AD DA変換器 - dsl.hiroshima-u.ac.jp

1 10 . AD DA . Analog-to-Digital Converter Digital-to-Analog Converter 1. 2009/2/2 .. AD .. 010. 5 100. (V). 4 101. 3. 011. 000. 2. 010. 1. 011. 0 010. Ts 010.. 2. 2009/2/2 .. 1. fs .. fs 2fs 3fs 4fs 5fs 6fs 7fs 8fs . 3. 2009/2/2 .. 1. fs .. fs 2fs 3fs 4fs 5fs 6fs 7fs 8fs . 4. 2009/2/2 .. 1. fs .. fs 2fs 3fs 4fs 5fs 6fs 7fs 8fs . 5. 2009/2/2 .. DA AD . V ref n V out =. 2 n i =1. b i 2 i 1. Vout/Vref 1 1000.. 7/8 111. 6/8 110. 5/8 101.. 4/8 100. 3/8 011. 2/8 010. 1/8 001. 000. 0. 0. 1. 1/8. 2/8. 3/8. 4/8. 5/8. 6/8. 7/8. 101. 011. 001. 100. 010. 110. 111. 1000. 000.. 6. 2009/2/2 .. DA .. R-2R .. PWM . 7. 2009/2/2 .. DA . 2 . C = 2 i 1 C. i 0. 2n-1 2n-2 4 2 1 1 . V0. Cn Cn-1 C3 C2 C1 C0.. Vref bn bn-1 b2 b1. b3. n . 8. 2009/2/2 .. DA .. Vref n 0 + . i =1. biC i - Vo Co + + n MOS FET . Co - - . i =1.

2 BiC i .. 0 . n n V o (C 0 + . i =1. b i C i ) ( V ref V o ) b i C i = 0. i =1. 9. 2009/2/2 .. DA .. Charge Redistribution n . i =1. biC i Vo = n Vref n Co + b i C i + . i =1. biC i i =1. V ref n =. 2 n i =1. b i 2 i 1 . 10. 2009/2/2 .. DA .. Vref R2n 2n-1. R2n-1 . bn 2n-2. Vout bn-1 R2n-2. 2n-3. b3 0 . MOS . b2. R2 . b1. 1. R1. 0. V ref n Vo =. 2 n . i =1. b i 2 i 1. 11. 2009/2/2 .. AD .. M.. MASH .. 12. 2009/2/2 .. (S/H) . CMOS .. 13. 2009/2/2 .. AD . (Vin) . (Vref) . Vref .. Vin Vin Vref .. Vin . Vref .. Vin . CLK .. 14. 2009/2/2 .. AD . (S/H) . DA 1/2FS , , 1/2FS "1", "0" . (1/2+1/4) FS or (1/2-1/4) FS . 2 "1","0" . n AD . Vin . D-A .. S/H . SAR FS. FS 8. 8 (LSB) 4. 7. 6. 5 Dout . FS. 4. 3 2. 2. 1 (MSB). DA . 15. 2009/2/2 .. SAR. D-A .. 1 0 0 0 0 1/2. C1 1 0 0 0 1/2 1/4. C1 C2 1 0 0. C1 C2 C3 1 0.

3 C1 C2 C3 C4 1. C1 C2 C3 C4 C5. FS: MSB LSB.. S/H . 16. 2009/2/2 .. AD . DA Vref1 Vrefn .. Vin Vrt Encoder Output Buffer L L. Vref3. L L. Dout Vref2. L L. Vref1 . NOR. Clk1 Clk2 Clk3 Clk4. Vrb Clock Generator Clock 17. 2009/2/2 .. AD .. n Vrefn 0. n-1 Vrefn-1 0. n-1 . Vref7 0. Vref6 0. Vref5 0. Vref4 0. Vref3 1. Vref2 1. Vref1 1. 18. 2009/2/2 .. n .. AD n 64 .. ( 8 ).. 1. f os . f os = 8 f s . 19. 2009/2/2 .. 1 AD . H(z) Quantizer x(n) + + Z-1 +. - y(n). - 1bit DA. Analog Digital 1. fos C 2. 1 C 2. Vin Comparator . x(n) 2 1 + y(n). 2 C. ( 1 ) 2 . Vref/2. 1 , y(n) high: 1 , 2. ( 2 ) y(n) low: 1 ) , 2 ). 20. 2009/2/2 .. 0. (S) . -20 . (dB). -40. -60. -80. S/S N . -100. -120. N. -140. 0 2fs 4fs 6fs 8fs 10fs . 21. 2009/2/2 .. AD .. D-A S/H .. D-A S/H . S/H , ( 2n-1) . LSI . , , . { ( 2 - 1 ) + (2 - 1 ) }.

4 M n m, n , A-D . S/H, D-A S/H, D-A .. S/H , , , , D-A . LSI .. 10 ksps .. , , .. 22. 2009/2/2 .. A-D . MODEM CD ISDN (64 128Kb/s). CODEC MD, DVD, DAT.. 22. 20. 18 Audio . 16. 14 .. 12 . Wireless 10 . Video . 8.. 6. 4 .. 2. 100 1k 10k 100k 1M 10M 100M 1G 10G. (Hz). 23. 2009/2/2 .. A-D .. 22. 20. 18 Audio 16 . 14 .. ISDN. 12 Wireless . 10 . Video .. 8.. 6. 4. 2. 100 1k 10k 100k 1M 10M 100M 1G 10G. (Hz). 24. 2009/2/2 .. 2009 1 20 .. C, MOS . R, MOS . MOS . 25. 2009/2/2 .. 2009 1 27 .. bit . 8 16 100 100M S/H, DAC, : 10uW. Comp 1 1mW. 3 8 10M 10G Comp 2n : 100mW. W. 10 24 10 10M comp : 1mW. DAC 1 100mW. 26. 2009/2/2.