AKM AK4201

CONFIDENTIAL
[AK4201]
= Preliminary =
AK4201
Stereo Cap-less HP-Amp
GENERAL DESCRIPTION
The AK4201 is an audio stereo cap-less headphone amplifier. The AK4201 eliminates the need for large
DC-blocking capacitors with a built-in Charge-pump circuit. The PSRR (Power supply Rejection Ratio)
can achieve to 100dB with a built-in regulator, and it can output 2Vrms with excellent linearity when used
as lineout amplifier. The AK4201 is available in tiny 12-pin USON (2.2 X 2.9mm), saving board space,
cost, and component height.
FEATURE
† Stereo Cap-less Amplifier (No DC-blocking capacitors required)
† High PSRR (100dB at 217Hz)
† Output Power:
65 mW x 2ch @ 16Ω, AVDD=PVDD=5.0V, THD+N=-40dB
30 mW x 2ch @ 16Ω, AVDD=PVDD=3.3V, THD+N=-40dB
† Output Noise Level: 11µVrms (Ri=20kΩ, Rf=30kΩ)
† Line-Out level:
2.0Vrms @ 5kΩ, AVDD=PVDD=5.0V
2.0Vrms @ 5kΩ, AVDD=PVDD=3.3V
† Regulator built-in
† THD+N:
-60 dB @ 16Ω, 50mW, AVDD=PVDD=5.0V
-60 dB @ 16Ω, 20mW, AVDD=PVDD=3.3V
-90 dB @ 5kΩ, 2Vrms, AVDD=PVDD=5.0V
-90 dB @ 5kΩ, 2Vrms, AVDD=PVDD=3.3V
† Low Power Shutdown Mode
0.1µA (typ)
† Adjustable Gain Range:
-16 dB ~ 16dB
† Pop noise free at power-ON/OFF
† Power Supply: 2.6V ~ 3.6V or 4.5V ~ 5.5V
† Ta: −40 ∼ 85°C
† Package: 12pin USON (2.2 x 2.9mm, 0.5mm pitch)
Rev 0.2
2008/07
-1-
CONFIDENTIAL
[AK4201]
■ Block Diagram
Rf
AVDD
Ci
Ri
Regulator
Amp
LIN
LOUT
AK4201
VSS2
Regulator
Ci
Ri
ROUT
RIN
Amp
Charge
Pump
PVDD
PDN
VSS1 CP
CN
PVEE
Rf
Figure 1. AK4201 Block Diagram
Rev 0.2
2008/07
-2-
CONFIDENTIAL
[AK4201]
■ Ordering Guide
AK4201EU
AKD4201
−40 ∼ +85°C
12pin USON (2.2mm x 2.9mm, 0.5mm pitch)
Evaluation board for AK4201
■ Pin Layout
LIN
1
LOUT
2
Top
View
12
RIN
11
ROUT
10
PVEE
AVDD
3
VSS1
4
9
VSS2
PVDD
5
8
PDN
CN
6
7
CP
Rev 0.2
2008/07
-3-
CONFIDENTIAL
[AK4201]
PIN/FUNCTION
No.
1
2
3
4
5
6
7
8
Pin Name
LIN
LOUT
AVDD
VSS1
PVDD
CN
CP
PDN
I/O
I
O
O
O
I
9
VSS2
10
PVEE
O
11
ROUT
O
12
RIN
I
Note. PDN pin should not be floated.
Function
L-channel analog input
L-channel analog output
Headphone positive power supply pin, 2.6V ~ 5.5V
Power ground
Charge-pump positive power supply pin, 2.6V ~ 5.5V
Negative charge-pump capacitor terminal pin
Positive charge-pump capacitor terminal pin
Power-down mode pin
“H”: Power-up, “L”: Power-down
Signal ground; connect to VSS1
Charge-pump circuit negative voltage output pin
R-channel analog output
R-channel analog input
■ Handling of Unused Pin
The unused I/O pins should be processed appropriately as below.
Classification
Pin Name
Analog
LIN, RIN, LOUT, ROUT
Setting
Connect Output pin to Input pin when one channel
is used and the other is not used.
(Example) Connect the LOUT pin to the LIN pin if
Lch is not used.
Rev 0.2
2008/07
-4-
CONFIDENTIAL
[AK4201]
ABSOLUTE MAXIMUM RATING
(VSS1=VSS2 =0V (Note 1))
Parameter
Symbol
min
Power Supplies:
Analog
AVDD
−0.3
(Note 2)
Charge Pump
PVDD
−0.3
Input Current, Any Pin Except Supplies
IIN
Input Voltage (Note 3)
VIN
−0.3
Ambient Temperature (powered applied)
Ta
−40
Storage Temperature
Tstg
−65
Maximum Power Dissipation (Note 4)
Pd
-
max
6.0
6.0
±10
(AVDD + 0.3) or 6.0
85
150
TBD
Units
V
V
mA
V
°C
°C
W
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
RECOMMEND OPERATING CONDITIONS
(VSS1=VSS2 =0V (Note 1))
Parameter
Symbol
min
Analog
4.5
AVDD, PVDD
Power
Charge Pump
2.6
Supplies (Note 5)
Difference
-0.3
AVDD − PVDD
Parameter
External Input Resistance
External Feedback Resistance
Load
Resistance (LOUT, ROUT pins)
Capacitance (LOUT, ROUT pins)
Capacitance (LIN, RIN pins)
typ
5.0
3.3
0
max
5.5
3.6
0.3
Units
V
V
Symbol
Ri
Rf
min
10
10
typ
-
max
100
100
Units
kΩ
kΩ
RL
CL
Csum
16
-
-
300
20
Ω
pF
pF
Note 1. All voltages are respect to ground.
Note 2. VSS1 and VSS2 must be connected to the same analog plane.
Note 3. LIN, RIN, PDN pin
The maximum value is low value either (AVDD+0.3) V or 6.0V.
Note 4. 2ch Output Power (Po, when load is 16Ω) should be less TBD W.
Note 5. The power up sequence among AVDD, PVDD is not critical. The PDN pin should be held to “L” when
powered-up. The PDN pin should be set to “H” after all power supplies are powered-up. The PDN pin should be
held to “L”, when powered-down. Operation by the power-supply voltage from 3.6 to 4.5V is prohibited.
Note: AKEMD assumes no responsibility for the usage beyond the conditions in this datasheet.
Rev 0.2
2008/07
-5-
CONFIDENTIAL
[AK4201]
ANALOG CHARACTERISTICS (AVDD=PVDD=5.0V)
(AVDD=PVDD=5.0V; PDN=5.0V; Ta=25ºC; VSS1=VSS2=0V; Input Signal Frequency =1kHz; Measurement band
width=10Hz ∼ 20kHz; Gain=+3.5dB (Ri=20kΩ, Rf=30kΩ); Headphone-Amp: RL =16Ω; Charge Pump Circuit External
Capacitance: C1=C2= 1μF (Figure 3), unless otherwise specified)
Parameter
min
typ
max
Units
Output Power
65
mW
RL =16Ω, 0.68Vrms Input
THD+N
TBD
dB
−40
0.68Vrms Input; Po = 65mW @ RL =16Ω
TBD
dB
−60
0.60Vrms Input; Po = 50mW @ RL =16Ω
TBD
dB
1.33Vrms Input; Vo = 2.0Vrms @ RL =5kΩ
−90
S/N (Signal-to-Noise Ratio)
TBD
102
dB
RL =16Ω (A-weighted) (Note 6)
TBD
108
dB
RL =5kΩ (A-weighted) (Note 7)
PSRR (Power Supply Rejection Ratio) (Note 8)
217Hz
100
dB
1kHz
90
dB
Interchannel Isolation
60
80
dB
RL =16Ω
80
dB
RL =5kΩ
±0.5
±5.0
mV
Output Offset Voltage
50
ms
Start-up time (Note 9)
Power Supplies
4
TBD
mA
AVDD + PVDD (Normal Mode; No Output)
0.1
TBD
uA
AVDD + PVDD (Power-Down Mode, PDN =0V)
Note 6. In case of 0.68Vrms Input (Po=65mW).
Note 7. In case of 1.33Vrms Input (Vo=2Vrms).
Note 8. PSR is applied to AVDD and PVDD with 500mVpp sine wave.
Note 9. The time from PDN pin= “H” to when the AK4201 can output the data.
Rev 0.2
2008/07
-6-
CONFIDENTIAL
[AK4201]
ANALOG CHARACTERISTICS (AVDD=PVDD=3.3V)
(AVDD=PVDD=3.3V; PDN=3.3V; Ta=25ºC; VSS1=VSS2=0V; Input Signal Frequency =1kHz; Measurement band
width=10Hz ∼ 20kHz; Gain=+3.5dB (Ri=20kΩ, Rf=30kΩ); Headphone-Amp: RL =16Ω; Charge Pump Circuit External
Capacitance: C1=C2= 1μF (Figure 3), unless otherwise specified)
Parameter
min
typ
max
Units
Output Power
30
mW
RL =16Ω, 0.46Vrms Input
THD+N
-40
TBD
dB
0.46Vrms Input; Po = 30mW @ RL =16Ω
-60
TBD
dB
0.27Vrms Input; Po = 10mW @ RL =16Ω
-90
TBD
dB
1.33Vrms Input; Vo = 2.0Vrms @ RL =5kΩ
S/N (Signal-to-Noise Ratio)
92
98
dB
RL =16Ω (A-weighted) (Note 10)
100
106
dB
RL =5kΩ (A-weighted) (Note 11)
PSRR (Power Supply Rejection Ratio) (Note 12)
217Hz
70
dB
1kHz
70
dB
Interchannel Isolation
60
80
dB
RL =16Ω
80
dB
RL =5kΩ
mV
Output Offset Voltage
±0.5
±5.0
50
ms
Start-up time (Note 13)
Power Supplies
4
TBD
mA
AVDD + PVDD (Normal Mode; No Output)
0.1
TBD
AVDD + PVDD (Power-Down Mode, PDN =0V)
μA
Note 10. In case of 0.46Vrms Input (Po=30mW).
Note 11. In case of 1.33Vrms Input (Vo=2Vrms).
Note 12. PSR is applied to AVDD and PVDD with 100mVpp sine wave.
Note 13. The time from PDN pin= “H” to when the AK4201 can output the data.
Rev 0.2
2008/07
-7-
CONFIDENTIAL
DC & SWITCHING CHARACTERISTICS
(Ta= -40 ∼ 85°C; AVDD=PVDD=2.6 ∼ 3.6V or 4.5 ∼ 5.5V, Note 14)
Parameter
Symbol
min
High-Level Input Voltage
VIH
1.5
Low-Level Input Voltage
VIL
Input Leakage Current
Iin
Power-down (PDN pulse Width)
tPD
150
Note 14. Apply to the PDN pin.
[AK4201]
typ
-
max
0.5
±2
-
Units
V
V
μA
ns
■ Timing Diagram
tPD
VIH
PDN
VIL
Figure 2. Power-down Timing
Rev 0.2
2008/07
-8-
CONFIDENTIAL
[AK4201]
OPERATION OVERVIEW
■ Charge Pump Circuit
The charge pump operates by the output of a regulator which uses PVDD voltage. The negative power supply (PVEE) for
headphone amplifiers is generated from internal charge pump circuit. The external capacitors are showed in Figure 3.
Low ESR (Equivalent Series Resistance) capacitors (more than –35% difference including temperature characteristics
and piece to piece variations) are recommended for C1 and C2.
Headphone-amp negative voltage
PVEE pin
C1: 1uF
CN pin
VSS1
Charge Pump Circuit
C2: 1uF
CP pin
Figure 3. Charge Pump Circuit External Capacitor
■ Headphone-Amp (LOUT/ROUT pins)
Power supply voltage for headphone amplifiers is supplied by a regulator for positive power and a charge-pump for
negative power. The positive power supply for Charge pump is generated from the output of a regulator which is driven
by PVDD. The headphone amplifier output is single-ended and centered on VSS1(0V). Therefore, a capacitor for
AC-coupling can be removed. The minimum load resistance is 16Ω. The output impedance is 20Ω (typ) when
powered-down.
Rev 0.2
2008/07
-9-
CONFIDENTIAL
[AK4201]
■ Power-Up/Down Sequence
The PDN pin must keep “L” until all power supply pins (AVDD, PVDD) are supplied, and must be set to “H” after all
powers are supplied.
Power Supply
(1)
Former Device
DAC etc
Power Up
(No Signal Output)
Don’t Care
Ta
(2)
Former Device
Click noise
Normal Operation
Don’t Care
(4)
A
0V
PDN pin
0V
PVEE pin
HPL/HPR pins
(5)
(3)
0V
PVEE pin Output =-3.3V(Typ.)
0V
Normal Operation(0V Common)
0V
Figure 4. Power-up/down Sequence example
(1) The interval from power Up to PDN pin = “L” → “H”
“L” time of 150ns or more is needed to reset the AK4201.
The power should be ON in state of the PDN pin = “L”. The PDN pin should be set to “H” after power supply
(AVDD, PVDD) are ON.
(2) The interval from former device of the AK4201(DAC etc) power up to the PDN pin = “L” → “H”
The former device of the AK4201 should be powered up with no output (MUTE). When step wave which generated
by former device is output (an instant change of DC offset), HPF response wave will occur at “A” period of the
Figure 4, according to the AK4201 input coupling condenser (Ci) and input resistor (Ri). In order to avoid click
noise, “Ta” wait time is needed after former device output.
Ta calculation example: (in the case of Ci =0.22uF, Ri = 20kΩ)
τ=0.22u * 20k = 4.4ms
Ta =τ* 7.6 = 33ms
(When noise level by former device= 2V, response wave level= 1mV. 7.6*τ is needed)
If waiting time is not sufficient, click noise maybe occur, but no problem for later working.
(3) 50ms (max.) later, after the PDN pin went to “H”, the AK4201 will be in normal operation mode and click noise is
decreased. In this interval (50ms), the former device should be MUTE.
(4) The former device should starts outputting the signal after the AK4201 starts Normal Operation. If click noise is
generated by former device when MUTE is canceled, it will be output from the AK4201.
(5) The PDN pin = “L”. LOUT/ROUT pins short to VSS1 with 20Ω(typ.). After 50ms (max.), the PVEE pin will be 0V
according to a capacitor which connected to PVEE and internal resistance (typ. 17.5kΩ). The AK4201 can be
powered up again after 150ns or more from the PDN = “L”.
Rev 0.2
2008/07
- 10 -
CONFIDENTIAL
[AK4201]
SYSTEM DESIGN
Ci
Analog Input
Power Supply
4.5∼5.5V,
2.6∼3.6V
0.22µ
Ri
20kΩ
+
10µ
10µ
+
Power Supply
4.5∼5.5V,
2.6∼3.6V
Ri
Top View
1 LIN
RIN 12
Rf
30kΩ
20kΩ
Rf
30kΩ
2 LOUT
ROUT 11
3 AVDD
PVEE 10
4 VSS1
VSS2 9
5 PVDD
PDN 8
0.1µ
Ci
0.22µ Analog Input
1µ
(+)
0.1µ
6 CN
DSP or μP
CP 7
1µ
(+)
Note:
1.
The PDN pin should be held to “L” when powered-up. The PDN pin should be set to “H” after all power supplies are
powered-up. When power-down the AK4201, the PDN pin should be held to “L”.
Refer to “Power-Up/Down Sequence” to avoid pop noise when power-up/down the AK4201.
1) Power-Up
The power should be ON when the PDN pin = “L”. The PDN pin should be set to “H” 150ns after all power supplies
(AVDD, PVDD) are ON. 150ns “L” time or more is needed to reset the AK4201.
2) Power-Down
The AK4201 should be powered-down when the PDN pin = “L”.
2. 1uF~2.2uF ceramic capacitors (±35% including temperature characteristics and piece-to-piece variations)should be
connected to between the Cp and Cn pins, and the VSS1 and PVEE1 pins.
3. Both lines from the LIN pin and RIN pin to each Input resistance Ri and feedback resistance Rf should be short as
possible.
4. A capacitor should be connected to the each LIN and RIN pin for AC coupling.
Rev 0.2
2008/07
- 11 -
CONFIDENTIAL
[AK4201]
PACKAGE
12pin USON (2.2mm x 2.9mm, 0.5mm pitch)
= Preliminary =
0.25 ± 0.05
0.05
M
0.6MAX
0.08 ± 0.05
0.175 ± 0.05
2.6 ± 0.05
1.35 ± 0.05
2.2 ± 0.05
2.2 ± 0.05
0.5
0.225 ± 0.05
2.9 ± 0.05
2.9± 0.05
Rev 0.2
2008/07
- 12 -
CONFIDENTIAL
[AK4201]
MARKING
4201
XXXX
1
XXXX: Date code (4 digit)
IMPORTANT NOTICE
z These products and their specifications are subject to change without notice.
When you consider any use or application of these products, please make inquiries the sales office of Asahi Kasei
EMD Corporation (AKEMD) or authorized distributors as to current status of the products.
z AKEMD assumes no liability for infringement of any patent, intellectual property, or other rights in the application or
use of any information contained herein.
z 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.
z AKEMD products are neither intended nor authorized for use as critical componentsNote1) in any safety, life support, or
other hazard related device or systemNote2), and AKEMD assumes no responsibility for such use, except for the use
approved with the express written consent by Representative Director of AKEMD. As used here:
Note1) 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.
Note2) 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.
z It is the responsibility of the buyer or distributor of AKEMD products, who distributes, disposes of, or otherwise
places the product with a third party, to notify such third 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 AKEMD harmless from any
and all claims arising from the use of said product in the absence of such notification.
Rev 0.2
2008/07
- 13 -