一個新的直流轉直流升壓轉換器具有高效率與低漣波電壓輸出被提出。我們利用開關電容式轉換器取代之前之電荷幫浦轉換器而改善了能源效率與在輸出端增加電壓調節器去降低漣波電壓。此轉換器比之前之轉換器降低了輸出漣波電壓36%，而且改善了能源效率從58%至73%。被提出之轉換器設計成一個提供1.6安培驅動力且輸出於5.3 ~ 5.4伏特電壓。電壓控制震盪器(VCO)當成轉換器之負載。而電壓控制震盪器對電源雜訊不感到靈敏。所提出電路之模擬皆以 TSMC 0.35-um Mixed-mode (2P4M) CMOS 製程來實現。

A new DC-DC up converter with high efficiency and low output ripple is proposed. We replace previous charge pump converters by switched-capacitor converters to improve the power efficiency and add a voltage regulator at the output to reduce the ripple voltage. The converter reduces the magnitude of output voltage ripples to 36% of the previous converter, and improves the power efficiency from 58% to 73%. The proposed converter is designed to obtain 1.6 mA driving capability with a output voltage around 5.3 ~ 5.4 V. A VCO is also added as the load to test the converter circuit. The VCO is insensititive to power supply noises. The proposed converter circuit is simulated in a TSMC 0.35-um Mixed-mode (2P4M) CMOS process.

1. Introduction 01
2. Previous Charge Pump DC-DC Converter and Voltage Doubler 03
2-1 Cross-Coupled Voltage Doubler 03
2-2 Previous DC-DC Converter Circuit 09
2-2-1 Dickson’s Charge Pump 09
2-2-2 Charge Pump Employing NMOS Switches 10
2-2-3 Previous DC-DC converter 11
(a) Charge Pump with PMOS Switches 11
(b) Previous DC-DC Converter Circuit 12
2-3 Comparison and Discussion 14
(a) Swicthed-Capacitor & Charge Pump Type Converters 14
(b) Cross-Coupled Voltage Doubler & Previous DC-DC Converter 15
2-4 On Chip Capacitor 16

3. Architecture and Principle of Switched-Capacitor DC-DC Converter 18
3-1 The Proposed Architecture of Switched-Capacitor DC-DC Converter 18
3-2 Proposed Switched-Capacitor DC-DC Converter Circuit 19
3-2-1 Nonoverlapping Clock Circuit 19
3-2-2 SC Converter Circuits 20
3-2-3 Insensitive Voltage Source Reference&Voltage Regulator 21
3-3 VCO as a Test Circuit 24
3-3-1 Basic Theory of VCO Based on Ring Oscillator 24
3-3-2 VCO Based on Ring Oscillator 25

4. Simulation Result and Discussion 27
4-1 Simulation Result 27
4-2 Discussion 29

5. Conclusion 31
Appendix 32
Reference 34

[1] J. F. Dickson, “ On-chip high-voltage generation in MNOS integrated circuits using an improved voltage multiplier technique, “ IEEE J. Solid-State Circuits, vol. sc-11, no. 3, pp. 374-378, June 1976.

[2] P. Favrat, P. Deval, and M.J.Declercq,“ A new high efficiency CMOS voltage doubler ”, in IEEE Custom Integrated Circuits Conf.,1997, pp.259-262.

[3] J.T.Wu, K.L.Chang,“MOS charge pumps for low-voltage operation, ”IEEE journal of Solid-State Circuits ”, Vol.33, No.4, April 1998, pp.592-597.

[4] Seung-Chul Lee, Dong-Soo Park, Jung-Hee Song, Myung-Whan,“ A low-ripple switched-capacitor DC-DC up converter for low voltage applications ”, ASICs, 2000. AP-ASIC 2000. Proceedings of the Second IEEE Asia Pacific Conference on , 2000. pp.13-16.

[5] D. Maksimovic, S. Dhar,“ Switched-capacitor DC-DC converters for low-power on-chip applications ”, Power Electronics Specialists Conference, 1999. PESC 99. 30th Annual IEEE. Vol.1, Aug 1999. pp. 54-59.

[6] Adrian Ioinovici,“ Switched-capacitor power electronics circuits ”, IEEE Circuits and Systems Magazine, Vol.1, Issue.3, Third Quarter 2001. pp. 37-42.

[7] Shyh-Jye Jou, Tsu-Lin Chen,“ On-chip voltage down converter for low-power digital system ”, Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on. Vol.45. Issue.5. May 1998. pp. 617-625.

[8] Wang Qi; Shao Bingxian, “ A design of CMOS voltage doubler for 1V operation ”, ASIC, 2001. Proceedings. 4th International Conference on , 2001.pp. 255-258.

[9] Li Geng; Zhiming Chen; Jian Liu;“ Design of a hybrid monolithic integrated switched capacitor DC-DC step-up converter ”, Power Electronics and Motion Control Conference, 2000. Proceedings. PIEMC 2000. The Third International , Volume: 1 , 2000. pp. 263-266.

[10] J. Millman and A. Grabel, Microelectronics, 2 nd. New York: McGraw-Hill, 1987.