ETC BA20861

2W Stereo Class-D Audio
Power Amplifier with Two Selectable
Gain Settings and MUX Control
BA20861
Data Sheet
Rev.1.0, 2009.04.22
Biforst Technology Inc.
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
2W Stereo Class-D Audio Power Amplifier with Two Selectable
Gain Settings and MUX Control
BA20861
GENERAL DESCRIPTION
The BA20861 is a 5V class-D amplifier from Biforst Technology. BA20861 provides DC volume
control with two selectable gain curve, lower supply current, high efficiency, and few external
components for driving speaker directly. BA20861 also integrates Anti-Pop, Output Short & Over-Heat
protection circuitry to increase device reliability. An Internal MUX allows two sets of stereo input to the
amplifier. The HP /LINE pin allows user to control which MUX input is active. The functionality makes
this device ideal for Portable DVD/CD Player, Photo Frame and other applications that demand on
battery life.
FEATURE
2.3W Per Channel Into 4-Ω Speakers (THD+N = 10%@5V)
Operation Voltage From 3.3 To 5.5V
DC Volume Control with Two Gain Curve Selection
Low Shutdown Control : <10µA
Low Noise Floor, -80dBV
Maximum Efficiency into 4-Ω, 84%
Maximum Efficiency into 8-Ω, 87%
PSRR, -70dB
Embedded Two Sets of Stereo Input MUX
Filter Free PWM Output Technology without LC Output Filter
Integrated Anti-Pop Circuitry
Integrated Output Short Protection Circuitry
Integrated Over-Heat Protection Circuitry
Provide DC Volume Control
Package Type: TQFN24
APPLICATION
Photo Frame
Portable DVD/CD Players
PDA
Battery Powered Application
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Page 1 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
FUNCTION BLOCK DIAGRAM
VDD VDD VDD VDD
RLINEIN
RHPIN
R
MUX
Gain
Adj.
PVDD_A
Driver
ROUTN
PVSS_A
PVDD_A
Driver
Gain
Adj.
RIN
ROUTP
PVSS_A
HP/LINE
BYPASS
SHUTDOWN_B
GAIN
Volume
Control
Baises &
References
Clock
Generator
Protection
Circuit
VOLUME
COSC
ROSC
LLINEIN
LHPIN
L
MUX
Gain
Adj.
PVDD_A
Driver
LOUTP
PVSS_A
PVDD_A
Driver
LIN
Gain
Adj.
LOUTN
PVSS_A
VSS VSS VSS VSS
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Page 2 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
These device 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.
ABSOLUTE MAXIMUM RATINGS (Note 1)
SYMBOL
PARAMETER
VALUE
UNIT
VDD, PVDD_A
Supply Voltage Range
-0.3 to 6
V
Input Voltage Range
0 to VDD
V
Input Voltage Range
0 to VDD
V
Operating Free-Air Temperature Range
-40 ~ +85
o
VI
(RLINEIN, RHPIN, RIN,
LLINEIN, LHPIN, LIN)
VI
(VOLUME)
TA
C
TJ
Operating Junction Temperature Range
-40 to 150
o
TSTG
Storage Temperature Range
-65 to 85
o
C
C
Note 1: Stress beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
Exposure to absolute-maximum-rating conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
SYMBOL
VDD,
SPECIFICATION
PARAMETER
MIN
TYP
MAX
UNIT
Supply Voltage
3.3
5.5
V
Volume Terminal Voltage
0
VDD
V
VIH
Input High Voltage (SHUTDOWN_B)
2.0
VIL
Input Low Voltage (SHUTDOWN_B)
FPWM
PWM Frequency
TA
Operating Free-Air Temperature
TJ
Operating Junction Temperature
PVDD_A
V
0.8
V
200
320
KHz
-40
85
o
125
o
C
C
ELECTRICAL CHARACTERISTICS (TA=25℃, VDD=PVDD_A =5V; unless otherwise specified)
SYMBOL
| VOS |
PSRR
PARAMETER
TEST CONDITIONS
Output Offset Voltage
VI = 0V, AV = 20dB,
(Measured Differentially)
RL = 8Ω
Power supply rejection ratio
SPECIFICATION
MIN
VDD=PVDD_A =
4.5V to 5.5V
TYP
MAX
15
25
-70
UNIT
mV
dB
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Page 3 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
ELECTRICAL CHARACTERISTICS (TA=25℃, VDD=PVDD_A =5V; unless otherwise specified)
SYMBOL
PARAMETER
｜I ｜
High-level input current
｜I ｜
IL
Low -level input current
IDD
Supply Current
No Filter (No Load)
RMS Supply Current
RL = 3Ω, PO =
At Max Power
2.5W/Channel (Stereo)
IH
IDD(MAX)
IDD(SD)
rds(on)
TEST CONDITIONS
VDD=PVDD_A =5.5V,
VI = VDD=PVDD_A =0V
VDD=PVDD_A =5.5V,
VI = 0V
Supply Current
VDD = 5V,
Drain-Source On-State
℃
TJ = 25
Maximum Output
Power Bandwidth
SNR
Signal-to-Noise Rate
TTP
Thermal Trip Point
TH
Thermal Hystersis
Vn
Integrated Noise
Floor
20
mA
A
10
High Side
500
650
Low Side
500
650
uA
m
Ω
L
TEST CONDITIONS
SPECIFICATION
MIN
TYP
MAX
UNIT
2
W
THD+N = 10%
2.5
W
F = 1KHz, RL = 4Ω, THD+N = 1%
1.8
W
THD+N = 10%
2.3
W
F = 1KHz, RL = 8Ω, THD+N = 1%
1.2
W
1.5
W
Stereo Operation
THD+N = 10%
Total Harmonic
PO = 1.5W, f= 20Hz to 20KHz
Distortion Plus Noise
BOM
uA
℃, VDD=PVDD_A =5V; R =4ΩΩ;unless otherwise specified)
Stereo Operation
THD+N
1
1
(TA=25
Stereo Operation
Output Power
uA
1.8
F = 1KHz, RL = 3Ω, THD+N = 1%
PO
UNIT
1
IO=500mA,
Resistance
PARAMETER
10
SHUTDOWN_B = 0V
In Shutdown Mode
OPERATING CHARACTERISTICS
SYMBOL
SPECIFICATION
THD = 10%
Maximum Output at
THD+N < 0.5%
20Hz to 20KHz, Input AC
Grounded
<0.9%
20
KHz
93
dB
150
o
20
o
49
92
C
C
uVrms
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Page 4 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
PIN ASSIGNMENTS
N
T
U
O
R
PVSSR
VSS
VDD
RHPIN
RIN
BYPASS
19
20
21
22
23
24
P
T
U
O
R
R
D
D
V
P
L
D
D
V
P
P
T
U
O
L
N
T
U
O
L
8
1
1 7
1 6
1 5
1 4
1 3
12
Class-D Amplifier 11
10
BA20861
9
(TQFN24PIN)
8
7
1 2 3 4 5 6
B
_
N
W
O
D
T
U
H
S
N
I
E
N
IL
R
E
N
IL
_P
H
N
I
A
G
N
I
E
IN
L
L
PVSSL
VDD
LHPIN
LIN
ROSC
VOLUME
C
S
O
C
PIN LIST & DESCRIPTION
Pin No.
Pin
I/O Pad Function
Type
1
SHUTDOWN_B
Input
2
RLINEIN
Input
3
HP _LINE
4
GAIN
Input
5
LLINEIN
Input
6
COSC
Input
7
VOLUME
Input
8
ROSC
Input
9
LIN
Input
Shut down control for BA20861, Logic low is placed on this pin for
shut-down mode, Logic high is placed on this pin for normal operation
HP /LINE is the MUX control input. When the HP /LINE pin is held high,
the line inputs (LLINEIN[5] and RLINEIN[2]) are active. When the
HP /LINE pin is held low, the line inputs (LHPIN[10] and RHPIN[22]) are
active.
Gain Curve Selection Input
10
LHPIN
Input
Left channel line input. Selected when HP /LINE is held high
A capacitor connected to this pin sets the oscillation in conjunction with
COSC. For proper operation, connect a 220-pF capacitor from COSC to
ground
DC volume control for setting internal amplifier gain. Range can be 0 to
VDD
A resistor connected to this pin sets the oscillation in conjunction with
ROSC. For proper operation, connect a 120-kΩ resistor from ROSC to
ground
Common left input for fully differential input. AC ground for single-ended
inputs
Left channel headphone input. Selected when HP /LINE is held low
11
VDD
Power
5V power supply
12
P_VSSA
Power
5V ground for speaker driver
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Page 5 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
PIN LIST & DESCRIPTION (Cont.)
Power
5V power supply for speaker driver
ROUTP
Output
Right channel positive output
18
ROUTN
Output
Right channel negative output
19
PVSS_A
Power
5V ground for speaker driver
20
VSS
Power
5V ground for speaker driver
21
VDD
Power
5V power supply for speaker driver
22
RHPIN
Input
Right channel headphone input. Selected when HP /LINE is held low
23
RIN
Input
24
BYPASS
Input
15 ~ 16 PVDD_A
17
Common right input for fully differential input. AC ground for single-ended
inputs
Connect a 1µF to 10µF capacitor from BYPASS to ground for internal
bias reference
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Page 6 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
FUNCTION DESCRIPTION
Output Power Efficiency
The output transistors of BA20861 act as switches. The amount of power dissipated in the
speaker may be estimated by first considering the overall efficiency of the system. If the on-resistance
of the output transistors is considered to cause the dominant loss in the system, the on-resistance of
output transistors is small that the power loss is small and the power efficiency is high. When BA20861
is with 8-ohm load, the power efficiency can be better than 87%.
Shutdown Mode
The BA20861 provides a shutdown mode for reduce supply current to the absolute minimum level
during periods of non-use for battery-power conservation. The SHUTDOWN_B input pin should be
held high during normal operation when the amplifier is in use. Pulling SHUTDOWN_B low causes the
outputs to mute and the amplifier to enter a low-current state. SHUTDOWN_B should never be left
unconnected because the amplifier state would be unpredictable.
Input MUX Operation
The BA20861 offers the capability for the designer to use separate headphone input (RHPIN,
LHPIN) and line inputs (RLINEIN, LLINEIN). The inputs can be different if the input signal-ended. If
using a differential input signal, the inputs must be the same because the inputs share a common RIN,
LIN. If using the BA20861 with a single-ended input, the RIN and LIN pins must be tied through a
capacitor to ground as show in Figure 1. RIN and LIN must not be tied to bypass or an offset occurs on
the output causing the device to pop when turning on. It is recommended RLINEIN [2], LLINEIN[5],
RHPIN[22], and LHPIN[10] four input pins, and each pin must connect 10MΩ resistor to VDD and
connect from 10MΩ resistor to ground.
The HP /LINE pin allows user to control which MUX input is active. HP /LINE pin is the MUX
control input. When the HP /LINE pin is held high, the line inputs (LLINEIN[5] and RLINEIN[2]) are
active. When the HP /LINE pin is held low, the line inputs (LHPIN[10] and RHPIN[22]) are active.
Table 1 list the configuration of HP /LINE pin.
Table 1. HP / LINE Configuration List
HP / LINE
Input Path Select
L
LHPIN[10] and RHPIN[22]
H
LLINEIN[5] and RLINEIN[2]
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Page 7 of 27
BA20861
Right Line-In
Input Signal
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
VDD
CLINEIN
0.1uF 10ΜΩ
10ΜΩ
VDD
CHPIN
0.1uF 10ΜΩ
Right Headphone-In
Input Signal
VDD VDD VDD VDD
RLINEIN
RHPIN
R
MUX
Gain
Adj.
PVDD_A
Driver
PVSS_A
10ΜΩ
PVDD_A
RIN
CRIN
0.1uF
ROUTN
Driver
Gain
Adj.
ROUTP
PVSS_A
HP/LINE
Figure 1. BA20861 Input MUX Operation Example
Volume Control & GAIN Control
The VOLUME pin controls the volume of the BA20861. It is controlled with a dc voltage, which
should not exceed VDD. BA20861 provide two gain curve for volume control that is controlled by GAIN
pin. Table 2 lists the voltage on the VOLUME pin and the corresponding gain when GAIN set in low.
Table 3 lists the voltage on the VOLUME pin and the corresponding gain when GAIN set in high. It is
recommended two type of volume control for BA20861.
Case 1 : Fix gain curve & control by VOLUME pin :
Select one gain curve that is selected by GAIN pin. The volume control circuitry of the
BA20861 is internally referenced to the VDD and 0V. Any common-mode noise between
the VOLUME pin and these pins will be sensed by the volume control circuitry. If the
noise exceeds the step size voltage, the gain will change. In order to minimize this effect,
care must be taken to ensure the signal driving the VOLUME pin is referenced to the
VDD and 0V of the BA20861. DC volume application circuit shows in Figure 2.
Case 1 : Fix voltage on VOLUME pin & control by GAIN pin :
BA20861 can fix one voltage of the VOLUME pin in the application. Use GAIN pin to
control BA20861 internal gain only. BA20861 will decrease internal gain about –11dB
when GAIN pin from Low to High, or will increase internal gain about 11dB from High to
Low. For example: Set 2.4V on VOLUME pin and set GAIN pin at low for 0dB gain of
BA20861 that shows in Table 2. We can find typical gain of BA20861 is –11dB when
GAIN pin at high and 2.4V on VOLUME pin that shows in table 3.
The trip point, where the gain actually changes, is different depending on whether the voltage on
the VOLUME pin is increasing or decreasing as a result of hysteresis about each trip point. The
hysteresis ensures that the gain control is monotonic and does not oscillate from one gain step to
another. A pictorial representation of the volume control can be found in Figure 3. The graph focuses
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Page 8 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
on three gain steps with the trip points defined in the first and second columns of Table 2. The dotted
lines represent the hysteresis about each gain step.
Table 2. Typical DC Volume Control When GAIN = L
Voltage On Volume Pin
(V)
(Increasing or Fixed Gain)
0.00 ~ 0.29
0.30 ~ 0.38
0.39 ~ 0.50
0.51 ~ 0.63
0.64 ~ 0.72
0.73 ~ 0.83
0.84 ~ 0.95
0.96 ~ 1.04
1.05 ~ 1.14
1.15 ~ 1.26
1.27 ~ 1.38
1.39 ~ 1.49
1.50 ~ 1.61
1.62 ~ 1.70
1.71 ~ 1.80
1.81 ~ 1.91
1.92 ~ 2.03
2.04 ~ 2.14
2.15 ~ 2.24
2.25 ~ 2.35
2.36 ~ 2.47
2.48 ~ 2.59
2.60 ~ 2.69
2.70 ~ 2.81
2.82 ~ 2.92
2.93 ~ 3.03
3.04 ~ 3.14
3.15 ~ 3.14
3.26 ~ 3.35
3.36 ~ 3.44
3.45 ~ 3.57
3.58 ~ VDD
Voltage On Volume Pin
(V)
(Decreasing Gain)
0.00 ~ 0.18
0.19 ~ 0.30
0.31 ~ 0.42
0.43 ~ 0.54
0.55 ~ 0.66
0.67 ~ 0.77
0.78 ~ 0.86
0.87 ~ 0.98
0.99 ~ 1.10
1.11 ~ 1.21
1.22 ~ 1.31
1.32 ~ 1.43
1.44 ~ 1.53
1.54 ~ 1.63
1.64 ~ 1.74
1.75 ~ 1.85
1.86 ~ 1.97
1.98 ~ 2.08
2.09 ~ 2.18
2.19 ~ 2.29
2.30 ~ 2.41
2.42 ~ 2.55
2.56 ~ 2.64
2.65 ~ 2.76
2.77 ~ 2.87
2.86 ~ 2.99
3.00 ~ 3.09
3.10 ~ 3.22
3.23 ~ 3.29
3.30 ~ 3.39
3.40 ~ 3.50
3.51 ~ VDD
Typical Gain Of Amplifier
(dB)
-37
-36
-35
-33
-31
-29
-27
-25
-23
-21
-19
-17
-15
-13
-11
-10
-8
-6
-4
-2
0
2
4
6
7.5
9.5
11.5
13.5
15.5
17.5
19
20
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Page 9 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Table 3. Typical DC Volume Control When GAIN = H
Voltage On Volume Pin
(V)
(Increasing or Fixed Gain)
0.00 ~ 0.93
0.94 ~ 1.04
1.05 ~ 1.15
1.16 ~ 1.25
1.26 ~ 1.36
1.37 ~ 1.48
1.49 ~ 1.58
1.59 ~ 1.69
1.70 ~ 1.80
1.81 ~ 1.92
1.93 ~ 2.01
2.02 ~ 2.13
2.14 ~ 2.24
2.25 ~ 2.33
2.34 ~ 2.44
2.45 ~ 2.54
2.55 ~ 2.66
2.67 ~ 2.76
2.77 ~ 2.87
2.88 ~ 2.98
2.99 ~ 3.08
3.09 ~ 3.20
3.21 ~ 3.30
3.31 ~ 3.41
3.42 ~ 3.51
3.52 ~ 3.62
3.63 ~ 3.74
3.75 ~ 3.83
3.84 ~ 3.96
3.97 ~ VDD
Voltage On Volume Pin
(V)
(Decreasing Gain)
0.00 ~ 0.84
0.85 ~ 0.96
0.97 ~ 1.09
1.10 ~ 1.19
1.20 ~ 1.29
1.30 ~ 1.39
1.40 ~ 1.49
1.50 ~ 1.63
1.64 ~ 1.73
1.74 ~ 1.85
1.86 ~ 1.95
1.96 ~ 2.06
2.07 ~ 2.16
2.17 ~ 2.28
2.29 ~ 2.38
2.39 ~ 2.50
2.51 ~ 2.60
2.61 ~ 2.71
2.72 ~ 2.81
2.82 ~ 2.93
2.94 ~ 3.04
3.05 ~ 3.14
3.15 ~ 3.26
3.27 ~ 3.38
3.39 ~ 3.48
3.49 ~ 3.60
3.61 ~ 3.71
3.72 ~ 3.82
3.83 ~ 3.90
3.91 ~ VDD
Typical Gain Of Amplifier
(dB)
-36.5
-36
-35
-33
-31
-29
-27
-25
-23
-21
-19
-17
-15
-13
-11
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
14
16
18
VDD
50K~10Kohm
Volume
Figure 2. DC Volume Application Circuit
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Page 10 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Decreasing Voltage
on VOLUME pin
+2dB
0dB
Increasing Voltage
on VOLUME pin
-2dB
2.29V
2.41V
2.36V
2.48V
Figure 3. DC Volume Control Operation
COSC & ROSC Pin
The switching frequency is determined using the values of the components connected to ROSC
and COSC. The frequency may be varied from 200 kHz to 320 kHz by adjusting the values chosen for
ROSC and COSC. The recommended values are COSC = 220 pF, ROSC = 120 kΩ for a switching
frequency of 250 kHz.
Over-Heat Protection
Over-Heat protection on the BA20861 prevents damage to the device when the internal die
temperature exceeds 125°C. Once the die temperature exceeds the thermal set point, the device
enters the shutdown state and the outputs are disabled. The device will back to normal operation when
die temperature is reduced without external system interaction.
Output Short Protection
The BA20861 has output short circuit protection circuitry on the outputs that prevents damage to
the device during output-to-output short, output-to-GND short and output-to-VDD short. BA20861
enters the shutdown state and the outputs are disabled when detects output short. The device will
back to normal operation automatically after 2 ~ 3 minute.
Anti-Pop
A soft start capacitor must be added to the BYPASS pin. It recommends connecting a capacitor of
1µF to 10µF from BYPASS pin to Ground. BA20861 provides fade-in function when power-on or input
voltage level from 0V to VDD on SHUTDOWN_B pin, and fade-out function when SHUTDOWN_B pin
input voltage level from VDD to 0V. The pop noise can be eliminated by fade-in/fade-out function.
BYPASS Pin
It’s recommended to connect a 1µF to 10µF ceramic or tantalum low-ESR capacitor from BYPASS
pin to ground for the best THD and noise performance.
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Page 11 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Output Filter Application Note
Design the BA20861 without the filter if the traces from amplifier to speaker are short (< 1 inch),
where the speaker is in the same enclosure as the amplifier is a typical application for class-D without
a filter.
Many applications require a ferrite bead filter. The ferrite filter reduces EMI around 30 MHz. When
selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at
low frequencies.
Use an LC output filter if there are low frequency (<1 MHz) EMI sensitive circuits and/or there are
long wires from the amplifier to the speaker.
22uH
OUTP
0.1uF
0.47uF
22uH
0.1uF
OUTN
Figure 4. Typical LC Output Filter
BEAD (600R)
OUTP
330pF
470pF
BEAD (600R)
330pF
OUTN
Figure 5. Typical Ferrite Chip Bead Output Filter
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Page 12 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Typical Characteristics
Table of Graphs
Figure No.
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
Description
Frequency Response
Frequency Response
Frequency Response
THD+N VS. Frequency
THD+N VS. Frequency
THD+N VS. Frequency
THD+N VS. Output Power
THD+N VS. Output Power
THD+N VS. Output Power
Crosstalk
Crosstalk
Crosstalk
Output Load
5V, 0.5W Output
5V, 1W Output
5V, 1.5W Output
3.6V, 0.5W Output
5V, 0.5W Output
5V, 1W Output
5V, 1.5W Output
3.6V, 0.5W Output
5V, 0.5W Output
5V, 1W Output
3.6V, 0.5W Output
5V, 0.5W Output
5V, 1W Output
5V, 1.5W Output
3.6V, 0.5W Output
5V, 0.5W Output
5V, 1W Output
5V, 1.5W Output
3.6V, 0.5W Output
5V, 0.5W Output
5V, 1W Output
3.6V, 0.5W Output
5V
3.6V
5V
3.6V
5V
3.6V
5V
3.6V
5V
3.6V
5V
3.6V
Ω
3
Ω
4
Ω
8
Ω
3
Ω
4
Ω
8
Ω
4Ω
8Ω
3Ω
4Ω
8Ω
3
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Page 13 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Frequency Response (3Ω
Ω Load)
Figure 6: Frequency Response, Operate at 5V, 3Ω Load & 0.5W Output, Volume at 2.5V
Figure 7: Frequency Response, Operate at 5V, 3Ω Load & 1W Output, Volume at 2.5V
Figure 8. Frequency Response, Operate at 5V, 3Ω Load & 1.5W Output, Volume at 2.5V
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Page 14 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 9. Frequency Response, Operate at 3.6V, 3Ω Load & 0.5W Output, Volume at 1.8V
Frequency Response (4Ω
Ω Load)
Figure 10. Frequency Response, Operate at 5V, 4Ω Load & 0.5W Output, Volume at 2.5V
Figure 11. Frequency Response, Operate at 5V, 4Ω Load & 1W Output, Volume at 2.5V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
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BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 12. Frequency Response, Operate at 5V, 4Ω Load & 1.5W Output, Volume at 2.5V
Figure 13. Frequency Response, Operate at 3.6V, 4Ω Load & 0.5W Output, Volume at 1.8V
Frequency Response (8Ω
Ω Load)
Figure 14. Frequency Response, Operate at 5V, 8Ω Load & 0.5W Output, Volume at 2.5V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
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BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 15. Frequency Response, Operate at 5V, 8Ω Load & 1W Output, Volume at 2.5V
Figure 16. Frequency Response, Operate at 3.6V, 8Ω Load & 0.5W Output, Volume at 2V
THD+N VS. Frequency (3Ω
Ω Load)
Figure 17. THD+N VS. Frequency, Operate at 5V, 3Ω Load & 0.5W Output, Volume at 2.5V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 17 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 18. THD+N VS. Frequency, Operate at 5V, 3Ω Load & 1W Output, Volume at 2.5V
Figure 19. THD+N VS. Frequency, Operate at 5V, 3Ω Load & 1.5W Output, Volume at 2.5V
Figure 20. THD+N VS. Frequency, Operate at 3.6V, 3Ω Load & 0.5W Output, Volume at 1.8V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 18 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
THD+N VS. Frequency (4Ω
Ω Load)
Figure 21. THD+N VS. Frequency, Operate at 5V, 4Ω Load & 0.5W Output, Volume at 2.5V
Figure 22. THD+N VS. Frequency, Operate at 5V, 4Ω Load & 1W Output, Volume at 2.5V
Figure 23. THD+N VS. Frequency, Operate at 5V, 4Ω Load & 1.5W Output, Volume at 2.5V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 19 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 24. THD+N VS. Frequency, Operate at 3.6V, 4Ω Load & 0.5W Output, Volume at 1.8V
THD+N VS. Frequency (8Ω
Ω Load)
Figure 25. THD+N VS. Frequency, Operate at 5V, 8Ω Load & 0.5W Output, Volume at 2.7V
Figure 26. THD+N VS. Frequency, Operate at 5V, 8Ω Load & 1W Output, Volume at 2.7V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 20 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 27. THD+N VS. Frequency, Operate at 3.6V, 8Ω Load & 0.5W Output, Volume at 2V
THD+N VS. Output Power (3Ω
Ω Load)
Figure 28. THD+N VS. Output Power, Operate at 5V, 3Ω Load, Volume at 2.5V
Figure 29. THD+N VS. Output Power, Operate at 3.6V, 3Ω Load, Volume at 1.8V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 21 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
THD+N VS. Output Power (4Ω
Ω Load)
Figure 30. THD+N VS. Output Power, Operate at 5V, 4Ω Load, Volume at 2.5V
Figure 31. THD+N VS. Output Power, Operate at 3.6V, 4Ω Load, Volume at 1.8V
THD+N VS. Output Power (8Ω
Ω Load)
Figure 32. THD+N VS. Output Power, Operate at 5V, 8Ω Load, Volume at 2.7V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 22 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 33. THD+N VS. Output Power, Operate at 3.9V, 8Ω Load, Volume at 2V
Crosstalk (3Ω
Ω Load)
Figure 34.Classtalk, Operate at 5V, 3Ω Load, Output Power at 2W, Volume at 2.5V
Figure 35.Classtalk, Operate at 3.6V, 3Ω Load, Output Power at 1W, Volume at 1.8V
Crosstalk (4Ω
Ω Load)
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 23 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 36.Classtalk, Operate at 5V, 4Ω Load, Output Power at 2W, Volume at 2.5V
Figure 37.Classtalk, Operate at 3.6V, 4Ω Load, Output Power at 1W, Volume at 1.8V
Crosstalk (8Ω
Ω Load)
Figure 38.Classtalk, Operate at 5V, 8Ω Load, Output Power at 1.2W, Volume at 2.7V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 24 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
Figure 39.Classtalk, Operate at 3.6V, 8Ω Load, Output Power at 0.7W, Volume at 2V
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
Page 25 of 27
BA20861
2W Stereo Class-D Audio Power Amplifier with Two Selectable Gain Settings and MUX Control
PACKAGE DIMENSION
TQFN24
CONTACT INFORMATION
Biforst Technology Inc.
3F-3, No.32, Tai Yuen St., Jubei City, Hsin-Chu, Taiwan, R.O.C.
Tel: 886-3-552-6521; Fax: 886-3-552-6558; Email: [email protected]
Version History
Version
Date
1.0
2009.04.22
Page
Description
Initial Release
Biforst Technology, Inc., reserves the right to change product or specifications without notice.
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