to the zener diode; and

a current monitor located on the substrate to monitor the current through the zener diode and adjust the supply voltage provide by the voltage source to maintain the zener diode in the avalanchezone, wherein the zener diode provides a random noise output.

11. The apparatus of claim 10, wherein the zener diode is a heavily doped pn junction zener diode.

12. The apparatus of claim 11, wherein voltage source comprises a counter and a digital to analog converter wherein the digital to analog converter provides a threshold voltage to an amplifier, the amplifier providing the supply voltage.

13. The apparatus of claim 12, wherein the zener diode comprises a multi-finger structure.

14. The apparatus of claim 11, wherein the avalanche zone is around 1.5 volts.

15. An apparatus comprising:

A plurality of noise generating unit pairs, each of said pair of noise generating units having a first and a second noise generating units;

a first set of single-stage differential stochastic amplifiers, wherein each of said noise generating units pairs is input into one of the first set of single-stage differential stochastic amplifiers the first noise generating unit is input into a negative input of one of the first set of single-stage differential stochastic amplifiers, and the second noise generating unit is input into the positive input of one of the first set of single-stage differential stochastic amplifiers; and

at least a second single-stage differential stochastic amplifier receiving an input from two of the first set of single-stage differential stochastic amplifiers.

16. The apparatus of claim 15 wherein each of the noise generating unit comprises:

a zener diode located on a substrate;

a voltage source located on the substrate to provide a supply voltage to the zener diode; and

a current monitor located on the substrate to monitor the current through the zener diode and adjust the supply voltage provide by the voltage source to maintain the zener diode in the avalanche zone, wherein the zener diode provides a random noise output.

17. The apparatus of claim 16, wherein the zener diode is a heavily doped pn junction zener diode.

18. The apparatus of claim 17, wherein voltage source comprises a counter and a digital to analog converter wherein the digital to analog converter provides a threshold voltage to an amplifier, the amplifier providing the supply voltage.

19. The apparatus of claim 18, wherein the zener diode comprises a multi-finger structure.

20. The apparatus of claim 17, wherein the avalanche zone is around 1.5 volts.