BB PCM1808PWR

 PCM1808
SLES177A – APRIL 2006 – REVISED AUGUST 2006
SINGLE-ENDED, ANALOG-INPUT 24-BIT, 96-kHz STEREO A/D CONVERTER
FEATURES
APPLICATIONS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
24-Bit Delta-Sigma Stereo A/D Converter
Single-Ended Voltage Input: 3 Vp-p
High Performance:
– THD + N: –93 dB (Typical)
– SNR: 99 dB (Typical)
– Dynamic Range: 99 dB (Typical)
Oversampling Decimation Filter:
– Oversampling Frequency: ×64
– Pass-Band Ripple: ±0.05 dB
– Stop-Band Attenuation: –65 dB
– On-Chip High-Pass Filter: 0.91 Hz (48 kHz)
Flexible PCM Audio Interface
– Master/Slave Mode Selectable
– Data Formats: 24-Bit I2S, 24-Bit
Left-Justified
Power Down and Reset by Halting System
Clock
Analog Antialias LPF Included
Sampling Rate: 8 kHz–96 kHz
System Clock: 256 fS, 384 fS, 512 fS
Dual Power Supplies:
– 5-V for Analog
– 3.3-V for Digital
Package: 14-Pin TSSOP
DVD Recorder
Digital TV
AV Amplifier/Receiver
MD Player
CD Recorder
Multitrack Receiver
Electric Musical Instrument
DESCRIPTION
The PCM1808 is high-performance, low-cost,
single-chip, stereo analog-to-digital converter with
single-ended analog voltage input. The PCM1808
uses a delta-sigma modulator with 64-times
oversampling and includes a digital decimation filter
and high-pass filter that removes the dc component
of the input signal. For various applications, the
PCM1808 supports master and slave mode and two
data formats in serial audio interface.
The PCM1808 supports the power-down and reset
function by means of halting the system clock.
The PCM1808 is suitable for wide variety of
cost-sensitive consumer applications where good
performance and operation with a 5-V analog supply
and 3.3-V digital supply is required. The PCM1808 is
fabricated using a highly advanced CMOS process
and is available in a small, 14-pin TSSOP package.
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.
System Two, Audio Precision are trademarks of Audio Precision, Inc.
All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2006, Texas Instruments Incorporated
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
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.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range (unless otherwise noted)
(1)
PCM1808
Analog supply voltage, VCC
–0.3 V to 6.5 V
Digital supply voltage, VDD
–0.3 V to 4 V
Ground voltage differences, AGND, DGND
±0.1 V
Digital input voltage, LRCK, BCK, DOUT
–0.3 V to (VDD + 0.3 V) < 4 V
Digital input voltage, SCKI, MD0, MD1, FMT
–0.3 V to 6.5 V
Analog input voltage, VINL, VINR, VREF
–0.3 V to (VCC + 0.3 V) < 6.5 V
±10 mA
Input current (any pins except supplies)
Ambient temperature under bias, TA
–40°C to 125°C
Storage temperature, Tstg
–55°C to 150°C
Junction temperature, TJ
150°C
Lead temperature (soldering)
260°C, 5 s
Package temperature (reflow, peak)
(1)
260°C
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
over operating free-air temperature range (unless otherwise noted)
MIN
NOM
MAX
Analog supply voltage, VCC
4.5
5
5.5
V
Digital supply voltage, VDD
2.7
3.3
3.6
V
Analog input voltage, full scale (–0 dB)
VCC = 5 V
3
Digital input logic family
Vp-p
TTL compatible
Digital input clock frequency, system clock
Digital input clock frequency, sampling clock
2.048
49.152
MHz
8
96
kHz
20
pF
85
°C
Digital output load capacitance
Operating free-air temperature, TA
2
UNIT
–40
Submit Documentation Feedback
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
ELECTRICAL CHARACTERISTICS
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 512 fS, 24-bit data, unless
otherwise noted
PARAMETER
TEST CONDITIONS
MIN
Resolution
TYP
MAX
24
UNIT
Bits
DATA FORMAT
I2S, left-justified
Audio data interface format
Audio data bit length
24
Audio data format
fS
Sampling frequency
System clock frequency
Bits
MSB-first, 2s complement
8
48
96
256 fS
2.048
12.288
24.576
384 fS
3.072
18.432
36.864
512 fS
4.096
24.576
49.152
kHz
MHz
INPUT LOGIC
VIH (1)
2
VDD
VIL (1)
0
0.8
2
5.5
VIH (2) (3)
Input logic level
VIL (2) (3)
0
IIH (2)
IIL (2)
IIH
(1) (3)
Input logic current
IIL (1) (3)
0.8
VIN = VDD
±10
VIN = 0 V
±10
VIN = VDD
VDC
65
100
µA
±10
VIN = 0 V
OUTPUT LOGIC
VOH (4)
VOL (4)
Output logic level
IOUT = –4 mA
2.8
IOUT = 4 mA
0.5
VDC
DC ACCURACY
Gain mismatch, channel-to-channel
±1
±3
% of FSR
Gain error
±3
±6
% of FSR
–93
–87
DYNAMIC PERFORMANCE
(5)
VIN = –0.5 dB, fS = 48 kHz
THD + N
Total harmonic distortion + noise
VIN = –0.5 dB, fS = 96 kHz
S/N
Signal-to-noise ratio
Channel separation
(1)
(2)
(3)
(4)
(5)
(6)
–87
VIN = –60 dB, fS = 48 kHz
VIN = –60 dB, fS = 96 kHz
Dynamic range
(6)
–37
(6)
fS = 48 kHz, A-weighted
fS = 96 kHz, A-weighted
fS = 96 kHz, A-weighted
95
95
99
101
93
(6)
99
101
(6)
fS = 48 kHz
fS = 96 kHz
–39
(6)
fS = 48 kHz, A-weighted
dB
97
91
dB
dB
dB
Pins 7, 8: LRCK, BCK (Schmitt-trigger input, with 50-kΩ typical pulldown resistor, in slave mode)
Pin 6: SCKI (Schmitt-trigger input, 5-V tolerant)
Pins 10–12: MD0, MD1, FMT (Schmitt-trigger input, with 50-kΩ typical pulldown resistor, 5-V tolerant)
Pins 7–9: LRCK, BCK (in master mode), DOUT
Analog performance specifications are tested using a System Two™ audio measurement system by Audio Precision™ with 400-Hz HPF
and 20-kHz LPF in RMS mode.
fS = 96 kHz, system clock = 256 fS.
Submit Documentation Feedback
3
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
ELECTRICAL CHARACTERISTICS (continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 512 fS, 24-bit data, unless
otherwise noted
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
ANALOG INPUT
Input voltage
0.6 VCC
Center voltage (VREF)
0.5 VCC
Input impedance
Antialiasing filter frequency
response
–3 dB
Vp-p
V
60
kΩ
1.3
MHz
DIGITAL FILTER PERFORMANCE
Pass band
0.454 fS
Stop band
0.583 fS
Hz
±0.05
Pass-band ripple
Stop-band attenuation
–65
Delay time
Hz
dB
dB
17.4/fS
HPF frequency response
–3 dB
0.019 fS/1000
POWER SUPPLY REQUIREMENTS
VCC
VDD
Voltage range
fS = 48 kHz, 96 kHz
ICC
Powered down
Supply current
(7)
4.5
5
5.5
2.7
3.3
3.6
8.6
11
(8)
(9)
fS = 96 kHz
5.9
(8)
Powered down
(9)
fS = 48 kHz
Power dissipation
(7)
fS = 96 kHz
Powered down
8
mA
150
µA
81
77
(9)
mA
10.2
62
(8)
mA
µA
1
fS = 48 kHz
IDD
VDC
mW
µW
500
TEMPERATURE RANGE
TA
Operation temperature
θJA
Thermal resistance
(7)
(8)
(9)
4
–40
85
170
Minimum load on LRCK (pin 7), BCK (pin 8), DOUT (pin 9)
fS = 96 kHz, system clock = 256 fS.
Power-down and reset functions enabled by halting SCKI, BCK, LRCK.
Submit Documentation Feedback
°C
°C/W
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
PIN ASSIGNMENTS
PW PACKAGE
(TOP VIEW)
VREF
AGND
VCC
VDD
DGND
SCKI
LRCK
1
2
3
4
5
6
7
VINR
VINL
FMT
MD1
MD0
DOUT
BCK
14
13
12
11
10
9
8
P0032-02
TERMINAL FUNCTIONS
TERMINAL
NAME
I/O
DESCRIPTION
PIN
AGND
2
–
BCK
8
I/O
DGND
5
–
Digital GND
DOUT
9
O
Audio data digital output
FMT
12
I
Audio interface format select
LRCK
7
I/O
MD0
10
I
Audio interface mode select 0
(2)
MD1
11
I
Audio interface mode select 1
(2)
SCKI
6
I
System clock input; 256 fS, 384 fS or 512 fS (3)
VCC
3
–
Analog power supply, 5-V
VDD
4
–
Digital power supply, 3.3-V
VINL
13
I
Analog input, L-channel
VINR
14
I
Analog input, R-channel
VREF
1
–
Reference voltage decoupling (= 0.5 VCC)
(1)
(2)
(3)
Analog GND
Audio data bit clock input/output
(1)
(2)
Audio data latch enable input/output
(1)
Schmitt-trigger input with internal pulldown (50-kΩ, typical)
Schmitt-trigger input with internal pulldown (50-kΩ, typical), 5-V tolerant
Schmitt-trigger input, 5-V tolerant
Submit Documentation Feedback
5
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
Functional Block Diagram
Antialias
LPF
VINL
VREF
Delta-Sigma
Modulator
BCK
×1/64
Decimation
Filter
with
High-Pass Filter
Reference
Antialias
LPF
VINR
DOUT
FMT
Mode/
Format
Control
MD1
Delta-Sigma
Modulator
MD0
Clock and Timing Control
Power Supply
VCC
LRCK
Serial
Interface
AGND DGND
SCKI
VDD
B0004-10
TYPICAL PERFORMANCE CURVES OF INTERNAL FILTERS
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 512 fS, 24-bit data, unless
otherwise noted.
DECIMATION FILTER FREQUENCY RESPONSE
OVERALL CHARACTERISTICS
STOP-BAND ATTENUATION CHARACTERISTICS
50
0
−10
0
−20
Amplitude − dB
Amplitude − dB
−30
−50
−100
−40
−50
−60
−70
−150
−80
−90
−200
0
8
16
24
Normalized Frequency [× fS]
32
−100
0.00
G001
Figure 1.
6
0.25
0.50
Frequency [× fS]
Figure 2.
Submit Documentation Feedback
0.75
1.00
G002
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
TYPICAL PERFORMANCE CURVES OF INTERNAL FILTERS (Continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 512 fS, 24-bit data, unless
otherwise noted.
DECIMATION FILTER FREQUENCY RESPONSE (Continued)
PASS-BAND RIPPLE CHARACTERISTICS
TRANSITION BAND CHARACTERISTICS
0.2
0
−1
−2
−3
−0.2
Amplitude − dB
Amplitude − dB
0.0
−0.4
−0.6
−4
–4.13 dB at 0.5 fS
−5
−6
−7
−8
−0.8
−9
−1.0
0.0
0.1
0.2
0.3
0.4
0.5
Normalized Frequency [× fS]
−10
0.45 0.46 0.47 0.48 0.49 0.50 0.51 0.52 0.53 0.54 0.55
0.6
Normalized Frequency [× fS]
G003
Figure 3.
G004
Figure 4.
HIGH-PASS FILTER FREQUENCY RESPONSE
HPF STOP-BAND CHARACTERISTICS
HPF PASS-BAND CHARACTERISTICS
0.2
0
−10
0.0
−20
Amplitude − dB
Amplitude − dB
−30
−40
−50
−60
−70
−80
−0.2
−0.4
−0.6
−0.8
−90
−100
0.0
−1.0
0.1
0.2
0.3
0.4
Normalized Frequency [× fS/1000]
0
G005
Figure 5.
1
2
3
Normalized Frequency [× fS/1000]
4
G006
Figure 6.
Submit Documentation Feedback
7
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
TYPICAL PERFORMANCE CURVES
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 512 fS, 24-bit data, unless
otherwise noted.
DYNAMIC RANGE AND SNR
vs
TEMPERATURE
−87
105
−88
104
−89
103
Dynamic Range and SNR − dB
THD + N − Total Harmonic Distortion + Noise − dB
THD + N
vs
TEMPERATURE
−90
−91
−92
−93
−94
−95
−96
−97
−50
101
100
99
98
97
−25
0
25
50
75
95
−50
100
0
25
50
75
G007
Figure 7.
Figure 8.
THD + N
vs
SUPPLY VOLTAGE
DYNAMIC RANGE AND SNR
vs
SUPPLY VOLTAGE
−88
104
−89
103
Dynamic Range and SNR − dB
105
−90
−91
−92
−93
−94
−95
−96
100
G008
102
101
100
Dynamic Range
99
SNR
98
97
96
4.50
4.75
5.00
5.25
VCC − Supply Voltage − V
5.50
5.75
95
4.25
G009
Figure 9.
8
−25
TA − Free-Air Temperature − °C
−87
−97
4.25
Dynamic Range
SNR
96
TA − Free-Air Temperature − °C
THD + N − Total Harmonic Distortion + Noise − dB
102
4.50
4.75
5.00
Figure 10.
Submit Documentation Feedback
5.25
VCC − Supply Voltage − V
5.50
5.75
G010
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
TYPICAL PERFORMANCE CURVES (Continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 512 fS, 24-bit data, unless
otherwise noted.
DYNAMIC RANGE AND SNR
vs
fSAMPLE CONDITION
−87
105
−88
104
−89
103
Dynamic Range and SNR − dB
THD + N − Total Harmonic Distortion + Noise − dB
THD + N
vs
fSAMPLE CONDITION
−90
−91
−92
−93
−94
−95
Dynamic Range
SNR
102
101
100
99
98
97
(1) System
(1) System
Clock = 384 fS
(2) System Clock = 512 f
S
(3) System Clock = 256 f
S
−96
−97
Clock = 384 fS
System Clock = 512 fS
(3) System Clock = 256 f
S
(2)
96
95
44.1(1)
44.1(1)
48(2)
96(3)
fSAMPLE Condition − kHz
48(2)
96(3)
fSAMPLE Condition − kHz
G011
Figure 11.
Figure 12.
OUTPUT SPECTRUM (–0.5 dB, N = 8192)
OUTPUT SPECTRUM (–60 dB, N = 8192)
G012
OUTPUT SPECTRUM
0
0
Input Level = −60 dB
Data Points = 8192
−20
−20
−40
−40
Amplitude − dB
Amplitude − dB
Input Level = −0.5 dB
Data Points = 8192
−60
−80
−60
−80
−100
−100
−120
−120
−140
−140
0
5
10
15
20
0
f − Frequency − kHz
5
10
15
20
f − Frequency − kHz
G013
Figure 13.
G014
Figure 14.
Submit Documentation Feedback
9
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
TYPICAL PERFORMANCE CURVES (Continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 512 fS, 24-bit data, unless
otherwise noted.
OUTPUT SPECTRUM (Continued)
THD + N − Total Harmonic Distortion + Noise − dB
THD + N
vs
SIGNAL LEVEL
0
−10
−20
−30
−40
−50
−60
−70
−80
−90
−100
−100 −90 −80 −70 −60 −50 −40 −30 −20 −10
0
Signal Level − dB
G015
Figure 15.
SUPPLY CURRENT
SUPPLY CURRENT
vs
fSAMPLE CONDITION
15
ICC and IDD − Supply Current − mA
ICC
IDD
10
5
(1) System
Clock = 384 fS
System Clock = 512 fS
(3) System Clock = 256 f
S
(2)
0
44.1(1)
48(2)
96(3)
fSAMPLE Condition − kHz
G016
Figure 16.
10
Submit Documentation Feedback
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
SYSTEM CLOCK
The PCM1808 supports 256 fS, 384 fS and 512 fS as system clock, where fS is the audio sampling frequency.
The system clock must be supplied on SCKI (pin 6).
The PCM1808 has a system clock detection circuit which automatically senses if the system clock is operating
at 256 fS, 384 fS, or 512 fS in slave mode. In master mode, the system clock frequency must be controlled
through the serial control port, which uses MD1 (pin 111) and MD0 (pin 10). The system clock is divided down
automatically to generate frequencies of 128 fS and 64 fS, which are used to operate the digital filter and the
delta-sigma modulator, respectively.
Table 1 shows some typical relationships between sampling frequency and system clock frequency, and
Figure 17 shows system clock timing.
Table 1. Sampling Frequency and System Clock Frequency
SAMPLING FREQUENCY (kHz)
SYSTEM CLOCK FREQUENCY (fSCLK) (MHz)
256 fS
384 fS
512 fS
8
2.048
3.072
4.096
16
4.096
6.144
8.192
32
8.192
12.288
16.384
44.1
11.2896
16.9344
22.5792
48
12.288
18.432
24.576
64
16.384
24.576
32.768
88.2
22.5792
33.8688
45.1584
96
24.576
36.864
49.152
tw(SCKH)
tw(SCKL)
SCKI
2V
SCKI
0.8 V
T0005B07
SYMBOL
PARAMETER
MIN
MAX
UNIT
tw(SCKH)
System clock pulse duration, HIGH
8
ns
tw(SCKL)
System clock pulse duration, LOW
8
ns
System clock duty cycle
40%
60%
Figure 17. System Clock Timing
FADE-IN AND FADE-OUT FUNCTIONS
The PCM1808 has fade-in and fade-out functions on DOUT (pin 9) to avoid pop noise, and the functions come
into operation in some cases as described in several following sections. The level changes from 0 dB to mute or
mute to 0 dB are performed using calculated pseudo S-shaped characteristics with zero-cross detection.
Because of the zero-cross detection, the time needed for the fade in and fade out depends on the analog input
frequency (fin). It takes 48/fin until processing is completed. If there is no zero cross during 8192/fS, DOUT is
faded in or out by force during 48/fS (TIME OUT). Figure 18 illustrates the fade-in and fade-out operation
processing.
Submit Documentation Feedback
11
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
Fade-Out Start
Fade-In Complete
Fade-In Start
DOUT
(Contents)
Fade-Out Complete
BPZ
48/fin or 48/fS
48/fin or 48/fS
T0080-01
Figure 18. Fade-In and Fade-Out Operations
POWER ON
The PCM1808 has an internal power-on-reset circuit, and initialization (reset) is performed automatically when
the power supply (VDD) exceeds 2.2 V (typical). While VDD < 2.2 V (typical), and for 1024 system-clock counts
after VDD > 2.2 V (typical), the PCM1808 stays in the reset state and the digital output is forced to zero. The
digital output is valid after the reset state is released and the time of 8960/fS has elapsed. Because the fade-in
operation is performed, it takes additional time of 48/fin or 48/fS until the data corresponding to the analog input
signal is obtained. Figure 19 illustrates the power-on timing and the digital output.
VDD
2.6 V
2.2 V
1.8 V
Reset
Reset Release
Internal
Reset
Operation
1024 System Clocks
8960/fS
System
Clock
DOUT
Zero Data
Normal Data
Fade-In Complete
Fade-In Start
DOUT
BPZ
(Contents)
48/fin or 48/fS
T0014-09
Figure 19. Power-On Timing
12
Submit Documentation Feedback
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
CLOCK-HALT POWER-DOWN AND RESET FUNCTION
The PCM1808 has a power-down and reset function, which is triggered by halting SCKI (pin 6) in both master
and slave modes. The function is available anytime after power on. Reset and power down are performed
automatically 4 µs (minimum) after SCKI is halted. While the clock-halt reset is asserted, the PCM1808 stays in
the reset and power-down mode, and DOUT (pin 9) is forced to zero. SCKI must be supplied to release the
reset and power-down mode. The digital output is valid after the reset state is released and the time of 1024
SCKI + 8960/fS has elapsed. Because the fade-in operation is performed, it takes additional time of 48/fin or
48/fS until the level corresponding to the analog input signal is obtained. Figure 20 illustrates the clock-halt reset
timing.
To avoid ADC performance degradation, BCK (pin 8) and LRCK (pin 7) are required to synchronize with SCKI
within 4480/fS after SCKI is resumed. If it takes more than 4480/fS for BCK and LRCK to synchronize with SCKI,
SCKI should be masked until the synchronization is achieved again, taking care of glitch and jitter. See the
typical circuit connection diagram, Figure 26.
To avoid ADC performance degradation, the clock-halt reset also should be asserted when system clock SCKIor
the audio interface clocks BCK and LRCK (sampling rate fS) are changed on the fly.
SCKI Halt
SCKI Resume
Fixed to Low or High
SCKI
t(CKR)
Reset: t(RST)
Clock-Halt Reset
Internal
Reset
DOUT
Reset Release: t(REL)
Operation
Operation
Normal Data
Zero Data
Normal Data
Fade-In Complete
Fade-In Start
DOUT
BPZ
(Contents)
Normal Data
48/fin or 48/fS
T0081-01
SYMBOL
PARAMETER
MIN
MAX
UNIT
µs
t(CKR)
Delay time from SCKI halt to internal reset
4
t(RST)
Delay time from SCKI resume to reset release
1024 SCKI
µs
t(REL)
Delay time from reset release to DOUT output
8960/fS
µs
Figure 20. Clock-Halt Power-Down and Reset Timing
Submit Documentation Feedback
13
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
SERIAL AUDIO DATA INTERFACE
The PCM1808 interfaces the audio system through LRCK (pin 7), BCK (pin 8), and DOUT (pin 9).
INTERFACE MODE
The PCM1808 supports master mode and slave mode as interface modes, which are selected by MD1 (pin 11)
and MD0 (pin 10), as shown in Table 2. MD1 and MD0 must be set prior to power on.
In master mode, the PCM1808 provides the timing of serial audio data communications between the PCM1808
and the digital audio processor or external circuit. While in slave mode, the PCM1808 receives the timing for
data transfer from an external controller.
Table 2. Interface Modes
MD1 (Pin 11)
MD0 (Pin 10)
INTERFACE MODE
Low
Low
Slave mode (256 fS, 384 fS, 512 fS autodetection)
Low
High
Master mode (512 fS)
High
Low
Master mode (384 fS)
High
High
Master mode (256 fS)
Master mode
In master mode, BCK and LRCK work as output pins, and these pins are controlled by timing which is generated
in the clock circuit of the PCM1808. The frequency of BCK is fixed at 64 BCK/frame.
Slave mode
In slave mode, BCK and LRCK work as input pins. The PCM1808 accepts 64-BCK/frame or 48-BCK/frame
format (only for a 384-fS system clock), not 32-BCK/frame format.
DATA FORMAT
The PCM1808 supports two audio data formats in both master and slave modes. The data formats are selected
by FMT (pin 12), as shown in Table 3. Figure 21 illustrates the data formats in slave mode and master mode.
Table 3. Data Format
14
FORMAT NO.
FMT (Pin 12)
0
Low
I2S, 24-bit
FORMAT
1
High
Left-justified, 24-bit
Submit Documentation Feedback
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
FORMAT 0: FMT = LOW
24-Bit, MSB-First, I2S
Left-Channel
LRCK
Right-Channel
BCK
DOUT
1
2
3
22 23 24
MSB
1
LSB
2
3
22 23 24
MSB
LSB
FORMAT 1: FMT = HIGH
24-Bit, MSB-First, Left-Justified
Left-Channel
LRCK
Right-Channel
BCK
DOUT
1
2
MSB
3
22 23 24
LSB
1
2
3
MSB
22 23 24
1
LSB
T0016-17
Figure 21. Audio Data Format (LRCK and BCK Work as Inputs in Slave Mode
and as Outputs in Master Mode)
Submit Documentation Feedback
15
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
INTERFACE TIMING
Figure 22 and Figure 23 illustrate the interface timing in slave mode and master mode, respectively.
t(LRCP)
1.4 V
LRCK
t(BCKL)
t(LRSU)
t(BCKH)
t(LRHD)
1.4 V
BCK
t(CKDO)
t(BCKP)
t(LRDO)
0.5 VDD
DOUT
T0017-02
SYMBOL
PARAMETER
t(BCKP)
BCK period
t(BCKH)
t(BCKL)
t(LRSU)
MIN
TYP
MAX
UNIT
1/(64 fS)
ns
BCK pulse duration, HIGH
1.5 × t(SCKI)
ns
BCK pulse duration, LOW
1.5 × t(SCKI)
ns
LRCK setup time to BCK rising edge
50
ns
t(LRHD)
LRCK hold time to BCK rising edge
10
ns
t(LRCP)
LRCK period
10
t(CKDO)
Delay time, BCK falling edge to DOUT valid
–10
40
ns
t(LRDO)
Delay time, LRCK edge to DOUT valid
–10
40
ns
tr
Rise time of all signals
20
ns
tf
Fall time of all signals
20
ns
µs
NOTE: Timing measurement reference level is 1.4 V for input and 0.5 VDD for output. Rise and fall times are from 10% to
90% of the input/output signal swing. Load capacitance of DOUT is 20 pF. t(SCKI) is the SCKI period.
Figure 22. Audio Data Interface Timing (Slave Mode: LRCK and BCK Work as Inputs)
16
Submit Documentation Feedback
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
t(LRCP)
0.5 VDD
LRCK
t(BCKL)
t(BCKH)
t(CKLR)
0.5 VDD
BCK
t(CKDO)
t(BCKP)
t(LRDO)
0.5 VDD
DOUT
T0018-02
MIN
TYP
MAX
UNIT
t(BCKP)
SYMBOL
BCK period
PARAMETER
150
1/(64 fS)
2000
ns
t(BCKH)
BCK pulse duration, HIGH
65
1200
ns
t(BCKL)
BCK pulse duration, LOW
65
1200
ns
t(CKLR)
Delay time, BCK falling edge to LRCK valid
–10
20
ns
t(LRCP)
LRCK period
10
125
µs
t(CKDO)
Delay time, BCK falling edge to DOUT valid
–10
20
ns
t(LRDO)
Delay time, LRCK edge to DOUT valid
–10
20
ns
tr
Rise time of all signals
20
ns
tf
Fall time of all signals
20
ns
1/fS
NOTE: Timing measurement reference level is 0.5 VDD. Rise and fall times are from 10% to 90% of the input/output signal
swing. Load capacitance of all signals is 20 pF.
Figure 23. Audio Data Interface Timing (Master Mode: LRCK and BCK Work as Outputs)
1.4 V
SCKI
t(SCKBCK)
t(SCKBCK)
0.5 VDD
BCK
T0074-01
SYMBOL
t(SCKBCK)
PARAMETER
Delay time, SCKI rising edge to BCK edge
MIN
5
TYP
MAX
UNIT
30
ns
NOTE: Timing measurement reference level is 1.4 V for input and 0.5 VDD for output. Load capacitance of BCK is 20 pF.
This timing is applied when SCKI frequency is less than 25 MHz.
Figure 24. Audio Clock Interface Timing (Master Mode: BCK Works as Output)
Submit Documentation Feedback
17
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
SYNCHRONIZATION WITH DIGITAL AUDIO SYSTEM
In slave mode, the PCM1808 operates under LRCK (pin 7), synchronized with system clock SCKI (pin 6). The
PCM1808 does not require a specific phase relationship between LRCK and SCKI, but does require the
synchronization of LRCK and SCKI.
If the relationship between LRCK and SCKI changes more than ±6 BCKs for 64 BCK/frame (±5 BCKs for 48
BCK/frame) during one sample period due to LRCK or SCKI jitter, internal operation of the ADC halts within 1/fS
and digital output is forced to zero data (BPZ code) until resynchronization between LRCK and SCKI is
established.
In the case of changes less than ±5 BCKs for 64 BCK/frame (±4 BCKs for 48 BCK/frame), resynchronization
does not occur and the previously described digital output control and discontinuity do not occur.
Figure 25 illustrates the digital output response for loss of synchronization and resynchronization. During
undefined data, the PCM1808 can generate some noise in the audio signal. Also, the transition of normal data to
undefined data creates a discontinuity in the digital output data, which can generate some noise in the audio
signal. The digital output is valid after resynchronization completes and the time of 32/fS has elapsed. Because
the fade-in operation is performed, it takes additional time of 48/fin or 48/fS until the level corresponding to the
analog input signal is obtained. If synchronization is lost during the fade-in or fade-out operation, the operation
stops and DOUT (pin 9) is forced to zero data immediately. The fade-in operation resumes from mute after the
time of 32/fS following resynchronization.
Resynchronization
Resynchronization
Synchronization Lost
State of
Synchronization
Synchronous
Asynchronous
1/fS
DOUT
Normal Data
Synchronization Lost
Synchronous
Asynchronous
Synchronous
32/fS
Undefined
Data
Zero Data
Normal Data
Zero Data
Normal Data
Fade-In Complete
Fade-In Start
DOUT
BPZ
(Contents)
Fade-In Restart
Normal Data
32/fS
48/fin or 48/fS
48/fin or 48/fS
T0082-01
Figure 25. ADC Digital Output for Loss of Synchronization and Resynchronization
18
Submit Documentation Feedback
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
APPLICATION INFORMATION
TYPICAL CIRCUIT CONNECTION DIAGRAM
Figure 26 is a typical circuit connection diagram. The antialiasing low-pass filters are integrated on the analog
inputs, VINL and VINR. If the performance of these filters is not adequate for an application, appropriate external
antialiasing filters are needed. A passive RC filter (100 Ω and 0.01 µF to 1 kΩ and 1000 pF) generally is used.
PCM1808
C5(3)
C4(2)
4 µs (min)
5V
3.3 V
Mask
PLL170x
X1(4)
+
(2) +
(5)
+
1
VREF
VINR
14
2
AGND
VINL
13
3
VCC
FMT
12
4
VDD
MD1
11
5
DGND
MD0
10
6
SCKI
DOUT
9
7
LRCK
BCK
8
C3
+
C1(1)
+
C2(1)
R-ch IN
L-ch IN
High/Low
Pin
Setting
DSP
or
Audio
Processor
S0113-02
(1)
C1, C2: A 1-µF electrolytic capacitor gives 2.7 Hz (τ = 1 µF × 60 kΩ) cutoff frequency for the input HPF in normal
operation and requires a power-on settling time with a 60-ms time constant in the power-on initialization period.
(2)
C3, C4: Bypass capacitors, 0.1-µF ceramic and 10-µF electrolytic, depending on layout and power supply
(3)
C5: 0.1-µF ceramic and 10-µF electrolytic capacitors are recommended.
(4)
X1: X1 masks the system clock input when using the clock-halt reset function with external control.
(5)
Optional external antialiasing filter could be required, depending on the application.
Figure 26. Typical Circuit Connection Diagram
BOARD DESIGN AND LAYOUT CONSIDERATIONS
VCC, VDD PINS
The digital and analog power supply lines to the PCM1808 should be bypassed to the corresponding ground
pins with both 0.1-µF ceramic and 10-µF electrolytic capacitors as close to the pins as possible to maximize the
dynamic performance of the ADC.
AGND, DGND PINS
To maximize the dynamic performance of the PCM1808, the analog and digital grounds are not internally
connected. These grounds should have low impedance to avoid digital noise feedback into the analog ground.
They should be connected directly to each other under the PCM1808 package to reduce potential noise
problems.
VINL, VINR PINS
VINL and VINR are single-ended inputs. The antialias low-pass filters are integrated on these inputs to remove
the high-frequency noise outside the audio band. If the performance of these filters is not adequate for an
application, appropriate external antialiasing filters are required. A passive RC filter (100 Ω and 0.01 µF to 1 kΩ
and 1000 pF) is generally used.
Submit Documentation Feedback
19
PCM1808
www.ti.com
SLES177A – APRIL 2006 – REVISED AUGUST 2006
APPLICATION INFORMATION (continued)
VREF PIN
To ensure low source impedance of the ADC references, 0.1-µF ceramic and 10-µF electrolytic capacitors are
recommended between VREF and AGND. These capacitors should be located as close as possible to the VREF
pin to reduce dynamic errors on the ADC references.
DOUT PIN
The DOUT pin has a large load-drive capability, but if the DOUT line is long, locating a buffer near the PCM1808
and minimizing load capacitance is recommended to minimize the digital-analog crosstalk and maximize the
dynamic performance of the ADC.
SYSTEM CLOCK
The quality of the system clock can influence dynamic performance, as the PCM1808 operates based on a
system clock. Therefore, it may be necessary to consider the system clock duty, jitter, and the time difference
between system clock transition and BCK or LRCK transition in slave mode.
20
Submit Documentation Feedback
PACKAGE OPTION ADDENDUM
www.ti.com
5-Jul-2006
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
PCM1808PW
ACTIVE
TSSOP
PW
14
90
Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
PCM1808PWG4
ACTIVE
TSSOP
PW
14
90
Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
PCM1808PWR
ACTIVE
TSSOP
PW
14
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
PCM1808PWRG4
ACTIVE
TSSOP
PW
14
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-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 - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
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.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry 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
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
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
MECHANICAL DATA
MTSS001C – JANUARY 1995 – REVISED FEBRUARY 1999
PW (R-PDSO-G**)
PLASTIC SMALL-OUTLINE PACKAGE
14 PINS SHOWN
0,30
0,19
0,65
14
0,10 M
8
0,15 NOM
4,50
4,30
6,60
6,20
Gage Plane
0,25
1
7
0°– 8°
A
0,75
0,50
Seating Plane
0,15
0,05
1,20 MAX
PINS **
0,10
8
14
16
20
24
28
A MAX
3,10
5,10
5,10
6,60
7,90
9,80
A MIN
2,90
4,90
4,90
6,40
7,70
9,60
DIM
4040064/F 01/97
NOTES: A.
B.
C.
D.
All linear dimensions are in millimeters.
This drawing is subject to change without notice.
Body dimensions do not include mold flash or protrusion not to exceed 0,15.
Falls within JEDEC MO-153
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI’s terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Applications
Amplifiers
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
Low Power Wireless www.ti.com/lpw
Mailing Address:
Telephony
www.ti.com/telephony
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright  2006, Texas Instruments Incorporated