ASAHI KASEI
[AK4319A]
AK4319A
18Bit SCF DAC
General Description
The AK4319A is a high performance 1bit stereo DAC for digital audio systems. A 1bit DAC can achieve
monotonicity and low distortion with no adjustment. On chip SCF filter makes the device less affected to the
clock jitter and also suppresses the undesirable radio emission noise. The device equips differentially
configurated output pins, but either of the pins can be used as single-end. The AK4319A achieves lower Outband noise characteristic and it is suitable for digital broadcasting tuner and other digital audio applications.
Features
Sampling Rate Ranging from 8kHz to 54kHz
128 times Oversampling
18bit 8 times Digital Filter
2nd order SCF with High Tolerance to Clock Jitter
Differential outputs(Single-end use is available)
Digital de-emphasis for 32, 44.1, 48kHz sampling
Soft mute
I/F format : MSB justified, LSB justified, IIS
THD+N: -87dB
DR: 92dB
Master Clock: 256fs or 384fs
Power supply: 4.5 to 5.5V
Small Package: 24pin SSOP
AK4319 Compatible
M0011-E-01
1998/6
-1-
ASAHI KASEI
[AK4319A]
Ordering Guide
AK4319AVM
AKD4319A
-40∼+85°C
Evaluation Board
24pin SSOP(0.65mm pitch)
Pin Layout
Different Points from AK4319
Parameter
AK4319
AK4319A
fs(min)
10kHz
8kHz
THD+N
-90dB
-87dB
DR
96dB
92dB
S/N
96dB
92dB
M0011-E-01
1998/6
-2-
ASAHI KASEI
[AK4319A]
PIN/FUNCTION
No.
Pin Name
I/O
Function
1
DIF1
I
Digital Input Format Pin
(Internal Pull-down pin)
2
DVDD
-
Digital Power Supply
3
DVSS
-
Digital Ground Pin
4
LRCK
I
L/R Clock Pin
5
BICK
I
Audio Serial Data Clock Pin
6
SDATA
I
Audio Serial Data Input Pin
2's complement MSB-first data is input on this pin.
7
PD
I
Power-Down Mode Pin
When at "L", the AK4319A is in power-down mode and is held in reset.
The AK4319A should always be reset upon power-up.
8
XTI
I
Master Clock Input Pin
A crystal can be connected between this pin and XTO, or an external
CMOS clock can be input on XTI.
9
XTO
O
Crystal Oscillator Output Pin
When an external clock is input, this pin should be left floating.
10
CLKO
O
Clock Output Pin
The inverted XTI clock is output.
11
SMUTE
I
Soft Mute Pin
(Internal Pull-down pin)
When this pin goes "H", soft mute cycle is initiated.
When returning "L", the output mute releases.
12
DEM0
I
De-emphasis Frequency Select Pin
13
DEM1
I
De-emphasis Frequency Select Pin
14
CKS
I
Master Clock Select Pin
(Internal Pull-down pin)
"L": MCLK=256fs,"H": MCLK=384fs
15
TST
I
Test Pin
(Internal Pull-down pin)
Must be left floating or tied to AVSS.
16
AOUTR-
O
Rch Negative analog output pin
17
AOUTR+
O
Rch Positive analog output pin
18
AOUTL-
O
Lch Negative analog output pin
19
AOUTL+
O
Lch Positive analog output pin
20
VREF
O
Voltage Reference Output Pin, 3.0V (typ, respects to AVSS)
Normally connected to AVSS with a 0.1uF ceramic capacitor in parallel
witha 10uF electrolytic capacitor.
21
AVDD
-
Analog Power Supply Pin
22
AVSS
-
Analog Ground pin
23
DZF
O
Zero Input Detect Pin
24
DIF0
I
Digital Input Format Pin
(Internal Pull-down pin)
Note: All input pins except pull-down pins should not be left floating.
M0011-E-01
1998/6
-3-
ASAHI KASEI
[AK4319A]
ABSOLUTE MAXIMUM RATINGS
(AVSS,DVSS=0V; Note 1 )
Parameter
Power Supplies:
Analog
Digital
DVDD-AVDD
Symbol
min
max
Units
AVDD
DVDD
VDA
-0.3
-0.3
-
6.0
6.0
0.3
V
V
V
-
±10
mA
Input Current, Any Pin Except Supplies
IIN
Input Voltage
VIND
-0.3
AVDD+0.3
V
Ambient Operating Temperature
Ta
-40
85
°C
Storage Temperature
Tstg
-65
150
°C
Note: 1 . All voltages with respect to ground..
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
(AVSS,DVSS=0V; Note 1 )
Parameter
Power Supplies: Analog (Note 2 )
Digital
Symbol
AVDD
DVDD
min
4.5
4.5
typ
5.0
5.0
max
5.5
AVDD
Units
V
V
Notes:2 . AVDD and DVDD should be powered at the same time or AVDD should be powered earlier
than DVDD.
* AKM assumes no responsibility for the usage beyond the conditions in this data sheet.
M0011-E-01
1998/6
-4-
ASAHI KASEI
[AK4319A]
ANALOG CHARACTERISTICS
(Ta=25°C; AVDD,DVDD=5.0V; fs=44.1kHz; BICK=64fs; Signal Frequency=1kHz; 18bit Input Data;
Measurement Bandwidth=10Hz∼20kHz; RL≥5kΩ; unless otherwise specified)
Parameter
min
typ
Resolution
Dynamic Characteristics
max
Units
18
Bits
-80
dB
(Note 3 )
THD+N
(0dB Output)
-87
Dynamic Range
(-60dB Output, A weight)
88
92
dB
S/N
(A weight)
88
92
dB
Interchannel Isolation(1kHz)
90
100
dB
Interchannel Gain Mismatch
0.15
0.3
dB
100
-
ppm/°C
±2.80
±3.00
Vpp
DC Accuracy
Gain Drift
Output Voltage
(Note 4 )
±2.60
Load Resistance
5
kΩ
Output Current
300
uA
20
7
mA
mA
Power Supplies
Power Supply Current
Normal Operation (PD="H")
AVDD
DVDD
Power-Down-Mode (PD="L")
AVDD+DVDD
(Note 5 )
10
Power Dissipation (AVDD+DVDD)
Normal Operation
Power-Down-Mode
(Note 5 )
85
50
Power Supply Rejection
(Note 6 )
40
13
4
uA
135
mW
uW
dB
Notes: 3. Measured by AD725C(SHIBASOKU). Averaging mode. Refer to the eva board manual.
4. Full-scale voltage(0dB). When summing the differential outputs by unity gain,
AOUT(typ.@0dB)=(AOUT+)-(AOUT-)= ±2.80Vpp*VREF/5.
5. In the power-down mode, all digital input pins including clock pins(XTI,,BICK,LRCK) are
held DVDD or DVSS.
6. PSR is applied to AVDD,DVDD with 1kHz, 100mVpp.
M0011-E-01
1998/6
-5-
ASAHI KASEI
[AK4319A]
FILTER CHARACTERISTICS
(Ta=25°C; AVDD,DVDD=4.5V∼5.5V; fs=44.1kHz; DEM0="1",DEM1="0")
Parameter
Symbol
min
typ
max
Units
PB
0
-
22.05
20.0
-
kHz
kHz
Digital Filter
Passband
(Note 7 )
±0.06dB
-6.0dB
Stopband
(Note 7 )
SB
24.1
kHz
Passband Ripple
PR
Stopband Attenuation
SA
43
GD
-
14.7
-
1/fs
-
±0.2
-
dB
Group Delay
(Note 8 )
±0.06
dB
dB
Digital Filter + SCF
Frequency Response 0∼20.0kHz
Note: 7. The passband and stopband frequencies scale with fs.
For example, PB=0.4535*fs(@±0.1dB), SB=0.546*fs.
8. The calculating delay time which occurred by digital filtering. This time is from setting the
16/18bit data of both channels to input register to the output of analog signal.
DIGITAL CHARACTERISTICS
(Ta=25°C; AVDD,DVDD=4.5∼5.5V)
Parameter
Symbol
min
typ
max
Units
High-Level Input Voltage
(XTI pin)
(All pins except XTI pin)
Low-Level Input Voltage
(XTI pin)
(All pins except XTI pin)
AC coupled Input Voltage
(XTI pin)
VIH1
VIH2
VIL1
VIL2
VAC
70%DVDD
2.2
1
-
30%DVDD
0.8
-
V
V
V
V
Vpp
High-Level Output Voltage
Low-Level Output Voltage
VOH
VOL
DVDD-0.5
-
-
0.5
V
V
-
-
±10
uA
Input Leakage Current
(Iout=-100uA)
(Iout=100uA)
(Note 9 )
Iin
Notes: 9. TST,SMUTE,DIF0,DIF1,CKS pins have internal pull-down devices, nominally 130kΩ.
M0011-E-01
1998/6
-6-
ASAHI KASEI
[AK4319A]
SWITCHING CHARACTERISTICS
(Ta=25°C; AVDD,DVDD=4.5∼5.5V; CL=20pF)
Parameter
Symbol
Master Clock Timing
Crystal Resonator 256fs:
384fs:
External Clock
256fs:
Pulse Width Low
Pulse Width High
384fs:
Pulse Width Low
Pulse Width High
fCLK
fCLK
fCLK
tCLKL
tCLKH
fCLK
tCLKL
tCLKH
LRCK Frequency
Duty Cycle
fs
Duty
min
typ
13.9
20.7
13.824
7.10
10.70
2.048
28
28
3.072
20
20
8
45
20.736
44.1
Serial Interface Timing
290
tBCK
BICK Period
100
tBCKL
BICK Pulse Width Low
100
tBCKH
Pulse Width High
40
tBLR
BICK rising to LRCK edge (Note 10 )
40
tLRB
LRCK Edge to BICK rising (Note 10 )
40
tSDH
SDATA Hold Time
40
tSDS
SDATA Setup Time
Reset Timing
tPD
100
PD Pulse Width
(Note 11 )
Notes: 10. BICK rising edge must not occur at the same time as LRCK edge.
11. The AK4319A can be reset by bringing PD "L" to "H" only upon power up.
M0011-E-01
max
54
55
Unit
MHz
MHz
MHz
MHz
ns
ns
MHz
ns
ns
kHz
%
ns
ns
ns
ns
ns
ns
ns
ns
1998/6
-7-
ASAHI KASEI
[AK4319A]
Timing Diagram
Reset Timing
M0011-E-01
1998/6
-8-
ASAHI KASEI
[AK4319A]
OPERATION OVERVIEW
System Clock
The external clocks which are required to operate the AK4319A are XTI, LRCK, BICK. The master clock(XTI)
should be synchronized with LRCK but the phase is not critical. The XTI is used to operate the digital
interpolation filter and the delta-sigma modulator. The frequency of XTI is determined by the sampling rate
(LRCK) and CKS pin. Table 1 illustrates corresponding clock frequencies. When the 384fs is selected, the
internal master clock becomes 256fs(=384fs*2/3). Refer to Figure 1 .
The master clock can be either a crystal resonator placed across the XTI and XTO pin, or external clock input
to the XTI pin with the XTO pin left floating. Not only CMOS clock but sine wave signal with 1Vp-p can be input
to the XTI pin by AC coupling. Table 1 illustrates corresponding clock frequencies used in each speed. When
using internal oscillation, CLKO can not be used by external circuit at the power-down mode.
All external clocks(XTI,BICK,LRCK) should always be present whenever the AK4319A is in normal operation
mode(PD ="H"). If these clocks are not provided, the AK4319A may draw excess current because the device
utilizes dynamic refreshed logic internally. The AK4319A should be reset by PD ="L" after these clocks are
provided. If the external clocks are not present, the AK4319A should be in the power-down mode(PD ="L").
After exiting reset at power-up etc., the AK4319A is in power-down mode until XTI and LRCK are input.
Clock
frequency
LRCK (fs)
8k∼540kHz
∼64fs
BICK
MCLK
CKS="L"
256fs
CKS="H"
384fs
Table 1 . System Clocks
Figure 1 . Internal clock circuit
Figure 2 . X'tal resonator connection
M0011-E-01
1998/6
-9-
ASAHI KASEI
[AK4319A]
Audio Serial Interface Format
Data is shifted in via the SDATA pin using BICK and LRCK inputs. Four serial data modes can be
selected by the DIF0 and DIF1 pins as shown in Table 2 . In all modes the serial data is MSB-first, 2's
compliment format and is latched on the rising edge of BICK. Mode 2 can be used for 16 MSB justified
formats by zeroing the unused LSBs.
DIF1 DIF0
Mode
BICK
Figure
0
0
0: 16bit LSB Justified
≥32fs
Figure 2
0
1
1: 18bit LSB Justified
≥36fs
Figure 2
1
0
2: 18bit MSB Justified
≥36fs
Figure 3
1
1
3: I S Compatible
≥36fs Figure 4
or 32fs
2
Table 2 . Serial Data Modes
Figure 3 . Mode 0,1 Timing
Figure 4 . Mode 2 Timing
Figure 5 . Mode 3 Timing
M0011-E-01
1998/6
- 10 -
ASAHI KASEI
[AK4319A]
De-emphasis filter
The AK4319A includes the digital de-emphasis filter(tc=50/15us) by IIR filter. This filter corresponds to
three sampling frequencies(32kHz,44.1kHz,48kHz). De-emphasis is enabled by the following two ways.
DEM1
DEM0
Mode
0
0
44.1kHz
0
1
OFF
1
0
48kHz
1
1
32kHz
Table 3 . De-emphasis filter control
Zero detection
After the input data at both channels are continuously zeros for 8192 LRCK cycles or when the muting
period exceeds 8192+1022 LRCK cycles, DZF goes to "H". DZF goes "L" immediately after non zero
data is input or soft mute is released.
Soft mute operation
When SMUTE goes "H", the output signal is attenuated into -∞ during 1022 LRCK cycles. SMUTE is
returned to "L", the mute condition is released and the output attenuation gradually changes to 0dB
during 1022 LRCK cycles. If the soft mute is released within 1022LRCK cycles, the attenuation is
recovered to 0dB with same gradient and cycles.
The soft mute function is effective when changing the signal source without stopping the signal
transmission.
Notes:
1
{
2
{
3
{
4
{
The output signal is attenuated into -∞ during 1022 LRCK cycles(1022/fs).
Analog output corresponding to digital input have the group delay(GD).
If the soft mute is released within 1022 LRCK cycles, the attenuation is recovered to 0dB.
When the input data at both channels are continuously zeros for 8192 LRCK cycles, DZF goes to
"H". DZF goes "L" immediately after non-zero data is input.
Figure 6 . Soft mute and zero detection
M0011-E-01
1998/6
- 11 -
ASAHI KASEI
[AK4319A]
Power-Down
The AK4319A are placed in the power-down mode by bringing PD pin "L" and the analog outputs are
floating(Hi-Z). Figure 7 shows an example of the system timing at the power-down and power-up.
1
{
2
{
3
{
4
{
5
{
Analog output has the group delay(GD).
When power-down is initiated, analog outputs are set into Hi-Z. Output noise level is about
-110dB.
Some -50dB of click noise occurs at the transition("↑↓") of PD pin.
When the master clock is stopped, the AK4319A should have been in the power-down mode.
3 )is a problem, an external mute circuit which generates above timing ({
5 )is
If the click noise({
needed. Please refer to Figure 7 .
Figure 7 . Power-down/up sequence example
System Reset
The AK4319A should be reset once by bringing PD "L" upon power-up. The AK4319A is powered up and
the internal timing starts clocking by LRCK "↑" after exiting reset and power down state by XTI. The
AK4319A is in power-down mode until LRCK is input.
External mute circuit
Some click noise may occur at the transition("↑↓") of PD signal. The click noise of PD signal can be
avoided by controlling the external mute circuit. The S/N of -110dB could be achieved by muting the
analog outputs using DZF signal.
M0011-E-01
1998/6
- 12 -
ASAHI KASEI
[AK4319A]
SYSTEM DESIGN
Figure 8 shows the system connection diagram. An example of external analog filter is shown in Figure 9 .
An evaluation board[AKD4319A] is available in order to allow an easy study on the layout of a
surrounding circuit.
Figure 8 . Typical Connection Diagram
Notes:
- Power lines of AVDD and DVDD should be distributed separately from the point with low
impedance of regulator etc.
- When AOUT drives some capacitive load, some resistor should be added in series between
AOUT and capacitive load.
- All input pins except internal pull-down pins should not be left floating.
1. Grounding and Power Supply Decoupling
To minimize coupling by digital noise, decoupling capacitors should be connected to AVDD and DVDD,
respectively. AVDD is supplied from analog supply in system and DVDD is supplied from AVDD as shown
in Figure 8 . Alternatively if AVDD and DVDD are supplied separately, AVDD and DVDD should be
powered at the same time or AVDD should be powered earlier than DVDD. Analog ground and digital
ground should be connected together near to where the supplies are brought onto the printed circuit
board. Decoupling capacitors for high frequency should be placed as near as possible.
M0011-E-01
1998/6
- 13 -
ASAHI KASEI
[AK4319A]
2. Voltage reference
The on-chip voltage reference is output on the VREF pin. An electrolytic capacitor smaller than 10uF in
parallel with a 0.1uF ceramic capacitor attached to this pin eliminates the effects of high frequency noise.
Especially, the ceramic capacitor should be connected to VREF pin within a few mm as near as possible.
No load current may be taken from the VREF output pin. All signals, especially clocks, should be kept
away from the VREF pin in order to avoid unwanted coupling into the AK4319A.
3. Analog Outputs
The analog signals are output from the differential output pins of each channel, therefore they are
summed externally. The analog outputs are the differential voltage,∆VAOUT=(AOUT+)-(AOUT-) between
AOUT+ and AOUT-. The bias voltage(Vop/2) for this summing circuit is supplied externally. The output
signal range is ±1.40V(0.99Vrms, typ) centered at an internal common voltage(AVDD/2). If the summing
gain is 1, the output range is ±2.80V (1.98Vrms, typ). The input data format is 2's complement. The
output voltage(∆VAOUT) is a positive full scale for 7FFFH(@16bit) and a negative full scale for
8000H(@16bit). The ideal ∆VAOUT is 0V for 0000H(@16bit).
DC offsets on analog outputs are eliminated by AC coupling the signals since DAC outputs have a few
mV offsets.
The noise generated by the delta-sigma modulator beyond the audio passband is sufficiently attenuated
by the high speed over-sampling and by the on-chip SCF filter. However, as the outband noise moves
into the audible band at low sampling rate, careful attention is required. On Figure 9 , the differential
outputs of AK4319A are summed by the
1st-order LPF and the 1.98Vrms output signal range is acquired.
Figure 9 . External LPF example
M0011-E-01
1998/6
- 14 -
ASAHI KASEI
[AK4319A]
4. Single-end usage
The load impedance for the output pin should be higher than 5kΩ. When the AK4319A drives some capacitive
load, series resistor(220ohm or more than) should be added the analog output and it should be connected to
the analog output pin as near as possible. The output pin which is not used could be left open. When the
AK4319A is used as a single-end configuration, the analog characteristics (such as THD+N, DR, S/N) may
degrade by 1dB.
For single-end operation, in the circuit example of Figure 9 , DC isolation capacitance is added between
AOUT- and 10kΩ. Then the 10kΩ resistor which is connected to AOUT+ is removed. In this case, the output
level becomes 0.99Vrms. With a single-end configuration, the AK4319A interfaces directly to external circuit
such as volume AMP, which simplifies the circuit.
Figure 10 shows a circuit example for single end operation. The series resistor should be connected to
the AOUT pin as near as possible. The operation mode setting in this circuit is as follows.
[Operation mode]
fs=44.1kHz
De-emphasis ON/OFF for fs=44.1kHz
Data format: Mode 0, 16bit LSB justified
BICK: 64fs
MCLK: 256fs
[Performancet example]
THD+N: -86dB
DR,S/N: 91dB
Figure 10 . System Connection External for single end operation
M0011-E-01
1998/6
- 15 -
ASAHI KASEI
[AK4319A]
PACKAGE
z 24pin SSOP (Unit: mm)
NOTE: Dimension “*” does not include mold flash.
Package & Lead frame material
Package molding compound:
Lead frame material:
Lead frame surface treatment:
M0011-E-01
Epoxy
Cu
Solder plate
1998/6
- 16 -
ASAHI KASEI
[AK4319A]
MARKING
Contents of AAXXXX
AA: Lot#
XXXX: Date Code
M0011-E-01
1998/6
- 17 -
IMPORTANT NOTICE
zThese products and their specifications are subject to change without notice. Before
considering any use or application, consult the Asahi Kasei Microsystems Co., Ltd. (AKM)
sales office or authorized distributor concerning their current status.
zAKM assumes no liability for infringement of any patent, intellectual property, or other
right in the application or use of any information contained herein.
zAny export of these products, or devices or systems containing them, may require an
export license or other official approval under the law and regulations of the country of
export pertaining to customs and tariffs, currency exchange, or strategic materials.
zAKM products are neither intended nor authorized for use as critical components in any
safety, life support, or other hazard related device or system, and AKM assumes no
responsibility relating to any such use, except with the express written consent of the
Representative Director of AKM. As used here:
(a) A hazard related device or system is one designed or intended for life support or
maintenance of safety or for applications in medicine, aerospace, nuclear energy, or
other fields, in which its failure to function or perform may reasonably be expected to
result in loss of life or in significant injury or damage to person or property.
(b) A critical component is one whose failure to function or perform may reasonably be
expected to result, whether directly or indirectly, in the loss of the safety or
effectiveness of the device or system containing it, and which must therefore meet
very high standards of performance and reliability.
zIt is the responsibility of the buyer or distributor of an AKM product who distributes,
disposes of, or otherwise places the product with a third party to notify that party in
advance of the above content and conditions, and the buyer or distributor agrees to
assume any and all responsibility and liability for and hold AKM harmless from any and
all claims arising from the use of said product in the absence of such notification.