MOSA MS6894

MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
Mono 1.1W, Fully Differential Input
Excellent PSRR, Low Voltage Operation
Selectable Shutdown Logic Level
FEATURES
APPLICATIONS
‧PSRR at 217Hz, 80dB at 5V
‧Operation range: 2.5V ~ 6.5V
‧Shutdown Current 0.1uA at 5V
‧Output power, THD+N=1%
RL=8Ω, 1.1W at 5V, 0.4W at 3.3V, 200mW at 2.5V
‧Unity-gain stable
‧Space-saving MSOP10, enhance thermal pad
‧Portable electronic devices
‧PDAs
‧Communication headsets
‧Cross-reference:
LM4894
DESCRIPTION
The MS6894 is a fully differential power amplifier that can drive 1.1W of continuous average power into a mono 8Ω
bridged-tied load (BTL). Operation with 2.5V supply, it can drive 200mw into a mono 8Ω. The shutdown may be
enabled by either logic high or logic low that depending on shutdown mode selection. The BTL configuration
eliminates the need for external coupling capacitors on the output in most applications. The MS6894 is unity-gain
stable and can be configured by external gain-setting resistors.
The MS6894 has good feature for portable equipment, these features include the fully differential input, low voltage
operation, micropower consumption shutdown mode, enhance thermal pad and small package MSOP10, make the
MS6894 ideally suited for use in portable electronic equipments.
BLOCK DIAGRAM
VDD
7
-IN
2
SD
SD Mode
1
3
BP
5
+IN
4
+
10
Vo2
-
6
Vo1
Common
mode
Bias
+
7
GND
REV 1
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
PIN CONFIGURATION
Symbol
Pin
Description
SD
1
Shutdown places the entire device in shutdown mode depending on SD Mode selection.
TTL compatible input.
SD Mode = 0, the device entries shutdown when SD is logic low.
SD Mode = 1, the device entries shutdown when SD is logic high.
+IN
2
Positive differential input
SD Mode
3
The shutdown mode controls the shutdown logic level of the SD pin1.
TTL compatible input
-IN
4
Negative differential input
BP
5
Bypass is the cap to the voltage divider for internal mid-supply bias.
This terminal should be connected to a 0.1-μF to 10-μF capacitor CBP.
Vo1
6
Negative BTL output
GND
7
Ground
NC
8
No connected
VDD
9
Supply voltage
Vo2
10
Positive BTL output
MSOP10
SD
1
10
Vo2
-IN
2
9
VDD
SD Mode
3
8
NC
+IN
4
7
GND
BP
5
6
Vo1
Thermal
Pad
ORDERING INFORMATION
Package
Part number
Packaging Marking
Transport Media
10-Pin MSOP (lead free)
MS6894MGTR
6894G
3.5k Units Tape and Reel
10-Pin MSOP (lead free)
RoHS Compliance
MS6894MGU
6894G
80 Units Tube
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Rating
Unit
6.5
V
3500
VDD
Supply voltage
VESD
Electrostatic handling
TSTG
Storage temperature range
-65 to 150
V
℃
TA
Operating ambient temperature range
-40 to 85
℃
TJ
Maximum junction temperature
150
℃
TS
Soldering temperature, 10 seconds
260
℃
RTHJA
Thermal resistance from junction to ambient in free air
MSOP10 (enhance thermal pad)
50
REV 1
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
OPERATING RATINGS
Symbol
VDD
Parameter
Supply voltage
Min
Typ
Max
Unit
2.5
5
6.5
V
Min
Typ
Max
Unit
5V ELECTRICAL CHARACTERISTICS
Ta = 25°C, VDD=5V, f=1kHz, BW<30kHz, unless otherwise specified.
Symbol
Parameter
Conditions
IQ
Quiescent current
VIN=0V, IO=0A
-
2.7
-
mA
ISHDN
Shutdown current
VSHDN=0V
-
0.1
-
uA
VSDH
Shutdown input voltage high
2.0
-
-
V
VSDL
Shutdown input voltage low
-
-
0.8
V
VSDMH
SD Mode input voltage high
2.0
-
-
V
VSDML
SD Mode input voltage low
-
-
0.8
V
PSRR
Power supply rejection ratio
RL=8Ω, CBP=1uF, f=217Hz
-
80
-
dB
THD+N
Total harmonic distortion plus
noise
RL=8Ω, 1.1W
-
-60
-55
dB
-
0.1
0.178
%
S/N
Signal-to-noise ratio
RL=8Ω, 1.1W
90
103
-
dB
Po
Output power
RL=8Ω, THD+N = 1%
1.1
1.3
-
W
Min
Typ
Max
Unit
3.3V ELECTRICAL CHARACTERISTICS
Ta = 25°C, VDD=3.3V, f=1kHz, BW<30kHz, unless otherwise specified.
Symbol
Parameter
Conditions
IQ
Quiescent current
VIN=0V, IO=0A
-
2.4
-
mA
ISD
Shutdown current
-
0.1
-
uA
PSRR
Power supply rejection ratio
VSHDN=0V
RL=8Ω, CBP=1uF, f=217Hz
-
70
-
dB
THD+N
Total harmonic distortion plus
noise
RL=8, 0.4W
-
-60
-55
dB
0.1
0.178
%
S/N
Signal-to-noise ratio
RL=8Ω, 0.4W
90
100
-
dB
Po
Output power
RL=8Ω, THD+N = 1%
0.4
0.5
-
W
Min
Typ
Max
Unit
2.5V ELECTRICAL CHARACTERISTICS
Ta = 25°C, VDD=2.5V, f=1kHz, BW<30kHz, unless otherwise specified.
Symbol
Parameter
Conditions
IQ
Quiescent current
VIN=0V, IO=0A
-
2.2
-
mA
ISD
Shutdown current
-
0.1
-
uA
PSRR
Power supply rejection ratio
VSHDN=0V
RL=8Ω, CBP =1uF, f=217Hz
-
60
-
dB
-
-60
-55
dB
-
0.1
0.178
%
THD+N
Total harmonic distortion plus
noise
RL=8Ω, 0.2W
S/N
Signal-to-noise ratio
RL=8Ω, 0.2W
90
98
-
dB
Po
Output power
RL=8Ω, THD+N = 1%
0.2
0.28
-
W
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
TYPICAL PERFORMANCE CHARACTERISTICS
Ta = 25°C, BW<30kHz, unless otherwise specified.
VDD=3.3V
RL=8Ω
Po=0.4W
THD+N (%)
THD+N (%)
VDD=2.5V
RL=8Ω
Po=0.2W
THD+N (%)
VDD=5V
RL=8Ω
Po=1.1W
FREQUENCY (Hz)
FREQUENCY (Hz)
THD+N vs. frequency
THD+N vs. frequency
f=20kHz
f=20kHz
f=1kHz
f=1kHz
f=1kHz
f=20Hz
VDD=5V
RL=8Ω
f=20Hz
THD+N (%)
f=20kHz
THD+N (%)
THD+N (%)
FREQUENCY (Hz)
THD+N vs. frequency
VDD=3.3V
RL=8Ω
f=20Hz
VDD=2.5V
RL=8Ω
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER (W)
THD+N vs. output power
THD+N vs. output power
THD+N vs. output power
CBP=1uF
CBP=1uF
VDD=5V
RL=8Ω
REV 1
PSRR (dB)
PSRR (dB)
PSRR (dB)
CBP=1uF
VDD=3.3V
RL=8Ω
VDD=2.5V
RL=8Ω
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
PSRR vs. frequency
PSRR vs. frequency
PSRR vs. frequency
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
QUIESCENT CURRENT (mA)
VIN=0V
No load
SUPPLY VOLTAGE (V)
Quiescent current vs. supply voltage
REV 1
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
APPLICATION INFORMATION
Basic application example
20k
RF1
VDD
1uF
9
VDD
0.39uF
20k
2
-IN
-
RI1
- Differential Input
+
MCU
VDD
1
3
SD
SD Mode
5
BP
4
+IN
Vo2
10
+
Common
mode
Bias
RL
8Ω
100k
0.39uF
+ Differential Input
20k
1uF
-
Vo1
6
-
+
RI2
GND
7
20k
RF2
Fig.1
A audio amplifier application circuit.
Shutdown Control
The shutdown may be enabled by either logic high or logic low that depending on shutdown mode selection. Both the
SD pin and the SD Mode pin are TTL compatible input. The SD Mode is logic low, the device entries shutdown when
SD is logic low. The SD Mode is logic high, the device entries shutdown when SD is logic high.
External gain-setting
As shown in Fig.1, RI1 =RI2 and RF1 =RF2, the respective closed-loop gain is set at -RF/RI. It is important to match input
resistors and feedback resistors to each other. The outputs are used to drive the mono bridged-tied load (BTL).
High Pass Filter
The input capacitor CIN and resister RIN are decided the cut-off frequency of the HPF. The equation is as follows:
fcut-off = 1 / (2π*RIN *CIN)
Thermal pad considerations
The thermal pad must be connected to ground. The package with thermal pad of the MS6894 requires special attention
on thermal design. The thermal pad on the bottom of the MS6894 should be soldered down to a copper pad on the
circuit board. Heat can be conducted away from the thermal pad through the copper plane to ambient. If the copper
plane is not on the top surface of the circuit board, 9 vias of 13 mil or smaller in diameter should be used to thermally
couple the thermal pad to the bottom plane. For good thermal conduction, the vias must be plated through and solder
filled.
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
EXTERNAL DIMENSIONS
MSOP10 (Thermal Pad)
Thermal Pad
A
A1
A2
b
c
D
H
E
W1
H
W2
E
Symbol
e
L
θ
W1
W2
Dimension in mm
Min
Nom
0.81
0.05
0.76
0.15
0.13
2.90
4.70
2.90
0.92
0.86
0.20
0.15
3.00
4.90
3.00
0.50 BASIC
0.40
0.53
0o
1.27
1.02
-
Dimension in inches
Max
Min
1.12
0.15
0.97
0.30
0.23
3.10
5.10
3.10
0.032
0.002
0.030
0.006
0.005
0.114
0.185
0.114
0.66
6o
1.52
1.27
Nom
Max
0.036
0.044
0.006
0.034
0.038
0.008
0.012
0.006
0.009
0.118
0.122
0.193
0.201
0.118
0.122
0.02 BASIC
0.016
0.021
0.026
0o
6o
0.050
0.060
0.040
0.050
D
A
A2
θ
e
A1
L
B
C
TAPE AND REEL (Unit : mm)
MSOP10
2.0
0.30
0.05
0.05
1.5+0.1/-0.0 DIA
4.0
1.75
0.3R MAX
5.5
0.05
12.0 0.3
5.4
3.0
3.6
8.0
1.5 MIN
6.9
0.5 Radius Typical
2.0 1.7
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
DEMO BOARD
2
1
3
5
4
Function description
Label 1: Supply Voltage
Supply voltage range is 2.5V to 6.5V, the left of jump is positive and the right of jump is negative.
Label 2: Shutdown mode selection (SD Mode)
The shutdown mode is low logic level shutdown mode when the jump is placed left position (SD), the SD Mode is
connected to GND. On the other hand , the chip is high logic level shutdown mode when the jump is placed right
position (SD), the SD Mode is connected to VDD.
Label 3: Shutdown pin (SD pin)
The shutdown may be enabled by either logic high or logic low that depending on shutdown mode selection. The SD
Mode is placed left position (SD), the chip entries shutdown when SD pin is placed left position (L), the SD Mode is
connected to GND. On the other hand, the SD Mode is placed right position (SD), the chip entries shutdown when
SD pin is placed right position (H), the SD Mode is connected to VDD.
Label 4: Signal Input
Connected to audio signals.
Label 5: Speaker Output
Connected to speaker with 8ohm or 4 ohm.
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MOSA
MS6894
Mono 1.1W Fully Differential Power Amplifier with Shutdown Selection
Circuit
J1
1
2
AVDD
C1
AVDD
+ C2
1u
0.1u
20K
U1
C4
0.39u
+
1
2
3
J2
1
2
3
4
BP 5
R1
20K
SD
1
2
J4
R2
SD
Vo2
INVDD
SDM
NC
IN+ GND
BP
Vo1
10
9
8
7
6
LS1
SPEAKER
MS6894
-IN
20K
1
2
3
R4
+ C3
1u
J3 SD Mode
J5
C5
0.39u
R3
+
1
2
20K
+IN
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