TI PCM1681-Q1

PCM1681
PCM1681-Q1
Burr-Brown Audio
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
24-Bit, 192-kHz Sampling, Enhanced Multilevel Delta-Sigma,
Eight-Channel Audio Digital-to-Analog Converter
FEATURES
1
• 24-Bit Resolution
• Analog Performance:
– Dynamic Range: 105 dB Typical
– SNR: 105 dB Typical
– THD+N: 0.002% Typical
– Full-Scale Output: 3.75 VPP Typical
• 4×/8× Oversampling Interpolation Filter:
– Stop-Band Attenuation: –57 dB
– Pass-Band Ripple: ±0.015 dB
• Sampling Frequency: 5 kHz to 200 kHz
• System Clock: 128 fS, 192 fS, 256 fS, 384 fS, 512
fS, 768 fS, or 1152 fS with Autodetect
• Zero Flags for Selectable Channel
Combinations
• Flexible Mode Control:
– SPI™/I2C™ Dual Mode for Serial Port
– Parallel Hardware Control with 4 Functions
• User-Programmable Functions (in SPI/I2C):
– Flexible Audio Data Formats:
– Right-Justified, I2S™, Left-Justified,
TDM, DSP
– 16- and 24-Bit Audio Data
– Digital Attenuation: Mode Selectable
– 0 dB to –63 dB, 0.5 dB/step
– 0 dB to –100 dB, 1 dB/step
– Soft Mute
– Digital De-Emphasis
– Digital Filter Roll-Off: Sharp or Slow
– Oversampling Mode
• User-Programmable Functions (in H/W):
– Flexible Audio Data Formats:
– Right-Justified, I2S, Left-Justified, TDM
– Soft Mute
– Digital De-Emphasis
– Oversampling Mode
23456
•
•
•
Power Supply Voltage: +5-V Analog, +3.3-V
Digital
Package: 28-Lead TSSOP PowerPAD™
Operation Temperature Range:
– –40°C to +85°C for Consumer Grade
– –40°C to +105°C for Automotive Audio
Grade
APPLICATIONS
•
•
•
•
•
•
•
•
Car Audio External Amplifiers
Car Audio AVN Applications
Integrated A/V Receivers
DVD Movie and Audio Players
HDTV Receivers
DVD Add-On Cards for High-End PCs
Digital Audio Workstations
Other Multichannel Audio Systems
DESCRIPTION
The PCM1681 and PCM1681-Q1 are CMOS
monolithic integrated circuits which feature an
eight-channel 24-bit audio digital-to-analog converter
(DAC) and support circuitry in small 28-lead TSSOP
PowerPAD packages. The DACs utilize Burr-Brown's
enhanced multilevel delta-sigma (ΔΣ) architecture to
achieve excellent signal-to-noise performance and a
high tolerance to clock jitter.
The PCM1681 and PCM1681-Q1 accept TDM
(time-division multiplexed) format in addition to
industry-standard audio data formats with 16- to
24-bit audio data width. Sampling rates up to 200 kHz
are supported. The PCM1681 and PCM1681-Q1
provide a sub-set of user-programmable functions
through a parallel control port, in addition to a full set
of user-programmable functions through a serial
control port, SPI, or I2C. The PCM1681 supports
–40°C to +85°C for consumer grade applications and
the PCM1681-Q1 supports –40°C to +105°C for
automotive audio grade systems.
1
2
3
4
5
6
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.
PowerPAD is a trademark of Texas Instruments.
System Two, Audio Precision are trademarks of Audio Precision, Inc.
SPI is a trademark of Motorola.
I2C, I2S are trademarks of NXP Semiconductors.
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 © 2008, Texas Instruments Incorporated
PCM1681
PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
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 (1)
Over operating free-air temperature range (unless otherwise noted).
PCM1681 and PCM1681-Q1
Supply voltage:
VCC1, VCC2
–0.3 V to 6.5 V
VDD
–0.3 V to 4.0 V
Supply voltage differences: VCC1, VCC2
±0.1 V
Ground voltage differences: AGND1, AGND2, DGND
Input voltage to
digital pins
±0.1 V
ZR1/ZR1/FMT0, ZR2, MSEL
–0.3 V to VDD + 0.3 V, < 4.0 V
MS/ADR/FMT1, MC/SCL/DEMP, MD/SDA/MUTE, SCK, BCK, LRCK,
DATA1, 2, 3, 4
–0.3 V to 6.5 V
Input voltage to analog pins
–0.3 V to VCC + 0.3 V, < 6.5 V
Input current (any pins except supplies)
±10 mA
Ambient temperature under bias
–40°C to +125°C
Storage temperature
–55°C to +150°C
Junction temperature
+150°C
Lead temperature (soldering)
+260°C, 5 s
Package temperature (IR 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.
Analog supply voltage, VCC1, VCC2
Digital supply voltage, VDD
MIN
NOM
MAX
4.5
5
5.5
V
3
3.3
3.6
V
Digital input logic family
Digital input clock frequency
UNIT
TTL
System clock
Sampling clock
Analog output load resistance
1.024
36.864
MHz
8
192
kHz
5
kΩ
Analog output load capacitance
50
pF
Digital output load capacitance
20
pF
Operating free-air temperature, TA
2
PCM1681
–40
+85
°C
PCM1681-Q1
–40
+105
°C
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PCM1681
PCM1681-Q1
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
ELECTRICAL CHARACTERISTICS
All specifications at VCC = 5.0 V, VDD = 3.3 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, narrow o/s mode, unless
otherwise noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
RESOLUTION
MAX
UNIT
24
Bits
DATA FORMAT
Right-justified, I2S,
left-justified, TDM
Audio data interface format
16-, 18-, 20-, or 24-bits,
selectable
Audio data bit length
Audio data format
fS
MSB-first, 2s complement
Sampling frequency
5
200
kHz
128, 192, 256, 384,
512, 768, 1152 fS
System clock frequency
DIGITAL INPUT/OUTPUT
Logic family
TTL compatible
VIH (1)
VIL
2.0
VDD
(1)
VIH (2)
0.8
Input logic level
2.0
VIL (2)
IIH
(1) (2)
IIL
(1) (2)
VOH (3)
VOL (3) (4)
VDC
5.5
0.8
Input logic current
Output logic level
VIN = VDD
10
VIN = 0 V
–10
IOH = –1 mA
µA
2.4
IOL = 1 mA
VDC
0.4
DYNAMIC PERFORMANCE (5)
THD+N
Total harmonic distortion + noise
VOUT = 0 dB, fS = 48 kHz
0.002
VOUT = 0 dB, fS = 96 kHz, system clock = 256 fS
0.002
VOUT = 0 dB, fS = 192 kHz,
system clock = 128 fS
0.002
EIAJ, A-weighted, fS = 48 kHz
Dynamic range
100
A-weighted, fS = 96 kHz, system clock = 256 fS
SNR
Signal-to-noise ratio
dB
105
105
A-weighted, fS = 192 kHz, system clock = 128 fS
Channel separation
105
105
100
A-weighted, fS = 96 kHz, system clock = 256 fS
fS = 48 kHz
%
105
A-weighted, fS = 192 kHz, system clock = 128 fS
EIAJ, A-weighted, fS = 48 kHz
0.008
dB
105
94
102
fS = 96 kHz, system clock = 256 fS
102
fS = 192 kHz, system clock = 128 fS
102
dB
DC ACCURACY
Gain error
±2.0
±6
% of FSR
Gain mismatch,
channel-to-channel
±2.0
±6
% of FSR
±30
±80
mV
Bipolar zero error
(1)
(2)
(3)
(4)
(5)
VOUT = 0.486 VCC at BPZ input
Pins 1, 14: ZR1/ZR1/FMT0 (input mode), MSEL
Pins 2, 3, 4, 5, 6, 7, 8, 11, 12, 13: MS/ADR/FMT1, MC/SCL/DEMP, MD/SDA/MUTE (input mode), SCK, DATA1, BCK, LRCK, DATA2,
DATA3, DATA4
Pins 1, 28: ZR1/ZR1/FMT0 (output mode), ZR2
Pin 4: MD/SDA/MUTE (output mode)
Analog performance characteristics are measured using the System Two™ Cascade audio measurement system by Audio Precision™,
fIN = 1 kHz, average mode, with 20-kHz LPF and 400-Hz HPF.
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PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
All specifications at VCC = 5.0 V, VDD = 3.3 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, narrow o/s mode, unless
otherwise noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
ANALOG OUTPUT
Output voltage
Full-scale (–0 dB)
Bipolar zero voltage
Load impedance
AC-coupled load
0.75
VCC
VPP
0.486
VCC
VDC
5
kΩ
DIGITAL FILTER PERFORMANCE
Filter Characteristics (Sharp Roll-Off)
Passband
±0.015 dB
Stop band
0.454 fS
0.546 fS
Passband ripple
Stop band attenuation
±0.015
Stop band = 0.546 fS
–57
dB
dB
Filter Characteristics (Slow Roll-Off)
Passband
±0.004 dB
Stop band
0.261 fS
0.727 fS
Passband ripple
Stop band attenuation
±0.004
Stop band = 0.727 fS
–56
dB
dB
Filter Characteristics
Delay time
24/fS
De-emphasis error
±0.1
dB
ANALOG FILTER PERFORMANCE
Frequency response
at 20 kHz
–0.02
at 44 kHz
–0.07
dB
POWER-SUPPLY REQUIREMENTS
VDD
VCC
IDD
ICC
3
3.3
3.6
4.5
5.0
5.5
fS = 48 kHz
13
20
fS = 96 kHz, system clock = 256 fS
18
fS = 192 kHz, system clock = 128 fS
23
fS = 48 kHz
62
fS = 96 kHz, system clock = 256 fS
62
fS = 192 kHz, system clock = 128 fS
62
Voltage range
Supply current
Supply current
Power dissipation
fS = 48 kHz
353
fS = 96 kHz, system clock = 256 fS
369
fS = 192 kHz, system clock = 128 fS
386
VDC
mA
80
mA
466
mW
TEMPERATURE RANGE
Operating temperature
θJA
4
Thermal resistance
PCM1681
–40
+85
PCM1681-Q1
–40
+105
28-pin TSSOP PowerPAD™
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28
°C
°C
°C/W
Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): PCM1681 PCM1681-Q1
PCM1681
PCM1681-Q1
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
PIN ASSIGNMENTS
PCM1681 and PCM1681-Q1
PWP (TSSOP PowerPAD) PACKAGE
(TOP VIEW)
ZR1/ZR1/FMT0
MS/ADR/FMT1
MC/SCL/DEMP
MD/SDA/MUTE
SCK
DATA1
BCK
LRCK
VDD
DGND
DATA2
DATA3
DATA4
MSEL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
ZR2
VOUT1
VOUT2
VCOM
AGND2
VCC2
VOUT3
VOUT4
VOUT5
VOUT6
AGND1
VCC1
VOUT7
VOUT8
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PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
TERMINAL FUNCTIONS
TERMINAL
NAME
NO.
I/O
DESCRIPTION
AGND1
18
–
Analog ground
AGND2
24
–
Analog ground
BCK
7
I
Shift clock input for serial audio data
DATA1
6
I
Serial audio data input for VOUT1 and VOUT2
(1) (2)
DATA2
11
I
Serial audio data input for VOUT3 and VOUT4
(1) (2)
DATA3
12
I
Serial audio data input for VOUT5 and VOUT6
(1) (2)
DATA4
13
I
Serial audio data input for VOUT7 and VOUT8
(1) (2)
DGND
10
–
Digital ground
LRCK
8
I
Left and right clock input. The frequency of this clock is equal to the sampling rate, fS.
MC/SCL/
DEMP
3
I
Shift clock input for SPI, serial clock input for I2C, de-emphasis control for H/W
MD/SDA/
MUTE
4
I/O
Serial data input for SPI, serial data input/output for I2C, mute control for H/W
MS/ADR/
FMT1
2
I
Select input for SPI, address input for I2C, format control input 1 for H/W
MSEL
14
I
Mode control select, I2C, H/W with narrow mode O/S, H/W with wide mode O/S, SPI select (1) (4)
SCK
5
I
System clock input. Input frequency is 128, 192, 256, 384, 512, 768, or 1152 fS.
VCC1
17
–
Analog power supply, 5-V
VCC2
23
–
Analog power supply, 5-V
VCOM
25
–
Common voltage output. This pin should be bypassed with a 10-µF capacitor to AGND.
(1) (2)
(1) (2)
(1) (2) (3)
(1) (2)
(1) (2)
VDD
9
–
Digital power supply, 3.3-V
VOUT1
27
O
Voltage output for audio signal corresponding to L-ch on DATA1
VOUT2
26
O
Voltage output for audio signal corresponding to R-ch on DATA1
VOUT3
22
O
Voltage output for audio signal corresponding to L-ch on DATA2
VOUT4
21
O
Voltage output for audio signal corresponding to R-ch on DATA2
VOUT5
20
O
Voltage output for audio signal corresponding to L-ch on DATA3
VOUT6
19
O
Voltage output for audio signal corresponding to R-ch on DATA3
VOUT7
16
O
Voltage output for audio signal corresponding to L-ch on DATA4
VOUT8
15
O
Voltage output for audio signal corresponding to R-ch on DATA4
ZR1/ZR1
/FMT0
1
I/O
Zero-flag output 1 for SPI, zero-flag output 1 for I2C, format control input 0 for H/W (1)
ZR2
28
O
Zero-flag output 2
(1)
(2)
(3)
(4)
6
(1) (2)
Schmitt-trigger input.
5-V tolerant.
Open-drain output in I2C mode.
VDD/2 biased, quad state input.
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PCM1681
PCM1681-Q1
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
FUNCTIONAL BLOCK DIAGRAM
DAC
BCK
LRCK
DAC
DATA1 (1, 2)
DATA2 (3, 4)
Enhanced
Multilevel
Delta-Sigma
Modulator
MD/SDA/MUTE
Function
Control
I/F
VOUT2
Output Amp and
Low-Pass Filter
VOUT3
DAC
Output Amp and
Low-Pass Filter
VCOM
DAC
Output Amp and
Low-Pass Filter
DAC
Output Amp and
Low-Pass Filter
DAC
Output Amp and
Low-Pass Filter
DAC
Output Amp and
Low-Pass Filter
MS/ADR/FMT1
MC/SCL/DEMP
Output Amp and
DAC
DATA3 (5, 6)
8y
Oversampling
Digital Filter
With
Function
Controller
VOUT1
Low-Pass Filter
Serial
Input
I/F
DATA4 (7, 8)
Output Amp and
Low-Pass Filter
MSEL
VOUT4
VOUT5
VOUT6
VOUT7
VOUT8
System Clock
AGND2
VCC2
AGND1
VCC1
Power Supply
DGND
Zero Detect
VDD
Manager
ZR2
System Clock
ZR1/ZR1/FMT0
SCK
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PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
TYPICAL CHARACTERISTICS
All specifications at TA = +25°C, VCC = 5 V, VDD = 3.3 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise
noted.
DIGITAL FILTER (DE-EMPHASIS OFF)
FREQUENCY RESPONSE
(SHARP ROLL-OFF)
PASSBAND FREQUENCY RESPONSE
(SHARP ROLL-OFF)
0.05
0
0.04
0.03
0.02
−40
Amplitude – dB
Amplitude – dB
−20
−60
−80
0.01
0.00
−0.01
−0.02
−0.03
−100
−0.04
−0.05
0.0
−120
0
1
2
3
4
Frequency [× fS]
0.1
0.2
0.3
0.4
Frequency [× fS]
G001
0.5
G002
Figure 1.
Figure 2.
FREQUENCY RESPONSE
(SLOW ROLL-OFF)
TRANSITION CHARACTERISTICS
(SLOW ROLL-OFF)
0.0
0
−0.5
−1.0
−1.5
−40
Amplitude – dB
Amplitude – dB
−20
−60
−80
−2.0
−2.5
−3.0
−3.5
−4.0
−100
−4.5
−120
0
1
2
Frequency [× fS]
3
−5.0
0.0
4
0.1
G003
Figure 3.
8
0.2
0.3
Frequency [× fS]
0.4
0.5
G004
Figure 4.
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PCM1681
PCM1681-Q1
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
TYPICAL CHARACTERISTICS (Continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise
noted.
DE-EMPHASIS FILTER
DE-EMPHASIS
DE-EMPHASIS ERROR
0.5
0
fS = 32 kHz
−1
0.3
De-Emphasis Error – dB
−2
De-Emphasis Level – dB
fS = 32 kHz
0.4
−3
−4
−5
−6
−7
0.2
0.1
0.0
−0.1
−0.2
−8
−0.3
−9
−0.4
−0.5
−10
0
2
4
6
8
10
12
0
14
2
4
6
8
10
12
G006
G005
Figure 5.
Figure 6.
DE-EMPHASIS
DE-EMPHASIS ERROR
0.5
0
fS = 44.1 kHz
−1
fS = 44.1 kHz
0.4
0.3
De-Emphasis Error – dB
−2
De-Emphasis Level – dB
14
f – Frequency – kHz
f – Frequency – kHz
−3
−4
−5
−6
−7
0.2
0.1
0.0
−0.1
−0.2
−8
−0.3
−9
−0.4
−0.5
−10
0
2
4
6
8
10
12
14
16
18
20
0
2
4
6
8
10
12
14
16
18
20
f – Frequency – kHz
f – Frequency – kHz
G008
G007
Figure 7.
Figure 8.
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PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
TYPICAL CHARACTERISTICS (Continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise
noted.
DE-EMPHASIS FILTER (Continued)
DE-EMPHASIS
DE-EMPHASIS ERROR
0.5
0
fS = 48 kHz
−1
0.3
De-Emphasis Error – dB
−2
De-Emphasis Level – dB
fS = 48 kHz
0.4
−3
−4
−5
−6
−7
0.2
0.1
0.0
−0.1
−0.2
−8
−0.3
−9
−0.4
−0.5
−10
0
2
4
6
8
10
12
14
16
18
20
0
22
2
4
6
8
10
12
14
16
18
20
22
f – Frequency – kHz
f – Frequency – kHz
G010
G009
Figure 9.
Figure 10.
ANALOG FILTER
ANALOG FILTER PERFORMANCE
10
0
Amplitude − dB
−10
−20
−30
−40
−50
−60
−70
1
10
100
1,000
10,000
f − Frequency − kHz
G011
Figure 11.
10
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PCM1681-Q1
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
TYPICAL CHARACTERISTICS (Continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, fS = 48 kHz, 96 kHz, 192 kHz, system clock = 512 fS, 256 fS, 128
fS,and 24-bit data, narrow o/s (oversampling) mode, unless otherwise noted.
ANALOG DYNAMIC PERFORMANCE
Supply Voltage Characteristics
TOTAL HARMONIC DISTORTION + NOISE
vs
SUPPLY VOLTAGE
DYNAMIC RANGE
vs
SUPPLY VOLTAGE
0.01
THD+N − Total Harmonic Distortion + Noise − %
108
Dynamic Range – dB
106
102
100
0.001
4.75
5.00
98
4.50
5.25
VCC − Supply Voltage − V
5.00
5.25
VCC – Supply Voltage – V
Figure 12.
Figure 13.
SIGNAL-TO-NOISE RATIO
vs
SUPPLY VOLTAGE
CHANNEL SEPARATION
vs
SUPPLY VOLTAGE
108
108
106
106
104
102
100
98
4.50
4.75
G012
Channel Separation – dB
SNR – Signal-to-Noise Ratio − dB
104
5.50
G013
104
102
100
4.75
5.00
5.25
VCC – Supply Voltage – V
5.50
98
4.50
4.75
G014
Figure 14.
5.00
5.25
VCC – Supply Voltage – V
5.50
G015
Figure 15.
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PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
TYPICAL CHARACTERISTICS (Continued)
All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, fS = 48 kHz, 96 kHz, 192 kHz, system clock = 512 fS, 256 fS, 128
fS,and 24-bit data, narrow o/s (oversampling) mode, unless otherwise noted.
Temperature Characteristics
TOTAL HARMONIC DISTORTION + NOISE
vs
TEMPERATURE
DYNAMIC RANGE
vs
TEMPERATURE
0.01
THD+N − Total Harmonic Distortion + Noise − %
108
Dynamic Range – dB
106
102
100
0.001
−40
−15
10
35
60
85
TA − Free-Air Temperature − °C
98
−40
110
G016
35
60
Figure 17.
SIGNAL-TO-NOISE RATIO
vs
TEMPERATURE
CHANNEL SEPARATION
vs
TEMPERATURE
108
106
106
104
102
100
85
110
G017
104
102
100
−15
10
35
60
TA − Free-Air Temperature − °C
85
110
G018
98
−40
−15
10
35
60
TA − Free-Air Temperature − °C
Figure 18.
12
10
Figure 16.
108
98
−40
−15
TA − Free-Air Temperature − °C
Channel Separation – dB
SNR – Signal-to-Noise Ratio − dB
104
85
110
G019
Figure 19.
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SYSTEM CLOCK INPUT
The PCM1681 and PCM1681-Q1 require a system clock for operating the digital interpolation filters and
multilevel ΔΣ modulators. The system clock is applied at the SCK input (pin 5). Table 1 shows examples of
system clock frequencies for common audio sampling rates.
Figure 20 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. Texas Instruments’ PLL170x multi-clock generator is an
excellent choice for providing the PCM1681 and PCM1681-Q1 system clock source.
Table 1. System Clock Frequencies for Common Audio Sampling Frequencies
SYSTEM CLOCK FREQUENCY (fSCK), MHz
SAMPLING
FREQUENCY
128 fS
192 fS
256 fS
384 fS
512 fS
768 fS
8 kHz
1.024
1.536
2.048
3.072
4.096
6.144
9.216
16 kHz
2.048
3.072
4.096
6.144
8.192
12.288
18.432
32 kHz
4.096
6.144
8.192
12.288
16.384
24.576
36.864
44.1 kHz
5.6448
8.4672
11.2896
16.9344
22.5792
33.8688
— (1)
48 kHz
6.144
9.216
12.288
18.432
24.576
36.864
— (1)
88.2 kHz
11.2896
16.9344
22.5792
33.8688
— (1)
— (1)
— (1)
—
(1)
—
(1)
— (1)
—
(1)
—
(1)
— (1)
96 kHz
192 kHz
(1)
1152 fS
12.288
18.432
24.576
24.576
36.864
—
(1)
36.864
—
(1)
This system clock frequency is not supported for the given sampling frequency.
tw(SCKH)
H
2V
System Clock
0.8 V
L
tw(SCKL)
tc(SCK)(1)
T5A08
(1)
System clock pulse cycle time; 1/128 fS, 1/192 fS, 1/256 fS, 1/384 fS, 1/512 fS, 1/768 fS, or 1/1152 fS
PARAMETER
MIN
MAX
UNIT
tc(SCK)
System clock cycle time
25
ns
tw(SCKH)
System clock pulse duration, HIGH
10
ns
tw(SCKL)
System clock pulse duration, LOW
10
ns
System clock duty cycle
40%
60%
Figure 20. System Clock Timing
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POWER-ON-RESET FUNCTION
The PCM1681 and PCM1681-Q1 include a power-on-reset function. Figure 21 shows the operation of this
function. With the system clock active and VDD > 2.2 V (typical, 1.4 V to 2.9 V), the power-on-reset function is
enabled. The initialization sequence requires 65,536 system clocks from the time VDD > 2.2 V. VDD must rise up
with a ramp-up rate greater than 1V/ms to ensure reliable initialization. After the initialization period, the
PCM1681 and PCM1681-Q1 are set to the respective reset default state, as described in the Mode Control
Registers section of this data sheet.
During the reset period (65,536 system clocks), the analog output is forced to the common voltage (VCOM), 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 PCM1681 and PCM1681-Q1 provide the proper analog output with group delay
corresponding to the input data.
VDD
2.9 V
2.2 V
1.4 V
Need ramp−up more than 1V/ms
0V
Reset
Release Reset State
Fix Mode Control Selection
Internal Reset
Don’t Care
65536 System Clocks
System Clock
Figure 21. Power-On-Reset Timing
AUDIO SERIAL INTERFACE
The audio serial interface for the PCM1681 and PCM1681-Q1 is comprised of a 6-wire synchronous serial port. It
includes LRCK (pin 8), BCK (pin 7), and DATA1 (pin 6), DATA2 (pin 11), DATA3 (pin 12), and DATA4 (pin 13).
BCK is the serial audio bit clock, and it is used to clock the serial data present on DATA1, DATA2, DATA3, and
DATA4 into the audio interface serial shift register. Serial data are clocked into the PCM1681 and PCM1681-Q1
on the rising edge of BCK. LRCK is the serial audio left/right word clock. It is used to latch serial data into the
serial audio interface internal registers.
Both LRCK and BCK must be synchronous with the system clock, SCK. Ideally, it is recommended that LRCK
and BCK are derived from SCK. LRCK is operated at the sampling frequency, fS. BCK can be operated at 32, 48,
or 64 times the sampling frequency for the PCM formats and times at 128 and 256 the sampling frequency for
the TDM formats.
Internal operation of the PCM1681 and PCM1681-Q1 is synchronized with LRCK. Accordingly, internal operation
is suspended when LRCK is changed or when SCK and/or BCK is interrupted for at least 3-bit clock cycles. If
SCK, BCK, and LRCK are provided continuously after this held condition, the internal operation is
resynchronized automatically within the following 3/fS period. External resetting is not required.
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AUDIO DATA FORMATS AND TIMING
The PCM1681 and PCM1681-Q1 support industry-standard audio data formats, including right-justified, I2S,
left-justified, and DSP. The PCM1681 and PCM1681-Q1 also support a time-division-multiplexed (TDM) format.
The TDM format is supported only at system clocks of 128 fS, 256 fS, and 512 fS. The data formats are shown in
Figure 22 and Figure 23. Data formats are selected using the format bits, FMT[3:0], located in control register 9
of the PCM1681 and PCM1681-Q1. The default data format is 16- to 24-bit left-justified. All formats require
binary 2s complement, MSB-first audio data. Figure 24 shows a detailed timing diagram for the serial audio
interface.
DATA1, DATA2, DATA3, and DATA4 each carry two audio channels, designated as the left and right channels in
the right-justified, I2S, left-justified, and DSP formats. The left-channel data always precedes the right-channel
data in the serial data stream for all data formats. Table 2 shows the mapping of the digital input data to the
analog output pins. DATA1 carries eight audio channels in 256 fS mode TDM fornat, and DATA1 and DATA2
each carry four audio channels in 128 fS mode TDM format.
Table 2. Audio Input Data to Analog Output Mapping
DATA INPUT
DATA1
DATA2
DATA3
DATA4
CHANNEL
ANALOG OUTPUT
Left
VOUT1
Right
VOUT2
Left
VOUT3
Right
VOUT4
Left
VOUT5
Right
VOUT6
Left
VOUT7
Right
VOUT8
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(1) Right-Justified Data Format; L-Channel = HIGH, R-Channel = LOW
1/fS
LRCK
L-Channel
R-Channel
BCK
(= 32 fS, 48 fS, or 64 fS)
16-Bit Right-Justified, BCK = 32 fS
DATA
14 15 16
1
2
3
14 15 16
1
LSB
MSB
2
3
14 15 16
MSB
LSB
16-Bit Right-Justified, BCK = 48 fS or 64 fS
DATA
14 15 16
1
2
3
14 15 16
MSB
1
2
3
14 15 16
MSB
LSB
LSB
24-Bit Right-Justified, BCK = 48 fS or 64 fS
DATA
22 23 24
1
2
3
22 23 24
MSB
1
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
(= 32 fS, 48 fS or 64 fS)
DATA
1
2
3
N–2 N–1
MSB
LSB
N
1
2
3
N–2
MSB
N–1
N
1
2
N
1
2
LSB
(3) Left-Justified Data Format; L-Channel = HIGH, R-Channel = LOW (default)
1/fS
LRCK
L-Channel
R-Channel
BCK
(= 32 fS, 48 fS, or 64 fS)
DATA
1
2
3
N–2 N–1
MSB
LSB
N
1
2
3
MSB
N–2 N–1
LSB
Figure 22. Audio Data Input Formats
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(4) 24-Bit DSP Format
1/fs (64 BCKs)
LRCK
BCK
(= 64fS)
LJ mode
DATA
1
2
3
1
2
22 23 24
1
2
3
1
2
22 23 24
1
2
3
1
2
2
I S mode
DATA
22 23 24
3
3
22 23 24
(5) 24-Bit TDM Format
1/fs (256 BCKs or 128 BCKs)
LRCK
tLRW
BCK
(= 128 fS or 256 fS)
tLRW
tLRW
LJ mode
DATA1 *1
2
I S mode
DATA1 *1
LJ mode
DATA1/2 *2
1 2
1 2
CH1
32 BCKs
1 2
24
1 2
24
1 2
CH2
32 BCKs
1 2
24
23 24
1 2
24
1 2
CH3
32 BCKs
1 2
1 2
CH1/CH5
32 BCKs
2
I S mode
DATA1/2 *2
24
24
24
1 2
CH4
32 BCKs
1 2
23 24
24
1 2
23 24
1 2
CH5
32 BCKs
1 2
1 2
24
24
1 2
CH6
32 BCKs
1 2
23 24
1 2
23 24
24
1 2
CH7
32 BCKs
24
1 2
1 2
CH3/CH7
32 BCKs
CH2/CH6
32 BCKs
23 24
24
24
24
1 2
CH8
32 BCKs
1 2
23 24
24
1 2
1 2
CH4/CH8
32 BCKs
1 2
23 24
1 2
*1: BCK = 256 fS mode
*2: BCK = 128 fS mode
Figure 23. Audio Data Input Formats
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t(LRW)
1.4 V
LRCK
t(BCL)
t(BCH)
t(LH)
t(LS)
1.4 V
BCK
t(BCY)
t(DS)
t(DH)
DATA1, DATA2,
DATA3, DATA4
1.4 V
PARAMETER
TYP
MAX
UNIT
ns
BCK pulse duration HIGH
35
ns
BCK pulse duration LOW
35
BCK cycle time
t(BCH)
t(BCL)
t(LRW)
MIN
75(1)
t(BCY)
ns
LRCK pulse duration HIGH, right-justified, I2S, left-justified
1/2 fS
LRCK pulse duration HIGH, DSP format
t(BCY)
t(BCY)
LRCK pulse duration HIGH, TDM format
t(BCY)
1/fS – t(BCY)
1/2 fS
t(LS)
LRCK setup time to BCK rising edge
10
ns
t(LH)
LRCK hold time to BCK rising edge
10
ns
t(DS)
DATA1, DATA2, DATA3, DATA4 setup time to BCK rising edge
10
ns
t(DH)
DATA1, DATA2, DATA3, DATA4 hold time to BCK rising edge
10
ns
(1)
2
For right-justified, I S, left-justified, and DSP formats, there is no fS (sampling frequency) limitation for all of 1/32 fS,
1/48 fS, or 1/64 fS. However, for TDM format, allowable fS is limited to fS ≤ 50 kHz for BCK = 256 fS mode and fS ≤
100 kHz for BCK = 128 fS mode.
Figure 24. Audio Interface Timing
DE-EMPHASIS FILTER
The PCM1681 and PCM1681-Q1 include a digital de-emphasis filter for 32 kHz, 44.1 kHz, and 48 kHz sampling
frequencies.
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OVERSAMPLING RATE CONTROL
The PCM1681 and PCM1681-Q1 automatically control the oversampling rate of the ΔΣ DACs according to
system clock frequency and oversampling mode. Oversampling mode, narrow or wide, can be selected by the
MSEL pin in H/W control mode and the OVER bit of control register 12 in S/W control mode. The oversampling
rate is set to 64× oversampling with a 1152 fS, 768 fS, 512 fS system clock, 32× oversampling with a 384 fS, 256
fS system clock, and 16× oversampling with a 192 fS, 128 fS system clock in default, narrow mode, and 128×
oversampling with a 1152 fS, 768 fS, 512 fS system clock, 64× oversampling with a 384 fS, 256 fS system clock,
and 32× oversampling with a 192 fS, 128 fS system clock in wide mode. Wide mode is recommended for fS ≤ 96
kHz at SCK = 128 fS or 192 fS, fS ≤ 48 kHz at SCK = 256 fS or 384 fS, and fS ≤ 24 kHz at SCK = 512 fS, 768 fS, or
1152 fS.
Table 3. Oversampling Rate Control
OVERSAMPLING RATE
OVERSAMPLING MODE
SCK = 128 fS or 192 fS
SCK = 256 fS or 384 fS
Narrow mode
16×
32×
SCK = 512 fS, 768 fS, or 1152 fS
64×
Wide mode
32×
64×
128×
ZERO FLAG
The PCM1681 and PCM1681-Q1 have two zero-flag pins, ZR1 (pin 1) and ZR2 (pin 28), which are assigned to
the combinations A through D as shown in Table 4. Zero-flag combinations are selected using the zero-flag
combination bits, AZRO[1:0], located in control register 13 of the PCM1681 and PCM1681-Q1. If the input data of
the L-channel and/or R-channel of all assigned channels remains at a logic-0 level for 1024 sampling periods
(LRCK clock periods), ZR1 and ZR2 are set to logic-1 states, or high level. If the input data of any of the
assigned channels contains a logic-1 level, ZR1 and ZR2 are set to logic-0 states or low level immediately.
The active polarity of a zero-flag output can be inverted by setting the ZREV bit of control register 10 to 1. The
reset default is ZREV = 0, active-high for zero detection.
In parallel hardware control mode, ZR1 is not applicable due to the reassignment of ZR1 as the FMT0 control
pin, and the zero-flag output combination is fixed as all 8 channel (DATA1-DATA4) data zero on the ZR2 pin.
Table 4. Zero-Flag Output Combinations
ZERO-FLAG COMBINATION
ZR1/ZR1/FMT0 (PIN 1)
ZR2 (PIN 28)
A
DATA1 L-ch
DATA1 R-ch
B
DATA1-4
DATA1-4
C
DATA4
DATA1-3
D
DATA1
DATA2-4
MODE CONTROL
The PCM1681 and PCM1681-Q1 support three types of interface mode control with three types of oversampling
configuration, according to the input state of MSEL (pin 14) as listed in Table 5. The required values of the
pull-up and pull-down resistors are 220 kΩ ± 5%.
Table 5. Interface Mode Control
MSEL
INTERFACE MODE CONTROL
Tied with DGND
2-Wire (I2C) serial control, selectable oversampling configuration
Pull-down resistor to DGND
4-Wire parallel H/W control, narrow mode oversampling configuration
Pull-up resistor to VDD
4-Wire parallel H/W control, wide mode oversampling configuration
Tied with VDD
3-Wire (SPI) serial control, selectable oversampling configuration
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The input state of the MSEL pin is sampled at power-on with the system clock input; therefore, an input change
after a reset is ignored until the next power-on. The assignments of the four pins are controlled by the interface
mode control setting as listed in Table 6.
Table 6. Interface Mode Control Pin Assignments
DEFINITION (Assignment)
PIN
2
I C
SPI
PARALLEL H/W
4
SDA (input/output)
MD (input)
MUTE (input)
3
SCL (input)
MC (input)
DEMP (input)
2
ADR (input)
MS (input)
FMT1 (input)
1
ZR1 (output)
ZR1 (output)
FMT0 (input)
In serial control mode, actual mode control is performed by a register write (and read) through the I2C or SPI
compatible serial control port. In parallel H/W control mode, the specific four functions are controlled directly
through high-level/low-level control of five specific pins (see Parallel Hardware Control section), and the zero-flag
function of ZR1 is not applicable.
PARALLEL HARDWARE CONTROL
Four functions are controlled by five pins, MSEL, FMT0, FMT1, DEMP, and MUTE in parallel hardware control
mode.
MSEL TERMINATION (1)
DESCRIPTION
Pull-down resistor to DGND
Narrow oversampling mode
Pull-up resistor to VDD
Wide oversampling mode
(1)
The MSEL termination controls the oversampling mode for all eight channels.
FMT1 (1)
FMT0 (1)
DESCRIPTION
LOW
LOW
24-bits right-justified format
LOW
HIGH
16 to 24-bits I2S format
HIGH
LOW
16 to 24-bits left-justified format
HIGH
HIGH
24-bits I2S mode TDM format
(1)
The FMT0 and FMT1 pins control the audio interface format for all eight channels.
DEMP (1)
DESCRIPTION
LOW
De-emphasis off
HIGH
44.1-kHz De-emphasis on
(1)
The DEMP pin controls the 44.1-kHz digital de-emphasis function of all eight channels.
MUTE (1)
DESCRIPTION
LOW
Mute off (mute disable)
HIGH
Mute on (mute enable)
(1)
The MUTE pin controls all 8 channel outputs at the same time.
SPI CONTROL INTERFACE
The SPI control interface of the PCM1681 and PCM1681-Q1 is a 3-wire synchronous serial port that operates
asynchronously to the serial audio interface. The SPI control interface is used to program the on-chip mode
registers. The control interface includes MD (pin 4), MC (pin 3), and MS (pin 2). MD is the serial data input, used
to program the mode registers. MC is the control port for the serial bit clock, used to shift in the serial data, and
MS is the control port for mode control select, which is used to enable the mode control. The SPI control
interface is available when MSEL (pin 14) is tied with VDD and after power-on reset completion.
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REGISTER WRITE OPERATION
All write operations for the serial control port use 16-bit data words. Figure 25 shows the control data word
format. The most significant bit is a fixed 0 for the write operation. Seven bits, labeled IDX[6:0], 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 26 shows the functional timing diagram for writing to the serial control port. MS is held at a logic-1 state
until a register needs to be written. To start the register write cycle, MS is set to logic-0. 16 clock cycles are then
provided on MC, corresponding to the 16 bits of the control data word on MD. After completion of the 16th clock
cycle, MS is set to logic-1 to latch the data into the indexed mode control register.
LSB
MSB
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
D7
D6
D5
D4
Register Index (or Address)
D3
D2
D1
D0
Register Data
R0001-01
Figure 25. Control Data Word Format for MD
MS
MC
MD
X
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
D7
D6
D5
D4
D3
D2
D1
D0
X
X
0
IDX6
T0048-01
Figure 26. Write Operation Timing
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INTERFACE TIMING REQUIREMENTS
Figure 27 shows a detailed timing diagram for the serial control interface. Special attention to the setup and hold
times is required. Also, t(MSS) and t(MSH), which define the minimum delays between the edges of the MS and MC
clocks, require special attention. These timing parameters are critical for proper control port operation.
t(MHH)
MS
t(MSS)
t(MCL)
t(MCH)
t(MSH)
MC
t(MCY)
LSB
MD
t(MDS)
t(MDH)
T0013-03
PARAMETER
MIN
UNIT
t(MCY)
MC cycle time
100
ns
t(MCL)
MC pulse duration, LOW
50
ns
t(MCH)
MC pulse duration, HIGH
50
ns
t(MHH)
MS pulse duration, HIGH
(1)
ns
t(MSS)
MS falling edge to MC rising edge
20
ns
t(MSH)
MS hold time, MC rising edge for LSB to MS rising edge
20
ns
t(MDH)
MD hold time
15
ns
t(MDS)
MD setup time
20
ns
(1)
3/(256 fS) s (minimum), fS: sampling rate
Figure 27. Interface Timing
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I2C INTERFACE
The PCM1681 and PCM1681-Q1 support the I2C serial bus and the data transmission protocol for standard
mode as a slave device. This protocol is explained in the I2C specification 2.0. The PCM1681 and PCM1681-Q1
do not support a board-to-board interface. The I2C control interface is available when MSEL (pin 14) is tied with
DGND and after power-on reset completion.
SLAVE ADDRESS
MSB
LSB
1
0
0
1
1
0
ADR
R/W
The PCM1681 and PCM1681-Q1 have seven bits for the respective slave address. The first six bits (MSBs) of
the slave address are factory preset to 1001 10. The next bit of the address byte is the device select bit, which
can be user-defined using the ADR terminal. A maximum of two PCM1681s or PCM1681-Q1s can be connected
on the same bus at one time. Each PCM1681 or PCM1681-Q1 responds when it receives its own slave address.
PACKET PROTOCOL
A master device must control packet protocol, which consists of a start condition, slave address, read/write bit,
data if writing or acknowledge if reading, and stop condition. The PCM1681 and PCM1681-Q1 support only slave
receivers and slave transmitters. The details about DATA for write and read operation are described in the
following sections.
SDA
SCL
St
1−7
8
9
1−8
9
1−8
9
9
Slave Address
R/W
ACK
DATA
ACK
DATA
ACK
ACK
R/W: Read Operation if 1; Otherwise, Write Operation
ACK: Acknowledgement of a Byte if 0
DATA: 8 Bits (Byte), the details are described in write and read operation
NACK: Not Acknowledgement if 1
Start
Condition
Write Operation
Sp
Stop
Condition
Transmitter
M
M
M
S
M
S
M
S
S
M
Data Type
St
Slave Address
W
ACK
DATA
ACK
DATA
ACK
ACK
Sp
Read Operation
Transmitter
M
M
M
S
S
M
S
M
M
M
Data Type
St
Slave Address
R
ACK
DATA
ACK
DATA
ACK
NACK
Sp
M: Master Device S: Slave Device St: Start Condition
Sp: Stop Condition W: Write R: Read
T0049-01
2
Figure 28. Basic I C Framework
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WRITE OPERATION
A master can write to any PCM1681 and PCM1681-Q1 registers using a single access. The master sends a
PCM1681 or PCM1681-Q1 slave address with a write bit, a register address, and the data. When undefined
registers are accessed, the PCM1681 or PCM1681-Q1 sends an acknowledgement, but the write operation does
not occur. Figure 29 is a diagram of the write operation.
Transmitter
M
M
M
S
M
S
M
S
M
Data Type
St
Slave Address
W
ACK
Reg Address
ACK
Write Data
ACK
Sp
M: Master Device S: Slave Device
St: Start Condition W: Write ACK: Acknowledge Sp: Stop Condition
R0002-01
Figure 29. Write Operation
READ OPERATION
A master can read any PCM1681 or PCM1681-Q1 register using a single access. The master sends a PCM1681
or PCM1681-Q1 slave address with a read bit after transferring the register address. Then the PCM1681 or
PCM1681-Q1 transfers the data in the register specified. Figure 30 is a diagram of the read operation.
Transmitter
M
M
M
S
M
S
M
M
M
S
Data Type
St
Slave Address
W
ACK
Reg Address
ACK
Sr
Slave Address
R
ACK
S
M
M
Read Data NACK Sp
M: Master Device S: Slave Device St: Start Condition
Sr: Repeated Start Condition ACK: Acknowledge Sp: Stop Condition NACK: Not Acknowledge
W: Write R: Read
R0002-02
NOTE: The slave address after the repeated start condition must be the same as the previous slave address.
Figure 30. Read Operation
24
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TIMING DIAGRAM
Start
Repeated Start
Stop
t(D-HD)
t(BUF)
t(D-SU)
t(SDA-F)
t(P-SU)
t(SDA-R)
SDA
t(SCL-R)
t(RS-HD)
t(SP)
t(LOW)
SCL
t(S-HD)
t(HI)
t(RS-SU)
t(SCL-F)
T0050-01
PARAMETER
MIN
MAX
UNIT
100
kHz
f(SCL)
SCL clock frequency
t(BUF)
Bus free time between a STOP and START condition
4.7
µs
t(LOW)
Low period of the SCL clock
4.7
µs
t(HI)
High period of the SCL clock
4
µs
t(RS-SU)
Setup time for (repeated) START condition
4.7
µs
t(S-HD)
t(RS-HD)
Hold time for (repeated) START condition
4
µs
t(D-SU)
Data setup time
250
t(D-HD)
Data hold time
0
900
ns
t(SCL-R)
Rise time of SCL signal
20 + 0.1 CB
1000
ns
t(SCL-R1)
Rise time of SCL signal after a repeated START condition and after an acknowledge bit
20 + 0.1 CB
1000
ns
t(SCL-F)
Fall time of SCL signal
20 + 0.1 CB
1000
ns
t(SDA-R)
Rise time of SDA signal
20 + 0.1 CB
1000
ns
t(SDA-F)
Fall time of SDA signal
20 + 0.1 CB
1000
t(P-SU)
Setup time for STOP condition
CB
Capacitive load for SDA and SCL lines
VNH
Noise margin at high level for each connected device (including hysteresis)
ns
ns
µs
4
400
0.2 VDD
pF
V
Figure 31. Interface Timing
MODE CONTROL REGISTERS
USER-PROGRAMMABLE MODE CONTROLS
The PCM1681 and PCM1681-Q1 include a number of user-programmable functions which are accessed via
control registers. The registers are programmed using the serial control interface which is discussed in the Mode
Control section of this data sheet. Table 7 lists the available mode control functions, along with the respective
reset default conditions and associated register index.
REGISTER MAP
The mode control register map is shown in Table 8. The MSB of all registers is fixed to 0. Each register also
includes an index (or address) indicated by the IDX[6:0] bits.
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RESERVED REGISTERS
Registers 0 and 15 are reserved for factory use. To ensure proper operation, the user should not write to these
registers.
Table 7. User-Programmable Mode Control Functions
FUNCTION
RESET DEFAULT
REGISTER
BIT
Digital attenuation control, 0 dB to –63 dB in
0.5-dB steps
0 dB, no attenuation
1–6, 16, 17
AT1[7:0], AT2[7:0], AT3[7:0], AT4[7:0],
AT5[7:0], AT6[7:0], AT7[7:0], AT8[7:0]
Soft mute control
Mute disabled
7, 18
MUT[8:1], MUT[8:7]
DAC1–DAC8 operation control
DAC1–DAC8 enabled
8, 19
DAC[8:1], DAC[8:7]
Audio data format control
16- to 24-bit, left-justified
9
FMT[3:0]
Digital filter roll-off control
Sharp roll-off
9
FLT
De-emphasis all-channel function control
De-emphasis of all channels
disabled
10
DMC
De-emphasis all-channel sample rate selection
44.1 kHz
10
DMF[1:0]
Output phase select
Normal phase
10
DREV
Zero-flag polarity select
High
10
ZREV
Software reset control
Reset disabled
10
SRST
Output phase select per channel
Reverse phase
11
REV[8:1]
Oversampling rate control
Narrow (×64, ×32, ×16) mode
12
OVER
Digital filter roll-off control per DATA group
Slow roll-off
12
FLT[4:1]
Zero-flag combination select
ZR1: DATA1 Lch
ZR2: DATA1 Rch
13
AZRO[1:0]
Digital attenuation mode select
0 to –63 dB, 0.5-dB step
13
DAMS
Zero-detect status
(read-only, I2C interface only)
N/A
14
ZERO[8:1]
Table 8. Mode Control Register Map
IDX
(B8–B14)
REGISTER
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
00h
0
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
N/A (1)
N/A (1)
N/A (1)
N/A (1)
N/A (1)
N/A (1)
N/A (1)
N/A (1)
01h
1
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT17
AT16
AT15
AT14
AT13
AT12
AT11
AT10
02h
2
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT27
AT26
AT25
AT24
AT23
AT22
AT21
AT20
03h
3
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT37
AT36
AT35
AT34
AT33
AT32
AT31
AT30
04h
4
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT47
AT46
AT45
AT44
AT43
AT42
AT41
AT40
05h
5
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT57
AT56
AT55
AT54
AT53
AT52
AT51
AT50
06h
6
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT67
AT66
AT65
AT64
AT63
AT62
AT61
AT60
07h
7
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
MUT8
MUT7
MUT6
MUT5
MUT4
MUT3
MUT2
MUT1
08h
8
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
DAC8
DAC7
DAC6
DAC5
DAC4
DAC3
DAC2
DAC1
09h
9
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV (2)
RSV (2)
FLT
RSV (2)
FMT3
FMT2
FMT1
FMT0
0Ah
10
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
SRST
ZREV
DREV
DMF1
DMF0
RSV (2)
RSV (2)
DMC
0Bh
11
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
REV8
REV7
REV6
REV5
REV4
REV3
REV2
REV1
0Ch
12
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
OVER
RSV (2)
RSV (2)
RSV (2)
FLT4
FLT3
FLT2
FLT1
0Dh
13
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
DAMS
AZRO1
AZRO0
RSV (2)
RSV (2)
RSV (2)
RSV (2)
RSV (2)
0Eh
14
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
ZERO8
ZERO7
ZERO6
ZERO5
ZERO4
ZERO3
ZERO2
ZERO1
10h
16
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT77
AT76
AT75
AT74
AT73
AT72
AT71
AT70
11h
17
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
AT87
AT86
AT85
AT84
AT83
AT82
AT81
AT80
12h
18
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV (2)
RSV (2)
RSV (2)
RSV (2)
RSV (2)
RSV (2)
MUT8
MUT7
13h
19
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV (2)
RSV (2)
RSV (2)
RSV (2)
RSV (2)
RSV (2)
DAC8
DAC7
(1)
(2)
26
Not assigned. No operation even if setting any data
Reserved for test operation. It should be set to 0 during normal operation.
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REGISTER DEFINITIONS
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
REGISTER 1
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT17
AT16
AT15
AT14
AT13
AT12
AT11
AT10
REGISTER 2
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT27
AT26
AT25
AT24
AT23
AT22
AT21
AT20
REGISTER 3
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT37
AT36
AT35
AT34
AT33
AT32
AT31
AT30
REGISTER 4
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT47
AT46
AT45
AT44
AT43
AT42
AT41
AT40
REGISTER 5
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT57
AT56
AT55
AT54
AT53
AT52
AT51
AT50
REGISTER 6
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT67
AT66
AT65
AT64
AT63
AT62
AT61
AT60
REGISTER 16
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT77
AT76
AT75
AT74
AT73
AT72
AT71
AT70
REGISTER 17
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
AT87
AT86
AT85
AT84
AT83
AT82
AT81
AT80
ATx[7:0]: Digital Attenuation Level Setting
where x = 1–8, corresponding to the DAC output VOUTx. Default value: 1111 1111b
ATTENUATION LEVEL SETTING
ATx[7:0]
DECIMAL VALUE
DAMS = 0
DAMS = 1
1111 1111b
255
0 dB, no attenuation (default)
0 dB, no attenuation (default)
1111 1110b
254
–0.5 dB
–1 dB
1111 1101b
253
–1 dB
–2 dB
:
:
:
:
1001 1100b
156
–49.5 dB
–99 dB
1001 1011b
155
–50 dB
–100 dB
1001 1010b
154
–50.5 dB
Mute
:
:
:
:
1000 0010b
130
–62.5 dB
Mute
1000 0001b
129
–63 dB
Mute
1000 0000b
128
Mute
Mute
:
:
:
:
0000 0000b
0
Mute
Mute
Each DAC output, VOUT1 through VOUT8, has a digital attenuation function. The attenuation level can be set from
0 dB to R dB, in S-dB steps. Changes in attenuation levels are made by incrementing or decrementing by one
step (S-dB) for every 8/fS time interval until the programmed attenuation setting is reached. Alternatively, the
attenuation level can be set to infinite attenuation (or mute). Range (R) and step (S) are –63 and 0.5,
respectively, for DAMS = 0 and –100 and 1, respectively, for DAMS = 1. The DAMS bit is defined in register 13.
The attenuation data for each channel can be set individually. The attenuation level can be calculated using the
following formula:
Attenuation level (dB) = S • (ATx[7:0]DEC – 255)
where ATx[7:0]DEC = 0 through 255. For ATx[7:0]DEC = 0 through 128 with DAMS = 0 or for ATx[7:0]DEC = 0
through 154 with DAMS = 1, the attenuation is set to infinite attenuation (mute).
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B15
B14
B13
B12
B11
B10
B9
B8
B7
REGISTER 7
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 MUT8
REGISTER 18
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
RSV
B6
B5
B4
B3
B2
B1
B0
MUT7
MUT6
MUT5
MUT4
MUT3
MUT2
MUT1
RSV
RSV
RSV
RSV
RSV
MUT8
MUT7
MUTx: Soft Mute Control
where x = 1–8, corresponding to the DAC output VOUTx. Default value: 0
MUTx = 0
Mute disabled (default)
MUTx = 1
Mute enabled
The mute bits, MUT1 through MUT8, are used to enable or disable the soft mute function for the corresponding
DAC outputs, VOUT1 through VOUT8. MUT7 and MUT8 of register 7 and register 18 work as an OR function,
either one or both can be used according to the requirements of the application. 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 is
decreased from the current setting to the infinite-attenuation setting one attenuator step (S-dB) at a time. This
provides a quiet, pop-free muting of the DAC output. On returning from soft mute, by setting MUTx = 0, the
attenuator is increased one step at a time to the previously programmed attenuator level. The step size, S, is 0.5
dB for DAMS = 0 and 1 dB for DAMS = 1.
B7
B6
B5
B4
B3
B2
B1
B0
REGISTER 8
B15
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
B14
B13
B12
B11
B10
B9
B8
DAC8
DAC7
DAC6
DAC5
DAC4
DAC3
DAC2
DAC1
REGISTER 19
0
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
RSV
RSV
RSV
RSV
RSV
RSV
DAC8
DAC7
DACx: DAC Operation Control
where x = 1–8, corresponding to the DAC output VOUTx. Default value: 0
DACx = 0
DAC operation enabled (default)
DACx = 1
DAC operation disabled
The DAC operation controls are used to enable and disable the DAC outputs, VOUT1 through VOUT8. When
DACx = 0, the output amplifier input is connected to the DAC output. When DACx = 1, the output amplifier input
is switched to the dc common voltage (VCOM), equal to VCC/2. DAC7 and DAC8 of register 8 and register 19 work
as an OR function, either one or both can be used according to the requirements of the application.
B15
REGISTER 9
0
B11
B10
IDX6 IDX5 IDX4 IDX3
B14
B13
B12
IDX2
B9
B8
IDX1 IDX0
B7
B6
B5
B4
B3
B2
B1
B0
RSV
RSV
FLT
RSV
FMT3
FMT2
FMT1
FMT0
FLT: Digital Filter Roll-Off Control
Default value: 0
FLT = 0
Sharp roll-off (default)
FLT = 1
Slow roll-off
The FLT bit allows users to select the digital filter roll-off that is best suited to their application. Two filter roll-off
selections are available: sharp or slow. The filter responses for these selections are shown in the Typical
Characteristics section of this data sheet.
28
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FMT[3:0]: Audio Interface Data Format
Default value: 0101b
FMT[3:0] Audio Data Format Selection
0000
Right-justified format, 24-bit
0001
Reserved
0010
Reserved
0011
Right-justified format, 16-bit
0100
I2S format, 16- to 24-bit
0101
Left-justified format, 16- to 24-bit (default)
0110
I2S format, TDM format, 24-bit
0111
Left-justified format, TDM format, 24-bit
1000
I2S format, DSP format, 24-bit
1001
Left-justified format, DSP format, 24-bit
The FMT[3:0] bits are used to select the data format for the serial audio interface.
The format details and restrictions related with the system clock are described in the previous section, AUDIO
DATA FORMATS AND TIMING.
B15
REGISTER 10
0
B14
B13
B12
B11
B10
B9
B8
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
B7
B6
B5
B4
B3
B2
B1
B0
SRST
ZREV
DREV
DMF1
DMF0
RSV
RSV
DMC
SRST: Reset
Default value: 0
SRST = 0
Reset disabled (default)
SRST = 1
Reset enabled
The SRST bit is used to enable or disable the soft reset function. The operation is the same as the
power-on-reset function with the exception of the reset period, which is 1024 system clocks for the SRST
function. All registers are initialized.
ZREV: Zero-Flag Polarity Select
Default value: 0
ZREV = 0
Zero-flag pins high at a zero detect (default)
ZREV = 1
Zero-flag pins low at a zero detect
The ZREV bit allows the user to select the polarity of the zero-flag pins.
DREV: Output Phase Select
Default value: 0
DREV = 0
Normal output (default)
DREV = 1
Inverted output
The DREV bit allows the user to select the phase of the analog output signal.
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DMF[1:0]: Sampling Frequency Selection for the De-Emphasis Function
Default value: 00b
DMF[1:0] De-Emphasis Sampling Rate Selection
00
44.1 kHz (default)
01
48 kHz
10
32 kHz
11
Reserved
The DMF[1:0] bits select the sampling frequency used for the digital de-emphasis function when it is enabled.
The de-emphasis curves are shown in the Typical Characteristics section of this data sheet. The preceding table
shows the available sampling frequencies.
DMC: Digital De-Emphasis All-Channel Function Control
Default value: 0
DMC = 0
De-emphasis disabled for all channels (default)
DMC = 1
De-emphasis enabled for all channels
The DMC bit is used to enable or disable the de-emphasis function for all channels.
B15
REGISTER 11
0
B14
B13
B12
B11
B10
B9
B8
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
B7
B6
B5
B4
B3
B2
B1
B0
REV8
REV7
REV6
REV5
REV4
REV3
REV2
REV1
REV[8:1]: Output Phase Select per Channel
Where x = 1 – 8, corresponding to the DAC output VOUTx. Default value: 1
REVx = 0
Normal output
REVx = 1
Inverted output (default)
The REVx bit allows the user to select the phase of the analog output signal per channel when DREV = 1 is set
on Register 10 .
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
OVER
RSV
RSV
RSV
REGISTER 12
B3
B2
B1
B0
FLT4 FLT3 FLT2 FLT1
OVER: Oversampling Rate Control
Default value: 0
OVER
512 fS, 768 fS, 1152 fS
256 fS, 384 fS
128 fS, 192 fS
OVER = 0
×64 oversampling, narrow
mode (default)
×32 oversampling, narrow
mode (default)
×16 oversampling, narrow
mode (default)
OVER = 1
×128 oversampling, wide
mode
×64 oversampling, wide mode ×32 oversampling, wide
mode
FLTx: Digital Filter Roll-Off Control per DATA Group
Where x = 1 – 4, corresponding to the DATAx. Default value: 1
FLTx = 0
Sharp roll-off
FLTx = 1
Slow roll-off (default)
The FLTx bit allows the user to select the digital filter roll-off characteristic per 2 channels when FLT = 1 is set,
so that it is best suited to the application. Two filter roll-off sections are available: sharp or slow. The filter
responses for these selections are shown in the Typical Characteristics section.
30
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B15
REGISTER 13
0
B14
B13
B12
B11
B10
B9
B8
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
B7
B6
B5
B4
B3
B2
B1
B0
DAMS
AZRO1
AZRO0
RSV
RSV
RSV
RSV
RSV
DAMS: Digital Attenuation Mode Select
Default value: 0
DAMS = 0
Fine step, 0.5 dB/step for 0 to –63 dB range (default)
DAMS = 1
Wide range, 1 dB/step for 0 to –100 dB range
The DAMS bit is used to select the digital attenuation mode.
AZRO[1:0]: Zero-Flag Channel-Combination Select
Default value: 00b
AZRO[1:0]
Zero-Flag Channel-Combination Select
00
Combination A (ZR1: DATA1 L-ch, ZR2: DATA1 R-ch) (default)
01
Combination B (ZR1: DATA1–DATA4, ZR2: DATA1–DATA4)
10
Combination C (ZR1: DATA4, ZR2: DATA1–DATA3)
11
Combination D (ZR1: DATA1, ZR2: DATA2–DATA4)
The AZRO[1:0] bits are used to select the zero-flag channel combinations for ZR1 and ZR2.
B15
REGISTER 14
0
B14
B13
B12
B11
B10
B9
B8
IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0
B7
B6
B5
B4
B3
B2
B1
B0
ZERO8
ZERO7
ZERO6
ZERO5
ZERO4
ZERO3
ZERO2
ZERO1
ZERO[8:1]: Zero-Detect Status (Read-Only, I2C Interface Only)
Default value: N/A
The ZERO[8:1] bits show the status of zero detect for each channel. The status is set to 1 by detecting a zero
state without regard to the ZREV bit setting.
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PCM1681
PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
ANALOG OUTPUTS
The PCM1681 and PCM1681-Q1 include eight independent output channels, VOUT1 through VOUT8. These are
unbalanced outputs, each capable of driving 3.75 VPP typical into a 5-kΩ ac load with VCC = 5 V. The internal
output amplifiers for VOUT1 through VOUT8 are biased to the dc common voltage, equal to 0.486 VCC.
The output amplifiers include an RC continuous-time filter, which helps to reduce the out-of-band noise energy
present at the DAC outputs due to the noise-shaping characteristics of the PCM1681 and PCM1681-Q1 ΔΣ
DACs. The frequency response of this filter is shown in Figure 11. By itself, this filter is not enough to attenuate
the out-of-band noise to an acceptable level for most applications. 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
Application Information section of this data sheet.
VCOM OUTPUT
One unbuffered common voltage output pin, VCOM (pin 25), is brought out for decoupling purposes. This pin is
nominally biased to the dc common voltage, equal to VCC/2. If this pin is to be used to bias external circuitry, a
voltage follower is required for buffering purposes. Figure 32 shows an example of a 5 V single-supply filter
circuit using the VCOM pin for external biasing applications.
AV = -
R2
R1
PCM1681
PCM1681-Q1
C1
R3
VOUTX
5V
2
3
C2
-
1/2 of
OPA2353
1
+
5V
VCOM
+
+
OPA337
C3
10 mF
-
R4
C4
10 mF
+
R2
R1
47 W
R5
10 kW
To Additional
Low-Pass
Filter Circuits
Example:
R1: 6.2 kΩ
R2: 6.8 kΩ
R3: 430 Ω
C1: 470 pF
C2: 4700 pF
AV: –1.10 (1.45 Vrms Output)
fC: 70 kHz
Figure 32. Single-Supply Filter Circuit Using VCOM for External Biasing Applications
32
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PCM1681
PCM1681-Q1
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
APPLICATION INFORMATION
CONNECTION DIAGRAMS
A basic connection diagram is shown in Figure 33, with the necessary power supply bypassing and decoupling
components. Texas Instruments’ PLL170x is used to generate the system clock input at SCK, as well as
generating the clock for the audio signal processor. The use of series resistors (22 Ω to 100 Ω) is recommended
for SCK, LRCK, BCK, DATA1, DATA2, DATA3, and DATA4. The series resistor combines with the stray PCB
capacitance and device input capacitance to form a low-pass filter that removes high-frequency noise from the
digital signal, thus reducing high-frequency emission.
1
ZR1/ZR1/FMT0
2
MS/ADR/FMT1
VOUT1 27
3
MC/SCL/DEMP
VOUT2
26
4
MD/SDA/MUTE
VCOM
25
5
SCK
AGND2
24
mC or mP
ZR2
28
C2
L
C11
27-MHz
Master
Clock
6
7
VCC2
DATA1
VOUT3
BCK
8
C9
9
LRCK
VOUT4
VOUT5
VDD
R
23
22
R3
Audio DSP
or
Decoder
+
C12
R4
R2
C1
+
R1
PLL170x
+
21
20
10 DGND
VOUT6
19
11 DATA2
AGND1
18
12 DATA3
VCC1
17
13 DATA4
VOUT7
16
14 MSEL
VOUT8
15
+
C3
+
C4
+
C5
+
C6
Output
Low-Pass
Filter
LF
RF
LS
RS
CTR
SUB
R5
R6
C10
R7
Termination
3.3 V Digital
5 V Analog
C13
+
C7
+
C8
PCM1681
PCM1681-Q1
+
C14
+
0V
C1-C8: 4.7-mF to 10-mF Electrolytic Typical
C9-C11: 1-mF Ceramic Typical
C12: 2.2-mF to 10-mF Electrolytic Typical
C13, C14: 10-mF Electrolytic Typical
R1-R7: 22 W to 100 W Typical
The termination for mode/configuration control:
Either one of the following circuits has to be applied
according to necessary mode/configuration.
Resistor value has to be 220 kW ±5% tolerant.
3.3 V
3.3 V
14
14
(1)
(2)
14
14
0V
0V
(3)
(4)
Figure 33. Basic Connection Diagram
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PCM1681
PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
POWER-SUPPLY AND GROUNDING
The PCM1681 and PCM1681-Q1 require 5 V for the analog supply and 3.3 V for the digital supply. The 5-V
supply is used to power the DAC analog and output filter circuitry, and the 3.3 V supply is used to power the
digital filter and serial interface circuitry. For best performance, a 5-V supply and a 3.3-V supply with linear
regulators are recommended.
Five capacitors are required for supply bypassing, as shown in Figure 33. These capacitors should be located as
close as possible to the PCM1681 and PCM1681-Q1 package. The 10-µF capacitor should be tantalum or
aluminum electrolytic, while the three 1-µF capacitors are ceramic.
D/A OUTPUT FILTER CIRCUITS
ΔΣ DACs use 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 optimal converter performance. This is accomplished by a
combination of on-chip and external low-pass filtering.
Figure 32 and Figure 34 show the recommended external low-pass active filter circuits for dual- and
single-supply applications. These circuits are second-order Butterworth filters using a multiple-feedback (MFB)
circuit arrangement, which reduces sensitivity to passive component variations over frequency and temperature.
For more information regarding MFB active filter design, see Dynamic Performance Testing of Digital Audio D/A
Converters (SBAA055).
Because the overall system performance is defined by the quality of the D/A converters and their associated
analog output circuitry, high-quality audio operational amplifiers are recommended for the active filters. Texas
Instruments’ OPA2353 and OPA2134 dual operational amplifiers are shown in Figure 32 and Figure 34, and are
recommended for use with the PCM1681 and PCM1681-Q1.
R2
R1
+
R3
VIN
C3
10 µF
AV + *
C1
C2
2
3
–
OPA2134
+
1
R4
47 Ω
R2
R1
VOUT
Example:
R1: 5.1 kΩ
R2: 8.2 kΩ
R3: 560 Ω
C1: 470 pF
C2: 4700 pF
AV: −1.61
fc: 57 kHz
Figure 34. Dual-Supply Filter Circuit
PCB LAYOUT GUIDELINES
A typical printed circuit board (PCB) floor plan for the PCM1681 and PCM1681-Q1 is shown in Figure 35. 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 PCM1681 and PCM1681-Q1 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.
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 PCM1681 and PCM1681-Q1.
The PowerPAD can be left open without being soldered to the ground plane of the PCB for the PCM1681.
However, it must be soldered to the ground plane which has low thermal resistance for the PCM1681-Q1.
34
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PCM1681
PCM1681-Q1
www.ti.com.................................................................................................................................................... SLES211B – FEBRUARY 2008 – REVISED JUNE 2008
Analog Power
Digital Power
+3.3VD
DGND
AGND
+5VA +VS
±VS
VDD VCC
Digital Logic
and
Audio
Processor
DGND
PCM1681
PCM1681-Q1
Output
Circuits
Digital
Ground
AGND
Digital Section
Analog Section
Analog
Ground
Return Path for 3.3 VD and Digital Signals
Figure 35. Recommended PCB Layout
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35
PCM1681
PCM1681-Q1
SLES211B – FEBRUARY 2008 – REVISED JUNE 2008.................................................................................................................................................... www.ti.com
Revision History
Changes from Revision A (June 2008) to Revision B .................................................................................................... Page
•
•
•
•
Added new device grade PCM1681-Q1 ................................................................................................................................ 1
Changed device names in Operating Free-Air Temperature row of the Recommended Operating Conditions table .......... 2
Changed device names in Operating Temperature row of Temperature Range section in the Electrical
Characteristics table .............................................................................................................................................................. 4
Added third paragraph to PCB Layout Guidelines section .................................................................................................. 34
Changes from Original (February 2008) to Revision A .................................................................................................. Page
•
•
•
•
•
36
Added last sub-level bullet to Features..................................................................................................................................
Added first two bullets to Applications ...................................................................................................................................
Changed last sentence in Description ...................................................................................................................................
Added last row to Recommended Operating Conditions table..............................................................................................
Added second row to Temperature Range section of the Electrical Characteristics table....................................................
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1
1
1
2
4
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Product Folder Link(s): PCM1681 PCM1681-Q1
PACKAGE OPTION ADDENDUM
www.ti.com
18-Sep-2008
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
PCM1681PWP
ACTIVE
HTSSOP
PWP
28
50
Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
PCM1681PWPG4
ACTIVE
HTSSOP
PWP
28
50
Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
PCM1681PWPR
ACTIVE
HTSSOP
PWP
28
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
PCM1681PWPRG4
ACTIVE
HTSSOP
PWP
28
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
PCM1681TPWPQ1
ACTIVE
HTSSOP
PWP
28
50
Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-4-260C-72 HR
PCM1681TPWPQ1G4
ACTIVE
HTSSOP
PWP
28
50
Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-4-260C-72 HR
PCM1681TPWPRQ1
ACTIVE
HTSSOP
PWP
28
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-4-260C-72 HR
PCM1681TPWPRQ1G4
ACTIVE
HTSSOP
PWP
28
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-4-260C-72 HR
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
PACKAGE MATERIALS INFORMATION
www.ti.com
5-Jul-2008
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
Diameter Width
(mm) W1 (mm)
PCM1681PWPR
HTSSOP
PWP
28
2000
330.0
PCM1681TPWPRQ1
HTSSOP
PWP
28
2000
330.0
A0 (mm)
B0 (mm)
K0 (mm)
P1
(mm)
W
Pin1
(mm) Quadrant
16.4
6.9
10.2
1.8
12.0
16.0
Q1
16.4
6.9
10.2
1.8
12.0
16.0
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
5-Jul-2008
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
PCM1681PWPR
HTSSOP
PWP
28
2000
346.0
346.0
33.0
PCM1681TPWPRQ1
HTSSOP
PWP
28
2000
346.0
346.0
33.0
Pack Materials-Page 2
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