Digital Signal Processing Reference
In-Depth Information
b
10
b
9
b
8
b
7
b
6
b
5
b
4
b
3
b
2
b
1
Thermometer decoder
Binary decoder
I+
I-
Switching core
Current source array
Fig. 16
Architecture of a 10-bit segmented current-steering DAC
I
out
2
R
2
R
2
R
2
R
R
R
R
2
R
I
I
I
I
V
ss
Fig. 17
A 6-bit segmented current-steering DAC
Din
Digital
Interpolation
Filter
Analog
Lowpass
Filter
Vou
t
Sigma - Delta
Modulator
1-bit D/A
OSR
b
Fig. 18
Block diagram of a sigma-delta modulator-based DAC
sampled at the Nyquist rate (or a slightly higher rate). The signal is oversampled
by the OSR factor, denoted by the arrow upwards. Oversampling is in principle
carried out by inserting an appropriate number of zero-valued samples between
each two original samples, and filtering the resulting sparse signal with a digital
