1. DESIGN OF LOW POWER CURRENT-MODE FLASH ADC
Bhat, M.S.; Rekha, S.; Jamadagni, H.S
TENCON IEEE Region 10 Conference
指導教授：易序忠
學生：劉得吉
學號：

2. OutLine Abstract Introduction Basics of Current-Mirroring
Circuit Implementation
Concusions
References

3. Abstract
For high-speed operation, current mirroring technique with current comparison architecture is used.
The optimization procedure is aimed at minimizing static power consumption, and its impact on circuit performance.

4. Introduction
Generally, current mode circuits neither require amplifiers with high voltage gains there by reducing the need for high performance amplifiers nor require high precision resistors or capacitors.
The current comparators have high output impedance, which in turn limit the circuit speed.
This paper describes current-mirroring technique with optimal device sizing to achieve signal conversion at low power.

5. Basics of Current-Mirroring

6. Basic current comparator circuit
The drawback of large output resistance is the increased circuit delay.

7. Current-mode ADC

8. Circuit Implementation
MP0 – MPP：

9. Modified current comparator
In a higher conversion speed at the expense of increased static power
consumption.

10. Power consumption

11. Concusions
The maximum sampling rate is found to be 80Ms/Sec and a dynamic range of 32uA.
The circuit operates at 5 volts power supply dissipating an average power of 78mW.

12. References
C.-C. Chen, C.-Y low-power CMOS current-mode cyclic analog-to-digital converters”, IEEE Trans. on circuits and systems – II: Analog and digital signal processing, vol. 45, no. 1, pp , Jan
M. P. Fl converters with current-mode interpolation”, IEEE J. of solid-state circuits, vol. 31, no. 9, pp , Sept
D. G. Nairn and C. A. T. Salama, “A ratio-independent algorithmic analog-to-digital converter combining current-mode and dynamic techniques,” IEEE Trans. Circuits and Systems, vol. 37, pp. 319–325, Mar
D. G. Nairn and C. A. T. Salama, “Current-mod analog-to-digital converters,” IEEE J. Solid-State Circuits, vol. 25, pp. 997–1004, Aug
S. J. Daubert and D. Vallanco current-mode modulator,” IEEE J. Solid-State Circuits, vol. 27, pp. 821–830, May 1992.
D. Macq and P. G. A. Jespers, “A 10-bit pi switched-current A/D converter,” IEEE J. Solid-State Circuits, vol. 29, pp. 967–971, Aug
R. C. C. Hui and H. C. Luong pipeline ADC using zero-voltage sampling technique”, IEEE International Symposium on circuits and systems, vol. 1, pp. 9-12, 31 May – 3 Jun, 1998.