BB PCM1748E/2K

PCM1748
PCM
1748
SBAS165A – MAY 2001
24-Bit, 96kHz Sampling
Enhanced Multilevel, Delta-Sigma, Audio
DIGITAL-TO-ANALOG CONVERTER
FEATURES
APPLICATIONS
● 24-BIT RESOLUTION
● A/V RECEIVERS
● ANALOG PERFORMANCE (VCC = +5V):
Dynamic Range: 106dB typ (PCM1748KE)
100dB typ (PCM1748E)
SNR: 106dB typ (PCM1748KE)
100dB typ (PCM1748E)
THD+N: 0.002% typ (PCM1748KE)
0.003% typ (PCM1748E)
Full-Scale Output: 3.1Vp-p typ
● DVD MOVIE PLAYERS
● 8x OVERSAMPLING DIGITAL FILTER:
Stopband Attenuation: –55dB
Passband Ripple: ±0.03dB
● SAMPLING FREQUENCY: 5kHz to 100kHz
● SYSTEM CLOCK: 256, 384, 512, 768fS with
Auto Detect
● ACCEPTS 16-, 18-, 20-, AND 24-BIT AUDIO
DATAzx
● DATA FORMATS: Standard, I2S, and
Left-Justified
● USER-PROGRAMMABLE MODE CONTROLS:
Digital Attenuation: 0dB to –63dB, 0.5dB/Step
Digital De-Emphasis
Digital Filter Roll-Off: Sharp or Slow
Soft Mute
Zero Flags for Each Output
● DVD ADD-ON CARDS FOR HIGH-END PCs
● HDTV RECEIVERS
● CAR AUDIO SYSTEMS
● OTHER MULTICHANNEL AUDIO SYSTEMS
DESCRIPTION
The PCM1748 is a CMOS, monolithic, integrated circuit which
includes stereo Digital-to-Analog Converters (DACs) and support
circuitry in a small SSOP-16 package. The data converters utilize
Texas Instrument’s enhanced multilevel delta-sigma architecture
that employs fourth-order noise shaping and 8-level amplitude
quantization to achieve excellent dynamic performance and improved tolerance to clock jitter. The PCM1748 accepts industry
standard audio data formats with 16- to 24-bit data, providing easy
interfacing to audio DSP and decoder chips. Sampling rates up to
100kHz are supported. A full set of user-programmable functions
are accessible through a 3-wire serial control port that supports
register write functions.
● DUAL-SUPPLY OPERATION:
+5V Analog, +3.3V Digital
● 5V TOLERANT DIGITAL INPUTS
● SMALL SSOP-16 PACKAGE
● SAME PACKAGE SIZE AS SOP-8
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright © 2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
www.ti.com
ELECTROSTATIC
DISCHARGE SENSITIVITY
ABSOLUTE MAXIMUM RATINGS
Power Supply Voltage, VDD .............................................................. +4.0V
VCC .............................................................. +6.5V
Ground Voltage Differences .............................................................. ±0.1V
Digital Input Voltage ................................................ –0.3V to (6.5V + 0.3V)
Input Current (except power supply) ............................................... ±10mA
Ambient Temperature Under Bias .................................. –40°C to +125°C
Storage Temperature ...................................................... –55°C to +150°C
Junction Temperature .................................................................... +150°C
Lead Temperature (soldering, 5s) ................................................. +260°C
Package Temperature (IR reflow, 10s) .......................................... +235°C
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degradation
to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric
changes could cause the device not to meet its published
specifications.
PACKAGE/ORDERING INFORMATION
PRODUCT
PACKAGE
PACKAGE
DRAWING
NUMBER
PCM1748E
SPECIFIED
TEMPERATURE
RANGE
PACKAGE
MARKING
ORDERING
NUMBER(1)
TRANSPORT
MEDIA
PCM1748E
PCM1748E/2K
PCM1748KE
PCM1748KE/2K
Rails
Tape and Reel
Rails
Tape and Reel
SSOP-16
322
–25°C to +85°C
PCM1748E
"
"
"
"
"
PCM1748KE
SSOP-16
322
–25°C to +85°C
PCM1748KE
"
"
"
"
"
NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K indicates 2000 devices per reel). Ordering 2000 pieces
of “PCM1748E/2K” will yield a single 2000-piece Tape and Reel.
PIN CONFIGURATION
PIN ASSIGNMENTS
TOP VIEW
SSOP
BCK
1
16
SCK
DATA
2
15
ML
LRCK
3
14
MC
DGND
4
13
MD
PCM1748
VDD
5
12
ZEROL/NA
VCC
6
11
ZEROR/ZEROA
VOUTL
7
10
VCOM
VOUTR
8
9
AGND
PIN
NAME
TYPE
1
BCK
IN
FUNCTION
2
DATA
IN
Audio Data Digital Input.(1)
3
LRCK
IN
L-Channel and R-Channel Audio Data Latch Enable Input.(1)
4
DGND
–
Digital Ground
5
VDD
–
Digital Power Supply, +3.3V
Audio Data Bit Clock Input.(1)
6
VCC
–
7
VOUTL
OUT
8
VOUTR
OUT
9
AGND
–
Analog Ground
–
Common Voltage Decoupling.
10
VCOM
11
ZEROR/
ZEROA
OUT
Analog Power Supply, +5V
Analog Output for L-Channel.
Analog Output for R-Channel.
Zero Flag Output for R-Channel/Zero Flag Output
for L/R-Channel.
12
ZEROL/NA
OUT
13
MD
IN
Mode Control Data Input.(2)
14
MC
IN
Mode Control Clock Input.(2)
15
ML
IN
Mode Control Latch Input.(2)
16
SCK
IN
System Clock Input.
Zero Flag Output for L-Channel/No Assign.
NOTES: (1) Schmitt-trigger input, 5V tolerant. (2) Schmitt-trigger with internal
pull-down, 5V tolerant.
2
PCM1748
SBAS165
ELECTRICAL CHARACTERISTICS
All specifications at TA = +25°C, VCC = 5.0V, VDD = 3.3V, fS = 44.1kHz, system clock = 384fS, and 24-bit data, unless otherwise noted.
PCM1748E
PCM1748KE
PARAMETER
CONDITIONS
MIN
RESOLUTION
DYNAMIC PERFORMANCE(4)
PCM1748E
THD+N at VOUT = 0dB
THD+N at VOUT = –60dB
Dynamic Range
Signal-to-Noise Ratio
Channel Separation
Level Linearity Error
PCM1748KE
THD+N at VOUT = 0dB
THD+N at VOUT = –60dB
Dynamic Range
Signal-to-Noise Ratio
Channel Separation
Level Linearity Error
DC ACCURACY
Gain Error
Gain Mismatch, Channel-to-Channel
Bipolar Zero Error
ANALOG OUTPUT
Output Voltage
Center Voltage
Load Impedance
DIGITAL FILTER PERFORMANCE
Filter Characteristics 1, Sharp Roll-Off
Passband
Passband
Stopband
Passband Ripple
Stopband Attenuation
Stopband Attenuation
PCM1748
SBAS165
MAX
24
DATA FORMAT
Audio Data Interface Formats
Audio Data Bit Length
Audio Data Format
Sampling Frequency (fS)
System Clock Frequency
DIGITAL INPUT/OUTPUT
Logic Family
Input Logic Level
VIH
VIL
Input Logic Current
IIH(1)
IIL(1)
IIH(2)
IIL(2)
Output Logic Level
VOH(3)
VOL(3)
TYP
UNITS
Bits
Standard, IIS, Left-Justified
16-, 18-, 20-, 24-Bits Selectable
MSB-First, Binary Two’s Complement
5
100
256, 384, 512, 768fS
kHz
TTL-Compatible
2.0
VIN = VDD
VIN = 0V
VIN = VDD
VIN = 0V
IOH = –2mA
IOL = +2mA
fS = 44.1kHz
fS = 96kHz
fS = 44.1kHz
fS = 96kHz
EIAJ, A-Weighted, fS = 44.1kHz
A-Weighted, fS = 96kHz
EIAJ, A-Weighted, fS = 44.1kHz
A-Weighted, fS = 96kHz
fS = 44.1kHz
fS = 96kHz
VOUT = –90dB
fS = 44.1kHz
fS = 96kHz
fS = 44.1kHz
fS = 96kHz
EIAJ, A-Weighted, fS = 44.1kHz
A-Weighted, fS = 96kHz
EIAJ, A-Weighted, fS = 44.1kHz
A-Weighted, fS = 96kHz
fS = 44.1kHz
fS = 96kHz
VOUT = –90dB
65
94
94
91
100
100
97
Full Scale (0dB)
10
–10
100
–10
µA
µA
µA
µA
1.0
VDC
VDC
0.003
0.004
1.2
1.6
100
98
100
98
98
96
±0.5
0.008
%
%
%
%
dB
dB
dB
dB
dB
dB
dB
0.002
0.003
0.65
0.8
106
104
106
104
103
101
±0.5
0.006
%
%
%
%
dB
dB
dB
dB
dB
dB
dB
±1.0
±1.0
±30
±6
±3
±60
% of FSR
% of FSR
mV
62% of VCC
50% VCC
Vp-p
VDC
kΩ
5
±0.03dB
–3dB
0.454fS
0.487fS
0.546fS
Stopband = 0.546fS
Stopband = 0.567fS
VDC
VDC
2.4
VOUT = 0.5 VCC at Bipolar Zero
AC Load
0.8
–50
–55
±0.03
dB
dB
dB
3
ELECTRICAL CHARACTERISTICS (Cont.)
All specifications at TA = +25°C, VCC = 5.0V, VDD = 3.3V, system clock = 384fS (fS = 44.1kHz), and 24-bit data, unless otherwise noted.
PCM1748E
PCM1748KE
PARAMETER
CONDITIONS
DIGITAL FILTER PERFORMANCE (Cont.)
Filter Characteristics 2, Slow Roll-Off
Passband
Passband
Stopband
Passband Ripple
Stopband Attenuation
Delay Time
De-Emphasis Error
MIN
TYP
±0.5dB
–3dB
Stopband = 0.884fS
±0.5
+3.0
+4.5
Power Dissipation
–0.03
–0.20
dB
dB
+3.3
+5.0
6.0
13
8.5
9.0
62
88
fS = 44.1kHz
fS = 96kHz
fS = 44.1kHz
fS = 96kHz
fS = 44.1kHz
fS = 96kHz
ICC
20/fS
±0.1
dB
dB
sec
dB
–40
f = 20kHz
f = 44kHz
POWER SUPPLY REQUIREMENTS(4)
Voltage Range, VDD
VCC
Supply Current, IDD(6)
+3.6
+5.5
10
VDC
VDC
mA
mA
mA
mA
mW
mW
13
98
–25
–55
θJA
UNITS
0.198fS
0.390fS
0.884fS
ANALOG FILTER PERFORMANCE
Frequency Response
TEMPERATURE RANGE
Operation Temperature
Storage Temperature
Thermal Resistance
MAX
°C
°C
°C/W
+85
+125
SSOP-16
115
NOTES: (1) Pins 16, 1, 2, 3 (SCK, BCK, LRCK, DATA). (2) Pins 13-15 (MD, MC, ML). (3) Pins 11, 12 (ZEROR, ZEROL). (4) Analog performance specifications
are tested with a Shibasoku #725 THD Meter with 400Hz HPF on, 30kHz LPF on, and an average mode with 20kHz bandwidth limiting. The load connected
to the analog output is 5kΩ or larger, via capacitive coupling.
BLOCK DIAGRAM
BCK
LRCK
Serial
Input
I/F
DAC
8x
Oversampling
Digital Filter
with
Function
Controller
DATA
ML
MC
Output Amp and
Enhanced
Multi-Level
Delta-Sigma
Modulator
Function
Control
I/F
VOUTL
Low-Pass Filter
VCOM
DAC
Output Amp and
VOUTR
Low-Pass Filter
MD
System Clock
4
VCC
AGND
ZEROR
VDD
Power Supply
Zero Detect
DGND
System Clock
Manager
ZEROL
SCK
PCM1748
SBAS165
TYPICAL CHARACTERISTICS
All specifications at TA = +25°C, VCC = 5.0V, VDD = 3.3V, system clock = 384fS (fS = 44.1kHz), and 24-bit input data, unless otherwise noted.
DIGITAL FILTER
Digital Filter (De-Emphasis Off, fS = 44.1kHz)
FREQUENCY RESPONSE PASSBAND
(Sharp Roll-Off)
FREQUENCY RESPONSE (Sharp Roll-Off)
0
0.05
0.04
–20
0.03
0.02
Amplitude (dB)
Amplitude (dB)
–40
–60
–80
–100
0.01
0
–0.01
–0.02
–0.03
–120
–0.04
–0.05
–140
0
1
2
3
4
0
0.1
0.2
Frequency (x fS)
0.3
0.4
0.5
Frequency (x fS)
FREQUENCY RESPONSE (Slow Roll-Off)
TRANSITION CHARACTERISTICS (Slow Roll-Off)
0
5
4
–20
3
2
Amplitude (dB)
Amplitude (dB)
–40
–60
–80
–100
1
0
–1
–2
–3
–120
–4
–5
–140
0
1
2
3
0
4
0.1
0.2
0.3
0.4
0.5
Frequency (x fS)
Frequency (x fS)
De-Emphasis and De-Emphasis Error
DE-EMPHASIS ERROR (fS = 32kHz)
0.5
–1.0
0.4
–2.0
0.3
–3.0
0.2
–4.0
0.1
Error (dB)
Level (dB)
DE-EMPHASIS (fS = 32kHz)
0.0
–5.0
–6.0
0.0
–0.1
–7.0
–0.2
–8.0
–0.3
–9.0
–0.4
–0.5
–10.0
0
2
4
6
8
Frequency (kHz)
PCM1748
SBAS165
10
12
14
0
2
4
6
8
10
12
14
Frequency (kHz)
5
TYPICAL CHARACTERISTICS (Cont.)
All specifications at TA = +25°C, VCC = 5.0V, VDD = 3.3V, system clock = 384fS (fS = 44.1kHz), and 24-bit input data, unless otherwise noted.
De-Emphasis and De-Emphasis Error (Cont.)
DE-EMPHASIS ERROR (fS = 44.1kHz)
0.5
–1.0
0.4
–2.0
0.3
–3.0
0.2
–4.0
0.1
Error (dB)
Level (dB)
DE-EMPHASIS (fS = 44.1kHz)
0.0
–5.0
–6.0
0.0
–0.1
–7.0
–0.2
–8.0
–0.3
–9.0
–0.4
–0.5
–10.0
0
2
4
6
8
10
12
14
16
18
0
20
2
4
6
10
12
14
16
18
20
DE-EMPHASIS ERROR (fS = 48kHz)
DE-EMPHASIS (fS = 48kHz)
0.0
0.5
–1.0
0.4
–2.0
0.3
–3.0
0.2
–4.0
0.1
Error (dB)
Level (dB)
8
Frequency (kHz)
Frequency (kHz)
–5.0
–6.0
0.0
–0.1
–7.0
–0.2
–8.0
–0.3
–9.0
–0.4
–0.5
–10.0
0
2
4
6
8
10
12
14
16
18
20
22
0
2
4
6
Frequency (kHz)
8
10
12
14
16
18
20
22
Frequency (kHz)
ANALOG DYNAMIC PERFORMANCE
All specifications at TA = +25°C, VCC = 5.0V, VDD = 3.3V, and 24-bit input data, unless otherwise noted.
Supply-Voltage Characteristics
THD+N vs VCC (VDD = 3.3V)
10
1
–60dB/96kHz, 384fS
108
–60dB/44.1kHz, 384fS
106
0.1
SNR (dB)
THD+N (%)
DYNAMIC RANGE vs VCC (VDD = 3.3V)
110
0.01
0dB/96kHz, 384fS
44.1kHz, 384fS
104
96kHz, 384fS
102
100
0.001
0dB/44.1kHz, 384fS
98
0.0001
96
4
4.5
5
VCC (V)
6
5.5
6
4
4.5
5
5.5
6
VCC (V)
PCM1748
SBAS165
TYPICAL CHARACTERISTICS (Cont.)
All specifications at TA = +25°C, VCC = 5.0V, VDD = 3.3V, and 24-bit input data, unless otherwise noted.
Supply-Voltage Characteristics (Cont.)
SNR vs VCC (VDD = 3.3V)
CHANNEL SEPARATION vs VCC (VDD = 3.3V)
110
108
108
Channel Separation (dB)
110
SNR (dB)
106
104
96kHz, 384fS
102
100
98
106
104
44.1kHz, 384fS
102
96kHz, 384fS
100
98
96
96
4
4.5
5
5.5
6
4
4.5
5
VCC (V)
5.5
6
VCC (V)
Temperature Characteristics
DYNAMIC RANGE vs TA
THD+N vs TA
110
10
–60dB/96kHz, 384fS
108
–60dB/44.1kHz, 384fS
106
44.1kHz, 384fS
Dynamic Range (dB)
THD+N (%)
1
0.1
0.01
0dB/96kHz, 384fS
0.001
0dB/44.1kHz, 384fS
104
96kHz, 384fS
102
100
98
96
0.0001
–50
–25
0
25
50
75
100
–50
–25
0
Temperature (°C)
SNR vs TA
50
75
100
75
100
CHANNEL SEPARATION vs TA
110
110
108
108
Channel Separation (dB)
44.1kHz, 384fS
106
SNR (dB)
25
Temperature (°C)
104
96kHz, 384fS
102
100
98
106
104
44.1kHz, 384fS
102
96kHz, 384fS
100
98
96
96
–50
–25
0
25
Temperature (°C)
PCM1748
SBAS165
50
75
100
–50
–25
0
25
50
Temperature (°C)
7
SYSTEM CLOCK AND RESET
FUNCTIONS
POWER-ON RESET FUNCTIONS
The PCM1748 includes a power-on reset function, as shown in
Figure 2. With the system clock active, and VDD > 2.0V (typical
1.6V to 2.4V), the power-on reset function will be enabled.
After the initialization period, the PCM1748 will be set to its
reset default state, as described in the Mode Control Register
section of this data sheet.
SYSTEM CLOCK INPUT
The PCM1748 requires a system clock for operating the
digital interpolation filters and multilevel delta-sigma modulators. The system clock is applied at the SCK input (pin 16).
Table I shows examples of system clock frequencies for
common audio sampling rates.
Figure 1 shows the timing requirements for the system clock
input. For optimal performance, it is important to use a clock
source with low phase jitter and noise. The PLL1700 multiclock generator from Texas Instruments is an excellent choice
for providing the PCM1748 system clock.
During the reset period, the analog outputs are forced to the
bipolar zero level, or VCC/2. After the reset period, the
internal register is initialized in the next 1/fS period and, if
SCK, BCK, and LRCK are provided continuously, the
PCM1748 provides proper analog output with unit group
delay against the input data.
SYSTEM CLOCK FREQUENCY (fSCLK) (MHz)
SAMPLING
FREQUENCY
256fS
384fS
512fS
8kHz
2.0480
3.0720
4.0960
6.1440
16kHz
4.0960
6.1440
8.1920
12.2880
768fS
32kHz
8.1920
12.2880
16.3840
24.5760
44.1kHz
11.2896
16.9344
22.5792
33.8688
48kHz
12.2880
18.4320
24.5760
36.8640
88.2kHz
22.5792
33.8688
45.1584
See Note (1)
96kHz
24.5760
36.8640
49.1520
See Note (1)
NOTE: (1) The 768fS system clock rate is not supported for fS > 64kHz.
TABLE I. System Clock Rates for Common Audio Sampling Frequencies.
tSCKH
“H”
2.0V
“L”
0.8V
System Clock
tSCKL
System clock pulse
cycle time(1)
System Clock Pulse Width HIGH tSCKH: 7ns (min)
System Clock Pulse Width LOW tSCKL: 7ns (min)
NOTE: (1) 1/256fS, 1/384fS, 1/512fS, or 1/768fS.
FIGURE 1. System Clock Input Timing.
2.4V
VDD
2.0V
1.6V
0V
Reset
Reset Removal
Internal Reset
Don't Care
1024 System Clocks
System Clock
FIGURE 2. Power-On Reset Timing.
8
PCM1748
SBAS165
AUDIO SERIAL INTERFACE
The audio serial interface for the PCM1748 is comprised of
a 3-wire synchronous serial port. It includes LRCK (pin 3),
BCK (pin 1), and DATA (pin 2). BCK is the serial audio bit
clock, and is used to clock the serial data present on DATA
into the audio interface’s serial shift register. Serial data is
clocked into the PCM1748 on the rising edge of BCK.
LRCK is the serial audio left/right word clock used to latch
serial data into the serial audio interface’s internal registers.
Both LRCK and BCK should be synchronous to the
system clock. Ideally, it is recommended that LRCK and
BCK be derived from the system clock input, SCK. LRCK
is operated at the sampling frequency, fS. BCK may be
operated at 32, 48, or 64 times the sampling frequency.
Internal operation of the PCM1748 is synchronized with
LRCK. Accordingly, it is held when the sampling rate
clock of LRCK is changed or SCK and/or BCK is broken at
least for one clock cycle. If SCK, BCK, and LRCK are
provided continuously after this hold condition, the internal
operation will be resynchronized automatically, less than 3/fS
period. In this resynchronize period, and following 3/fS,
analog output is forced to the bipolar zero level, or VCC/2.
External resetting is not required.
AUDIO DATA FORMATS AND TIMING
The PCM1748 supports industry-standard audio data formats,
including Standard, I2S, and Left-Justified, as shown in
Figure 3. Data formats are selected using the format bits,
FMT[2:0], in Control Register 20. The default data format is
24-bit left justified. All formats require Binary Two’s Complement, MSB-first audio data. See Figure 4 for a detailed timing
diagram of the serial audio interface.
(1) Standard Data Format: L-Channel = HIGH, R-Channel = LOW
1/fS
LRCK
R-Channel
L-Channel
BCK
(= 32, 48 or 64fS)
16-Bit Right-Justified, BCK = 48fS or 64fS
DATA
14 15 16
1
14 15 16
3
MSB
16-Bit Right-Justified, BCK = 32fS
DATA
2
1
2
3
14 15 16
1
LSB
14 15 16
MSB
3
14 15 16
MSB
1
LSB
2
2
3
LSB
14 15 16
MSB
LSB
18-Bit Right-Justified
DATA
16 17 18
1
2
3
MSB
16 17 18
1
LSB
2
17 18
MSB
LSB
20-Bit Right-Justified
DATA
18 19 20
1
2
3
18 19 20
MSB
24-Bit Right-Justified
DATA
22 23 24
1
2
1
LSB
3
22 23 24
MSB
3
18 19 20
MSB
1
LSB
2
2
LSB
3
22 23 24
MSB
LSB
(2) I2S Data Format: L-Channel = LOW, R-Channel = HIGH
1/fS
LRCK
L-Channel
R-Channel
BCK
(= 48 or 64fS)
DATA
1
2
N-2 N-1 N
3
MSB
1
LSB
(3) Left-Justified Data Format: L-Channel = HIGH, R-Channel = LOW
2
N-2 N-1 N
3
MSB
1
2
1
2
LSB
1/fS
L-Channel
LRCK
R-Channel
BCK
(= 32, 48 or 64fS)
DATA
1
2
3
MSB
N-2 N-1 N
LSB
1
MSB
2
3
N-2 N-1 N
LSB
FIGURE 3. Audio Data Input Formats.
PCM1748
SBAS165
9
LRCK
50% of VDD
tBCH
tBCL
tLB
BCK
50% of VDD
tBCY
tBL
50% of VDD
DATA
tDS
SYMBOL
tBCY
tBCH
tBCL
tBL
tLB
tDS
tDH
tDH
PARAMETER
MIN
MAX
UNITS
32, 48, or 64fS(1)
BCK Pulse Cycle Time
BCK High Level Time
BCK Low Level Time
BCK Rising Edge to LRCK Edge
LRCK Falling Edge to BCK Rising Edge
DATA Set Up Time
DATA Hold Time
35
35
10
10
10
10
ns
ns
ns
ns
ns
ns
NOTE: (1) fS is the sampling frequency (e.g., 44.1kHz, 48kHz, 96kHz, etc.)
FIGURE 4. Audio Interface Timing.
SERIAL CONTROL INTERFACE
The serial control interface is a 3-wire serial port that
operates asynchronously to the serial audio interface. The
serial control interface is utilized to program the on-chip
mode registers. The control interface includes MD (pin 13),
MC (pin 14), and ML (pin 15). MD is the serial data input,
used to program the mode registers; MC is the serial bit
clock, used to shift data into the control port; and ML is the
control port latch clock.
REGISTER WRITE OPERATION
All Write operations for the serial control port use 16-bit
data words. Figure 5 shows the control data word format.
The most significant bit must be a “0”. There are seven bits,
labeled IDX[6:0], that set the register index (or address) for
the Write operation. The least significant eight bits, D[7:0],
contain the data to be written to the register specified by
IDX[6:0].
Figure 6 shows the functional timing diagram for writing the
serial control port. ML is held at a logic “1 ” state until a
register needs to be written. To start the register write cycle,
ML is set to logic “0”. Sixteen clocks are then provided on
MC, corresponding to the 16 bits of the control data word on
MD. After the sixteenth clock cycle has completed, ML is
set to logic “1” to latch the data into the indexed mode
control register.
CONTROL INTERFACE TIMING REQUIREMENTS
Figure 7 shows a detailed timing diagram for the serial
control interface. These timing parameters are critical for
proper control port operation.
MSB
0
LSB
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
D7
D6
Register Index (or Address)
D5
D4
D3
D2
D1
D0
D1
D0
X
Register Data
FIGURE 5. Control Data Word Format for MDI.
ML
MC
MDI
X
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 D7
D6
D5
D4
D3
D2
X
0
IDX6
FIGURE 6. Register Write Operation.
10
PCM1748
SBAS165
MODE CONTROL REGISTERS
User-Programmable Mode Controls
The PCM1748 includes a number of user-programmable
functions that are accessed via control registers. The registers are programmed using the Serial Control Interface that
was previously discussed in this data sheet. Table II lists the
available mode control functions, along with their reset
default conditions and associated register index.
Register Map
The mode control register map is shown in Table III. Each
register includes an index (or address) indicated by the
IDX[6:0] bits.
tMHH
50% of VDD
ML
tMCH
tMLS
tMCL
tMLH
50% of VDD
MC
tMCY
LSB
MD
50% of VDD
tMDS
tMCH
SYMBOL
tMCY
tMCL
tMCH
tMHH
tMLS
tMLH
tMDH
tMDS
PARAMETER
MIN
MC Pulse Cycle Time
MC Low Level Time
MC High Level Time
ML High Level Time
ML Falling Edge to MC Rising Edge
ML Hold Time(1)
MD Hold Time
MD Set Up Time
100
50
50
Note (2)
20
20
15
20
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
3
NOTES: (1) MC rising edge for LSB to ML rising edge. (2) 256 • F sec (min), FS = Sampling Rate.
S
FIGURE 7. Control Interface Timing.
FUNCTION
Digital Attenuation Control, 0dB to –63dB in 0.5dB Steps
Soft Mute Control
Oversampling Rate Control (64 or 128fS)
DAC Operation Control
De-Emphasis Function Control
De-Emphasis Sample Rate Selection
Audio Data Format Control
Digital Filter Roll-Off Control
Zero Flag Function Select
Output Phase Select
Zero Flag Polarity Select
RESET DEFAULT
CONTROL REGISTER
INDEX, IDX[6:0]
0dB, No Attenuation
Mute Disabled
64fS Oversampling
DAC1 and DAC2 Enabled
De-Emphasis Disabled
44.1kHz
24-Bit Left Justified
Sharp Roll-Off
L-/R-Channel Independent
Normal Phase
High
16 and 17
18
18
19
19
19
20
20
22
22
22
AT1[7:0], AT2[7:0]
MUT[2:0]
OVER
DAC[2:1]
DM12
DMF[1:0]
FMT[2:0]
FLT
AZRO
DREV
ZREV
TABLE II. User-Programmable Mode Controls.
IDX
(B8-B14) REGISTER
10H
11H
12H
13H
14H
15H
16H
16
17
18
19
20
21
22
B15
B14
B13
B12
B11
B10
B9
B8
B7
0
0
0
0
0
0
0
IDX6
IDX6
IDX6
IDX6
IDX6
IDX6
IDX6
IDX5
IDX5
IDX5
IDX5
IDX5
IDX5
IDX5
IDX4
IDX4
IDX4
IDX4
IDX4
IDX4
IDX4
IDX3
IDX3
IDX3
IDX3
IDX3
IDX3
IDX3
IDX2
IDX2
IDX2
IDX2
IDX2
IDX2
IDX2
IDX1
IDX1
IDX1
IDX1
IDX1
IDX1
IDX1
IDX0
IDX0
IDX0
IDX0
IDX0
IDX0
IDX0
AT17
AT27
RSV
RSV
RSV
RSV
RSV
B6
B5
AT16 AT15
AT26 AT25
OVER RSV
DMF1 DMF0
RSV
FLT
RSV
RSV
RSV
RSV
B4
B3
B2
B1
B0
AT14
AT24
RSV
DM12
RSV
RSV
RSV
AT13
AT23
RSV
RSV
RSV
RSV
RSV
AT12
AT22
RSV
RSV
FMT2
RSV
AZRO
AT11
AT21
MUT2
DAC2
FMT1
RSV
ZREV
AT10
AT20
MUT1
DAC1
FMT0
RSV
DREV
TABLE III. Mode Control Register Map.
PCM1748
SBAS165
11
REGISTER DEFINITIONS
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
Register 16
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT17
AT16
AT15
AT14
AT13
AT12
AT11
AT10
Register 17
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT27
AT26
AT25
AT24
AT23
AT22
AT21
AT20
ATx[7:0]
Digital Attenuation Level Setting
where x = 1 or 2, corresponding to the DAC output VOUTL (x = 1) and VOUTR (x = 2).
Default Value: 1111 1111B
Each DAC channel (VOUTL and VOUTR) includes a digital attenuator function. The attenuation level may be
set from 0dB to –63dB, in 0.5dB steps. The attenuation data for each channel can be set individually.
The attenuation level may be set using the formula below.
Attenuation Level (dB) = 0.5 (ATx[7:0]DEC – 255)
where: ATx[7:0]DEC = 0 through 255
for: ATx[7:0]DEC = 0 through 128, the attenuator is set to infinite attenuation.
The following table shows attenuator levels for various settings.
ATx[7:0]
Decimal Value
Attenuator Level Setting
255
254
253
131
130
129
128
•
•
•
0
0dB, No Attenuation (default)
–0.5dB
–1.0dB
–62.0dB
–62.5dB
–63.0dB
Mute
•
•
•
Mute
1111
1111
1111
1000
1000
1000
1000
1111B
1110B
1101B
0011B
0010B
0001B
0000B
•
•
•
0000 0000B
Register 18
MUTx
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
OVER
RSV
RSV
RSV
RSV
B1
B0
MUT2 MUT1
Soft Mute Control
Where x = 1 or 2, corresponding to the DAC output VOUTL (x = 1) and VOUTR (x = 2).
Default Value: 0
MUTx = 0
MUTx = 1
Mute Disabled (default)
Mute Enabled
The mute bits, MUT1 and MUT2, are used to enable or disable the Soft Mute function for the corresponding
DAC outputs, VOUTL and VOUTR. The Soft Mute function is incorporated into the digital attenuators. When
Mute is disabled (MUTx = 0), the attenuator and DAC operate normally. When Mute is enabled by setting
MUTx = 1, the digital attenuator for the corresponding output will be decreased from the current setting
to the infinite attenuation setting one attenuator step (0.5dB) at a time. This provides a quiet, “pop”-free
muting of the DAC output.
OVER
Oversampling Rate Control
Default Value: 0
OVER = 0
OVER = 1
64x Oversampling (default)
128x Oversampling
The OVER bit is used to control the oversampling rate of the delta-sigma DACs.
12
PCM1748
SBAS165
REGISTER 19
DACx
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
DMF1
DMF0
DM12
RSV
RSV
B1
B0
DAC2 DAC1
DAC Operation Control
where x = 1 or 2, corresponding to the DAC output VOUTL (x = 1) or VOUTR (x = 2).
Default Value: 0
DACx = 0
DACx = 1
DAC Operation Enabled (default)
DAC Operation Disabled
The DAC operation controls are used to enable and disable the DAC outputs, VOUTL and VOUTR. When
DACx = 0, the corresponding output will generate the audio waveform dictated by the data present on the
DATA pin. When DACx = 1, the corresponding output will be set to the bipolar zero level, or VCC/2.
DM12
Digital De-Emphasis Function Control
Default Value: 0
DM12 = 0
DM12 = 1
De-Emphasis Disabled (default)
De-Emphasis Enabled
The DM12 bit is used to enable or disable the Digital De-Emphasis function. Refer to the Typical Performance
Curves of this data sheet for more information.
DMF[1:0]
Sampling Frequency Selection for the De-Emphasis Function
Default Value: 00B
DMF[1:0]
00
01
10
11
De-Emphasis Same Rate Selection
44.1kHz (default)
48kHz
32kHz
Reserved
The DMF[1:0] bits are used to select the sampling frequency used for the Digital De-Emphasis function when
it is enabled.
REGISTER 20
FMT[2:0]
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
RSV
FLT
RSV
RSV
FMT2
FMT1
FMT0
Audio Interface Data Format
Default Value: 000B
The FMT[2:0] bits are used to select the data format for the serial audio interface. The following table shows
the available format options.
FMT[2:0]
000
001
010
011
100
101
110
111
PCM1748
SBAS165
Audio Data Format Selection
24-Bit Standard Format, Right-Justified
20-Bit Standard Format, Right-Justified
18-Bit Standard Format, Right-Justified
16-Bit Standard Format, Right-Justified
I2S Format, 16- to 24-bits
Left-Justified Format, 16- to 24-Bits
Reserved
Reserved
Data (default)
Data
Data
Data
13
Register 20 (Cont.)
FLT
Digital Filter Roll-Off Control
Default Value: 0
FLT = 0
FLT = 1
Sharp Roll-Off (default)
Slow Roll-Off
The FLT bit allows the user to select the digital filter roll-off that is best suited to their application. Two
filter roll-off sections are available: Sharp or Slow. The filter responses for these selections are shown in
the Typical Performance Curves section of this data sheet.
REGISTER 22
DREV
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
RSV
RSV
RSV
RSV
AZRO
B1
B0
ZREV DREV
Output Phase Select
Default Value: 0
DREV = 0
DREV = 1
Normal Output (default)
Inverted Output
The DREV bit is used to set the output phase of VOUTL and VOUTR.
ZREV
Zero Flag Polarity Select
Default Value: 0
ZREV = 0
ZREV = 1
Zero Flag Pins HIGH at a Zero Detect (default)
Zero Flag Pins LOW at a Zero Detect
The ZREV bit allows the user to select the active polarity of Zero Flag pins.
AZRO
Zero Flag Function Select
Default Value: 0
AZRO = 0
AZRO = 1
L-/R-Channel Independent Zero Flag (default)
L-/R-Channel Common Zero Flag
The AZRO bit allows the user to select the function of Zero Flag pins.
AZRO = 0:
Pin11: ZEROR; Zero Flag Output for R-Channel
Pin12: ZEROL; Zero Flag Output for L-Channel
AZRO = 1:
Pin11: ZEROA; Zero Flag Output for L-/R-Channel
Pin12: NA; No Assign
14
PCM1748
SBAS165
ANALOG OUTPUTS
enough to attenuate the out-of-band noise to an acceptable
level for many applications, therefore, an external low-pass
filter is required to provide sufficient out-of-band noise
rejection. Further discussion of DAC post-filter circuits is
provided in the Applications Information section of this data
sheet.
VCOM OUTPUT
The PCM1748 includes two independent output channels:
VOUTL and VOUTR. These are unbalanced outputs, each
capable of driving 3.1Vp-p typical into a 5kΩ AC-coupled
load. The internal output amplifiers for VOUTL and VOUTR
are biased to the DC common-mode (or bipolar zero) voltage, equal to VCC/2.
The output amplifiers include an RC continuous-time filter
that helps to reduce the out-of-band noise energy present at
the DAC outputs, due to the noise shaping characteristics of
the PCM1748’s delta-sigma DACs. The frequency response
of this filter is shown in Figure 8. By itself, this filter is not
One unbuffered common-mode voltage output pin, VCOM
(pin 10), is brought out for decoupling purposes. This pin is
nominally biased to a DC voltage level equal to VCC/2. This
pin may be used to bias external circuits. An example of
using the VCOM pin for external biasing applications is
shown in Figure 9.
ANALOG FILTER PERFORMANCE
(100Hz-10MHz)
ZERO FLAGS
Zero Detect Condition
0
Zero Detection for each output channel is independent from
the other. If the data for a given channel remains at a “0”
level for 1024 sample periods (or LRCK clock periods), a
Zero Detect condition exists for that channel.
Response (dB)
–10
–20
–30
–40
Zero Output Flags
–50
Given that a Zero Detect condition exists for one or more
channels, the Zero Flag pins for those channels will be set to
a logic “1” state. There are Zero Flag pins for each channel,
ZEROL (pin 12) and ZEROR (pin 11). These pins can be used
–60
0.1
1
10
100
1K
10K
Frequency (kHz)
FIGURE 8. Output Filter Frequency Response.
PCM1748
VOUTx
R2
10µF
R1
AV = –1, where AV = –
C1
R3
VCC
R2
R1
2
+
C2
3
1/2
OPA2353
1
Filtered
Output
VCOM
+
x = L or R
10µF
(a) Using VCOM to Bias a Single-Supply Filter Stage
VCC
PCM1748
Buffered
VCOM
OPA337
VCOM
+
10µF
(b) Using a Voltage Follower to Buffer VCOM when Biasing Multiple Nodes
V+
VCC
25kΩ
49.9kΩ
1%
–IN
PCM1748
VOUTx
SENSE
25kΩ
OUT
25kΩ
+IN
VCOM
+
10µF
25kΩ
To Low-Pass
Filter Stage
REF
INA134
x = L or R
V–
(c) Using an INA134 for DC-Coupled Output
FIGURE 9. Biasing External Circuits Using the VCOM Pin.
PCM1748
SBAS165
15
to operate external mute circuits, or used as status indicators
for a microcontroller, audio signal processor, or other digitally
controlled functions.
The active polarity of Zero Flag output can be inverted by
setting the ZREV bit of Control Register 22 to “1”. The reset
default is active high output, or ZREV = 0.
APPLICATIONS INFORMATION
Connection Diagrams
A basic connection diagram is shown in Figure 11, with the
necessary power-supply bypassing and decoupling components. Texas Instruments recommends using the component
values shown in Figure 11 for all designs.
AV ≈ –
R1
C1
R3
VIN
2
3
R1
R4
1
C2
R2
VOUT
OPA2134
FIGURE 10. Dual-Supply Filter Circuit.
The use of series resistors (22Ω to 100Ω) are recommended
for the SCK, LRCK, BCK, and DATA inputs. The series
resistor combines with stray PCB and device input capacitance to form a low-pass filter that reduces high-frequency
noise emissions and helps to dampen glitches and ringing
present on clock and data lines.
PCM
Audio Data
Input
+
BCK
2
DATA
ML 15
3
LRCK
MC 14
4
DGND
MDI 13
5
VDD
ZEROL/NA 12
6
VCC
ZEROR/ZEROA 11
System Clock
SCK 16
Mode
Control
10µF
+3.3V
Regulator
+
1
10µF
7
VOUTL
8
VOUTR
Zero Mute
Control
VCOM 10
+
R2
Power Supplies and Grounding
The PCM1748 requires a +5V analog supply and a +3.3V
digital supply. The +5V supply is used to power the DAC
analog and output filter circuitry, while the +3.3V supply is
used to power the digital filter and serial interface circuitry.
For best performance, the +3.3V supply should be derived
from the +5V supply using a linear regulator, as shown in
Figure 11. The REG1117-3.3 from Texas Instruments is an
ideal choice for this application.
Proper power-supply bypassing is shown in Figure 11. The
10µF capacitors should be tantalum or aluminum electrolytic.
DAC Output Filter Circuits
Delta-sigma DACs utilize noise-shaping techniques to improve in-band Signal-to-Noise Ratio (SNR) performance at
the expense of generating increased out-of-band noise above
the Nyquist Frequency, or fS/2. The out-of-band noise must
be low-pass filtered in order to provide the optimal converter
performance. This is accomplished by a combination of
on-chip and external low-pass filtering.
Figures 9(a) and 10 show the recommended external lowpass active filter circuits for single- and dual-supply applications. These circuits are second-order Butterworth filters
using the Multiple FeedBack (MFB) circuit arrangement
that reduces sensitivity to passive component variations over
frequency and temperature. For more information regarding
MFB active filter design, please refer to Burr-Brown Applications Bulletin #34 (AB-034), available from our web site
at http://www.ti.com.
Since the overall system performance is defined by the
quality of the DACs and their associated analog output
circuitry, high-quality audio op amps are recommended for
the active filters. The OPA2353 and OPA2134 dual op amps
from Texas Instruments are recommended for use with the
PCM1748, see Figures 9(a) and 10.
10µF
AGND
9
+5V VCC
Post LPF
Post LPF
L-Chan OUT
R-Chan OUT
FIGURE 11. Basic Connection Diagram.
16
PCM1748
SBAS165
PCB LAYOUT GUIDELINES
Separate power supplies are recommended for the digital and
analog sections of the board. This prevents the switching noise
present on the digital supply from contaminating the analog
power supply and degrading the dynamic performance of the
PCM1748. In cases where a common +5V supply must be
used for the analog and digital sections, an inductance (RF
choke, ferrite bead) should be placed between the analog and
digital +5V supply connections to avoid coupling of the digital
switching noise into the analog circuitry. Figure 13 shows the
recommended approach for single-supply applications.
A typical PCB floor plan for the PCM1748 is shown in
Figure 12. A ground plane is recommended, with the analog
and digital sections being isolated from one another using a
split or cut in the circuit board. The PCM1748 should be
oriented with the digital I/O pins facing the ground plane
split/cut to allow for short, direct connections to the digital
audio interface and control signals originating from the
digital section of the board.
Digital Power
+VD
Analog Power
DGND
AGND +5VA
+VS –VS
REG
VCC
VDD
Digital Logic
and
Audio
Processor
Output
Circuits
DGND
PCM1748
Digital
Ground
AGND
DIGITAL SECTION
Analog
Ground
ANALOG SECTION
Return Path for Digital Signals
FIGURE 12. Recommended PCB Layout.
Power Supplies
RF Choke or Ferrite Bead
+5V
AGND
+VS –VS
REG
VCC
VDD
VDD
DGND
Output
Circuits
PCM1748
AGND
Common
Ground
DIGITAL SECTION
ANALOG SECTION
FIGURE 13. Single-Supply PCB Layout.
PCM1748
SBAS165
17
THEORY OF OPERATION
The delta-sigma section of the PCM1748 is based on an
8-level amplitude quantizer and a fourth-order noise shaper. This
section converts the oversampled input data to 8-level delta-sigma
format. A block diagram of the 8-level delta-sigma modulator is
shown in Figure 14. This 8-level delta-sigma modulator has the
advantage of stability and clock jitter sensitivity over the typical
one-bit (2-level) delta-sigma modulator. The combined
oversampling rate of the delta-sigma modulator and the interpolation filter is 64fS.
The theoretical quantization noise performance of the
8-level delta-sigma modulator is shown in Figure 15. The enhanced multilevel delta-sigma architecture also has advantages
for input clock jitter sensitivity due to the multilevel quantizer,
with the simulated jitter sensitivity, as shown in Figure 16.
–
+
8fS
Z–1
+
+
Z–1
Z–1
+
Z–1
+
+
8-Level Quantizer
64fS
FIGURE 14. Eight-Level Delta-Sigma Modulator.
QUANTIZATION NOISE SPECTRUM
(128x Oversampling)
0
0
–20
–20
–40
–40
Amplitude (dB)
Amplitude (dB)
QUANTIZATION NOISE SPECTRUM
(64x Oversampling)
–60
–80
–100
–120
–60
–80
–100
–120
–140
–140
–160
–160
–180
–180
0
1
2
3
4
5
Frequency (fS)
6
7
8
0
1
2
3
4
5
6
7
8
Frequency (fS)
FIGURE 15. Quantization Noise Spectrum.
18
PCM1748
SBAS165
JITTER DEPENDENCE (64x Oversampling)
125
Dynamic Range (dB)
120
115
110
105
100
95
90
0
100
200
300
400
500
600
Jitter (ps)
FIGURE 16. Jitter Sensitivity.
KEY PERFORMANCE PARAMETERS
AND MEASUREMENT
This section provides information on how to measure key
dynamic performance parameters for the PCM1748. In all
cases, an Audio Precision System Two Cascade or equivalent
audio measurement system is utilized to perform the testing.
Total Harmonic Distortion + Noise
Total Harmonic Distortion + Noise (THD+N) is a significant
figure of merit for audio DACs, since it takes into account
both harmonic distortion and all noise sources within a
specified measurement bandwidth. The true rms value of the
distortion and noise is referred to as THD+N. Figure 17
shows the test setup for THD+N measurements.
For the PCM1748, THD+N is measured with a full-scale,
1kHz digital sine wave as the test stimulus at the input of the
DAC. The digital generator is set to a 24-bit audio word
length and a sampling frequency of 44.1kHz or 96kHz. The
digital generator output is taken from the unbalanced
S/PDIF connector of the measurement system. The S/PDIF
data is transmitted via a coaxial cable to the digital audio
receiver on the DEM-DAI1748 demo board. The receiver is
then configured to output 24-bit data in either I2S or leftjustified data format. The DAC audio interface format is
programmed to match the receiver output format. The analog output is then taken from the DAC post filter and
connected to the analog analyzer input of the measurement
system. The analog input is band limited using filters resident in the analyzer. The resulting THD+N is measured by
the analyzer and displayed by the measurement system.
Evaluation Board
DEM-DAI1748
S/PDIF
Receiver
PCM1748
2nd-Order
Low-Pass
Filter
f–3dB = 54kHz or 108kHz
S/PDIF
Output
Digital
Generator
Analyzer
and
Display
0dBFS,
1kHz Sine Wave
rms Mode
20kHz
Apogee
Filter
Band Limit
HPF = 22Hz
LPF = 30kHz
Notch Filter
fC = 1kHz
FIGURE 17. Test Setup for THD+N Measurements.
PCM1748
SBAS165
19
Dynamic Range
Dynamic range is specified as A-Weighted, THD+N measured with a –60dBFS, 1kHz digital sine wave stimulus at
the input of the DAC. This measurement is designed to give
a good indicator of how the DAC will perform given a lowlevel input signal.
The measurement setup for the dynamic range measurement
is shown in Figure 18, and is similar to the THD+N test
setup discussed previously. The differences include the band
limit filter selection, the additional A-Weighting filter, and
the –60dBFS input level.
Idle Channel Signal-to-Noise Ratio
The SNR test provides a measure of the noise floor of the
DAC. The input to the DAC is all “0”s data, and the DAC’s
Infinite Zero Detect Mute function must be disabled (default
condition at power up for the PCM1748). This ensures that
the delta-sigma modulator output is connected to the output
amplifier circuit so that idle tones (if present) can be observed and effect the SNR measurement. The dither function
of the digital generator must also be disabled to ensure an all
“0”s data stream at the input of the DAC. The measurement
setup for SNR is identical to that used for dynamic range,
with the exception of the input signal level (see the notes
provided in Figure 18).
Evaluation Board
DEM-DAI1748
S/PDIF
Receiver
PCM1748(1)
2nd-Order
Low-Pass
Filter
f–3dB = 54kHz
S/PDIF
Output
NOTES: (1) Infinite Zero Detect Mute disabled.
(2) Results without A-Weighting will be approximately 3dB worse.
Digital
Generator
Analyzer
and
Display
0% Full-Scale,
Dither Off (SNR)
–60dBFS,
1kHz Sine Wave
(Dynamic Range)
rms Mode
A-Weight
Filter(1)
Band Limit
HPF = 22Hz
LPF = 22kHz
Option = A-Weighting(2)
Notch Filter
fC = 1kHz
FIGURE 18. Test Setup for Dynamic Range and SNR Meeasurements.
20
PCM1748
SBAS165
PACKAGE OPTION ADDENDUM
www.ti.com
21-Dec-2004
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
PCM1748E
ACTIVE
SSOP/
QSOP
DBQ
16
98
None
CU SNPB
Level-1-235C-UNLIM
PCM1748E/2K
ACTIVE
SSOP/
QSOP
DBQ
16
2000
None
CU SNPB
Level-1-235C-UNLIM
PCM1748EG/2K
ACTIVE
SOIC
D
16
Pb-Free
(RoHS)
CU SNBI
Level-1-260C-UNLIM
PCM1748KE
ACTIVE
SSOP/
QSOP
DBQ
16
98
None
CU SNPB
Level-1-235C-UNLIM
PCM1748KE/2K
ACTIVE
SSOP/
QSOP
DBQ
16
2000
None
CU SNPB
Level-1-235C-UNLIM
Lead/Ball Finish
MSL Peak Temp (3)
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional
product content details.
None: Not yet available Lead (Pb-Free).
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens,
including bromine (Br) or antimony (Sb) above 0.1% of total product weight.
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
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In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 1
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