BB PCM3000

®
PCM3000
PCM3001
PCM
49%
300
1E
FPO
PCM
300
0E
For most current data sheet and other product
information, visit www.burr-brown.com
Stereo Audio CODEC
18-BITS, SERIAL INTERFACE
TM
FEATURES
DESCRIPTION
● MONOLITHIC 18-BIT ∆Σ ADC AND DAC
The PCM3000/3001 is a low cost single chip stereo
audio CODEC (analog-to-digital and digital-to-analog
converter) with single-ended analog voltage input and
output.
● 16- OR 18-BIT INPUT/OUTPUT DATA
● STEREO ADC:
Single-ended Voltage Input
64X Oversampling
High Performance:
–88dB
THD+N
94dB
SNR
94dB
Dynamic Range
Digital High-Pass Filter
Both ADCs and DACs employ delta-sigma modulation with 64X oversampling. The ADCs include a
digital decimation filter and the DACs include an 8X
oversampling digital interpolation filter. The DACs
also include digital attenuation, de-emphasis, infinite
zero detection and soft mute to form a complete
subsystem. The PCM3000/3001 operates with leftjustified, right-justified, I2S or DSP data formats.
● STEREO DAC:
Single-ended Voltage Output
Analog Low Pass Filter
64X Oversampling
High Performance:
–90dB
THD+N
98dB
SNR
97dB
Dynamic Range
PCM3000 can be programmed with a 3-wire serial
interface for special features and data formats.
PCM3001 can be pin-programmed for data formats.
Fabricated on a highly advanced CMOS process, the
PCM3000/3001 is suitable for a wide variety of costsensitive consumer applications where good performance is required. Applications include sampling keyboards, digital mixers, mini-disc recorders, hard-disk
recorders, karaoke systems, DSP-based car stereo,
DAT recorders, and video conferencing.
● SPECIAL FEATURES (PCM3000):
Digital De-emphasis
Digital Attenuation (256 Steps)
Soft Mute
Analog Loop Back
● SAMPLE RATE: Up to 48kHz
● SYSTEM CLOCK: 256fS, 384fS, 512fS
● SINGLE +5V POWER SUPPLY
● SMALL PACKAGE: SSOP-28
Lch In
Analog Front-End
Rch In
Lch Out
Rch Out
Low Pass Filter
and
Output Buffer
Delta-Sigma
Modulator
Multi-Level
Delta-Sigma
Modulator
Digital
Decimation
Filter
Digital
Interpolation
Filter
Digital Out
Serial Interface
and
Mode Control
Digital In
Mode Control
System Clock
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 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
®
© 1996 Burr-Brown Corporation
PDS-1342E
1
Printed in U.S.A., January, 2000
PCM3000/3001
SPECIFICATIONS
All specifications at +25°C, V DD = VCC = +5V, fS = 44.1kHz, SYSCLK = 384fS, CLKIO Input, 18-bit data, unless otherwise noted.
PCM3000E/3001E
PARAMETER
CONDITIONS
MIN
DIGITAL INPUT/OUTPUT
Input Logic
Input Logic Level: VIH(1)
VIL(1)
Input Logic Current: IIN(2)
Input Logic Current: IIN(3)
Input Logic Level: VIH(4)
VIL(4)
Input Logic Current: IIN(4)
Output Logic
Output Logic Level: VOH(5)
VOL(5)
Output Logic Level: VOH(6)
VOL(6)
CLOCK FREQUENCY
Sampling Frequency (fS)
System Clock Frequency
TYP
MAX
2.0
0.8
±1
–120
0.64 • VDD
0.28 • VDD
±40
IOUT
IOUT
IOUT
IOUT
=
=
=
=
–1.6mA
+3.2mA
–3.2mA
+3.2mA
4.5
0.5
48
12.2880
18.4320
24.5760
kHz
MHz
MHz
MHz
4.5
44.1
11.2896
16.9344
22.5792
VDC
VDC
µA
µA
VDC
VDC
µA
VDC
VDC
VDC
VDC
0.5
32(7)
8.1920
12.2880
16.3840
256fS
384fS
512fS
UNITS
ADC CHARACTERISTICS
RESOLUTION
18
DC ACCURACY
Gain Mismatch Channel-to-Channel
Gain Error
Gain Drift
Bipolar Zero Error
Bipolar Zero Drift
DYNAMIC PERFORMANCE(9)
THD+N: VIN = –0.5dB
VIN = –60dB
Dynamic Range
Signal-to-Noise Ratio
Channel Separation
±1.0
±2.0
±20
±1.7
±20
±5.0
±5.0
% of FSR
% of FSR
ppm of FSR/°C
%of FSR
ppm of FSR/°C
–88
–31
94
94
92
–80
dB
dB
dB
dB
dB
0.454fS
17.4/fS
Hz
Hz
dB
dB
sec
0.019fS
mHz
0dB (Full Scale)
2.9
2.1
15
Vp-p
V
kΩ
CEXT = 470pF
170
kHz
High-Pass Filter Off(8)
High-Pass Filter Off(8)
f=
f=
f = 1kHz,
f = 1kHz,
1kHz
1kHz
A-Weighted
A-Weighted
DIGITAL FILTER PERFORMANCE
Passband
Stopband
Passband Ripple
Stopband Attenuation
Delay Time (Latency)
ANTI-ALIASING FILTER
–3dB Frequency
90
90
88
0.583fS
±0.05
–65
DIGITAL HIGH PASS FILTER RESPONSE
–3dB Frequency
ANALOG INPUT
Voltage Range
Center Voltage
Input Impedance
Bits
NOTES: (1) Pins 16, 17, 18, 22, 25, 26, 27, 28: LRCIN, BCKIN, DIN, CLKIO, MC/FMT2, MD/FMT1, ML/FMT0, RSTB. (2) Pins 16, 17, 18, 22: LRCIN, BCKIN, DIN,
CLKIO (Schmitt Trigger Input). (3) Pins 25, 26, 27, 28: MC/FMT2, MD/FMT1, ML/FMT0, RSTB (Schmitt Trigger Input, 70kΩ Internal Pull-Up Resistor). (4) Pin 20:
XTI. (5) Pins 19, 22: DOUT,CLKIO. (6) Pin 21: XTO. (7) Refer to Application Bulletin AB-148 for information relating to operation at lower sampling frequencies.
(8) High Pass Filter disabled (PCM3000 only) to measure DC offset. (9) fIN = 1kHz, using Audio Precision System II, rms mode with 20kHz LPF, 400Hz HPF used
for performance calculation. (10) With no load on XTO and CLKIO.
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.
®
PCM3000/3001
2
SPECIFICATIONS (cont.)
All specifications at +25°C, V DD = VCC = 5V, fS = 44.1kHz, SYSCLK = 384fS, CLKIO Input, 18-bit data, unless otherwise noted.
PCM3000E/3001E
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
DAC CHARACTERISTICS
RESOLUTION
18
Bits
DC ACCURACY
Gain Mismatch Channel-to-Channel
Gain Error
Gain Drift
Bipolar Zero Error
Bipolar Zero Drift
±1.0
±1.0
±20
±1.0
±20
±5.0
±5.0
% of FSR
% of FSR
ppm of FSR/°C
% of FSR
ppm of FSR/°C
DYNAMIC PERFORMANCE(9)
THD+N: VOUT = 0dB (Full Scale)
VOUT = –60dB
Dynamic Range
Signal-to-Noise Ratio (Idle Channel)
Channel Separation
–90
–34
97
98
95
–80
dB
dB
dB
dB
dB
0.445fS
Hz
Hz
dB
dB
sec
EIAJ A-Weighted
EIAJ A-Weighted
90
92
90
DIGITAL FILTER PERFORMANCE
Passband
Stopband
Passband Ripple
Stopband Attenuation
Delay Time
0.555f S
±0.17
–35
11.1/fS
ANALOG OUTPUT
Voltage Range
Center Voltage
Load Impedance
ANALOG LOW PASS FILTER
Frequency Response
AC Load
Vp-p
VDC
kΩ
–0.16
dB
5
f = 20kHz
POWER SUPPLY REQUIREMENTS
Voltage Range: VCC
VDD
Supply Current: +ICC, +IDD(10)
Power Dissipation
0.62 • VCC
0.5 • VCC
4.5
4.5
VCC = VDD = 5V
VCC = VDD = 5V
TEMPERATURE RANGE
Operation
Storage
–25
–55
5
5
32
160
5.5
5.5
50
250
VDC
VDC
mA
mW
+85
+125
°C
°C
PACKAGE/ORDERING INFORMATION
PRODUCT
PACKAGE
PACKAGE
DRAWING
NUMBER
PCM3000E
"
PCM3001E
"
SSOP-28
"
SSOP-28
"
324
"
324
"
SPECIFIED
TEMPERATURE
RANGE
PACKAGE
MARKING
ORDERING
NUMBER(1)
TRANSPORT
MEDIA
–25°C to +85°C
"
–25°C to +85°C
"
PCM3000E
"
PCM3001E
"
PCM3000E
PCM3000E/2K
PCM3001E
PCM3001E/2K
Rails
Tape and Reel
Rails
Tape and Reel
NOTES: (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 “PCM3000E/2K” will get a single 2000-piece Tape and Reel.
ABSOLUTE MAXIMUM RATINGS
ELECTROSTATIC
DISCHARGE SENSITIVITY
Supply Voltage
+VDD, +VCC1, +VCC2 ...................................................................... +6.5V
Supply Voltage Differences ............................................................... ±0.1V
GND Voltage Differences .................................................................. ±0.1V
Digital Input Voltage ...................................................... –0.3 to VDD + 0.3V
Analog Input Voltage ......................................... –0.3 to VCC1, VCC2 + 0.3V
Power Dissipation .......................................................................... 300mW
Input Current ................................................................................... ±10mA
Operating Temperature Range ......................................... –25°C to +85°C
Storage Temperature ...................................................... –55°C to +125°C
Lead Temperature (soldering, 5s) .................................................. +260°C
(reflow, 10s) ..................................................... +235°C
Thermal Resistance, θJA .............................................................. 100°C/W
This integrated circuit can be damaged by ESD. Burr-Brown
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.
®
3
PCM3000/3001
PIN CONFIGURATION—PCM3000
Top View
PIN CONFIGURATION—PCM3001
SSOP
1
VINL
2
Top View
RSTB 28
1
VINL
RSTB 28
VCC1
ML 27
2
VCC1
FMT0 27
3
AGND1
MD 26
3
AGND1
FMT1 26
4
VREFL
MC 25
4
VREFL
FMT2 25
5
VREFR
DGND 24
5
VREFR
DGND 24
6
VINR
VDD 23
6
VINR
7
CINPR
CLKIO 22
7
CINPR
CLKIO 22
8
CINNR
XTO 21
8
CINNR
XTO 21
9
CINNL
XTI 20
9
CINNL
XTI 20
10
CINPL
DOUT 19
10
CINPL
DOUT 19
11
VCOM
DIN 18
11
VCOM
DIN 18
12
VOUTR
BCKIN 17
12
VOUTR
BCKIN 17
13
AGND2
LRCIN 16
13
AGND2
LRCIN 16
14
VCC2
VOUTL 15
14
VCC2
VOUTL 15
PIN ASSIGNMENTS PCM3000/3001
PIN
NAME
I/O
DESCRIPTION
VINL
IN
ADC Analog Input, Lch
2
VCC1
—
ADC Analog Power Supply
3
AGND1
—
ADC Analog Ground
4
VREFL
—
ADC Input Reference, Lch
5
VREFR
—
ADC Input Reference, Rch
6
VINR
IN
ADC Analog Input, Rch
1
SSOP
7
CINPR
—
ADC Anti-alias Filter Capacitor (+), Rch
8
C INNR
—
ADC Anti-alias Filter Capacitor (–), Rch
ADC Anti-alias Filter Capacitor (–), Lch
9
CINNL
—
10
CINPL
—
ADC Anti-alias Filter Capacitor (+), Lch
11
VCOM
—
DAC Output Common
12
VOUTR
OUT
13
AGND2
—
DAC Analog Ground
DAC Analog Power Supply
DAC Analog Output, Rch
14
VCC2
—
15
VOUTL
OUT
16
LRCIN
IN
Sample Rate Clock Input (fS)(2)
17
BCKIN
IN
Bit Clock Input(2)
18
DIN
IN
Data Input(2)
19
DOUT
OUT
Data Output
20
XTI
IN
21
XTO
OUT
22
CLKIO
I/O
DAC Analog Output, Lch
Oscillator Input
Oscillator Output
Buffered Output of Oscillator or External Clock
Input(2)
23
VDD
—
Digital Power Supply
24
DGND
—
Digital Ground
25
MC/FMT2
IN
Serial Control Bit Clock (PCM3000)/Data
Format Control 2 (PCM3001)(1, 2)
26
MD/FMT1
IN
Serial Control Data (PCM3000)/Data Format
Control 1 (PCM3001)(1, 2)
27
ML/FMT0
IN
Serial Control Strobe Pulse/Data Format
Control 0 (PCM3001)(1, 2)
28
RSTB
IN
Reset(1, 2)
NOTES: (1) With 70kΩ typical internal pull-up resistor. (2) Schmitt trigger input.
®
PCM3000/3001
4
VDD 23
TYPICAL PERFORMANCE CURVES
ADC SECTION
At TA = +25°C, VCC = VDD = +5V, fIN = 1.0kHz, fS = 44.1kHz, 18-bit data, V IN = 2.9Vp-p, and SYSCLK = 384fS, unless otherwise noted.
THD+N vs TEMPERATURE
THD+N vs POWER SUPPLY
0.01
4.0
0.01
4.0
2.0
0dB
0.004
0.002
–25
1.0
THD+N at 0dB (%)
0.006
0
0
25
50
75
85
0.008
3.0
0.006
2.0
0dB
0.004
1.0
0.002
THD+N at –60dB (%)
–60dB
3.0
THD+N at –60dB (%)
THD+N at 0dB (%)
–60dB
0.008
0
100
4.5
4.75
5.0
Temperature (°C)
5.25
5.5
VCC (V)
THD+N vs SYSTEM CLOCK
and SAMPLING FREQUENCY
0.01
SNR and DYNAMIC RANGE vs POWER SUPPLY
4.0
98
98
3.0
96
96
48kHz
0.004
1.0
Dynamic Range
94
94
SNR
92
92
Dynamic Range (dB)
2.0
48kHz
SNR (dB)
0.006
THD+N at –60dB (%)
–60dB
0dB
44.1kHz
0.002
90
0
384fS
90
4.5
512fS
4.75
5.0
5.25
5.50
VCC (V)
System Clock
THD+N vs OUTPUT DATA RESOLUTION
0.01
4.0
–60dB
0.008
3.0
0.006
2.0
0.004
1.0
THD+N at –60dB (%)
256fS
THD+N at 0dB (%)
THD+N at 0dB (%)
44.1kHz
0.008
0dB
0.002
0
16-Bit
18-Bit
Resolution
®
5
PCM3000/3001
TYPICAL PERFORMANCE CURVES
DAC SECTION
At TA = +25°C, VCC = VDD = +5V, fIN = 1.0kHz, fS = 44.1kHz, 18-bit data, and SYSCLK = 384fS, unless otherwise noted.
4.0
0.008
3.0
0.008
3.0
0.006
2.0
0.004
1.0
THD+N at 0dB (%)
–60dB
THD+N at –60dB (%)
0.01
–60dB
0.006
2.0
0.004
1.0
0dB
0.002
–25
0dB
0.002
0
0
25
50
75
85
0
4.5
100
4.75
5.0
5.25
5.5
Temperature (°C)
VCC (V)
SNR and DYNAMIC RANGE vs POWER SUPPLY
THD+N vs SYSTEM CLOCK
and SAMPLING FREQUENCY
100
100
0.01
4.0
98
0.008
3.0
96
SNR
94
94
48kHz
0.006
2.0
–60dB
48kHz
44.1kHz
0.004
1.0
0dB
44.1kHz
92
92
4.5
4.75
5.0
5.25
0.002
5.50
0
384fS
256fS
VCC (V)
System Clock
4.0
0.008
3.0
–60dB
0.006
2.0
0.004
1.0
0dB
0.002
0
16-Bit
18-Bit
Resolution
®
PCM3000/3001
6
THD+N at –60dB (%)
THD+N at 0dB (%)
THD+N vs INPUT DATA RESOLUTION
0.01
512fS
THD+N at –60dB (%)
96
THD+N at 0dB (%)
98
Dynamic Range (dB)
Dynamic Range
SNR (dB)
THD+N at 0dB (%)
4.0
THD+N at –60dB (%)
THD+N vs POWER SUPPLY
THD+N vs TEMPERATURE
0.01
TYPICAL PERFORMANCE CURVES
At TA = +25°C, VCC = VDD = +5V, and SYSCLK = 384fS, unless otherwise noted.
ADC DIGITAL FILTER
OVERALL CHARACTERISTICS
STOPBAND ATTENUATION CHARACTERISTICS
0
0
–20
Amplitude (dB)
Amplitude (dB)
–50
–100
–40
–60
–150
–80
–200
–100
0
8
16
24
32
0
0.25
Normalized Frequency (x fS Hz)
PASSBAND RIPPLE CHARACTERISTICS
0.75
1.00
HIGH PASS FILTER RESPONSE
0.2
0.2
0.0
0.0
–0.2
–0.2
Amplitude (dB)
Amplitude (dB)
0.50
Normalized Frequency (x fS Hz)
–0.4
–0.6
–0.8
–0.4
–0.6
–0.8
–1.0
–1.0
0
0.125
0.250
0.375
0.500
0
1
Normalized Frequency (x fS Hz)
2
3
4
Normalized Frequency (x fS /1000 Hz)
ANTI-ALIASING FILTER
ANTI-ALIASING FILTER PASSBAND
FREQUENCY RESPONSE (CEXT = 470pF, 1000pF)
0.2
ANTI-ALIASING FILTER OVERALL
FREQUENCY RESPONSE (CEXT = 470pF, 1000pF)
0
470pF
470pF
–10
–0.2
Amplitude (dB)
Amplitude (dB)
0.0
–0.4
1000pF
–0.6
–20
–30
1000pF
–40
–0.8
–50
–1.0
0
10
100
1k
10k
0
100k
10
100
1k
10k
100k
1M
10M
Frequency (Hz)
Frequency (Hz)
®
7
PCM3000/3001
TYPICAL PERFORMANCE CURVES
At TA = +25°C, VCC = VDD = +5V, and SYSCLK = 384fS, unless otherwise noted.
DAC DIGITAL FILTER
OVERALL FREQUENCY CHARACTERISTIC
PASSBAND RIPPLE CHARACTERISTIC
0
–20
–0.2
–40
–0.4
dB
dB
0
–60
–0.6
–80
–0.8
–100
0 0.4536fS
1.3605fS
2.2675fS
3.1745fS
–1
4.0815fS
0
0.1134fS
Frequency (Hz)
5k
10k
15k
20k
25k
0
3628
7256
15k
20k
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
25k
0
4999.8375
Frequency (Hz)
10k
15k
14999.5125
19999.35
DE-EMPHASIS ERROR (48kHz)
Error (dB)
Level (dB)
DE-EMPHASIS FREQUENCY RESPONSE (48kHz)
5k
9999.675
Frequency (Hz)
0
–2
–4
–6
–8
–10
–12
0
14512
DE-EMPHASIS ERROR (44.1kHz)
Error (dB)
Level (dB)
DE-EMPHASIS FREQUENCY RESPONSE (44.1kHz)
10k
10884
Frequency (Hz)
0
–2
–4
–6
–8
–10
–12
5k
0.4535fS
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
Frequency (Hz)
0
0.3402fS
DE-EMPHASIS ERROR (3kHz)
Error (dB)
Level (dB)
DE-EMPHASIS FREQUENCY RESPONSE (3kHz)
0
–2
–4
–6
–8
–10
–12
0
0.2268fS
Frequency (Hz)
20k
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
0
25k
5442
10884
Frequency (Hz)
16326
21768
Frequency (Hz)
ANALOG OUTPUT FILTER
INTERNAL ANALOG FILTER FREQUENCY RESPONSE
(10Hz~10MHz)
INTERNAL ANALOG FILTER FREQUENCY RESPONSE
(20Hz~24kHz, Expanded Scale)
1.0
dB
dB
0.5
0
–0.5
–1.0
20
100
1k
Frequency (Hz)
10k
10
24k
100
1k
10k
100k
Frequency (Hz)
®
PCM3000/3001
10
5
0
–5
–10
–15
–20
–25
–30
–35
–40
–45
–50
–55
–60
8
1M
10M
BLOCK DIAGRAM
CINPL
CINNL
(+)
Analog
Front-End
Circuit
VINL
Decimation
and
High Pass Filter
Delta-Sigma
Modulator
(–)
LRCIN
BCKIN
VREFL
Serial Data
Interface
ADC
Reference
VREFR
DIN
(–)
Analog
Front-End
Circuit
VINR
Decimation
and
High Pass Filter
Delta-Sigma
Modulator
(+)
DOUT
CINNR
Loop Control
CINPR
Analog
Low-Pass
Filter
VOUTL
Multi-Level
Delta-Sigma
Modulator
ML (FMT0)(1)
Interpolation
Filter
8X Oversampling
Mode
Control
Interface
DAC
VCOM
Analog
Low-Pass
Filter
VOUTR
Multi-Level
Delta-Sigma
Modulator
MC (FMT2)(1)
MD (FMT1)(1)
Interpolation
Filter
8X Oversampling
Reset
Power Supply
AGND2
VCC2
AGND1
VCC1
RSTB
Clock/OSC Manager
DGND
CLKIO
VDD
XTO
XTI
NOTE: (1) FMT0, FMT1, FMT2 are for PCM3001 only.
470pF
CINPL 10
2.2µF
+
1
VINL
1kΩ
4.7µF
CINNL
15kΩ
1kΩ
4
9
(+)
(–)
Delta-Sigma
Modulator
VREFL
+
VREF
FIGURE 1. Analog Front-End (Single-Channel).
®
9
PCM3000/3001
PCM AUDIO INTERFACE
The three-wire digital audio interface for PCM3000/3001 is
on LRCIN (Pin 16), BCKIN (Pin 17), DIN (Pin 18), and
DOUT (Pin 19). The PCM3000/3001 can operate with
seven different data formats. For the PCM3000, these formats are selected through PROGRAM REGISTER 3 in the
software mode. For PCM3001, data formats are selected by
pin-strapping the three format pins. Figures 2, 3 and 4
illustrate audio data input/output format and timing.
PCM3000/3001 can accept 32, 48, or 64 bit clocks (BCKIN)
in one clock of LRCIN. Only formats 0, 2, and 6 can be
selected when 32 bit clocks/LRCIN are applied.
FORMAT 0: FMT[2:0] = “000”
DAC: 16-Bit, MSB-First, Right-Justified
L–ch
LRCIN
R–ch
BCKIN
16
DIN
1
2
3
14 15 16
MSB
1
LSB
2
3
14 15 16
MSB
LSB
ADC: 16-Bit, MSB-First, Left-Justified
LRCIN
L–ch
R–ch
BCKIN
1
DOUT
2
3
14 15 16
MSB
1
LSB
2
3
14 15 16
MSB
1
LSB
FORMAT 1: FMT[2:0] = “001”
DAC: 18-Bit, MSB-First, Right-Justified
L–ch
LRCIN
R–ch
BCKIN
18
DIN
1
2
3
16 17 18
MSB
1
LSB
2
3
16 17 18
MSB
LSB
ADC: 18-Bit, MSB-First, Left-Justified
LRCIN
L–ch
R–ch
BCKIN
DOUT
1
2
16 17 18
3
1
LSB
MSB
2
3
1
16 17 18
LSB
MSB
FORMAT 2: FMT[2:0] = “010”
DAC: 16-Bit, MSB-First, Right-Justified
L–ch
LRCIN
R–ch
BCIN
16
DIN
2
1
3
MSB
14 15 16
1
LSB
2
3
MSB
14 15 16
LSB
ADC: 16-Bit, MSB-First, Right-Justified
LRCIN
L–ch
R–ch
BCIN
16
DOUT
1
2
3
MSB
14 15 16
LSB
FIGURE 2. Audio Data Input/Output Format.
®
PCM3000/3001
10
1
2
MSB
3
14 15 16
LSB
FORMAT 3: FMT[2:0] = "011"
DAC: 18-Bit, MSB-First, Right-Justified
LRCIN
R-ch
L-ch
BCKIN
DIN
18
2
1
3
16 17 18
1
LSB
MSB
2
3
16 17 18
MSB
LSB
ADC: 18-Bit, MSB-First, Right-Justified
LRCIN
R-ch
L-ch
BCKIN
DOUT
18
1
2
3
16 17 18
MSB
1
LSB
2
3
16 17 18
MSB
LSB
FORMAT 4: FMT[2:0] = "100 "
DAC: 18-Bit, MSB-First, Left-Justified
LRCIN
R-ch
L-ch
BCKIN
1
DIN
2
3
16 17 18
MSB
1
2
3
16 17 18
MSB
LSB
1
LSB
ADC: 18-Bit, MSB-First, Left-Justified
LRCIN
R-ch
L-ch
BCKIN
DOUT
1
2
16 17 18
3
1
LSB
2
3
1
16 17 18
LSB
MSB
FORMAT 5: FMT[2:0] = "101"
DAC: 18-Bit, MSB-First, I2S
L_ch
LRCIN
R-ch
BCKIN
1
DIN
2
3
16 17 18
MSB
ADC: 18-Bit, MSB-First,
1
2
3
16 17 18
MSB
LSB
LSB
I2S
L-ch
LRCIN
R-ch
BCKIN
1
DOUT
2
3
16 17 18
1
LSB
MSB
2
3
16 17 18
MSB
LSB
FORMAT 6: FMT[2:0] = "110"
DAC: 16-Bit, MSB-First, DSP-Frame
L-ch
LRCIN
R-ch
BCKIN
DIN
16
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
1
LSB
MSB
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
1
LSB
MSB
ADC: 16-Bit, MSB-First, DSP-Frame
L-ch
LRCIN
R-ch
BCKIN
DOUT
16
1
2
3
4
5
6
7
8
MSB
9
10 11 12 13 14 15 16
LSB
1
2
MSB
3
4
5
6
7
8
9
10 11 12 13 14 15 16
1
LSB
FIGURE 3. Audio Data Input/Output Format.
®
11
PCM3000/3001
tLRP
1.4V
LRCIN
tBL
tBCH
tLB
tBCL
1.4V
BCKIN
tBCY
tDIS
tDIH
1.4V
DIN
tLDO
tBDO
DOUT
0.5 x VDD
BCKIN Pulse Cycle Time
tBCY
300ns (min)
BCKIN Pulse Width High
t BCH
120ns (min)
BCKIN Pulse Width Low
tBCL
120ns (min)
BCKIN Rising Edge to LRCIN Edge
tBL
40ns (min)
LRCIN Edge to BCKIN Rising Edge
tLB
40ns (min)
LRCIN Pulse Width
tLRP
tBCY (min)
DIN Set-up Time
tDIS
40ns (min)
DIN Hold Time
t DIH
40ns (min)
DOUT Delay Time to BCKIN Falling Edge
tBDO
40ns (max)
DOUT Delay Time to LRCIN Edge
tLDO
40ns (max)
Rising Time of All Signals
tRISE
20ns (max)
Falling Time of All Signals
tFALL
20ns (max)
FIGURE 4. Audio Data Input/Output Timing.
SYSTEM CLOCK
256fS, 384fS, or 512fS. When a 384fS or 512fS system clock
is used, the clock is divided into 256fS automatically. The
256fS clock is used to operate the digital filters and the
modulators.
The system clock for the PCM3000/3001 must be either 256fS,
384fS or 512fS, where fS is the audio sampling frequency. The
system clock can be either a crystal oscillator placed between
XTI (Pin 20) and XTO (Pin 21), or an external clock input. If
an external clock is used, the clock is provided to either XTI
or CLKIO (Pin 22), and XTO is open. The PCM3000/3001
has an XTI clock detection circuit which senses if an XTI
clock is operating. When the external clock is delivered to
XTI, CLKIO is a buffered output of XTI. When XTI is
connected to ground, the external clock must be tied to
CLKIO. For best performance, the “External Clock Input 2”
circuit in Figure 5 is recommended.
Table I lists the relationship of typical sampling frequencies
and system clock frequencies, and Figures 5 and 6 illustrate
the typical system clock connections and external system
clock timing.
SAMPLING RATE FREQUENCY
(kHz)
32
The PCM3000/3001 also has a system clock detection circuit
which automatically senses if the system clock is operating at
256fS
384fS
512fS
8.1920
12.2880
16.3840
44.1
11.2896
16.9340
22.5792
48
12.2880
18.4320
24.5760
TABLE I. System Clock Frequencies.
®
PCM3000/3001
SYSTEM CLOCK FREQUENCY
(MHz)
12
CLKIO
256fS Internal System Clock
Clock Divider
C1
X’tal
XTI
R
C2
XTO
C1 = C2 = 10 to 33pF
PCM3000/3001
CRYSTAL RESONATOR CONNECTION (X’tal must be fundamental made, parallel resonant)
CLKIO
External Clock
(TTL I/F)
CLKIO
256fS Internal System Clock
256fS Internal System Clock
Clock Divider
External Clock
(CMOS I/F)
Clock Divider
XTI
XTI
R
R
XTO
XTO
PCM3000/3001
PCM3000/3001
EXTERNAL CLOCK INPUT 1: (XTO is open)
EXTERNAL CLOCK INPUT 2: (XTO is open)
FIGURE 5. System Clock Connections.
tCLKIH
tCLKIL
XTI
CLKIO
3.2V
2.0V
1.4V
0.8V
XTI or CLKIO
System Clock Pulse Width High
tCLKIH
12ns (min)
System Clock Pulse Width Low
tCLKIL
12ns (min)
FIGURE 6. External System Clock Timing.
®
13
PCM3000/3001
EXTERNAL RESET
The PCM3000 and PCM3001 include a reset input, RSTB
(pin 28). As shown in Figure 8, the external reset signal must
drive RSTB low for a minimum of 40 nanoseconds while
system clock is active in order to initiate the reset sequence.
Initialization starts on the rising edge of RSTB, and requires
1024 system clock cycles for completion. Figure 10 shows
the state of the DAC and ADC outputs during and after the
reset sequence.
POWER-ON RESET
Both the PCM3000 and PCM3001 have internal power-on
reset circuitry. Power-on reset occurs when system clock
(XTI or CLKIO) is active and VDD > 4.0V. For the PCM3001,
the system clock must complete a minimum of 3 complete
cycles prior to VDD > 4.0V to ensure proper reset operation.
The initialization sequence requires 1024 system cycles for
completion, as shown in Figure 7. Figure 10 shows the state
of the DAC and ADC outputs during and after the reset
sequence.
4.4V
4.0V
3.6V
VDD
Reset
Reset Removal
Internal Reset
1024 System Clock Periods
System Clock
(XTI or CLKIO)
FIGURE 7. Internal Power-On Reset Timing.
tRST = 40ns minimum
RSTB
tRST
Reset
Reset Removal
Internal Reset
1024 System Clock Periods
System Clock
(XTI or CLKIO)
FIGURE 8. External Forced Reset Timing.
ML
MC
MD
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
FIGURE 9. Control Data Input Format.
®
PCM3000/3001
14
to LRCIN. Internal operation of the ADC will also stop with
1/fS, and the digital output codes will be set to bipolar zero
until re-synchronization occurs. If LRCIN is synchronized
with 5 or less bit clocks to the system clock, operation will be
normal.
SYNCHRONIZATION WITH THE DIGITAL
AUDIO SYSTEM
PCM3000/3001 operates with LRCIN synchronized to the
system clock. The CODEC does not require any specific
phase relationship between LRCIN and the system clock, but
there must be synchronization. If the synchronization between the system clock and LRCIN changes more than 6 bit
clocks (BCKIN) during one sample (LRCIN) period because
of phase jitter on LRCIN, internal operation of the DAC will
stop within 1/fS, and the analog output will be forced to
bipolar zero (VCC/2) until the system clock is re-synchronized
Figure 11 illustrates the effects on the output when synchronization is lost. Before the outputs are forced to bipolar zero
(<1/fS seconds), the outputs are not defined and some noise
may occur. During the transitions between normal data and
undefined states, the output has discontinuities, which will
cause output noise.
Reset Removal or Power-Down(1) OFF
Internal Reset
Reset
32/fS
VCOM
DAC VOUT
(= 1/2 x VCC2)
4096/fS
ADC DOUT
Zero
(2)
NOTES: (1) Power-Down is for PCM3000 only. (2) The HPF transient response
(exponentially attenuationed signal with 200ms time constant) appears intially.
FIGURE 10. DAC Output and ADC Output for Reset and Power-Down.
State of
Synchronization
Synchronous
Asynchronous
Synchronous
within
1/fS
22.2/fS
Undefined Data
DAC VOUT
VCOM
(= 1/2 x VCC2)
Undefined
Data
Normal
32/fS
Undefined Data
ADC DOUT
Normal
Normal
ZERO
Normal(1)
NOTE: (1) The HPF transient response (exponentially attenuationed signal with 200ms time constant) appears initally.
FIGURE 11. DAC Output and ADC Output When Synchronization is Lost.
®
15
PCM3000/3001
OPERATIONAL CONTROL
(Pin 27). Table II indicates selectable functions, and Figures
9 and 12 illustrate control data input format and timing. The
PCM3001 only allows for control of data format.
PCM3000 can be controlled in a software mode with a threewire serial interface on MC (Pin 25), MD (Pin 26), and ML
FUNCTION
ADC/DAC
DEFAULT (PCM3000)
Audio Data Format (7 Selectable Formats)
ADC/DAC
LRCIN Polarity
Loop Back Control
Left Channel Attenuation
Right Channel Attenuation
Attenuation Control
Infinite Zero Detection
DAC Output Control
Soft Mute Control
De-emphasis (OFF, 32kHz, 44.1kHz, 48kHz)
Power Down Control
High Pass Filter Operation
ADC/DAC
ADC/DAC
DAC
DAC
DAC
DAC
DAC
DAC
DAC
ADC
ADC
DAC: 16-bit, MSB-first, Right-Justified
ADC: 16-bit, MSB-first, Left-Justified
Left/Right = High/Low
OFF
0dB
0dB
Left Channel and Right Channel = Individual Control
OFF
Output Enabled
OFF
OFF
OFF
ON
TABLE II. Selectable Functions.
tMHH
tMLH
tMLS
1.4V
ML
tMCH
tMCL
tMLL
1.4V
MC
tMCY
LSB
MD
tMDS
1.4V
tMDH
MC Pulse Cycle Time
MC Pulse Width LOW
MC Pulse Width HIGH
MD Setup Time
MD Hold Time
ML Low Level Time
ML High Level Time
ML Setup Time
ML Hold Time
tMCY
tMCL
tMCH
tMDS
tMDH
tMLL
tMLH
tMLS
tMLH
100ns (min)
40ns (min)
40ns (min)
40ns (min)
40ns (min)
40ns + 1SYSCLK (min)
40ns + 1SYSCLK (min)
40ns (min)
40ns (min)
SYSCLK: 1/256fS or 1/384fS or 1/512fS
FIGURE 12. Control Data Input Timing.
MAPPING OF PROGRAM REGISTERS
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
REGISTER 0
res
res
res
res
res
A1
A0
LDL
AL7
AL6
AL5
AL4
AL3
AL2
AL1
AL0
REGISTER 1
res
res
res
res
res
A1
A0
LDR
AR7
AR6
AR5
AR4
AR3
AR2
AR1
AR0
REGISTER 2
res
res
res
res
res
A1
A0
PDWN
BYPS
res
ATC
IZD
OUT
DM1
DM0
MUT
REGISTER 3
res
res
res
res
res
A1
A0
res
res
res
LOP
FMT2
FMT1
FMT0
LRP
res
®
PCM3000/3001
16
PROGRAM REGISTER (PCM3000)
AL (7:0): Bit 7 :0
AL7 and AL0 are MSB and LSB, respectively.
The attenuation level (ATT) is given by:
The software mode allows the user to control special functions.
PCM3000’s special functions are controlled using four program registers which are 16 bits long. There are four distinct
registers, with bits 9 and 10 determining which register is in
use. Table III describes the functions of the four registers.
REGISTER
NAME
BIT
NAME
Register 0
A (1:0)
res
LDL
AL (7:0)
Register Address “00”
Reserved, should be set to “0”
DAC Attenuation Data Load Control for Lch
Attenuation Data for Lch
A (1:0)
res
LDR
AR (7:0)
Register Address “01”
Reserved, should be set to “0”
DAC Attenuation Data Load Control for Rch
DAC Attenuation for Rch
A (1:0)
res
PDWN
BYPS
ATC
IZD
OUT
DEM (1:0)
MUT
Register Address “10”
Reserved, should be set to “0”
ADC Power Down Control
ADC High-Pass Filter Operation Control
DAC Attenuation Data Mode Control
DAC Infinite Zero Detection Circuit Control
DAC Output Enable Control
DAC De-emphasis Control
Lch and Rch Soft Mute Control
A (1:0)
res
LOP
FMT (2:0)
LRP
Register Address “11”
Reserved, should be set to “0”
ADC/DAC Analog Loop-back Control
ADC/DAC Audio Data Format Selection
ADC/DAC Polarity of LR-clock Selection
Register 1
Register 2
Register 3
ATT = 20 x log10 (ATT data/256) (dB)
DESCRIPTION
res:
LDR:
res:
0
A1
A0
0
1
Register 1
Bit 15 : 11 Reserved
Bit 8 DAC Attenuation Data Load Control for
Right Channel
AR (7:0): Bit 7 : 0
Register 0
Bit 11 : 15 Reserved
DAC Attenuation Data for Right
Channel
AR7 and AR0 are MSB and LSB respectively.
See REGISTER 0 for the attenuation formula.
These bits are reserved and should be set to “0”.
LDL:
–∞dB (Mute)
–48.16dB
:
–0.07dB
0dB (default)
This bit is used to simultaneously set analog
outputs of the left and right channels. The output
level is controlled by AR (7:0) attenuation data
when this bit is set to “1”. When set to “0”, the
new attenuation data will be stored into a register,
and the output level will remain at the previous
attenuation level. The LDL bit in REGISTER 0
has the equivalent function as LDR. When either
LDL or LDR is set to “1”, the output level of the
left and right channels are simultaneously controlled.
These bits define the address for REGISTER 0:
0
00h
01h
:
FEh
FFh
These bits are reserved and should be set to “0”
Register Address
A0
ATTENUATION LEVEL
These bits define the address for REGISTER 1:
PROGRAM REGISTER 0
A1
AL (7:0)
PROGRAM REGISTER 1
A (1:0): Register Address
TABLE III. Functions of the Registers.
A (1:0): Bit 10, 9
DAC Attenuation Data for Left Channel
Bit 8 DAC Attenuation Data Load Control for
Left Channel
PROGRAM REGISTER 2
A (1:0): Bit 10, 9
This bit is used to simultaneously set analog
outputs of the left and right channels. The output
level is controlled by AL (7:0) attenuation data
when this bit is set to “1”. When set to “0”, the
new attenuation data will be stored into a register,
and the output level will remain at the previous
attenuation level. The LDR bit in REGISTER 1
has the equivalent function as LDL. When either
LDL or LDR is set to “1”, the output level of the
left and right channels are simultaneously controlled.
Register Address
These bits define the address for REGISTER 2:
res:
A1
A0
1
0
Register 2
Bit 15:11, 6 Reserved
These bits are reserved and should be set to “0”.
PDWN: Bit 8
ADC Power-Down Control
This bit places the ADC section in a power-down
mode, forcing the output data to all zeroes. This
has no effect on the DAC section.
PDWN
0
Power Down Mode Disabled (default)
1
Power Down Mode Enabled
®
17
PCM3000/3001
BYPS:
Bit 7
ADC High-Pass Filter Bypass Control
PROGRAM REGISTER 3
A (1:0): Bit 10, 9
This bit determines enables or disables the highpass filter for the ADC.
These bits define the address for REGISTER 3:
BYPS
ATC:
0
High-Pass Filter Enabled (default)
1
High-Pass Filter Disabled (bypassed)
Bit 5
res:
DAC Attenuation Channel Control
1
1
Register 3
Bit 15:11, 8:6, 0
Reserved
Audio Data Format Select
These bits determine the input and output audio
data formats. (default: FMT [2:0] = 000H)
FMT2 FMT1 FMT0
DAC
Data Format
ADC
Data Format
0
Individual Channel Attenuation Data Control (default)
1
Common Channel Attenuation Data Control
0
0
0
16-bit, MSB-first,
Right-justified
16-bit, MSB-first,
Left-justified
DAC Infinite Zero Detection Circuit
Control
0
0
1
18-bit, MSB-first,
Right-justified
18-bit, MSB-first,
Left-justified
0
1
0
16-bit, MSB-first,
Right-justified
16-bit, MSB-first,
Right-justified
0
1
1
18-bit, MSB-first,
Right-justified
18-bit, MSB-first,
Right-justified
1
0
0
16-/18-bit, MSB-first,
Left-justified
18-bit, MSB-first,
Left-justified
1
0
1
16-/18-bit, MSB-first, I2S
18-bit, MSB-first, I2S
1
1
0
16-bit, MSB-first,
DSP-frame
16-bit, MSB-first,
DSP-frame
1
1
1
Reserved
Reserved
Bit 4
This bit enables the Infinite Zero Detection Circuit
in PCM3000. When enabled, this circuit will disconnect the analog output amplifier from the deltasigma DAC when the input is continuously zero for
65,536 consecutive cycles of BCKIN.
IZD
0
Infinite Zero Detection Disabled (default)
1
Infinite Zero Detection Enabled
Bit 3
DAC Output Enable Control
LOP:
When set to “1”, the outputs are forced to VCC/2
(bipolar zero). In this case, all registers in
PCM3000 hold the present data. Therefore, when
set to “0”, the outputs return to the previous
programmed state.
0
DAC Outputs Enabled (default normal operation)
DAC Outputs Disabled (forced to BPZ)
LRP:
DAC De-emphasis Control
These bits select the de-emphasis mode as shown
below:
DM0
0
0
1
0
1
0
De-emphasis OFF (default)
De-emphasis 48kHz ON
De-emphasis 44.1kHz ON
1
1
De-emphasis 32kHz ON
Loop-back Disable (default)
1
Loop-back Enable
Bit 1
Polarity of LRCIN Applies only to
Formats 0 through 4.
LRP
The input and output data formats are controlled by pins 27
(FMT0), 26 (FMT1), and 25 (FMT2). Set these pins to the
same values shown for the bit-mapped PCM3000 controls in
PROGRAM REGISTER 3.
When set to “1”, both left and right-channel DAC
outputs are muted at the same time. This muting
is done by attenuating the data in the digital filter,
so there is no audible click noise when soft mute
is turned on.
MUT
Mute Disable (default)
Mute Enable
®
PCM3000/3001
Left-Channel is “H”, Right-Channel is “L”. (default)
Left-Channel is “L”, Right-Channel is “H”.
PCM3001 DATA FORMAT CONTROL
DAC Soft Mute Control
0
1
0
0
1
DM1
Bit 0
ADC to DAC Loop-back Control
LOP
1
DM (1:0):Bit 2,1
Bit 5
When this bit is set to “1”, the ADC’s audio data
is sent directly to the DAC. The data format will
default to I2S. In Format 6 (DSP Frame), Loopback is not supported.
OUT
MUT:
A0
FMT (2:0) Bit 4:2
ATC
OUT:
A1
These bits are reserved, and should be set to “0”.
When set to “1”, the REGISTER 0 attenuation
data can be used for both DAC channels. In this
case, the REGISTER 1 attenuation data is ignored.
IZD:
Register Address
18
+5V
Register Control
Interface
1
(1)
Line In Left-Channel
2.2µF(2)
Line In Right-Channel
2.2µF(2)
+
4.7µF
+
4.7µF
+
+
28
2
27
3
26
4
Analog
Front-End
6
24
Analog
Front-End
(1)
23
7
22
470pF
Serial
Control
or
Format
Control
25
Reference
5
Reset
Delta-Sigma
8
10 to 33pF
21
CLK/OSC
Manager
9
20
470pF
Decimation
Filter
10
Line Out Right-Channel
10µF
Post
Low-Pass
Filter
+
11
Interpolation
Filter
12
19
Digital
Audio
Interface
18
17
Delta-Sigma
(1)
13
Digital
Audio
Data
16
Bias
14
LPF and
Buffer
Line Out Left-Channel
15
LPF and
Buffer
Post
Low-Pass
Filter
NOTES: (1) Bypass capacitor = 0.1µF to 10µF. (2) The input capacitor
affects the pole of the HPF. Example: 2.2µF sets the cut-off frequency
to 4.8Hz, with a 66ms time constant.
FIGURE 13. Typical Connection Diagram for PCM3000/3001.
VOLTAGE INPUT PINS
APPLICATION AND LAYOUT
CONSIDERATIONS
A tantalum or aluminum electrolytic capacitor, between 2.2µF
and 10µF, is recommended as an AC-coupling capacitor at
the inputs. Combined with the 15kΩ characteristic input
impedance, a 2.2µF coupling capacitor will establish a 4.8Hz
cutoff frequency for blocking DC. The input voltage range
can be increased by adding a series resistor on the analog
input line. This series resistor, when combined with the 15kΩ
input impedance, creates a voltage divider and enables larger
input ranges.
POWER SUPPLY BYPASSING
The digital and analog power supply lines to PCM3000/
3001 should be bypassed to the corresponding ground pins
with both 0.1µF ceramic and 10µF tantalum capacitors as
close to the device pins as possible. Although PCM3000/
3001 has three power supply lines to optimize dynamic
performance, the use of one common power supply is
generally recommended to avoid unexpected latch-up or pop
noise due to power supply sequencing problems. If separate
power supplies are used, back-to-back diodes are recommended to avoid latch-up problems.
VREF INPUTS
A 4.7µF to 10µF tantalum capacitor is recommended between VREFL, VREFR, and AGND to ensure low source
impedance for the ADC’s references. These capacitors should
be located as close as possible to the reference pins to reduce
dynamic errors on the ADC reference.
GROUNDING
In order to optimize dynamic performance of PCM3000/
3001, the analog and digital grounds are not internally
connected. PCM3000/3001 performance is optimized with a
single ground plane for all returns. It is recommended to tie
all PCM3000/3001 ground pins with low impedance connections to the analog ground plane. PCM3000/3001 should
reside entirely over this plane to avoid coupling high frequency digital switching noise into the analog ground plane.
CINP AND CINN INPUTS
A 470pF to 1000pF film or NPO ceramic capacitor is recommended between CINPL and CINNL, CINPR, and CINNR to
create an anti-alias filter, which will have an 170kHz to
80kHz cut-off frequency. These capacitors should be located
as close as possible to the CINP and CINN pins to avoid
introducing undesirable noise or dynamic errors into the
delta-sigma modulator.
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PCM3000/3001
VCOM INPUTS
The input signal is sampled at 64X oversampling rate,
eliminating the need for a sample-and-hold circuit, and
simplifying anti-alias filtering requirements. The 5th-order
delta-sigma noise shaper consists of five integrators which
use a switched-capacitor topology, a comparator and a
feedback loop consisting of a one-bit DAC. The delta-sigma
modulator shapes the quantization noise, shifting it out of
the audio band in the frequency domain. The high order of
the modulator enables it to randomize the modulator outputs, reducing idle tone levels.
A 4.7µF to 10µF tantalum capacitor is recommended between VCOM and AGND to ensure low source impedance
of the DAC output common. This capacitor should be
located as close as possible to the VCOM pin to reduce
dynamic errors on the DAC common.
SYSTEM CLOCK
The quality of the system clock can influence dynamic
performance of both the ADC and DAC in the PCM3000/
3001. The duty cycle, jitter, and threshold voltage at the
system clock input pin must be carefully managed. When
power is supplied to the part, the system clock, bit clock
(BCKIN) and a word clock (LCRIN) should also be supplied
simultaneously. Failure to supply the audio clocks will result
in a power dissipation increase of up to three times normal
dissipation and may degrade long term reliability if the
maximum power dissipation limit is exceeded.
The 64fS one-bit data stream from the modulator is converted to 1fS 18-bit data words by the decimation filter,
which also acts as a low pass filter to remove the shaped
quantization noise. The DC components are removed by a
high pass filter function contained within the decimation
filter.
THEORY OF OPERATION
DAC SECTION
THEORY OF OPERATION
The delta-sigma DAC section of PCM3000/3001 is based on
a 5-level amplitude quantizer and a 3rd-order noise shaper.
This section converts the oversampled input data to 5-level
delta-sigma format. A block diagram of the 5-level deltasigma modulator is shown in Figure 15. This 5-level deltasigma modulator has the advantage of improved stability
and reduced clock jitter sensitivity over the typical one-bit
(2 level) delta-sigma modulator.
ADC SECTION
The PCM3000/3001 ADC consists of a bandgap reference,
a stereo single-to-differential converter, a fully differential
5th-order delta-sigma modulator, a decimation filter (including digital high pass), and a serial interface circuit. The
Block Diagram in this data sheet illustrates the architecture
of the ADC section, Figure 1 shows the single-to-differential
converter, and Figure 14 illustrates the architecture of the
5th-order delta-sigma modulator and transfer functions.
The combined oversampling rate of the delta-sigma modulator and the internal 8X interpolation filter is 64fS for a
256fS system clock. The theoretical quantization noise performance of the 5-level delta-sigma modulator is shown in
Figure 16.
An internal high precision reference with two external capacitors provides all reference voltages which are required
by the ADC, which defines the full scale range for the
converter. The internal single-to-differential voltage converter saves the space and extra parts needed for external
circuitry required by many delta-sigma converters. The
internal full differential signal processing architecture provides a wide dynamic range and excellent power supply
rejection performance.
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PCM3000/3001
20
Analog In
X(z) +
–
1st SW-CAP
Integrator
–
–
2nd SW-CAP
Integrator
+
3rd SW-CAP
Integrator
4th SW-CAP
Integrator
+
5th SW-CAP
Integrator
Qn(z)
+
+
+
+
+
+
+
+
Digital Out
Y(z)
H(z)
Comparator
1-Bit
DAC
Y(z) = STF(z) • X(z) + NTF(z) • Qn(z)
Signal Transfer Function
Noise Transfer Function
STF(z) = H(z)/[1 + H(z)]
NTF(z) = 1/[1 + H(z)]
FIGURE 14. Simplified 5th-Order Delta-Sigma Modulator.
+
In
+
8fS
18-Bit
+
+
+
Z–1
–
+
Z–1
Z–1
–
+
+
+
5-level Quantizer
4
3
Out
2
1
64fS (256fS)
0
FIGURE 15. 5-Level ∆Σ Modulator Block Diagram.
Gain (–dB)
3rd ORDER ∆Σ MODULATOR
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
–140
–150
0
5
10
15
20
25
30
Frequency (kHz)
FIGURE 16. Quantization Noise Spectrum.
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PCM3000/3001