Panasonic sv-3200 Operating Instructions Manual page 42

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Technical Information 2
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4-bit 64fs
Digital filter
section
Digital output
16-bit fs
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MASH quantizer
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Figure 1. MASH-type l-bit ADC block diagram
l-bi! 512fs
MASH quanlization circuit
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Digital fitter section
Single-integral type noise-shaping
Digital inpul 4 x 8 x 32fs
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quantizer
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16-bit fs
FIR filter Doubte-integral type noise-shaping
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quantizer
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Figure 2. MASH-type I-bit DAC block diagram
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MASH is a trademark of NTT.
-42­
MASH Type 1-bit ADC/DAC
1. Features
In order to realize the ultimate in AD and DA conversion throughout
all frequency ranges , this unit has been equipped with the
revolulionary ADC /DAC unit which adopts " noise-shaping" and
over-sampling technologies .
The MASH-type I-bit ADCIDAC unit uses a single reference level,
thus in principle eliminating any non-linear distortion or zero-cross
distortion, and thus producing superb linearity across the range from
large to minute signal inputs. Further, the analog circuits connected
before and behind Ihe ADC/DAC unit makes unnecessary the
sample/hold circuits, de-glitcher circuit used in previous applications,
and also make it possible to use a simpler low-pass filter, thus
allowing accurate recording and playback reproduction even 01
minute signal inputs. This eliminates the " hard edge" of1en asso­
ciated wilh previous digital media, allowing you to enjoy a sof1er
sound closer to the analog original.
2. Construction
Figure 1 shows a block diagram of the MASH-type I-bit ADC unit.
The input analog signal is quantized at a 64 times oversampling by
the MASH quantization circuit, and transformed to 4-bit digital data,
af1er which it is IiItered by the digital filter, and output as 16-bit digital
data with the normal sampling frequency .
Fig. 2 is a block diagram of the MASH-type l-bit DAC unit. The 16-bit
input digital data passes through the digital filter section where it is 4
times sampted and transformed into 18-bit data. Next, the MASH
quantizing circuit provides tertiary noise shaping to yield 32 fs 8-level
data which is then transformed by the PWM l -bit DAC section into
pulse-width-modulated (PWM) waveforms, and output. The output is
a l-bit data with "low" and "high" states only.
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