digital-to-analog converter (DAC) with a phase-locked
loop (PLL) circuit included. The PLL derives either
256f
S
or 384f
S
system clock from an external 27MHz
reference frequency. The DAC contains a 3rd-order
鈭單?/div>
modulator, a digital interpolation filter, and an analog
output amplifier. The PCM1721 can accept 16-, 20-, or
24-bit input data in either normal or I
2
S formats.
The digital filter performs an 8X interpolation func-
tion and includes selectable features such as soft mute,
digital attenuation and digital de-emphasis. The PLL
can be programmed for sampling at standard digital
audio frequencies as well as one-half and double
sampling frequencies.
The PCM1721 is ideal for applications which combine
compressed audio and video data such as DVD, DVD-
ROM, set-top boxes and MPEG sound cards.
BCKIN
LRCIN
DIN
Serial
Input
I/F
8X Oversampling
Digital Filter
with Function
Controller
Multi-level
Delta-Sigma
Modulator
DAC
Low-pass
Filter
V
OUT
L
CAP
Multi-level
Delta-Sigma
Modulator
Low-pass
Filter
V
OUT
R
ML
MC
MD
Mode
Control
I/F
DAC
ZERO
BPZ-Cont.
256f
S
/384f
S
Open Drain
RSTB
Clock/OSC Manager and PLL
Power Supply
SCKI
MCKI
SCKO
V
CP
PGND V
CC
AGND V
DD
DGND
International Airport Industrial Park 鈥?Mailing Address: PO Box 11400, Tucson, AZ 85734 鈥?Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 鈥?Tel: (520) 746-1111 鈥?Twx: 910-952-1111
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