ETC PCM1771

PCM1770
PCM1771
SLES011B – SEPTEMBER 2001 – JUNE 2002
LOW-VOLTAGE AND LOW-POWER STEREO AUDIO
DIGITAL-TO-ANALOG CONVERTER WITH HEADPHONE AMPLIFIER
FEATURES
D Multilevel DAC Including Headphone
D
Amplifier
Analog Performance (VCC, VHP = 2.4 V):
– Dynamic Range: 98 dB Typ
– THD+N at 0 dB: 0.1% Typ
– THD+N at –20 dB: 0.04% Typ
– Output Power at RL = 16 Ω: 13 mW
(Stereo), 26 mW (Monaural)
D 1.6-V to 3.6-V Single Power Supply
D Low Power Dissipation: 6.5 mW at VCC,
VHP = 2.4 V
D System Clock: 128fS, 192fS, 256fS, 384fS
D Sampling Frequency: 5 kHz to 50 kHz
D Software Control (PCM1770):
– 16-, 20-, 24-Bit Word Available
– Left-, Right-Justified and I2S
– Slave/Master Selectable
D Digital Attenuation:
–
–
–
–
–
–
0 dB to –62 dB, 1 dB/Step
44.1-kHz Digital De-Emphasis
Zero Cross Attenuation
Digital Soft Mute
Monaural Analog-In With Mixing
Monaural Speaker Mode
D Hardware Control (PCM1771):
– Left-Justified and I2S
– 44.1-kHz Digital De-Emphasis
– Monaural Analog-In With Mixing
D Pop-Noise-Free Circuit
D 3.3-V Tolerant
D Packages: TSSOP-16 and VQFN-20, Lead Free
APPLICATIONS
D Portable Audio Player
D Cellular Phone
D PDA
D Other Applications Requiring Low-Voltage
Operation
DESCRIPTION
The PCM1770 and PCM1771 devices are CMOS,
monolithic, integrated circuits which include stereo
digital-to-analog converters, headphone circuitry, and
support circuitry in small TSSOP-16 and VQFN-20
packages.
The data converters utilize TI’s enhanced multilevel ∆-Σ
architecture, which employs noise shaping and
multilevel amplitude quantization to achieve excellent
dynamic performance and improved tolerance to clock
jitter. The PCM1770 and PCM1771 devices accept
several industry standard audio data formats with 16- to
24-bit data, left-justified, I2S, etc., providing easy
interfacing to audio DSP and decoder devices.
Sampling rates up to 50 kHz are supported. A full set of
user-programmable functions are accessible through a
3-wire serial control port, which supports register write
functions.
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.
PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
Copyright  2002, Texas Instruments Incorporated
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during
storage or handling to prevent electrostatic damage to the MOS gates.
PACKAGE/ORDERING INFORMATION
PRODUCT
PACKGE
PACKAGE
PACKAGE
CODE
TA
PACKAGE
MARKING
PCM1770PW
TSSOP 16
TSSOP–16
16PW
–25°C
25°C to 85°C
PCM1770
PCM1771PW
TSSOP 16
TSSOP–16
16PW
–25°C
25°C to 85°C
PCM1771
PCM1770RGA
PCM1771RGA
VQFN 20
VQFN–20
VQFN 20
VQFN–20
20RGA
20RGA
–25°C
25°C to 85°C
–25°C
25°C to 85°C
PCM1770
PCM1771
ORDERING
NUMBER
TRANSPORT
MEDIA
PCM1770PW
Tube
PCM1770PWR
Tape and Reel
PCM1771PW
Tube
PCM1771PWR
Tape and Reel
PCM1770RGA
Tray
PCM1770RGAR
Tape and Reel
PCM1771RGA
Tray
PCM1771RGAR
Tape and Reel
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted(1)
PCM1770
PCM1771
Supply voltage: VCC, VHP
Supply voltage differences: VCC, VHP
Ground voltage differences
Digital input voltage
Input current (any terminals except supplies)
4V
±0.1 V
±0.1 V
–0.3 V to 4.0 V
±10 mA
Operatingtemperature
–40°C to 125°C
Storage temperature
–55°C to 150°C
Junction temperature
Lead temperature (soldering)
150°C
260°C, 5 s
Package temperature (IR reflow, peak)
260°C, 10 s
(1) 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.
2
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
ELECTRICAL CHARACTERISTICS
all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, system clock = 256 fS and 24-bit data, RL = 16 Ω, unless otherwise noted
PARAMETER
TEST CONDITIONS
MIN
Resolution
TYP
MAX
24
UNIT
Bits
DATA FORMAT
Audio data interface
format
(PCM1770)
Standard, I2S, left justified
(PCM1771)
I2S, left justified
Audio data bit length
16-, 20-, 24-bits selectable
Audio data format
MSB first, twos complement
Sampling frequency (fS)
5
Internal system clock frequency
DIGITAL INPUT/OUTPUT(1)
Logic family
VIH
VIL
IIH
IIL
VOH
VOL
50
kHz
128fS, 192fS, 256fS, 384fS
CMOS compatible
0.7VCC
Input logic level
Input logic current
VIN = VCC
VIN = 0 V
Output logic level(2)
IOH = –2 mA
IOL = 2 mA
Vdc
0.3VCC
10
–10
0.7VCC
Vdc
µA
µA
Vdc
0.3VCC
Vdc
DYNAMIC PERFORMANCE
HEADPHONE OUTPUT
Full scale output voltage
0 dB
Dynamic range
EIAJ, A-weighted
90
Signal-to-noise ratio
EIAJ, A-weighted
90
THD+N
0 dB (13 mW)
0.55VHP
98
VP-P
dB
98
dB
0.1%
–20 dB (0.1 mW)
0.04%
0.1%
Stereo
10
13
mWrms
Monaural
20
26
mWrms
Channel separation
64
72
dB
Load resistance
14
16
Ω
Output power
dc ACCURACY
Gain error
±2
±8
%FSR
Gain mismatch,
channel-to-channel
±2
±8
%FSR
±30
±75
mV
Bipolar zero error
VOUT = 0.5VCC at BPZ
ANALOG LINE INPUT (MIXING CIRCUIT)
Analog input voltage range
0.584VHP
Gain (analog input to headphone
output)
0.67
Analog input impedance
THD+N
VP-P
10
AIN = 0.56VHP (peak-to-peak)
kΩ
0.1%
DIGITAL FILTER PERFORMANCE
Passband
Stopband
0.454fS
0.546fS
±0.04
Passband ripple
Stop band attenuation
Group delay
44.1-kHz de-emphasis error
–50
dB
dB
20/fS
±0.1
dB
(1) All logic inputs are 3.3-V tolerant and not terminated internally.
(2) LRCK and BCK terminals
3
PCM1770
PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
ELECTRICAL CHARACTERISTICS (continued)
all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, system clock = 256 fS and 24-bit data, RL = 16 Ω, unless otherwise noted
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
ANALOG FILTER PERFORMANCE
Frequency response
±0.2
at 20 kHz
dB
POWER SUPPLY REQUIREMENTS
Voltage range, VCC, VHP
ICC
IHP
ICC +
IHP
1.6
Supply current
2.4
3.6
BPZ input
1.5
2.5
BPZ input
1.2
2.5
5
15
µA
BPZ input
6.5
12
mW
Power down(3)
12
36
µW
85
°C
Power down(3)
Power dissipation
Vdc
mA
TEMPERATURE RANGE
Operationtemperature
θJA
–25
Thermal resistance
PCM1770PW, –71PW: 16-terminal TSSOP
150
PCM1770RGA, –71RGA: 20-terminal VQFN
130
°C/W
(1) All logic inputs are 3.3-V tolerant and not terminated internally.
(2) LRCK and BCK terminals
(3) All input signals are held static.
PIN ASSIGNMENTS
PCM1770
PW PACKAGE
(TOP VIEW)
SCKI
MS
MC
MD
VCC
VHP
AIN
HOUTL
LRCK
DATA
BCK
PD
AGND
HGND
VCOM
HOUTR
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
1
20 19 18 17 16
15
2
14
3
13
4
12
5
7
8
11
9 10
VCOM
HOUTR
NC
HOUTL
6
NC – No internal connection
4
AIN
DATA
BCK
PD
AGND
HGND
SCKI
FMT
AMIX
DEMP
VCC
VHP
AIN
HOUTL
LRCK
NC
NC
NC
SCKI
PCM1771
RGA PACKAGE
(TOP VIEW)
LRCK
NC
NC
NC
SCKI
PCM1770
RGA PACKAGE
(TOP VIEW)
MS
MC
MD
VCC
VHP
DATA
BCK
PD
AGND
HGND
1
20 19 18 17 16
15
2
14
AMIX
3
13
DEMP
4
12
VCC
VHP
5
6
7
8
11
9 10
AIN
16
15
14
13
12
11
10
9
VCOM
HOUT R
NC
HOUTL
1
2
3
4
5
6
7
8
LRCK
DATA
BCK
PD
AGND
HGND
VCOM
HOUTR
PCM1771
PW PACKAGE
(TOP VIEW)
FMT
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
Terminal Functions
PCM1770PW
TERMINAL
NAME
NO.
I/O
DESCRIPTIONS
I/O
Left and right clock. Determines which channel is being input on the audio data input, DATA. The frequency of LRCK
must be the same as the audio sampling rate. In the slave interface mode, this clock is input from an external device.
In the master interface mode, the PCM1770 device generates the LRCK output to an external device.
LRCK
1
DATA
2
I
BCK
3
I/O
Serial bit clock. Clocks the individual bits of the audio data input, DATA. In the slave interface mode, this clock is input
from external device. In the master interface mode, the PCM1770 device generates the BCK output to external device.
PD
4
I
Reset input. When low, the PCM1770 device is powered down and all mode control registers are reset to default
settings.
AGND
5
–
Analog ground. This is a return for VCC.
HGND
6
–
Analog ground. This is a return for VHP.
VCOM
7
–
Decoupling capacitor connection. An external 10-µF capacitor connected from this terminal to analog ground is
required for noise filtering. Voltage level of this terminal is 0.5VHP nominal.
HOUTR
HOUTL
8
O
R-channel analog signal output of the headphone amplifiers
9
O
L-channel analog signal output of the headphone amplifiers
AIN
10
I
Monaural analog signal mixer input. The signal can be mixed with the output of L- and R-channel DACs.
VHP
VCC
11
–
Analog power supply for the headphone amplifier circuits. The voltage level must be the same as VCC.
12
–
Analog power supply for all analog circuits except the headphone amplifier.
MD
13
I
Mode control port serial data input. Controls the operation mode on the PCM1770 device.
MC
14
I
Mode control port serial bit clock input. Clocks the individual bits of the control data input, MD.
MS
15
I
Mode control port select. The control port is active when this terminal is low.
SCKI
16
I
System clock input
Serial audio data input
PCM1770RGA
TERMINAL
NAME
NO.
I/O
DESCRIPTIONS
DATA
1
I
BCK
2
I/O
Serial bit clock. Clocks the individual bits of the audio data input, DATA. In the slave interface mode, this clock is input
from external device. In the master interface mode, the PCM1770 device generates the BCK output to external
device.
PD
3
I
Reset input. When low, the PCM1770 device is powered down and all mode control registers are reset to default
settings.
AGND
4
–
Analog ground. This is a return for VCC.
HGND
5
–
Analog ground. This is a return for VHP.
VCOM
6
–
Decoupling capacitor connection. An external 10-µF capacitor connected from this terminal to analog ground is
required for noise filtering. Voltage level of this terminal is 0.5VHP nominal.
HOUTR
NC
HOUTL
AIN
Serial audio data input
7
O
R-channel analog signal output of the headphone amplifiers
8, 17,
18, 19
–
No connect
9
O
L-channel analog signal output of the headphone amplifiers
10
I
Monaural analog signal mixer input. The signal can be mixed with output of L- and R-channel DACs.
VHP
VCC
11
–
Analog power supply for the headphone amplifier circuits. The voltage level must be the same as VCC.
12
–
Analog power supply for all analog circuits except the headphone amplifier.
MD
13
I
Mode control port serial data input. Controls the operation mode on the PCM1770 device.
MC
14
I
Mode control port serial bit clock input. Clocks the individual bits of the control data input, MD.
MS
15
I
Mode control port select. The control port is active when this terminal is low.
SCKI
16
I
System clock input
LRCK
20
I/O
Left and right clock. Determines which channel is being input on the audio data input, DATA. The frequency of LRCK
must be the same as the audio sampling rate. In the slave interface mode, this clock is input from an external device.
In the master interface mode, the PCM1770 device generates the LRCK output to an external device.d
5
PCM1770
PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
Terminal Functions
PCM1771PW
TERMINAL
NAME
NO.
I/O
DESCRIPTIONS
LRCK
1
I
Left and right clock. Determines which channel is being input on the audio data input, DATA. The frequency of LRCK
must be the same as the audio sampling rate.
DATA
2
I
Serial audio data input
BCK
3
I
Serial bit clock. Clocks the individual bits of the audio data input, DATA.
PD
4
I
Reset input. When low, the PCM1771 device is powered down and all mode control registers are reset to default
settings.
AGND
5
–
Analog ground. This is a return for VCC.
HGND
6
–
Analog ground. This is a return for VHP.
VCOM
7
–
Decoupling capacitor connection. An external 10-µF capacitor connected from this terminal to analog ground is
required for noise filtering. Voltage level of this terminal is 0.5VHP nominal.
HOUTR
HOUTL
8
O
R-channel analog signal output of the headphone amplifiers
9
O
L-channel analog signal output of the headphone amplifiers
AIN
10
–
Monaural analog signal mixer input. The signal can be mixed with the output of L- and R-channel DACs.
VHP
VCC
11
–
Analog power supply for the headphone amplifier circuits. The voltage level must be the same as VCC.
12
–
Analog power supply for all analog circuits except the headphone amplifier.
DEMP
13
I
De-emphasis control
AMIX
14
I
Analog mixing control
FMT
15
I
Data format select
SCKI
16
I
System clock input
PCM1771RGA
TERMINAL
NAME
NO.
I/O
DESCRIPTIONS
DATA
1
I
Serial audio data input
BCK
2
I
Serial bit clock. Clocks the individual bits of the audio data input, DATA.
PD
3
I
Reset input. When low, the PCM1771 device is powered down and all mode control registers are reset to default
settings.
AGND
4
–
Analog ground. This is a return for VCC.
HGND
5
–
Analog ground. This is a return for VHP.
VCOM
6
–
Decoupling capacitor connection. An external 10-µF capacitor connected from this terminal to analog ground is
required for noise filtering. Voltage level of this terminal is 0.5VHP nominal.
HOUTR
NC
HOUTL
AIN
7
O
R-channel analog signal output of the headphone amplifiers
8, 17,
18, 19
–
No connect
9
O
L-channel analog signal output of the headphone amplifiers
10
–
Monaural analog signal mixer input. The signal can be mixed with the output of L- and R-channel DACs.
VHP
VCC
11
–
Analog power supply for the headphone amplifier circuits. The voltage level must be the same as VCC.
12
–
Analog power supply for all analog circuits except the headphone amplifier
DEMP
13
I
De-emphasis control
AMIX
14
I
Analog mixing control
FMT
15
I
Data format select
SCKI
16
I
System clock input
LRCK
20
I
Left and right clock. Determines which channel is being input on the audio data input, DATA. The frequency of LRCK
must be the same as the audio sampling rate.
6
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
FUNCTIONAL BLOCK DIAGRAM
AIN
Digital
Attenuator
LRCK
×8
Digital
Filter
Audio
Interface
DATA
Headphone
Amplifier
∆Σ
DAC
HOUTR
+
BCK
VCOM
(FMT) MS
×8
Digital
Filter
SPI
Port
(AMIX) MC
∆Σ
DAC
VCOM
HOUTL
+
(DEMP) MD
Clock Manager
Power Supply
SCKI
PD
( ) : PCM1771
AGND
VCC
HGND
VHP
TYPICAL CHARACTERISTICS
DIGITAL FILTER
Digital Filter (De-Emphasis Off)
AMPLITUDE
vs
FREQUENCY
AMPLITUDE
vs
FREQUENCY
0
0.05
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
–20
0.04
0.03
0.02
Amplitude – dB
Amplitude – dB
–40
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
–60
–80
0.01
0.00
–0.01
–0.02
–100
–0.03
–120
–0.04
–140
0
1
2
f – Frequency [ fS]
Figure 1
3
4
–0.05
0.0
0.1
0.2
0.3
0.4
0.5
f – Frequency [ fS]
Figure 2
Electrical characteristics, all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, System clock = 256 fS and 24-bit data, RL = 16 Ω,
unless otherwise noted.
7
PCM1770
PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
TYPICAL CHARACTERISTICS
De-Emphasis Curves
DE-EMPHASIS ERROR
vs
FREQUENCY
DE-EMPHASIS LEVEL
vs
FREQUENCY
0.5
0
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
–1
0.3
De-emphasis Error – dB
De-emphasis Level – dB
–2
–3
–4
–5
–6
–7
0.2
0.1
–0.0
0.0
–0.1
–0.2
–8
–0.3
–9
–0.4
–10
0.0
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
0.4
–0.5
0.1
0.2
0.3
0.4
0.5
0
0.6
2
4
6
10
12
14
16
18
20
f – Frequency – kHz
f – Frequency – kHz
Figure 3
Figure 4
TOTAL HARMONIC DISTORTION + NOISE
vs
SUPPLY VOLTAGE
DYNAMIC RANGE
vs
SUPPLY VOLTAGE
1.00
1
104
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
102
Dynamic Range – dB
THD+N – Total Harmonic Distortion + Noise – %
8
0 dB
0.10
0.1
–20 dB
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
100
98
96
94
0.01
1.2
1.6
2.0
2.4
2.8
3.2
VCC – Supply Voltage – V
Figure 5
3.6
4.0
92
1.2
1.6
2.0
2.4
2.8
3.2
3.6
4.0
VCC – Supply Voltage – V
Figure 6
Electrical characteristics, all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, System clock = 256 fS and 24-bit data, RL = 16 Ω,
unless otherwise noted.
8
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PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
TYPICAL CHARACTERISTICS
SNR
vs
SUPPLY VOLTAGE
CHANNEL SEPARATION
vs
SUPPLY VOLTAGE
104
76
Channel Separation – dB
102
78
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
SNR – dB
100
98
96
94
92
1.2
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
74
72
70
68
1.6
2.0
2.4
2.8
3.2
3.6
66
1.2
4.0
1.6
VCC – Supply Voltage – V
2.0
Figure 7
2.8
3.2
3.6
4.0
80
100
Figure 8
TOTAL HARMONIC DISTORTION + NOISE
vs
FREE-AIR TEMPERATURE
DYNAMIC RANGE
vs
FREE-AIR TEMPERATURE
1.00
1
102
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
101
100
Dynamic Range – dB
THD+N – Total Harmonic Distortion + Noise – %
2.4
VCC – Supply Voltage – V
0 dB
0.10
0.1
–20 dB
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
99
98
97
96
95
0.01
–40
–20
0
20
40
60
TA – Free-Air Temperature – °C
Figure 9
80
100
94
–40
–20
0
20
40
60
TA – Free-Air Temperature – °C
Figure 10
Electrical characteristics, all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, System clock = 256 fS and 24-bit data, RL = 16 Ω,
unless otherwise noted.
9
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PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
TYPICAL CHARACTERISTICS
SNR
vs
FREE-AIR TEMPERATURE
CHANNEL SEPARATION
vs
FREE-AIR TEMPERATURE
102
100
SNR – dB
99
98
97
96
74
73
72
71
70
95
94
–40
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
75
Channel Separation – dB
101
76
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
69
–20
0
20
40
60
80
68
–40
100
–20
TA – Free-Air Temperature – °C
0
20
40
60
80
100
TA – Free-Air Temperature – °C
Figure 11
Figure 12
SUPPLY CURRENT
vs
SUPPLY VOLTAGE
ICC – Supply Current, Operational – mA
4.5
4.0
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
18
16
3.5
14
Operational
3.0
12
2.5
10
2.0
8
1.5
6
Power Down
1.0
4
0.5
2
0.0
1.2
ICC – Supply Current, Power Down – µA
20
5.0
0
1.6
2.0
2.4
2.8
3.2
3.6
4.0
VCC – Supply Current – V
Figure 13
Electrical characteristics, all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, System clock = 256 fS and 24-bit data, RL = 16 Ω,
unless otherwise noted.
10
PCM1770
PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
TYPICAL CHARACTERISTICS
SUPPLY CURRENT
vs
SAMPLING FREQUENCY
ICC – Supply Current, Operational – mA
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
4.5
4.0
18
16
3.5
14
3.0
12
Operational
2.5
10
2.0
8
Power Down
1.5
6
1.0
4
0.5
2
0.0
ICC – Supply Current, Power Down – µA
20
5.0
0
0
10
20
30
40
50
fS – Sampling Frequency – kHz
Figure 14
DYNAMIC RANGE
vs
JITTER
100
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
Dynamic Range – dB
99
98
97
96
95
94
0
100
200
300
400
500
600
700
Jitter – ps
Figure 15
Electrical characteristics, all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, System clock = 256 fS and 24-bit data, RL = 16 Ω,
unless otherwise noted.
11
PCM1770
PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
TYPICAL CHARACTERISTICS
OUTPUT SPECTRUM (–60 dB, N = 8192)
OUTPUT SPECTRUM (–60 dB, N = 8192)
0
0
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
–20
–20
–40
Amplitude – dB
–40
Amplitude – dB
VCC = 2.4 V
fS = 44.1 kHz
TA = 25°C
RL = 16 Ω
–60
–80
–60
–80
–100
–100
–120
–120
–140
–140
0
5
10
f – Frequency – kHz
Figure 16
15
20
0
20
40
60
80
100
120
f – Frequency – kHz
Figure 17
Electrical characteristics, all specifications at TA = 25°C, VCC = VHP = 2.4 V, fS = 44.1 kHz, System clock = 256 fS and 24-bit data, RL = 16 Ω,
unless otherwise noted.
12
PCM1770
PCM1771
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SLES011B – SEPTEMBER 2001 – JUNE 2002
APPLICATION INFORMATION
CONNECTION DIAGRAMS
POWER SUPPLIES AND GROUNDING
Figure 18 shows the basic connection diagram with the
necessary power supply bypassing and decoupling
components. It is recommended that the component
values shown in Figure 18 be used for all designs.
The PCM1770 and PCM1771 devices require a 2.4-V
typical analog supply for VCC and VHP. These 2.4-V
supplies power the DAC, analog output filter, and other
circuits. For best performance, these 2.4-V supplies must
be derived from the analog supply using a linear regulator,
as shown in Figure 18.
The use of series resistors (22 Ω to 100 Ω) are
recommended for the MCKI, LRCK, BCK, and DATA
inputs. The series resistor combines with the stray PCB
and device input capacitance to form a low-pass filter that
reduces high frequency noise emissions and helps to
dampen glitches and ringing present on the clock and data
lines.
Figure 18 shows the proper power supply bypassing. The
10-µF capacitors must be tantalum or aluminum
electrolytic, while the 0.1-µF capacitors are ceramic (X7R
type is recommended for surface-mount applications).
1.6 V to 3.6 V
Audio DSP
Controller
10 µF
1
LRCK
SCKI
16
2
DATA
MS
15
3
BCK
MC
14
4
PD
MD
13
VCC
12
PCM1770
5
AGND
6
HGND
VHP
11
7
VCOM
AIN
10
8
HOUTR
HOUTL
10 µF
10 µF
Analog In
9
10 µF
220 µF
0.022 µF
16 Ω
220 µF
Headphone
RL = 16 Ω
0.022 µF
16 Ω
Figure 18. Basic Connection Diagram
13
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DETAILED DESCRIPTION
Figure 19 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.
SYSTEM CLOCK, RESET, AND FUNCTIONS
System Clock Input
The PCM1770 and PCM1771 devices require a system
clock for operating the digital interpolation filters and
multilevel ∆-Σ modulators. The system clock is applied at
terminal 16 (SCKI). Table 1 shows examples of system
clock frequencies for common audio sampling rates.
Table 1. System Clock Frequency for Common Audio Sampling Frequencies
SAMPLING FREQUENCY, LRCK
SYSTEM CLOCK FREQUENCY, SCKI (MHz)
48 kHz
128fS
6.144
192fS
9.216
256fS
12.288
384fS
18.432
44.1 kHz
5.6448
8.4672
11.2896
16.9344
32 kHz
4.096
6.144
8.192
12.288
24 kHz
3.072
4.608
6.144
9.216
22.05 kHz
2.8224
4.2336
5.6448
8.4672
16 kHz
2.048
3.072
4.096
6.144
12 kHz
1.536
2.304
3.072
4.608
11.025 kHz
1.4112
2.1168
2.8224
4.2336
8 kHz
1.024
1.536
2.048
3.072
t(SCKH)
0.7 VCC
SCKI
0.3 VCC
t(SCKL)
System Clock
Pulse Cycle Time†
† 1/(128fS), 1/(192fS), 1/(256fS), and 1/(384fS)
PARAMETERS
System clock pulse width high
System clock pulse width low
Figure 19. System Clock Timing
14
SYMBOL
MIN
UNIT
t(SCKH)
t(SCKL)
7
ns
7
ns
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POWER ON/OFF RESET
Setting terminal 4 (PD) to high must be performed once
after power on. The internal logic state is kept in reset when
PD is low and during the 1024 system clock count after PD
is high. Then the power-on sequence is started. In this
sequence, terminals 9 (HOUTL) and 8 (HOUTR) increase
gradually from ground level and output corresponding
VCC, VHP
input data after 9334/fS. When power is off, the PD terminal
is reset to low first. Then HOUTL and HOUTR gradually
decrease to ground level. In order not to generate pop
noise when power is switched on or off, the power-on and
power-off sequences shown in Figure 20 and Figure 21
are recommended. Any other power-on or power-off
sequence may generate pop noise.
0V
1024 Internal System Clocks
LRCK, BCK, SCKI
PD
Internal Reset
9334/fS
HOUTL, HOUTR
0V
Figure 20. Power-On Sequence
VCC, VHP
0V
LRCK, BCK, SCKI
9334/fS
PD
HOUTL, HOUTR
0V
Figure 21. Power-Off Sequence
15
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POWER-UP/-DOWN SEQUENCE AND RESET
The PCM1770 device has two kinds of power-up/-down
methods: the PD terminal through hardware control and
PWRD (register 4, B0) through software control. The
PCM1771 device has only the PD terminal through
hardware control for the power-up/-down sequence. The
power-up or power-down sequence operates the same as
the power-on or power-off sequence. When powering up
or down using the PD terminal, all digital circuits are reset.
When powering up or down using PWRD, all digital circuits
are reset except for maintaining the logic states of the
registers. Figure 22 shows the power-up/power-down
sequence.
2.4 V
VCC, VHP
9334/fS
9334/fS
LRCK, BCK, SCKI
PD
HOUTL, HOUTR
0V
Figure 22. Power-Down and Power-Up Sequences
AUDIO SERIAL INTERFACE
The audio serial interface for the PCM1770 and PCM1771
devices is comprised of a 3-wire synchronous serial port.
It includes terminals 1 (LRCK), 2 (DATA), and 3 (BCK).
BCK is the serial audio bit clock, and it clocks the serial
data present on DATA into the audio interface serial shift
register. Serial data is clocked into the PCM1770 and
PCM1771 devices on the rising edge of BCK. LRCK is the
serial audio left/right word clock. It latches serial data into
the serial audio interface internal registers.
Both LRCK and BCK of the PCM1770 device support the
slave and master modes which are set by FMT (register 3).
LRCK and BCK are outputs during the master mode and
inputs during the slave mode.
In slave mode, BCK and LRCK are synchronous to the
audio system clock, SCKI. Ideally, it is recommended that
LRCK and BCK be derived from SCKI. LRCK is operated
at the sampling frequency, fS. BCK can be operated at 32,
48, and 64 times the sampling frequency.
In master mode, BCK and LRCK are derived from the
system clock and these terminals are outputs. The BCK
and LRCK are synchronous to SCKI. LRCK is operated at
the sampling frequency, fS. BCK can be operated at
64 times the sampling frequency.
16
The PCM1770 and PCM1771 devices operate under
LRCK synchronized with the system clock. The PCM1770
and PCM1771 devices do not need a specific phase
relationship between LRCK and the system clock, but do
require the synchronization of LRCK and the system clock.
If the relationship between the system clock and LRCK
changes more than ±3BCK during one sample period,
internal operation of the PCM1770 and PCM1771 devices
halt within 1/fS, and the analog output is kept in last data
until resynchronization between system clock and LRCK
is completed.
AUDIO DATA FORMATS AND TIMING
The PCM1770 device supports industry-standard audio
data formats, including standard, I2S, and left justified.
The PCM1771 device supports the I2S and left-justified
data formats. Figure 23 shows the data formats. Data
formats are selected using the format bits, FMT[2:0] of
control register 3 in case of the PCM1770 device, and are
selected using the FMT terminal in case of the PCM1771
device. The default data format is 24-bit, left-justified,
slave mode. All formats require binary twos complement,
MSB-first audio data. Figure 24 shows a detailed timing
diagram for the serial audio interface in slave mode.
Figure 25 shows a detailed timing diagram for the serial
audio interface in master mode.
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(1) Standard Data Format; L-Channel = High, R-Channel = Low (Slave Mode)
1/fS
LRCK
R-Channel
L-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
3
14 15 16
MSB
LSB
MSB
2
LSB
16-Bit Right-Justified, BCK = 48 fS or 64 fS
DATA 14 15 16
1
2
3
1
14 15 16
MSB
LSB
2
3
14 15 16
MSB
LSB
20-Bit Right-Justified
DATA 18 19 20
1
2
3
18 19 20
MSB
1
LSB
2
3
18 19 20
MSB
LSB
24-Bit Right-Justified
DATA 22 23 24
1
2
3
22 23 24
MSB
1
LSB
2
3
22 23 24
MSB
LSB
(2) I2S Data Format; L-Channel = Low, R-Channel = High (Slave Mode)
1/fS
LRCK
L-Channel
R-Channel
BCK
(= 32 fS, 48 fS or 64 fS)
DATA
1
2
3
N–2 N–1
MSB
N
1
LSB
2
3
N–2 N–1
MSB
N
1
2
LSB
(3) Left-Justified Data Format; L-Channel = High, R-Channel = Low (Slave Mode)
1/fS
LRCK
L-Channel
R-Channel
BCK
(= 32 fS, 48 fS or 64 fS)
DATA
1
2
3
MSB
N–2
N–1
N
1
LSB
2
3
N–2 N–1
MSB
N
1
2
N
1
2
LSB
(4) Left-Justified Data Format; L-Channel = High, R-Channel = Low (Master Mode)
(The frequency of BCK is 64fS and SCKI is 256fS only)
1/fS
LRCK
L-Channel
R-Channel
BCK
(= 64 fS)
DATA
1
2
3
MSB
N–2
N–1
LSB
N
1
2
3
MSB
N–2 N–1
LSB
Figure 23. Audio Data Input Formats
17
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50% of VDD
LRCK (Input)
t(BCL)
t(BCH)
t(LB)
50% of VDD
BCK (Input)
t(BCY)
t(BL)
50% of VDD
DATA
t(DS)
t(DH)
PARAMETERS
BCK pulse cycle time
BCK high-level time
BCK low-level time
BCK rising edge to LRCK edge
LRCK edge to BCK rising edge
DATA set-up time
DATA hold time
(1) fS is the sampling frequency.
SYMBOL
t(BCY)
t(BCH)
MAX
UNIT
32fS/48fS/64fS (1)
35
ns
t(BCL)
t(BL)
35
ns
10
ns
t(LB)
t(DS)
t(DH)
10
ns
10
ns
10
ns
Figure 24. Audio Interface Timing (Slave Mode)
18
MIN
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SLES011B – SEPTEMBER 2001 – JUNE 2002
t(SCY)
50% of VCC
SCKI
t(DL)
50% of VCC
LRCK (Output)
t(BCL)
t(BCH)
t(DB)
t(DB)
50% of VCC
BCK (Output)
t(BCY)
50% of VCC
DATA
t(DS)
t(DH)
PARAMETERS
SCKI pulse cycle time
LRCK edge from SCKI rising edge
BCK edge from SCKI rising edge
BCK pulse cycle time
SYMBOL
BCK low-level time
DATA set-up time
UNIT
256fS only (1)
0
40
ns
t(DB)
0
40
ns
t(DS)
t(DH)
DATA hold time
MAX
t(SCY)
t(DL)
t(BCY)
t(BCH)
t(BCL)
BCK high-level time
MIN
64fS only (1)
146
ns
146
ns
10
ns
10
ns
(1) fS is up to 48 kHz. fS is the sampling frequency.
Figure 25. Audio Interface Timing (Master Mode)
19
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SLES011B – SEPTEMBER 2001 – JUNE 2002
The software control interface is a 3-wire serial port that
operates asynchronously to the serial audio interface. The
serial control interface is utilized to program the on-chip
mode registers. MD is the serial data input, used to
program the mode registers. MC is the serial bit clock,
used to shift data into the control port. MS is the mode
control port select signal.
HARDWARE CONTROL (PCM1771)
The digital functions of the PCM1771 device are capable
of hardware control. Table 2 shows selectable formats,
Table 3 shows de-emphasis control, and Table 4 shows
analog mixing control.
Table 2. Data Format Select
FMT
REGISTER WRITE OPERATION (PCM1770)
DATA FORMAT
Low
16- to 24-bit, left-justified format
High
16- to 24-bit, I2S format
All write operations for the serial control port use 16-bit
data words. Figure 26 shows the control data word format.
The most significant bit must be 0. There are seven bits,
labeled IDX[6:0], that set the register index (or address) for
the write operation. The eight least significant bits, D[7:0],
contain the data to be written to the register specified by
IDX[6:0].
Table 3. De-Emphasis Control
DEMP
DE-EMPHASIS FUNCTION
Low
44.1-kHz de-emphasis OFF
High
44.1-kHz de-emphasis ON
Figure 27 shows the functional timing diagram for writing
to the serial control port. To write data into the mode
register, data is clocked into an internal shift register on the
rising edge of the MC clock. Serial data can change on the
falling edge of the clock and must be stable on the rising
edge of the clock. The MS signal must be low during the
write mode and the rising edge of the MS signal must be
aligned with the falling edge of the last MC clock pulse in
the 16-bit frame. The MC clock can run continuously
between transactions while the MS signal is low.
Table 4. Analog Mixing Control
AMIX
ANALOG MIXING
Low
Analog mixing OFF
High
Analog mixing ON
SOFTWARE CONTROL (PCM1770)
The PCM1770 device has many programmable functions
that can be controlled in the software control mode. The
functions are controlled by programming the internal
registers using MS, MC, and MD.
LSB
MSB
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
D7
D6
D5
Register Index (or Address)
D4
D3
D2
Register Data
Figure 26. Control Data Word Format for MD
(1) Single Write Operation
16-Bits
MS
MC
MD
MSB
LSB
MSB
(2) Continuous Write Operation
16-Bits x N Frames
MS
MC
MD
MSB
LSB
MSB
LSB
MSB
N Frames
Figure 27. Register Write Operation
20
LSB
D1
D0
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CONTROL INTERFACE TIMING REQUIREMENTS (PCM1770)
Figure 28 shows a detailed timing diagram for the serial control interface. These timing parameters are critical for proper
control port operation.
t(MHH)
MS
50% of VDD
t(MLS)
t(MCL)
t(MCH)
t(MLH)
MC
50% of VDD
t(MCY)
LSB
MD
50% of VDD
t(MDS)
t(MDH)
SYMBOL
PARAMETERS
MC pulse cycle time
t(MCY)
t(MCL)
MC low-level time
MC high-level time
t(MCH)
t(MHH)
MS high-level time
MS falling edge to MC rising edge
t(MLS)
t(MLH)
MS hold time
MIN
100(1)
TYP
MAX
UNITS
ns
50
ns
50
ns
(2)
ns
20
ns
20
ns
MD hold time
t(MDH)
15
MD set-up time
t(MDS)
20
(1) When MC runs continuously between transactions, MC pulse cycle time is specified as 3/(128fS), where fS is sampling rate.
(2) 3/(128fS) s (min), where fS is sampling rate.
ns
ns
Figure 28. Control Interface Timing
MODE CONTROL REGISTERS (PCM1770)
User-Programmable Mode Controls
The PCM1770 device has a number of user- programmable functions that can be accessed via mode control registers.
The registers are programmed using the serial control interface. Table 5 lists the available mode control functions, along
with their reset default conditions and associated register index.
Register Map
Table 6 shows the mode control register map. Each register includes an index (or address) indicated by the IDX[6:0] bits.
Table 5. User-Programmable Mode Controls
FUNCTION
RESET DEFAULT
REGISTER NO.
BIT(S)
Disabled
01
MUTL, MUTR
0 dB
01, 02
ATL[5:0], ATR[5:0]
128fS oversampling
Not inverted
03
OVER
Polarity control for analog output for R-channel DAC
03
RINV
Analog mixing control for analog in, AIN (terminal 14)
Disabled
03
AMIX
Soft mute control, L/R independently
Digital attenuation level setting, 0 dB to –63 dB in 1.0-dB steps, L/R
independently
Oversampling rate control (128fS, 192fS, 256fS, 384fS)
44.1-kHz de-emphasis control
Disabled
03
DEM
24-bit, left-justified format
03
FMT[2:0]
Zero cross attenuation
Disabled
04
ZCAT
Power down control
Disabled
04
PWRD
Audio data format select
21
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SLES011B – SEPTEMBER 2001 – JUNE 2002
Table 6. Mode Control Register Map
REGISTER
IDX [6:0]
(B14–B8)
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
Register 01
01h
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
MUTR
MUTL
ATL5
ATL4
ATL3
ATL2
ATL1
ATL0
Register 02
02h
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
RSV
ATR5
ATR4
ATR3
ATR2
ATR1
ATR0
Register 03
03h
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
OVER
RSV
RINV
AMIX
DEM
FMT2
FMT1
FMT0
Register 04
04h
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
RSV
RSV
ZCAT
RSV
RSV
RSV
PWRD
NOTE: RSV: Reserved for test operation. It must be set to 0 during regular operation.
Register Definitions
Register 01
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
MUTL
MUTR
ATL5
ATL4
ATL3
ATL2
ATL1
ATL0
IDX[6:0]:
0000 0001b
MUTx: Soft Mute Control
Where, x = L or R, corresponding to the headphone output HOUTL and HOUTR.
Default Value: 0
MUTL, MUTR = 0
MUTL, MUTR = 1
Mute disabled (default)
Mute enabled
The mute bits, MUTL and MUTR, enable or disable the soft mute function for the corresponding headphone
outputs, HOUTL and HOUTR. 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 are decreased from the current setting to the infinite attenuation,
one attenuator step (1.0 dB) at a time. This provides pop-free muting of the headphone output.
By setting MUTx = 0, the attenuator is increased one step at a time to the previously programmed attenuation
level.
ATL[5:0]: Digital Attenuation Level Setting for Headphone Output, HOUTL
Default value: 11 1111b
Headphone output, HOUTL includes a digital attenuation function. The attenuation level can be set from 0 dB to
–62 dB, in 1.0-dB steps. Changes in attenuator levels are made by incrementing or decrementing by one step
(1.0 dB) for every 8/fS time internal until the programmed attenuator setting is reached. Alternatively, the
attenuation level may be set to infinite attenuation (or mute).
Table 7 shows the attenuation levels for various settings:
Table 7. Attenuation Level Settings
ATL[5:0]
22
ATTENUATION LEVEL SETTING
11 1111b
11 1110b
0 dB, no attenuation (default)
–1.0 dB
11 1101b
:
–2.0 dB
:
00 0010b
00 0001b
–61.0 dB
–62.0 dB
00 0000b
Mute
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B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
RSV
Register 02
IDX[6:0]:
B5
B4
B3
ATR5 ATR4 ATR3
B2
B1
ATR2 ATR1
B0
ATR0
0000 0010b
ATR[5:0]: Digital Attenuation Level Setting for Headphone Output, HOUTR
Default Value: 11 1111b
Headphone output, HOUTR includes a digital attenuation function. The attenuation level can be set from 0 dB to
–62 dB, in 1.0-dB steps. Changes in attenuator levels are made by incrementing or decrementing by one step
(1.0 dB) for every 8/fS time internal until the programmed attenuator setting in reached. Alternatively, the
attenuation level can be set to infinite attenuation (or mute).
To set the attenuation levels for ATR[5:0], refer to the table above in ATL[5:0].
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
RSV
RINV
AMIX
DEM
FMT2
FMT1
FMT0
Register 03
IDX[6:0]: 0000 0011b
OVER: Over Sampling Control
Default Value: 0
OVER = 0
OVER = 1
128fS oversampling
192fS, 256fS, 384fS oversampling
The OVER bit controls the oversampling rate of the ∆-Σ D/A converters. When it operates at a low sampling rate,
less than 24 kHz, this function is recommended.
RINV: Polarity Control for Headphone Output, HOUTR
Default Value: 0
RINV = 0
RINV = 1
Not iinverted
Inverted output
The RINV bits allow the user to control the polarity of the headphone output, HOUTR. This function can be used to
connect the monaural speaker with BTL connection method. This bit is recommended to be 0 during the
power-up/-down sequence for minimizing audible pop noise.
AMIX: Analog Mixing Control for External Analog Signal, AIN
Default Value: 0
AMIX = 0
AMIX = 1
Disabled (not mixed)
Enabled (mixing to the DAC output)
AMIX bit allows the user to mix analog input (AIN) with headphone outputs (HOUTL/HOUTR) internally.
DEM: 44.1-kHz De-emphasis Control
Default Value: 0
DEM = 0
DEM = 1
Disabled
Enabled
The DEM bit enables or disables the digital de-emphasis filter for 44.1-kHz sampling rate.
23
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
FMT[2:0]: Audio Interface Data Format
Default Value: 000
The FMT[2:0] bits select the data format for the serial audio interface. Table 8 shows the available format options.
Table 8. Audio Data Format Selection
FMT[2:0]
Audio Data Format Selection
000
001
010
011
100
101
110
111
16- to 24-bit, left-justified format (default)
16- to 24-bit, I2S format
24-bit right-justified data
20-bit right-justified data
16-bit right-justified data
16- to 24-bit, left-justified format, master mode
Reserved
Reserved
Register 04
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
0
IDX6
IDX5
IDX4
IDX3
IDX2
IDX1
IDX0
RSV
RSV
RSV
ZCAT
RSV
RSV
RSV
PWRD
IDX[6:0]: 0000 0100b
ZCAT: Zero Cross Attenuation
Default Value: 0
ZCAT = 0
ZCAT = 1
Normal attenuation (default)
Zero cross attenuation
This bit enables the change signal level on zero crossing during attenuation control or muting. If the signal does
not cross BPZ beyond 512/fS (11.6 ms at 44.1-kHz sampling rate), the signal level is changed similar to normal
attenuation control. This function is independently monitored for each channel; moreover, change of signal level
is alternated between both channels. Figure 29 shows an example of zero cross attenuation.
ATT CTRL START
L-Channel
(2 kHz)
R-Channel
(1 kHz)
Level change point
Figure 29. Example of Zero Cross Attenuation
PWRD: Power Down Control
Default Value: 0
PWRD = 0
PWRD = 1
Normal operation (default)
Power-down state
This bit is used to enter into low-power mode. Note that PWRD has no reset function.
When this bit is set to 1, the PCM1770 device enters low-power mode and all digital circuits are reset except the
register states which remain unchanged.
24
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
ANALOG IN/OUT
HEADPHONE OUTPUT (STEREO)
The PCM1770 and PCM1771 devices have two
independent headphone amplifiers and each amplifier
output is provided at the HOUTL and HOUTR terminals.
Since the capability of the headphone output is designed
for driving a 16-Ω impedance headphone, less than a 16-Ω
impedance headphone is not recommended. A resistor
and a capacitor must be connected to HOUTL and HOUTR
to ensure proper output loading.
Monaural Output (BTL Mode/Monaural Speaker)
The monaural output can be created by summing left and
right headphone outputs. When in the BTL mode, the user
must set each headphone output levels to –3 dB using
ATL[5:0] bits on register 01 and ATR[5:0] bits on register
02. Moreover, invert the polarity of the right headphone
output by using the RINV bit on control register 03. The
RINV bit is recommended to be 0 during power-up/-down
sequence for minimizing audible pop noise.
Analog Input
The PCM1770 and PCM1771 devices have an analog
input, AIN (terminal 10). The AMIX bit (PCM1770) or the
AMIX terminal (PCM1771) allows the user to mix AIN with
the headphone outputs (HOUTL and HOUTR) internally.
When in the MIXING mode, an ac-coupling capacitor is
needed for AIN. But if AIN is not used, AIN must be open
and the AMIX bit (PCM1770) must be disabled or the AMIX
terminal (PCM1771) must be low.
Since AIN does not have an internal low pass filter, it is
recommended that the bandwidth of the input signal into
AIN is limited to less than 100 kHz. The source of signals
connected to AIN must be connected by low impedance.
Although the maximum input voltage on AIN is designed
to be as large as 0.584VHP [peak-to-peak], the user must
attenuate the input voltage on AIN and control digital input
data so that each headphone output (HOUTL and HOUTR)
does not exceed 0.55VHP [peak-to-peak] during mixing
mode.
VCOM Output
One unbuffered common-mode voltage output terminal,
VCOM is brought out for decoupling purposes. This
terminal is nominally biased to a dc voltage level equal to
0.5VHP and connected to a 10-µF capacitor. In the case of
a capacitor smaller than 10 µF, pop noise can be
generated during the power-on/-off or power-up/-down
sequences.
25
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
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°–ā8°
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.
26
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
PCM1770
PCM1771
www.ti.com
SLES011B – SEPTEMBER 2001 – JUNE 2002
RGA (S-PQFP-N20)
PLASTIC QUAD FLATPACK
4,05
3,95
4,30
4,10
0,50 NOM/2
A
“A”
4,30
4,10
B
DETAIL “A”
4,05
3,95
0,50 NOM
20
1,00 NOM
C0,70
Index
“C”
0,25
0,09
S 1,00 0,95
MAX 0,50
1
0,50 NOM
1,00 NOM
0,75
0,45
0,05
0,00
S
0,05 S
DETAIL “B”
“B”
0,05 M S AB
0,27
0,17
0,21
0,09
0,05
0,00
0,35 ± 0,11
0,23
0,17
0,69 ± 0,11
0,25
0,09
0,27
0,17
DETAIL “C”
0,22 ± 0,05
4202802/B 08/01
NOTES:A.
B.
C.
D.
All linear dimensions are in millimeters.
This drawing is subject to change without notice.
These dimensions include package bend.
Falls within EIAJ: EDR-7324.
27
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