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
∆Σ
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 • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111
NOTES: (1) Sysclk transient is the maximum frequency lock time when the PLL frequency is changed. (2) Dynamic performance specs are tested with 20kHz low
pass filter and THD+N specs are tested with 30kHz LPF, 400Hz HPF, Average-Mode. (3) SNR is tested at Infinite Zero Detection off.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no
responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice.
No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN
product for use in life support devices and/or systems.
®
PCM1721
2
PIN CONFIGURATION
TOP VIEW
SSOP
PIN ASSIGNMENTS
PIN
1
2
NAME
MCKI
SCKO
V
CP
SCKI
RES
ML
MC
MD
RSTB
ZERO
TYPE
IN
OUT
PWR
IN
N/A
IN
IN
IN
IN
OUT
FUNCTION
Master Clock Input.
System Clock Out. This output is 256f
S
or 384f
S
system clock generated by the internal PLL.
PLL Power Supply (+5V)
System Clock (256f
S
or 384f
S
) Input.
Reserved for factory use, do not connect.
Latch for serial control data
Clock for serial control data
Data for serial control
Reset Input. When this pin is low, the digital
filters and modulators are held in reset.
Zero Data Flag. This pin is low when the input
data is continuously zero for more than 65, 535
cycles of BCKIN.
Right Channel Analog Output
Analog Ground
Analog Power Supply (+5V)
Left Channel Analog Output
Common pin for analog output amplifiers.
IN
IN
IN
N/A
N/A
PWR
GND
GND
—
Bit clock for clocking in the audio data.
Serial audio data input
Left/Right Word Clock. Frequency is equal to f
S
.
Test pin, must be tied “LOW”.
Reserved for factory use, do not connect.
Analog Power Supply (+5V)
Digital Ground
PLL Ground
No Connection
MCKI
SCKO
V
CP
SCKI
RES
ML
MC
MD
RSTB
1
2
3
4
5
6
7
8
9
24 NC
23 PGND
22 DGND
21 V
DD
20
19
18
17
16
15
14
13
RES
TEST
LRCIN
DIN
BCKIN
CAP
V
OUT
L
V
CC
3
4
5
6*
7*
8*
9*
10
11
12
13
14
15
16*
17*
18*
19
V
OUT
R
AGND
V
CC
V
OUT
L
CAP
BCKIN
DIN
LRCIN
TEST
RES
V
DD
DGND
PGND
NC
OUT
GND
PWR
OUT
ZERO 10
V
OUT
R 11
AGND 12
PACKAGE INFORMATION
PRODUCT
PCM1721
PACKAGE
24-Pin SSOP
PACKAGE DRAWING
NUMBER
(1)
338
20
21
22
23
24
NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix C of Burr-Brown IC Data Book.
* These pins include internal pull-up resistors.
ABSOLUTE MAXIMUM RATINGS
Power Supply Voltage ....................................................................... +6.5V
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