Group member: Zhaoxin Mamengduo Cfang Stanley The
Implementation of Delta-Sigma Modulation in Digital-to-Analog
Converter 1
Slide 2
Project Idea Motivation: EE 505 CMOS Data Conversion circuits
During the process of digital-to-analog converting Use Delta-sigma
modulator to push noise in music to high frequency band Use
speaker/headphone as the low-pass filter to filtrate high frequency
white noise 2
Slide 3
Top Level Components Delta-sigma modulation Delta-sigma
modulation Low pass filter PCM(digital) In Serial Pulse Width
Modulation (PWM,digital) Signal In Serial 3
Slide 4
Level-shifter for DVD Output Signal Output signal(from DVD)
voltage: -0.5V~+0.5V Schmidt trigger: SN74LS14N 4 rheostat
Slide 5
Demo Film1 Play CD Film1
http://www.youtube.com/watch?v=582E_OXeVOU Film2 Input signal
voltage shift Film2
http://www.youtube.com/watch?v=uBhcLwn46QM&fea ture=youtu.be
Film3 Sleep mode Film3
http://www.youtube.com/watch?v=Q74URMVuhF8&fe ature=youtu.be
5
Slide 6
The Structure of DAC module 6
Slide 7
Input: PCM 7
Slide 8
The 3-stage Delta-sigma Modulation Y 1 X+(1 Z -1 )Q Y 2 Q 1 1 Z
1 )Q 2 Y 3 Q 2 (1 Z -1 )Q 3 Y X+ 1 Z 1 ) 3Q 3 PCM PWM 8
Slide 9
Eleven PWM Signals 9
Slide 10
Output: PWM PWM: digital signal but has analog info. 10
Slide 11
Matlab Simulation: Noise is pushed to higher frequencies
11
Slide 12
Using Filter to Cutoff Noise 12
Slide 13
One Order Noise Shaping Model Q Y U U Y Q U X Q 13
Slide 14
One Order Noise Shaping Model U (n) X (n) Q (n-1) Q (n) Y (n) U
(n) Y (n) X (n) Q (n 1) Q (n) X (n) Q (n) Q (n 1) Q (n) Q (n 1) 1 Z
1 Q Y X 1 Z 1 Q 14
Slide 15
The 3-stage Delta-Sigma Modulation Y 1 X+(1 Z -1 )Q Y 2 Q 1 1 Z
1 )Q 2 Y 3 Q 2 (1 Z -1 )Q 3 Y X+ 1 Z 1 ) 3Q 3 15
Slide 16
Clock Synchronization with DVD Input signal(from DVD) is in
serial: Need to decode SPDIF signal So need to synchronize clock
with DVD 16