Design Considerations for Low-Voltage Crystal Oscillator Circuit in a 1.8-V Single Chip Microprocessor
Summary :
A low-voltage, high-speed 4-bit CMOS single chip microprocessor, with instruction execution time of 1.0µs at a power supply voltage of 1.8V, has been developed. A single chip processor generally includes crystal oscillation circuits to generate a system clock or a time-base clock. But when the operating voltage is lowered, it becomes difficult to get oscillations to start reliably and to continue stably. This paper describes a low voltage circuit design method for built-in crystal oscillators. Simple design equations for oscillation starting voltage and oscillation starting time are introduced. Then effects of the circuit device parameters, such as power supply voltage, loop gain values, and subthreshold swing S, on the low voltage performance of the crystal oscillators are considered. It is shown that the crystal oscillators operate in a tailing (subthreshold) region at voltages lower than about 1.8 V. Subthreshold swing, threshold voltage, and open loop gain have a significant influence on low voltage oscillation capability. This design method can be applied to crystal oscillators for a wide range of operating voltages.
- Publication
- IEICE TRANSACTIONS on Electronics Vol.E76-C No.5 pp.701-707
- Publication Date
- 1993/05/25
- Publicized
- Online ISSN
- DOI
- Type of Manuscript
- Special Section PAPER (Special Section on Low-Power and Low-Voltage Integrated Circuits)
- Category
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Shigeo KUBOKI, Takehiro OHTA, Junichi KONO, Yoji NISHIO, "Design Considerations for Low-Voltage Crystal Oscillator Circuit in a 1.8-V Single Chip Microprocessor" in IEICE TRANSACTIONS on Electronics,
vol. E76-C, no. 5, pp. 701-707, May 1993, doi: .
Abstract: A low-voltage, high-speed 4-bit CMOS single chip microprocessor, with instruction execution time of 1.0µs at a power supply voltage of 1.8V, has been developed. A single chip processor generally includes crystal oscillation circuits to generate a system clock or a time-base clock. But when the operating voltage is lowered, it becomes difficult to get oscillations to start reliably and to continue stably. This paper describes a low voltage circuit design method for built-in crystal oscillators. Simple design equations for oscillation starting voltage and oscillation starting time are introduced. Then effects of the circuit device parameters, such as power supply voltage, loop gain values, and subthreshold swing S, on the low voltage performance of the crystal oscillators are considered. It is shown that the crystal oscillators operate in a tailing (subthreshold) region at voltages lower than about 1.8 V. Subthreshold swing, threshold voltage, and open loop gain have a significant influence on low voltage oscillation capability. This design method can be applied to crystal oscillators for a wide range of operating voltages.
URL: https://global.ieice.org/en_transactions/electronics/10.1587/e76-c_5_701/_p
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@ARTICLE{e76-c_5_701,
author={Shigeo KUBOKI, Takehiro OHTA, Junichi KONO, Yoji NISHIO, },
journal={IEICE TRANSACTIONS on Electronics},
title={Design Considerations for Low-Voltage Crystal Oscillator Circuit in a 1.8-V Single Chip Microprocessor},
year={1993},
volume={E76-C},
number={5},
pages={701-707},
abstract={A low-voltage, high-speed 4-bit CMOS single chip microprocessor, with instruction execution time of 1.0µs at a power supply voltage of 1.8V, has been developed. A single chip processor generally includes crystal oscillation circuits to generate a system clock or a time-base clock. But when the operating voltage is lowered, it becomes difficult to get oscillations to start reliably and to continue stably. This paper describes a low voltage circuit design method for built-in crystal oscillators. Simple design equations for oscillation starting voltage and oscillation starting time are introduced. Then effects of the circuit device parameters, such as power supply voltage, loop gain values, and subthreshold swing S, on the low voltage performance of the crystal oscillators are considered. It is shown that the crystal oscillators operate in a tailing (subthreshold) region at voltages lower than about 1.8 V. Subthreshold swing, threshold voltage, and open loop gain have a significant influence on low voltage oscillation capability. This design method can be applied to crystal oscillators for a wide range of operating voltages.},
keywords={},
doi={},
ISSN={},
month={May},}
Copy
TY - JOUR
TI - Design Considerations for Low-Voltage Crystal Oscillator Circuit in a 1.8-V Single Chip Microprocessor
T2 - IEICE TRANSACTIONS on Electronics
SP - 701
EP - 707
AU - Shigeo KUBOKI
AU - Takehiro OHTA
AU - Junichi KONO
AU - Yoji NISHIO
PY - 1993
DO -
JO - IEICE TRANSACTIONS on Electronics
SN -
VL - E76-C
IS - 5
JA - IEICE TRANSACTIONS on Electronics
Y1 - May 1993
AB - A low-voltage, high-speed 4-bit CMOS single chip microprocessor, with instruction execution time of 1.0µs at a power supply voltage of 1.8V, has been developed. A single chip processor generally includes crystal oscillation circuits to generate a system clock or a time-base clock. But when the operating voltage is lowered, it becomes difficult to get oscillations to start reliably and to continue stably. This paper describes a low voltage circuit design method for built-in crystal oscillators. Simple design equations for oscillation starting voltage and oscillation starting time are introduced. Then effects of the circuit device parameters, such as power supply voltage, loop gain values, and subthreshold swing S, on the low voltage performance of the crystal oscillators are considered. It is shown that the crystal oscillators operate in a tailing (subthreshold) region at voltages lower than about 1.8 V. Subthreshold swing, threshold voltage, and open loop gain have a significant influence on low voltage oscillation capability. This design method can be applied to crystal oscillators for a wide range of operating voltages.
ER -
English
