Data Sheet

ASAHI KASEI
[AK4352]
AK4352
2V & Low Power Multi-Bit ∆Σ DAC
GENERAL DESCRIPTION
The AK4352 is an 18bit low voltage & power stereo DAC for digital audio system. The AK4352 uses the
new developed Multi-Bit ∆Σ architecture, this new architecture achieves DR=94dB at low voltage
operation. The AK4352 includes post filter with single-ended output and does not need any external parts.
The AK4352 is suitable for the portable audio system like MD, etc as low power and small package.
FEATURES
• Multi-Bit ∆Σ DAC
• Sampling Rate Ranging: 8kHz ∼ 50kHz
• On chip post filter
• On chip Buffer with Single-ended Output
• On chip Perfect filtering 8 times FIR interpolator
Passband: 20kHz
Passband Ripple: ± 0.06dB
Stopband Attenuation: 43dB
• Digital Audio I/F format: 2’s compliment, MSB first
18bit MSB justified, 16/18bit LSB justified, I2S
• Digital de-emphasis for 44.1kHz sampling
• Master clock: 256fs or 384fs
• THD+N: -83dB@2V, -89dB@3V
• D-Range: 94dB@2V, 96dB@3V
• Output Voltage: 1.10Vpp@2V
• Low Voltage Operation: 2V (1.8 ∼ 3.6V)
• Low power Dissipation: 6mW@2V
• Very Small Package: 16pin TSSOP
DIF0 DIF1
LRCK
BICK
SDATA
Serial Input
Interface
VCML
8X
Interpolator
∆Σ
Modulator
LPF
AOUTL
8X
Interpolator
∆Σ
Modulator
LPF
AOUTR
VDD
VSS
PD
De-emphasis
Control
DEM
Clock Divider
MCLK
M0040-E-02
CKS
VCMR
VREF
2000/11
-1-
ASAHI KASEI
[AK4352]
n Ordering Guide
-40 ∼ +85°C
Evaluation Board
AK4352VT
AKD4352
16pin TSSOP (0.65mm pitch)
n Pin Layout
MCLK
1
16
CKS
PD
2
15
VCML
BICK
3
14
AOUTL
SDATA
4
13
AOUTR
LRCK
5
12
VCMR
DIF0
6
11
VREF
DIF1
7
10
VDD
DEM
8
9
VSS
Top
View
PIN/FUNCTION
No.
1
Pin Name
MCLK
I/O
I
2
PD
I
3
BICK
I
4
SDATA
I
5
LRCK
I
6
7
DIF0
DIF1
I
I
8
DEM
I
9
10
VSS
VDD
-
11
VREF
I
12
13
14
15
VCMR
AOUTR
AOUTL
VCML
O
O
O
O
16
CKS
I
Function
Master Clock Pin
Power-Down Pin
When at “L”, the AK4352 is in power-down mode and is held in reset.
The AK4352 should always be reset upon power-up.
Serial Bit Input Clock Pin
This clock is used to latch audio data.
Audio Data Input Pin
L/R Clock Pin
This input determines which audio channel is currently being input on
SDATA
pin.
Digital Input Format Pin
These pins select one of four input modes.
De-emphasis Enable Pin
When at “H”, de-emphasis of fs=44.1kHz is enabled.
Ground Pin
Power Supply Pin
Reference Voltage Input Pin
Normally connected to VDD.
Rch Common Voltage Pin
Rch Analog Output Pin
Lch Analog Output Pin
Lch Common Voltage Pin
Master Clock Select Pin
“L”: 256fs “H”: 384fs
Note: All input pins should not be left floating.
M0040-E-02
2000/11
-2-
ASAHI KASEI
[AK4352]
ABSOLUTE MAXIMUM RATINGS
(VSS=0V;Note 1)
Parameter
Power Supply
Input Current, Any Pin Except Supplies
Input Voltage
Ambient Operating Temperature
Storage Temperature
Symbol
VDD
IIN
VIND
Ta
Tstg
min
-0.3
-0.3
-40
-65
max
4.6
±10
VDD+0.3
85
150
Units
V
mA
V
°C
°C
Note 1. All voltages with respect to ground.
WARNING: Operation at or beyond these limits may results in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
RECOMMENDED OPERATING CONDITIONS
(VSS=0V;Note 1)
Parameter
Power Supply
Voltage Reference
(Note 2)
Symbol
VDD
VREF
min
1.8
typ
2.0
-
max
3.6
VDD
Units
V
V
Note 1. All voltages with respect to ground.
Note 2. Analog output voltage scales with the voltage of VREF.
AOUT (typ.@0dB)=1.10Vpp*VREF/2.
*AKM assumes no responsibility for the usage beyond the conditions in this data sheet.
M0040-E-02
2000/11
-3-
ASAHI KASEI
[AK4352]
ANALOG CHARACTERISTICS
(Ta=25°C; VDD=2.0V, VREF=VDD; fs=44.1kHz; BICK=64fs; Signal Frequency=1kHz; 18bit Input Data;
Measurement frequency=10Hz ∼ 20kHz; RL ≥10kΩ; unless otherwise specified)
Parameter
min
typ
max
Units
(Note 3)
Dynamic Characteristics
THD+N
(0dB Output)
-83
-74
dB
Dynamic Range
(-60dB Output, A-weight)
88
94
dB
S/N
(A-weight)
88
94
dB
Interchannel Isolation
90
100
dB
DC Accuracy
Interchannel Gain Mismatch
0.1
0.5
dB
Gain Drift
60
ppm/°C
Output Voltage
(Note 4)
1.02
1.10
1.18
Vpp
Load Resistance
10
kΩ
Power Supplies
Power Supply Current
Normal Operation ( PD = “H”)
3.0
4.7
mA
(Note 5)
10
50
µA
(Note 5)
6.0
20
50
9.4
100
-
mW
µW
dB
VDD
Power-Down Mode ( PD = “L”)
VDD
Power Dissipation (VDD)
Normal Operation
Power-Down Mode
Power Supply Rejection
-
Note 3. Measured by AD725C (SHIBASOKU). Averaging mode.
In case of VDD=3.0V,
THD+N: -89dB
DR: 96dB (A-weight)
S/N: 97dB (A-weight)
Note 4. Full-scale voltage (0dB). Output voltage scales with the voltage of VREF.
AOUT (typ.@0dB)=1.10Vpp*VREF/2.
Note 5. In case of power-down mode, all digital input pins including clock pins (MCLK,BICK and LRCK) are held VDD
or VSS.
M0040-E-02
2000/11
-4-
ASAHI KASEI
[AK4352]
FILTER CHARACTERISTICS
(Ta=25°C; VDD=1.8 ∼ 3.6V; fs=44.1kHz; DEM= “L”)
Parameter
Symbol
min
typ
Digital filter
Passband
-0.1dB
(Note 6)
PB
0
-6.0dB
22.05
Stopband
(Note 6)
SB
24.1
Passband Ripple
PR
Stopband Attenuation
SA
43
Group Delay
(Note 7)
GD
14.7
Digital Filter + Analog Filter
Frequency Response 0 ∼ 20.0kHz
± 0.2
max
Units
20.0
-
-
kHz
kHz
kHz
dB
dB
1/fs
-
dB
± 0.06
Note 6. The passband and stopband frequencies scale with fs.
For example, PB=0.4535*fs(@-0.1dB), SB=0.546*fs(@-43dB).
Note 7. The calculating delay time which occurred by digital filtering. This time is from setting the 18bit data of both
channels to input register to the output of analog signal.
DIGITAL CHARACTERISTICS
(Ta=25°C; VDD=1.8 ∼ 3.6V)
Parameter
High-Level Input Voltage
Low-Level Input Voltage
Input Leakage Current
Symbol
VIH
VIL
Iin
M0040-E-02
min
75%VDD
-
typ
-
max
25%VDD
± 10
Units
V
V
µA
2000/11
-5-
ASAHI KASEI
[AK4352]
SWITCHING CHARACTERISTICS
(Ta=25°C; VDD=1.8 ∼ 3.6V)
Parameter
Symbol
min
typ
256fs:
fCLK
2.048
11.2896
Master Clock Timing
Pulse Width Low
tCLKL
28
Pulse Width High
tCLKH
28
384fs:
fCLK
3.072
16.9344
Pulse Width Low
tCLKL
23
Pulse Width High
tCLKH
23
fs
8
44.1
LRCK Frequency
(Note
8)
Serial Interface Timing
BICK Period
tBCK
312.5
BICK Pulse Width Low
tBCKL
100
Pulse Width High
tBCKH
100
BICK rising to LRCK Edge
(Note 9)
tBLR
50
LRCK Edge to BICK rising
(Note 9)
tLRB
50
SDATA Hold Time
tSDH
50
SDATA Setup Time
tSDS
50
Reset Timing
PD Pulse Width
(Note 10)
tRST
300
max
12.8
Units
MHz
ns
ns
MHz
ns
ns
kHz
19.2
50
ns
ns
ns
ns
ns
ns
ns
ns
Note 8. Refer to the operating overview section “Audio Data Interface”.
Note 9. BICK rising edge must not occur at the same time as LRCK edge.
Note 10. The AK4352 can be reset by bringing PD = “L” to “H” only upon power up.
n Timing Diagram
50%
VDD
LRCK
tBLR
tLRB
tBCKH
tBCKL
50%
VDD
BICK
tSDS
SDATA
tSDH
50%
VDD
LSB
Audio Data Input Timing
tRST
PD
25%VDD
Reset Timing
M0040-E-02
2000/11
-6-
ASAHI KASEI
[AK4352]
OPERATION OVERVIEW
n System Clock
The external clocks which are required to operate the AK4352 are MCLK (256fs/384fs) LRCK (fs), BICK (32fs ∼).
The master clock (MCLK) should be synchronized with LRCK but the phase is not critical. The frequency of MCLK
is determined by the sampling rate (LRCK) and CKS pin. Setting CKS= “L” selects an MCLK frequency of 256fs
while setting CKS= “H” selects 384fs. When the 384fs is selected, the internal master clock becomes
256fs(=384fs*2/3). Table 1 illustrates standard audio word rates and corresponding frequencies used in the AK4352.
All external clocks (MCLK, BICK and LRCK) should always be present whenever the AK4352 is in normal operation
mode ( PD = “H”). If these clocks are not provided, the AK4352 may draw excess current because the device utilizes
dynamic refreshed logic internally. If the external clocks are not present, the AK4352 should be in the power-down
mode( PD = “L”).
As the AK4352 includes the phase detection circuit for LRCK, the AK4352 adjusts the phase of LRCK automatically
when the synchronization is out of phase by changing the clock frequencies. Therefore, the reset is only needed for
power-up.
LRCK (fs)
32.0kHz
44.1kHz
48.0kHz
CKS= “L”: 256fs
8.1920MHz
11.2896MHz
12.2880MHz
MCLK
CKS= “H”: 384fs
12.2880MHz
16.9344MHz
18.4320MHz
BICK (64fs)
2.0480MHz
2.8224MHz
3.0720MHz
Table 1. Examples of System Clock
256fs or 384fs
MCLK
2/3
H
L
256fs
CKS
Figure 1. Internal Clock Circuit
M0040-E-02
2000/11
-7-
ASAHI KASEI
[AK4352]
n Audio Serial Interface Format
The AK4352 interfaces with external system by using SDATA, BICK and LRCK pins. Four types of data format are
available and one of them is selected by setting DIF0 and DIF1. Format 0 is compatible with existing 16bit DACs and
digital filters. Format 1 is an 18bit version of format 0. Format 2 is similar to AKM ADCs and many DSP serial ports.
Format 3 is compatible with the I 2S serial data protocol. In format 2 and 3, 16bit data followed by two zeros also could
be input. In all modes, the serial data is MSB first and 2’s complement format.
DIF1
0
0
1
1
DIF0
0
1
0
1
Mode
0: 16bit LSB Justified
1: 18bit LSB Justified
2: 18bit MSB Justified
3: I2S Compatible
BICK
≥32fs
≥36fs
≥36fs
≥32fs or 36fs
Figure
Figure 2
Figure 2
Figure 3
Figure 4
Table 2. Digital Input Formats
LRCK
Rch
Lch
BICK
SDATA
Mode 0
Don’t care
15
14
0
Don’t care
15
14
0
Don’t care
15
14
0
15
14
0
15:MSB, 0:LSB (@16bit Data)
SDATA
Mode 1
Don’t care
17
16
17:MSB, 0:LSB (@18bit Data)
17
16
*Mode 1: BICK needs 36fs or more than 36fs.
Figure 2. Mode 0,1 Timing
Rch
Lch
LRCK
BICK
SDATA
16bit
15
14
1
0
SDATA
18bit
17
16
3
2
1
0
Don’t
care
15
14
1
0
Don’t
care
17
16
3
2
1
0
Don’t
care
15
14
Don’t
care
17
16
* BICK needs 36fs or more than 36fs.
Figure 3. Mode 2 Timing
M0040-E-02
2000/11
-8-
ASAHI KASEI
[AK4352]
Lch
LRCK
Rch
BICK
SDATA
16bit
15
14
1
0
SDATA
18bit
17
16
3
2
1
0
Don’t
care
15
14
1
0
Don’t
care
17
16
3
2
1
0
Don’t
care
15
Don’t
care
17
* BICK needs 32fs or 36fs or more than 36fs.
Figure 4. Mode 3 Timing
n De-emphasis filter
The AK4352 includes the digital de-emphasis filter (tc=50/15µs) by IIR filter. This filter corresponds to 44.1kHz
sampling. The de-emphasis is enabled by setting DEM pin “H”.
n Power-down
The AK4352 is placed in the power-down mode by bringing PD pin “L” and the anlog outputs are floating(Hi-Z).
Figure 5 shows an example of the system timing at the power-down and power-up.
PD
Internal
State
Normal Operation
Power-down
D/A In
(Digital)
Normal Operation
“0”data
GD (1)
(3)
D/A Out
(Analog)
Clock In
(2)
(3)
(4)
MCLK,LRCK,BICK
External
Mute
GD (1)
(5)
Mute On
Figure 5. Power-down/up sequence example
Notes:
(1) Analog output corresponding to digital input have the group delay (GD).
(2) Analog outputs are floating(Hi-Z) at the power-down mode.
(3) Click noise occures at the edges(“↑ ↓”) of the falling edge of PD signal.
(4) When the external clocks(MCLK,BICK,LRCK) are stopped, the AK4352 should be in the power-down
mode.
(5) Please mute the analog output externally if the click noise(3) influences system application.
The timing example is shown in this figure.
M0040-E-02
2000/11
-9-
ASAHI KASEI
[AK4352]
n System Reset
The AK4352 should be reset once by bringing PD = “L” upon power-up. The internal timing starts clocking by
LRCK “↑” upon exiting reset.
SYSTEM DESIGN
Figure 6 shows the system connection diagram. An evaluation board [AKD4352] is available in order to allow an easy
study on the layout of a surrounding circuit.
External
Clock
Reset
Audio
Data
Processor
Mode
Setting
System Ground
CKS
16
PD
VCML
15
3
BICK
AOUTL
14
4
SDATA
AOUTR
13
5
LRCK
VCMR
12
6
DIF0
VREF
11
7
DIF1
VDD
10
8
DEM
VSS
9
1
MCLK
2
AK4352
Top View
+
10µ
10µ
+
Lch
Out
+
Rch
Out
+
+
0.1µ 10µ
Analog 2V
Analog Ground
Figure 6. Typical Connection Diagram
Notes:
- LRCK = fs, BICK ≥ 32fs or 36fs, MCLK = 256fs/384fs.
- When AOUT drives some capacitive load, some resistor should be added in series between AOUT and capacitive
load.
M0040-E-02
2000/11
- 10 -
ASAHI KASEI
[AK4352]
1. Grounding and Power Supply Decoupling
Figure 6 shows the power supply connection example. VDD is supplied from analog supply in system. Decoupling
capacitors for high frequency should be as near to the AK4352 device as possible, with the low value ceramic capacitor
between VREF and VSS being the nearest.
2. Voltage Reference
The differential Voltage between VREF and VSS sets the analog output range. VREF pin is normally connected to VDD.
An electrolytic capacitor 10µF parallel with a 0.1µF ceramic capacitor are attached between VREF and VSS pins. VCML
and VCMR pins are a signal ground of this chip. An electrolytic capacitor less than 10µF parallel with a 0.1µF ceramic
capacitor attached between VCML, VCMR pins and VSS eliminates the effects of high frequency noise. Especially, the
ceramic capacitor should be connected to these pins as near as possible.
No load current may be drawn from VCML and VCMR pins. All signals, especially clocks, should be kept away from the
VREF, VCML and VCMR pins in order to avoid unwanted coupling into the AK4352.
3. Analog Outputs
The analog outputs are single-ended and centered around the VCML, VCMR voltage. The output signal range is typically
1.10Vpp. If the noise generated by the delta-sigma modulator beyond the audio band would be the problem, the
attenuation by external filter is required. The output voltage is a positive full scale for 7FFFH(@16bit) and a negative full
scale for 8000H(@16bit). The ideal output is VCML, VCMR voltage for 0000H(@16bit).
DC offsets on analog outputs are eliminated by AC coupling since analog outputs have DC offsets of VCML, VCMR
voltage + a few mV.
M0040-E-02
2000/11
- 11 -
ASAHI KASEI
[AK4352]
PACKAGE
16pin TSSOP (Unit: mm)
*5.0
1.10max
16
9
*4.4
6.4±0.2
A
8
1
0.22±0.1
0.65
0.17±0.05
0.1±0.1
| 0.10
1.0
Seating Plane
0.5±0.2
Detail A
NOTE: Dimension "*" does not include mold flash.
0-10°
n Package & Lead frame material
Package molding compound:
Lead frame material:
Lead frame surface treatment:
Epoxy
Cu
Solder plate
M0040-E-02
2000/11
- 12 -
ASAHI KASEI
[AK4352]
MARKING
AKM
4352VT
XXYYY
Contents of XXYYY
XX:
Lot#
YYY: Date Code
IMPORTANT NOTICE
• These 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.
• AKM assumes no liability for infringement of any patent, intellectual property, or other right in the
application or use of any information contained herein.
• Any 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.
• AKM 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.
• It 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.
M0040-E-02
2000/11
- 13 -