D/A+ A/D Converter; Block - Teac TASCAM DA-P20 Service Manual

42
8. D/A: A/D CONVERTER BLOCK
e.g.
DA Convertor
PCM55
Oo ie)
SSPPESee ey
OVBWNAUFPAN-~O
D/A Converter
Output signal from D/A converter is multiplex signal of
_L-ch and R-ch.
S/H (Sample and Hold) circuit separates L-ch and R-ch
signals.
LPFsofLine-out cut unnecessary frequency andsmoothes
stepped waveform( __[ —»_/ ).
A/D Converter
.A/D converter is constructed by D/A converter and com-
parator.
4-bit A/D Converter
D/A Converter
Output
SH Output a
R—-ch
(SH Output a
L~—ch
—¢c
(1) Comparator compares analog input signal with digital output signal (1000) of D/A Converter.
(2) When the analog signal is bigger than the digital signal (1000), CPUs output digital signal (1100)
and, again, the comparates them.
(3) As the same manner when the input is bigger than output, CPUs output signal (1110).
Also when the input is smaller than output, CPUs output signal (1010).
(4) The comparator compares the analog and the digital signals until both signals, value become the
same.
Thus, an analog signal is converted into a digital signal.