Cirrus CS4390-KS 24-bit, stereo d/a converter for digital audio Datasheet

CS4390
24-Bit, Stereo D/A Converter for Digital Audio
Features
Description
l 24-Bit Conversion
l 115 dB Signal-to-Noise-Ratio (EIAJ)
l Complete Stereo DAC System
The CS4390 is a complete stereo digital-to-analog output system. In addition to the traditional D/A function, the
CS4390 includes a digital interpolation filter followed by
an 128X oversampled delta-sigma modulator. The modulator output controls the reference voltage input to an
ultra-linear analog low-pass filter. This architecture allows for infinite adjustment of sample rate between 1 and
50 kHz while maintaining linear phase response simply
by changing the master clock frequency.
— 128X Interpolation Filter
— Delta-Sigma DAC
— Analog Post Filter
l 106 dB Dynamic Range
l Low Clock Jitter Sensitivity
l Filtered Line-Level Outputs
The CS4390 also includes an extremely flexible serial
port utilizing mode select pins to support multiple interface formats.
— Linear Phase Filtering
— Zero Phase Error Between Channels
The master clock can be either 256, 384, or 512 times
the input sample rate, supporting various audio
environments.
l Adjustable System Sampling Rates
— including 32 kHz, 44.1 kHz & 48 kHz
l Digital De-emphasis for 32 kHz, 44.1 kHz, &
ORDERING INFORMATION
CS4390-KP -10° to 70° C
CS4390-KS -10° to 70° C
CDB4390
48 kHz
l Pin-compatible with the CS4329
20-pin Plastic DIP
20-pin Plastic SSOP
Evaluation Board
I
DIF0 DIF1 DIF2
20
LRCK
SCLK
SDATA
19
12
DEM0
DEM1
1
2
VA
VD
3
6
7
9
10
Serial Input
Interface
De-emphasis
Interpolator
Delta-Sigma
Modulator
AUTO_MUTE 11
Interpolator
5
DGND
Cirrus Logic, Inc.
Crystal Semiconductor Products Division
P.O. Box 17847, Austin, Texas 78760
(512) 445 7222 FAX: (512) 445 7581
http://www.crystal.com
Voltage Reference
MUTE_L
16
Delta-Sigma
Modulator
8
MCLK
DAC
DAC
18
Analog
Low-Pass
Filter
14
4
AGND
AOUTL+
Analog
Low-Pass
Filter
AOUTL17
AOUTR+
AOUTR13
15
MUTE_R
Copyright  Cirrus Logic, Inc. 1998
(All Rights Reserved)
JUN ‘98
DS264F1
1
CS4390
ANALOG CHARACTERISTICS (TA = 25°C; Full-Scale Differential Output Sine wave, 997 Hz; Fs =
48 kHz; Input Data = 24 Bits; SCLK = 3.072 MHz; MCLK = 12.288 MHz; RL = 20 kΩ differential; VD = VA = 5 V;
Logic "1" = VD; Logic "0" = DGND; Measurement Bandwidth is 10 Hz to 20 kHz, unweighted unless otherwise
specified.)
Parameter
Specified Temperature Operating Range
Dynamic Performance
Dynamic Range
24-Bit
Symbol
TA
(Note 1)
(A-Weighted)
20-Bit
(A-Weighted)
16-Bit
Total Harmonic Distortion + Noise
24-Bit
20-Bit
16-Bit
(A-Weighted)
(Note 1)
0 dB
-20 dB
-60 dB
0 dB
-20 dB
-60 dB
0 dB
-20 dB
-60 dB
(Note 2)
Idle Channel Noise / Signal-to-Noise-Ratio
Interchannel Isolation
(1 kHz)
Combined Digital and Analog Filter Characteristics
Frequency Response 10 Hz to 20 kHz
(Note 3)
Deviation from linear phase
Passband: to -0.1 dB corner
(Note 3)
Passband Ripple
StopBand
(Note 3)
StopBand Attenuation
(Note 3)
Group Delay
(Note 4)
De-emphasis Error (referenced to 1 kHz)
Fs = 32 kHz
Fs = 44.1 kHz
Fs = 48 kHz
dc Accuracy
Interchannel Gain Mismatch
Gain Error
Gain Drift
Power Supplies
Power Supply Current:
Normal Operation
Power Dissipation
Power Supply Rejection Ratio (1 kHz)
2
Min
-10
Typ
-
Max
70
Unit
°C
98
101
-
103
106
103
106
94
96
-
dB
dB
dB
dB
dB
dB
-90
-78
-38
-
-98
-83
-43
-98
-83
-43
-93
-74
-34
115
-110
-
dB
dB
dB
dB
dB
dB
dB
dB
dB
dBFS
dB
0
26.23
75
-
±0.1
±0.5
25/Fs
-
21.77
±0.001
+0.3/-0.3
+0.2/-0.4
+0.1/-0.45
dB
deg
kHz
dB
kHz
dB
s
dB
dB
dB
-
0.1
±2
200
±5
-
dB
%
ppm/°C
-
30
12
42
500
210
2.5
60
45
225
-
mA
mA
mA
µA
mW
mW
dB
THD+N
IA
ID
IA+ID
Power-down
Normal Operation
Power-down
PSRR
DS264F1
CS4390
ANALOG CHARACTERISTICS (CONTINUED)
Parameter
Analog Output
Differential Full Scale Output Voltage
Output Common Mode Voltage
Differential Offset
AC Load Resistance
Load Capacitance
Symbol
Min
Typ
Max
Unit
RL
CL
1.90
4
-
2.0
2.2
3
-
2.10
15
100
Vrms
V
mV
kΩ
pf
(Note 5)
Notes: 1. Triangular PDF Dithered Data
2. AUTO-MUTE active. See parameter definitions
3. The passband and stopband edges scale with frequency. For input sample rates, Fs, other than 48 kHz,
the passband edge is 0.4535×Fs and the stopband edge is 0.5465×Fs.
4. Group Delay for Fs=48 kHz 25/48 kHz=520 µs
5. Specified for a fully differential output ±((AOUT+)-(AOUT-)). See Figure 12.
SWITCHING CHARACTERISTICS
(TA= -10 to 70°C; Logic 0 = AGND = DGND; Logic
1 = VD = VA = 5.25 to 4.75 Volts; CL = 20 pF)
Parameter
Input Sample Rate
MCLK Pulse Width High
MCLK Pulse Width Low
MCLK Pulse Width High
MCLK Pulse Width Low
MCLK Pulse Width High
MCLK Pulse Width Low
External SCLK Mode
SCLK Pulse Width Low
SCLK Pulse Width High
SCLK Period
Symbol
Fs
Min
1
10
10
21
21
31
32
Typ
-
Max
50
-
Unit
kHz
ns
ns
ns
ns
ns
ns
tsclkl
tsclkh
tsclkw
20
20
-
-
ns
ns
ns
MCLK / LRCK = 512
MCLK / LRCK = 512
MCLK / LRCK = 384
MCLK / LRCK = 384
MCLK / LRCK = 256
MCLK / LRCK = 256
1 ------------------128 ( Fs )
SCLK rising to LRCK edge delay
SCLK rising to LRCK edge setup time
SDATA valid to SCLK rising setup time
SCLK rising to SDATA hold time
Internal SCLK Mode
SCLK Period
SCLK / LRCK = 64
tslrd
tslrs
tsdlrs
tsdh
20
20
20
20
-
-
ns
ns
ns
ns
tsclkw
1 ---------------64 ( Fs )
-
-
ns
SDATA valid to SCLK rising setup time
tsdlrs
1 ------------------+ 10
512 ( Fs )
-
-
ns
SCLK rising to SDATA hold time
512
SCLK rising to SDATA hold time
MCLK / LRCK = 256 or
tsdh
1 ------------------+ 15
512 ( Fs )
-
-
ns
MCLK / LRCK = 384
tsdh
1 ------------------+ 15
384 ( Fs )
-
-
ns
DS264F1
3
CS4390
LRCK
t slrs
t sclkl t sclkh
t slrd
SCLK
t sdlrs
t sdh
SDATA
External Serial Mode Input Timing
LRCK
SDATA
t sclkw
t sdlrs t sdh
*INTERNAL SCLK
Internal Serial Mode Input Timing
* The SCLK pin must be terminated to ground.
The SCLK pulses shown are internal to the CS4390.
4
DS264F1
CS4390
DIGITAL CHARACTERISTICS (TA = 25°C; VD = 5 V ±5%)
Parameter
High-Level Input Voltage
Low-Level Input Voltage
Input Leakage Current
Digital Input Capacitance
Symbol
VIH
VIL
Vin
Min
2.0
-
Typ
10
Max
0.8
±10.0
-
Unit
V
V
µA
pF
ABSOLUTE MAXIMUM RATINGS (AGND = 0 V, all voltages with respect to ground.)
Parameter
DC Power Supply:
Positive Analog
Positive Digital
|VA - VD|
Input Current, Any Pin Except Supplies
Digital Input Voltage
Ambient Operating Temperature (power applied)
Storage Temperature
Symbol
VA
VD
Iin
VIND
TA
Tstg
Min
-0.3
-0.3
0.0
-0.3
-55
-65
Max
6.0
6.0
0.4
±10
(VD)+0.4
125
150
Unit
V
V
V
mA
V
°C
°C
WARNING: Operation at or beyond these limits may result in permanent damage to the device. Normal operation
is not guaranteed at these extremes.
RECOMMENDED OPERATING CONDITIONS (DGND = 0V; all voltages with respect to ground)
Parameter
DC Power Supply:
DS264F1
Positive Digital
Positive Analog
|VA - VD|
Symbol
VD
VA
Min
4.75
4.75
-
Typ
5.0
5.0
-
Max
5.25
5.25
0.4
Unit
V
V
V
5
CS4390
10Ω
+ 1 µF
0.1 µF
20
Mode
Select
19
12
7
9
10
Audio
Data
Processor
1
2
15
16
11
8
External Clock
+ 1 µF
6
VD
DIF0
3
VA
DIF1
AOUTL-
DIF2
+5V
Analog
17
CS4390
LRCK
SCLK*
0.1 µF
Analog
Conditioning
AOUTL+ 18
SDATA
DEM0
DEM1
AOUTR-
13
MUTE_R
Analog
Conditioning
MUTE_L
AUTO_MUTE
AOUTR+ 14
MCLK
DGND AGND
4
5
* SCLK must be connected to DGND
for operation in Internal SCLK Mode
Figure 1. Typical Connection Diagram
6
DS264F1
CS4390
GENERAL DESCRIPTION
The CS4390 is a complete stereo digital-to-analog
system including 128× digital interpolation, fourthorder delta-sigma digital-to-analog conversion,
128× oversampled one-bit delta-sigma modulator
and analog filtering. This architecture provides a
high insensitivity to clock jitter. The DAC converts
digital data at any input sample rate between 1 and
50 kHz, including the standard audio rates of 48,
44.1 and 32 kHz.
The primary purpose of using delta-sigma modulation techniques is to avoid the limitations of laser
trimmed resistive DAC architectures by using an
inherently linear 1-bit DAC. The advantages of a 1bit DAC include: ideal differential linearity, no distortion mechanisms due to resistor matching errors
and no linearity drift over time and temperature due
to variations in resistor values.
Digital Interpolation Filter
The digital interpolation filter increases the sample
rate by a factor of 4 and is followed by a 32× digital
sample-and hold to effectively achieve a 128× interpolation filter. This filter eliminates images of
the baseband audio signal which exist at multiples
of the input sample rate, Fs. This allows for the selection of a less complex analog filter based on outof-band noise attenuation requirements rather than
anti-image filtering. Following the interpolation
filter, the resulting frequency spectrum has images
Interpolator
Delta-Sigma
Modulator
of the input signal at multiples of 128× the input
sample rate. These images are removed by the external analog filter.
Delta-Sigma Modulator
The interpolation filter is followed by a fourth-order delta-sigma modulator which converts the 24bit interpolation filter output into 1-bit data at
128× Fs.
Switched-Capacitor Filter
The delta-sigma modulator is followed by a digitalto-analog converter which translates the 1-bit data
into a series of charge packets. The magnitude of
the charge in each packet is determined by sampling of a voltage reference onto a switched capacitor, where the polarity of each packet is controlled
by the 1-bit signal. This technique greatly reduces
the sensitivity to clock jitter and is a major improvement over earlier generations of 1-bit digitalto-analog converters where the magnitude of
charge in the D-to-A process is determined by
switching a current reference for a period of time
defined by the master clock.
The CS4390 incorporates a differential output to
maximize the output level to minimize the amount
of gain required in the output analog stage. The differential output also allows for the cancellation of
common mode errors in the differential to singledended converter.
DAC
Analog
Low-Pass
Filter
AOUTL+
AOUTL-
Figure 2. Block Diagram
DS264F1
7
CS4390
SYSTEM DESIGN
Master Clock
The Master Clock, MCLK, is used to operate the
digital interpolation filter and the delta-sigma modulator. MCLK must be either 256×, 384× or 512×
the desired Input Sample Rate, Fs. Fs is the frequency at which digital audio samples for each
channel are input to the DAC and is equal to the
LRCK frequency. The MCLK to LRCK frequency
ratio is detected automatically during the initialization sequence by counting the number of MCLK
transitions during a single LRCK period. Internal
dividers are then set to generate the proper clocks
for the digital filter, delta-sigma modulator and
switched-capacitor filter. LRCK must be synchronous with MCLK. Once the MCLK to LRCK frequency ratio has been detected, the phase and
frequency relationship between the two clocks
must remain fixed. If during any LRCK this relationship is changed, the CS4390 will reset. Table 1
illustrates the standard audio sample rates and the
required MCLK frequencies.
Fs
(kHz)
32
44.1
48
256x
8.1920
11.2896
12.2880
MCLK (MHz)
384x
12.2880
16.9344
18.4320
512x
16.3840
22.5792
24.5760
Table 1. Common Clock Frequencies
Serial Data Interface
The Serial Data interface is accomplished via the
serial data input, SDATA, serial data clock, SCLK,
and the left/right clock, LRCK. The CS4390 supports seven serial data formats which are selected
via the digital input format pins DIF0, DIF1 and
DIF2. The different formats control the relationship of LRCK to the serial data and the edge of
SCLK used to latch the data into the input buffer.
Table 2 lists the seven formats, along with the associated figure number. The serial data is represented
in 2's-complement format with the MSB-first in all
seven formats.
8
DIF2
DIF1
DIF0
Format
Figure
0
0
0
0
3
0
0
1
1
3
0
1
0
2
3
0
1
1
3
4
1
0
0
4
5
1
0
1
5
6
1
1
0
6
7
1
1
1
Calibrate
-
Table 2. Digital Input Formats
Formats 0, 1, and 2 are shown in Figure 3. The audio data is right-justified, LSB aligned with the
trailing edge of LRCK, and latched into the serial
input data buffer on the rising edge of SCLK. Formats 0, 1, and 2 are 16, 24, and 20-bit versions, respectively, and differ only in the number of data
bits required. Format 1 in the CS4390 is not compatible with Format 1 in the CS4329.
Formats 3 and 4 are 24-bit left justified, MSB
aligned with the leading edge of LRCK, and are
identical with the exception of the SCLK edge used
to latch data. Data is latched on the falling edge of
SCLK in Format 3 and the rising edge of SCLK in
Format 4. Both formats will support 16, 18, and 20bit inputs if the data is followed by 8, 6, or 4 zeros
to simulate a 24-bit input as shown in Figures 4 and
5. A very small offset will result if the 20, 18, or 16bit data is followed by static non-zero data.
Formats 5 and 6 are compatible with the I2S serial
data protocol and are shown in Figures 6 and 7. Notice that the MSB is delayed 1 period of SCLK following the leading edge of LRCK and LRCK is
inverted compared to the previous formats. Data is
latched on the rising edge of SCLK. Format 5 is 16bit I2S while Format 6 is 24-bit I2S. 20, 18, or 16bit I2S can be implemented in Format 6 if the data
is followed by 4, 6, or 8 zeros respectively to simulate a 24-bit input as shown in Figure 7. A very
small offset will result if the 20, 18, or 16-bit data
is followed by static non-zero data.
DS264F1
DS264F1
NOTE: Format 1 is not compatible with CS4329
Figure 3. Digital Input Format 0, 1 and 2.
9
CS4390
Figure 4. Digital Input Format 3.
10
Figure 5. Digital Input Format 4.
Figure 6. Digital Input Format 5.
CS4390
DS264F1
Figure 7. Digital Input Format 6.
CS4390
Serial Clock
De-Emphasis
The serial clock controls the shifting of data into
the input data buffers. The CS4390 supports both
external and internal serial clock generation modes.
Implementation of digital de-emphasis requires reconfiguration of the digital filter to maintain the filter response shown in Figure 8 at multiple sample
rates. The CS4390 is capable of digital de-emphasis for 32, 44.1 or 48kHz sample rates. Table 3
shows the de-emphasis control inputs for DEM 0
and DEM 1.
External Serial Clock
The CS4390 will enter the external serial clock
mode if 15 or more high\low transitions are detected on the SCLK pin during any phase of the LRCK
period. When this mode is enabled, internal serial
clock mode cannot be accessed without returning
to the power down mode.
Internal Serial Clock
In the Internal Serial Clock Mode, the serial clock
is internally derived and synchronous with MCLK.
The internal SCLK / LRCK ratio is always 64 and
operation in this mode is identical to operation with
an external serial clock synchronized with LRCK.
The SCLK pin must be connected to DGND for
proper operation.
The internal serial clock mode is advantageous in
that there are situations where improper serial
clock routing on the printed circuit board can degrade system performance. The use of the internal
serial clock mode simplifies the routing of the
printed circuit board by allowing the serial clock
trace to be deleted and avoids possible interference
effects.
Mute Functions
The CS4390 includes an auto-mute function which
will initiate a mute if 8192 consecutive 0’s or 1’s are
input on both the Left and Right channels. The
mute will be released when non-static input data is
applied to the DAC. The auto-mute function is useful for applications, such as compact disk players,
where the idle channel noise must be minimized.
This feature is active only if the AUTO_MUTE pin
is low and is independent of the status of MUTE_L
and MUTE_R. Either channel can also be muted
instantaneously with the MUTE_L or MUTE_R.
DS264F1
DEM 1
0
0
1
1
DEM 0
0
1
0
1
De-emphasis
32 kHz
44.1 kHz
48 kHz
OFF
Table 3. De-Emphasis Filter Selection
Gain
dB
T1 = 50 µs
0dB
T2 = 15 µs
-10dB
F1
3.183 kHz
F2
Frequency
10.61 kHz
Figure 8. De-emphasis Filter Response
Initialization, Calibration and Power-Down
Upon initial power-up, the DAC enters the powerdown mode. The interpolation filters and delta-sigma modulators are reset, and the internal voltage
reference, one-bit D/A converters and switched-capacitor low-pass filters are powered down. The device will remain in the power-down mode until
MCLK and LRCK are presented. Once MCLK and
LRCK are detected, MCLK occurrences are counted over one LRCK period to determine the
MCLK/LRCK frequency ratio. The phase and frequency relationship between the two clocks must
remain fixed. If during any LRCK this relationship
11
CS4390
The CS4390 will enter the power-down mode,
within 1 period of LRCK, if either MCLK or
LRCK is removed. The initialization sequence, as
described above, occurs when MCLK and LRCK
are restored.
Combined Digital and Analog Filter
Response
The frequency response of the combined analog
switched-capacitor and digital filters is shown in
Figures 9, 10 and 11. The overall response is clock
dependent and will scale with Fs. Note that the response plots have been normalized to Fs and can be
de-normalized by multiplying the X-axis scale by
Fs, such as 48 kHz.
Analog Output and Filtering
The analog output should be operated in a differential mode which allows for the cancellation of common mode errors including noise, distortion and
offset voltage. Each output will produce a nominal
2.83 Vpp (1 Vrms) output for a full scale digital input which equates to a 5.66 Vpp (2Vrms) differential signal as shown in Figure 12.
-10
Magnitude (dB)
-20
-30
-40
-50
-60
-70
-80
-90
-100
0.0
0.2 0.3 0.4 0.5 0.6 0.7 0.8
Frequency (x Fs)
0.1
0.9 1.0
Figure 9. CS4390 Combined Digital and Analog Filter
Stopband Rejection
0
-10
-20
-30
Magnitude (dB)
A offset calibration can also be invoked by taking
the Format select pins, DIF0, DIF1 and DIF2, to a
logic 1 as shown in Table 2. During calibration, the
differential outputs are shorted together and the
common-mode voltage appears at the output with
approximately an 8 kohm output impedance. Following calibration, the analog output impedance
becomes less than 10 ohms and the common mode
voltage will move to approximately 2.2 V .
0
-40
-50
-60
-70
-80
-90
-100
0.45
0.48
0.51
0.54
Frequency (x Fs)
0.57
0.60
Figure 10. CS4390 Combined Digital and Analog Filter
0
-1
-2
Magnitude (dB)
is changed, the CS4390 will reset. Power is applied
to the internal voltage reference, the D/A converters, switched-capacitor filters and the DAC will
then enter a calibration mode to properly set the
common mode bias voltage and minimize the differential offset. This initialization and calibration
sequence requires approximately 2700 cycles of
LRCK.
-3
-4
-5
-6
-7
-8
-9
-10
0.46
0.47
0.48
0.49
0.50
Frequency (x Fs)
0.51
0.52
Figure 11. Combined Digital and Analog Filter
12
DS264F1
CS4390
Figure 13 displays the CS4390 output noise spectrum. The noise beyond the audio band can be further reduced with additional analog filtering. The
applications note "Design Notes for a 2-Pole Filter
with Differential Input " discusses the second-order
Butterworth filter and differential to signal-ended
converter which was implemented on the CS4390
evaluation board, CDB4390. The CS4390 filter is a
linear phase design and does not include phase or
amplitude compensation for an external filter.
Therefore, the DAC system phase and amplitude
response will be dependent on the external analog
circuitry.
CS4390
(2.2 + 1.4)V
AOUT+
2.2V
(2.2 - 1.4)V
(2.2 + 1.4)V
AOUT-
2.2V
(2.2 - 1.4)V
Full Scale Input level= (AIN+) - (AIN-)= 5.66 Vpp
Figure 12. Full Scale Input Voltage
As with any high resolution converter, the CS4390
requires careful attention to power supply and
grounding arrangements to optimize performance.
Figure 1 shows the recommended power arrangements with VA connected to a clean +5volt supply.
VD should be derived from VA through a 10 Ω resistor. VD should not be used to power additional
digital circuitry. All mode pins which require VD
should be connected to pin 6 of the CS4390. All
mode pins which require DGND should be connected to pin 5 of the CS4390. Pins 4 and 5, AGND
and DGND, should be connected together at the
CS4390. DGND for the CS4390 should not be confused with the ground for the digital section of the
system. The CS4390 should be positioned over the
analog ground plane near the digital/analog ground
plane split. The analog and digital ground planes
must be connected elsewhere in the system. The
CS4390 evaluation board, CDB4390, demonstrates
this layout technique. This technique minimizes
digital noise and insures proper power supply
matching and sequencing. Decoupling capacitors
should be located as near to the CS4390 as possible.
Performance Plots
0
The following collection of CS4390 measurement
plots were taken from the CDB4390 evaluation
board using the Audio Precision Dual Domain System Two.
-20
-40
Magnitude (dB)
Grounding and Power Supply Decoupling
-60
-80
Figure 14 shows the frequency response at a
48 kHz sample rate. The response is flat to 20 kHz
+/-0.1 dB as specified.
-100
-120
-140
-160
0
.25 .50 .75 1.00 1.25 1.50 1.75 2.00 2.25 2.50
Frequency (x Fs)
Figure 13. CS4390 Output Noise Spectrum
DS264F1
Figure 15 shows THD+N versus signal amplitude
for a 1 kHz 24-bit dithered input signal. Notice that
the there is no increase in distortion as the signal
level decreases. This indicates very good low-level
linearity, one of the key benefits of delta-sigma
digital to analog conversion.
13
CS4390
Figure 16 shows a 16 k FFT of a 1 kHz full-scale
input signal. The signal has been filtered by a notch
filter within the System Two to remove the fundamental component of the signal. This minimizes
the distortion created in the analyzer analog-to-digital converter. This technique is discussed by Audio
Precision in the 10th anniversary addition of AUDIO.TST.
fade, the output from the CS4390 is measured and
compared to the ideal level. Notice the very close
tracking of the output level to the ideal, even at low
level inputs. The gradual shift of the plot away
from zero at signals levels < -110 dB is caused by
the background noise starting to dominate the measurement.
Figure 17 shows a 16 k FFT of a 1 kHz -20 dBFS
input signal. The signal has been filtered by a notch
filter within the System Two to remove the fundamental component of the signal.
Figure 18 shows a 16 k FFT of a 1 kHz -60 dBFS
input signal.
Figure 19 shows the fade-to-noise linearity. The input signal is a dithered 24-bit 500 Hz sine wave
which fades from -60 to -120 dBFS. During the
14
DS264F1
CS4390
-60
+1
-65
+0.8
-70
+0.6
-75
+0.4
-80
+0.2
d
B
r +0
d -85
B
r -90
A
A -95
-0.2
-100
-0.4
-105
-0.6
-110
-0.8
-115
-1
-120
20
50
100
200
500 1k
Hz
2k
5k
-60
10k 20k
Figure 14. Frequency Response
+0
+0
-10
-20
-20
-30
-30
-40
-40
-50
-50
-60
-60
d -70
B
r -80
d -70
B
r -80
A -90
A -90
-100
-100
-110
-110
-120
-120
-130
-130
-140
-140
-150
-150
-160
5k
7.5k
10k
Hz
12.5k
15k
17.5k
-40
-30
dBFS
-20
-10
+0
Figure 15. THD+N vs. Amplitude
-10
2.5k
-50
20k
-160
2.5k
Figure 16. 0 dBFS FFT
5k
7.5k
10k
Hz
12.5k
15k
17.5k
20k
Figure 17. -20 dBFS FFT
+0
+5
-10
+4
-20
+3
-30
-40
+2
-50
d +1
B
r -0
A
-1
-60
d
B -70
r
-80
A
-90
-100
-2
-110
-3
-120
-4
-130
-140
-150
-5
2k
4k
6k
8k
10k
Hz
12k
14k
16k
Figure 18. -60 dBFS FFT
DS264F1
18k 20k
-120
-100
-80
-60
dBFS
-40
-20
+0
Figure 19. Fade-to-Noise Linearity
15
CS4390
PIN DESCRIPTIONS
PDIP and SSOP
DEM0
DEM1
VA
AGND
DGND
VD
LRCK
MCLK
SCLK
SDATA
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
DIF0
DIF1
AOUTL+
AOUTLMUTE_L
MUTE_R
AOUTR+
AOUTRDIF2
AUTO-MUTE
Power Supply Connections
VA - Positive Analog Power, PIN 3.
Positive analog supply. Nominally +5 volts.
VD - Positive Digital Power, PIN 6.
Positive supply for the digital section. Nominally +5 volts.
AGND - Analog Ground, PIN 4.
Analog ground reference.
DGND - Digital Ground, PIN 5.
Digital ground for the digital section.
Analog Outputs
AOUTR+,AOUTR- - Differential Right Channel Analog Outputs, PIN 14, PIN 13.
Analog output connections for the Right channel differential outputs. Nominally 2 Vrms
(differential) for full-scale digital input signal.
AOUTL+,AOUTL- - Differential Left Channel Analog Outputs, PIN 18, PIN 17.
Analog output connections for the Left channel differential outputs. Nominally 2 Vrms
(differential) for full-scale digital input signal.
16
DS264F1
CS4390
Digital Inputs
MCLK - Clock Input, PIN 8.
The frequency must be either 256×, 384× or 512× the input sample rate (Fs).
LRCK - Left/Right Clock, PIN 7.
This input determines which channel is currently being input on the Serial Data Input pin,
SDATA. The format of LRCK is controlled by DIF0, DIF1 and DIF2.
SCLK - Serial Bit Input Clock, PIN 9.
Clocks the individual bits of the serial data in from the SDATA pin. The edge used to latch
SDATA is controlled by DIF0, DIF1 and DIF2.
SDATA - Serial Data Input, PIN 10.
Two's complement MSB-first serial data of either 16, 18, 20 or 24 bits is input on this pin. The
data is clocked into the CS4390 via the SCLK clock and the channel is determined by the
LRCK clock. The format for the previous two clocks is determined by the Digital Input Format
pins, DIF0, DIF1 and DIF2.
DIF0, DIF1, DIF2 - Digital Input Format, PINS 20, 19, 12
These three pins select one of seven formats for the incoming serial data stream. These pins set
the format of the SCLK and LRCK clocks with respect to SDATA. The formats are listed in
Table 2.
DEM0, DEM1 - De-Emphasis Select, PINS 1, 2.
Controls the activation of the standard 50/15us de-emphasis filter for either 32, 44.1 or 48 kHz
sample rates.
AUTO-MUTE - Automatic Mute on Zero-Data, PIN 11.
When Auto-Mute is low the analog outputs are muted following 8192 consecutive LRCK
cycles of static 0 or 1 data. Mute is canceled with the return of non-static input data.
MUTE_R , MUTE_L Mute, PINS 15, 16.
MUTE_L low activates a muting function for the Left channel. MUTE_R low activates a
muting function for the Right channel.
DS264F1
17
CS4390
PARAMETER DEFINITIONS
Dynamic Range
The ratio of the full scale rms value of the signal to the rms sum of all other spectral
components over the specified bandwidth. Dynamic range is a signal-to-noise measurement
over the specified bandwidth made with a -60 dBFS signal. 60 dB is then added to the resulting
measurement to refer the measurement to full scale. This technique ensures that the distortion
components are below the noise level and do not effect the measurement. This measurement
technique has been accepted by the Audio Engineering Society, AES17-1991, and the
Electronic Industries Association of Japan, EIAJ CP-307.
Total Harmonic Distortion + Noise
The ratio of the rms value of the signal to the rms sum of all other spectral components over
the specified bandwidth (typically 10 Hz to 20 kHz), including distortion components.
Expressed in decibels.
Idle Channel Noise / Signal-to-Noise-Ratio
The ratio of the rms analog output level with 1kHz full scale digital input to the rms analog
output level with all zeros into the digital input. Measured A-weighted over a 10 Hz to 20 kHz
bandwidth. Units in decibels. This specification has been standardized by the Audio
Engineering Society, AES17-1991, and referred to as Idle Channel Noise. This specification has
also been standardized by the Electronic Industries Association of Japan, EIAJ CP-307, and
referred to as Signal-to-Noise-Ratio.
Interchannel Isolation
A measure of crosstalk between the left and right channels. Measured for each channel at the
converter’s output with all zeros to the input under test and a full-scale signal applied to the
other channel. Units in decibels.
Frequency Response
A measure of the amplitude response variation from 10 Hz to 20 kHz relative to the amplitude
response at 1 kHz. Units in decibels.
De-Emphasis Error
A measure of the difference between the ideal de-emphasis filter and the actual de-emphasis
filter response. Measured from 10 Hz to 20 kHz relative to 1 kHz. Units in decibels.
Interchannel Gain Mismatch
The gain difference between left and right channels. Units in decibels.
Gain Error
The deviation from the nominal full scale analog output for a full scale digital input.
Gain Drift
The change in gain value with temperature. Units in ppm/°C.
18
DS264F1
CS4390
PACKAGE DIMENSIONS
20L SSOP PACKAGE DRAWING
N
D
E11
A2
E
e
b2
SIDE VIEW
A
A1
END VIEW
L
SEATING
PLANE
1 2 3
TOP VIEW
INCHES
DIM
A
A1
A2
b
D
E
E1
e
L
∝
MIN
-0.002
0.064
0.009
0.272
0.291
0.197
0.022
0.025
0°
MILLIMETERS
MAX
0.084
0.010
0.074
0.015
0.295
0.323
0.220
0.030
0.041
8°
MIN
-0.05
1.62
0.22
6.90
7.40
5.00
0.55
0.63
0°
MAX
2.13
0.25
1.88
0.38
7.50
8.20
5.60
0.75
1.03
8°
NOTE
2,3
1
1
Notes: 1. “D” and “E1” are reference datums and do not included mold flash or protrusions, but do include mold
mismatch and are measured at the parting line, mold flash or protrusions shall not exceed 0.20 mm per
side.
2. Dimension “b” does not include dambar protrusion/intrusion. Allowable dambar protrusion shall be
0.13 mm total in excess of “b” dimension at maximum material condition. Dambar intrusion shall not
reduce dimension “b” by more than 0.07 mm at least material condition.
3. These dimensions apply to the flat section of the lead between 0.10 and 0.25 mm from lead tips.
DS264F1
19
CS4390
20 PIN PLASTIC (PDIP) PACKAGE DRAWING
eB
D
eC
E
E1
1
TOP VIEW
A2 A
SEATING
PLANE
A1
∝
e
b1
INCHES
∝
20
MIN
0.000
0.015
0.115
0.014
0.045
0.008
0.980
0.300
0.240
0.090
0.280
0.300
0.000
0.115
0°
eA
c
b
BOTTOM VIEW
DIM
A
A1
A2
b
b1
c
D
E
E1
e
eA
eB
eC
L
L
MAX
0.210
0.025
0.195
0.022
0.070
0.014
1.060
0.325
0.280
0.110
0.320
0.430
0.060
0.150
15°
SIDE VIEW
MILLIMETERS
MIN
MAX
0.00
5.33
0.38
0.64
2.92
4.95
0.36
0.56
1.14
1.78
0.20
0.36
24.89
26.92
7.62
8.26
6.10
7.11
2.29
2.79
7.11
8.13
7.62
10.92
0.00
1.52
2.92
3.81
0°
15°
DS264F1
• Notes •
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