MPS MP1740

MP1740
3W HIGH EFFICIENCY
MONO CLASS-D AUDIO AMPLIFIER
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP1740 is a high efficiency Class-D Hbridge audio amplifier. It utilizes a full bridge
output structure capable of delivering 3W into
4Ω speaker. The device exhibits the high fidelity
of a class AB amplifier with an efficiency of 91%.
It also dramatically reduces solution size by
integrating the following:
•
•
z
z
z
z
300mΩ (high side or low side) power MOSFETs
(VCC=3.6V)
Startup / Shutdown pop elimination
Short circuit protection
9 Balls Wafer chip scale package (WLCSP) and
requires a few external components.
This amplifier also improves GSM power supply
rejection, and operates on a single cellular Liion battery.
The gain of this amplifier can be controlled
easily by a few modification of external
configuration while minimizing noise to 37
μVRMS.
•
•
•
•
•
•
•
•
•
•
•
3W Into 4Ω with 5 V Supply @ 10% THD+N
Efficiency up to 90% at 1.7W Pout, 8 ohm
load
2.5V to 5.5V Supply Voltage Operation
THD+N = 0.1% @ 1.8W, 5V, 4Ω
2mA Quiescent current and 0.5μA
shutdown current
Full Bridge Output Drive
Internal 250kHZ Switching frequency
Fully Differential input
Improved CMRR Eliminates Two Input
Coupling Capacitors
1ms start-up time Eliminates pop
Integrated Short Circuit Protection
Integrated Thermal Shutdown
9 Balls Wafer chip scale package (WLCSP)
APPLICATIONS
•
•
Wireless or Cellular Handsets
PDAs
All MPS parts are lead-free and adhere to the RoHS directive. For MPS
green status, please visit MPS website under Products, Quality
Assurance page.
“MPS” and “The Future of Analog IC Technology” are registered
trademarks of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
TND+N vs. POUT
fs=1kHz, VCC=5V, Gain=2V/V
No Weighting
To Battery
20
Cs
10
PVCC
AVCC
5
RI
INP
RI
IN-
INN
EN
VOP
OUT+
MP1740
VON
EN
AGND
PGND
OUT-
2
THD+N (%)
IN+
1
0.5
0.2
0.1
0.05
0.02
0.01
60m 100m 200m 300m 500m
1
2
3 4
POUT (W)
MP1740 Rev. 1.0
1/5/2012
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1
MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
ORDERING INFORMATION
Part Number*
MP1740EC
Package
WLCSP
Top Marking
Free Air Temperature (TA)
6F
–20°C to +85°C
PACKAGE REFERENCE
TOP VIEW
1
A
B
C
INP
AVCC
INN
2
AGND
PVCC
EN
BOTTOM VIEW
3
C
INN
EN
VOP
B
AVCC
PVCC
PGND
A
INP
AGND
VON
1
2
3
VON
PGND
VOP
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance
Supply Voltage VCC ........................-0.3V to 6.5V
Input Voltage VIN ................. –0.3V to VCC + 0.3V
Input Voltage VEN ................ –0.3V to VCC + 0.3V
Ambient Temperature TA .......... –40°C to +85°C
(2)
Continuous Power Dissipation (TA = +25°C)
................................................................ 1W
Junction Temperature TJ......... –40°C to +140°C
Lead Temperature ....................................260°C
Storage Temperature.............. –65°C to +150°C
WLCSP ..................................114 ..... 12 ... °C/W
Recommended Operating Conditions
(3)
Supply Voltage VCC .........................2.5V to 5.5V
Enable Voltage VEN ..................... 70%VCC to VCC
Disable Voltage VEN ..................... 0V to 15%VCC
Common Mode Input Voltage VIC
............................... 0.5V to VCC-0.8V
Operating Junct. Temp (TJ)..... –20°C to +125°C
MP1740 Rev. 1.0
1/5/2012
(4)
θJA
θJC
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ(MAX), the junction-to-ambient
thermal resistance θJA, and the ambient temperature TA. The
maximum allowable continuous power dissipation at any
ambient temperature is calculated by PD(MAX)=(TJ(MAX)-TA)/θJA.
Exceeding the maximum allowable power dissipation will
cause excessive die temperature, and the regulator will go
into thermal shutdown. Internal thermal shutdown circuitry
protects the device from permanent damage.
3) VCC Include AVCC and PVCC, VIN include INP and INN
4) Measured on JESD51-7, 4-layer PCB
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MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
ELECTRICAL CHARACTERISTICS
TA = +25°C, unless otherwise noted.
Parameter
Symbol
Output Offset Voltage
Power
Ratio
Supply
|VOS|
Rejection
Common Mode Rejection
Ratio
PSRR
CMRR
High-level Input Current
IIH
Low-level Input Current
IIL
Quiescent Current
IQ
Shut down Current
VEN Enable L-H
VEN Enable H-L
UVLO_H
UVLO_L
Ids
Static On-state Resistance
Output
impedance
disable
Switching frequency
GAIN (VO/VI)
RPD
MP1740 Rev. 1.0
1/5/2012
in
Rds_on
Conditions
VI=0V, Av=2V/V, VCC=2.5V to
5.5V
Min
VCC=2.5V to 5.5V
VCC=2.5V to 5.5V,
VIC＝1/2VCC to 0.5V,
VIC＝1/2VCC to VCC -0.8V
VCC=5.5V,
VI=5.5V,RI=150kΩ
VCC=5.5V,
VI=0V,RI=150kΩ
VCC=5.5V, no load, switching
VCC=3.6V, no load, switching
VCC=2.5V, no load, switching
VEN=0, VCC=2.5V to 5.5V
VCC=2.5V to 5.5V
VCC=2.5V to 5.5V
VCC from Low to High
VCC from High to Low
VCC=5.5V
VCC=3.6V
VCC=2.5V
RO
VEN<0.8V
FSW
VCC=2.5V to 5.5V
RI =15 kΩ, no load
Resistance from EN to GND
Typ
Max
Unit
1
25
mV
-70
-45
dB
-70
dB
20
30
μA
20
30
μA
2.7
2
1.6
0.5
5.8
4.6
3.6
2
1.6
1.95
2.4
2.1
250
300
360
0.4
2.48
250
20
300
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μA
V
V
V
V
mΩ
2
200
19
mA
kΩ
300
21
kHz
V/V
kΩ
3
MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
MPS CONFIDENTIAL AND PROPRIETARY INFORMATION – INTERNAL USE ONLY
OPERATION CHARACTERISTICS
VCC=AVCC=PVCC=EN, AGND = PGND = 0V, signal frequency fs=1kHz, RI=150 Ω, Gain=2 V/V,
CI=2.2uF, T A = +25°C, unless otherwise noted.
Parameter
Symbol
Conditions
Min
THD+N=1%,
fS=1kHz,
RL=4Ω
THD+N=10%,
fS=1kHz,
RL=4Ω
Output Power
POUT
THD+N=1%,
fS=1kHz,
RL=8Ω
D
I
Total Distorsion Plus
Noise
P
O
C
THD+N
S
Supply
Ripple
Rejection Ratio
KSVR
Signal to Noise Ratio
SNR
M
Output Noise
Common
Mode
Rejection Ratio
Start-up Time From
Disable
MP1740MP1740 Rev. 1.0
1/5/2012
N
POUT=2W, fS=1kHz,
RL=4Ω
POUT=1W, fS=1kHz,
RL=4Ω
POUT=0.4W, fS=1kHz,
RL=4Ω
POUT=1W, fS=1kHz,
RL=8Ω
POUT=0.5W, fS=1kHz,
RL=8Ω
POUT=0.2W, fS=1kHz,
RL=8Ω
fRIPPLE=217Hz,
VRIPPLE=400mVpp,
input AC-ground with
CI=0.22μF
POUT=1W,
RL=8Ω
VCC=5V, f=20 to
20kHz, input ACground
with
CI=0.22μF
VIC-RIPPLE=1 VPP,
fRIPPLE =217Hz
Vn
CMRR
O
TS
D
N
T
O
L
Typ
2.82
2.32
1.16
0.54
3.62
3.0
1.51
0.70
1.65
1.36
0.71
0.33
2.12
1.74
0.91
0.42
A
I
T
N
E
THD+N=10%,
fS=1kHz,
RL=8Ω
F
VCC=5.5V
VCC=5V
VCC=3.6V
VCC=2.5V
VCC=5.5V
VCC=5V
VCC=3.6V
VCC=2.5V
VCC=5.5V
VCC=5V
VCC=3.6V
VCC=2.5V
VCC=5.5V
VCC=5V
VCC=3.6V
VCC=2.5V
0.19%
VCC=3.6V
0.14%
T
S
I
D
E
T
0.11%
VCC=5V
VCC=5V
W
R
VCC=2.5V
VCC=2.5V
Unit
U
IB
VCC=5V
VCC=3.6V
Max
0.11%
0.12%
0.13%
-62
dB
97.7
dB
No
weighting
53
A-weighting
37
VCC=5V
-65
dB
1
ms
μVRMS
4
MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
PIN FUNCTIONS
Ball
WLCSP
Name
A1
A2
A3
B1
B2
B3
C1
C2
C3
INP
AGND
VON
AVCC
PVCC
PGND
INN
EN
VOP
Input/Ouput
/Power
(I/O/P)
I
P
O
P
P
P
I
I
O
Description
Positive differential input
Analog Ground
Negative BTL output
Analog Power Supply
Power Supply
Power Ground
Negative differential input
Enable Input. (drive high to enable the MP1740)
Positive BTL output
TYPICAL PERFORMANCE CHARACTERISTICS
TEST SET-UP FOR GRAPHS
VCC
Cs
10uF
Measurement
Output
+
-
AVCC
Cs
PVCC
CI
RI
+
VOP
INP
Load
MP1740
CI
Cs
0.22uF
0.22uF
INN
VON
40kHz Low
Pass Filter
RI
EN
Measurement
Input
-
EN
AGND
PGND
Notes:
5) CI was Shorted for any Common-Mode input voltage measurement
6) A 33µH inductor was placed in series with the load resistor to emulate a small speaker for efficiency measurements.
7) The 40 kHz low-pass filter is required even if the analyzer has a low-pass filter.
8) For PSRR test, Please remove the great 10uF decoupling capacitor and just keep the small decoupling capacitors for recovery switching
currents.
MP1740 Rev. 1.0
1/5/2012
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MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
TYPICAL PERFORMANCE CHARACTERISTICS
VCC=AVCC=PVCC=EN, AGND = PGND = 0V, signal frequency fs=1kHz, RI=150kohm, Gain=2 V/V,
CI=2.2uF, TA = +25°C, unless otherwise noted.
20
20
20
10
10
10
5
5
5
3.6V
2
5V
THD+N (%)
THD+N (%)
2
1
0.5
0.2
0.1
3.6V
5V
0.5
0.2
5.5V
0.1
5.5V
0.05
2.5V
1
THD+N (%)
2.5V
2
1
0.2
0.05
0.05
0.02
0.02
0.01
0.01
0.01
1
2
3 4
2W
0.1
0.02
60m 100m 200m 300m 500m
100mW
0.5
60m 100m
200m 300m 500m
1
2
3
500mW
20
50
100 200
POUT (W)
POUT (W)
500 1k
2k
5k
10k 20k
Frequency (Hz)
20
+4
+4
+2
+2
50mW
1
+0
250mW
d
B
r
0.1
-2
-4
A
1W
0.01
0.001
20
50
100 200
500
1k
2k
5k
+0
d
B
r
-6
-8
-8
50 100 200 500 1k 2k
Frequency (Hz)
90
EFFICIENCY(%)
-10
PSRR (dB)
-20
-30
-40
- 50
-60
-70
60
50
40
30
20
-90
10
-100
0
500
1k
2k
MP1740 Rev. 1.0
1/5/2012
5 k 10k 20k
0.6
RL
70
5k 10k 20k 40k
VCC=5V
RL
80
-80
Frequency (Hz)
50 100 200 500 1k 2k
Power Dissipation vs. POUT
VCC=5V
100
100 200
10 20
Frequency (Hz)
Efficiency vs. POUT
+0
50
-10
5k 10k 20k 40k
Frequency (Hz)
PSRR vs.Frequency
20
-4
-6
-10
10 20
10k 20k
-2
A
POWER DISSIPATION(W)
THD+N (%)
5
0.5
0.4
RL
0.3
0.2
0.1
RL
0
0
0.5
1
1.5
2
2.5
3
3.5
0
0.5
1
POUT (W)
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1.5
2
2.5
3
POUT (W)
6
MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VCC=AVCC=PVCC=EN, AGND = PGND = 0V, signal frequency fs=1kHz, RI=150kohm, Gain=2 V/V,
CI=2.2uF, TA = +25°C, unless otherwise noted.
4
+0
3.5
-10
3
-20
CMRR (dB)
Output Power(W)
Output Power vs.
Supply Voltage
2.5
2
-30
-40
1.5
-50
1
-60
0.5
-70
-80
0
2
2.5
3
3.5
4
4.5
5
Supply Voltage(V)
MP1740 Rev. 1.0
1/5/2012
5.5
6
20
50
100 200
500
1k
2k
5 k 10k 20k
Frequency (Hz)
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MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
FUNCTION BLOCK DIAGRAM
AVCC
PVCC
R3
PVCC
Start- up&
Other logic
external
Internal
VON
INN
Comparator
C
Gate
Drive
Audio Input -Ri
R1
R2
PGND
FDA
FDA
PVCC
INP
speaker
C
Audio Input +
Ri
R1
R2
Comparator
Gain=(R1/Ri)*(R3/R2)
Gate
Drive
VOP
PGND
R3
EN
EN
UVLO
Reference
Thermal Protection
Triangular
Generator
AGND
OCP&
De- POP
PGND
Figure 1—Functional Block Diagram
MP1740 Rev. 1.0
1/5/2012
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MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
APPLICATION INFORMATION
COMPONENT SELECTION
The MP1740 uses a minimum number of external
components to complete a fully bridged Class D
audio amplifier. Use the following sections to
customize the amplifier for your particular
application.
1. Setting the Voltage Gain
The voltage gain sets the output voltage swing
for a given input voltage swing and is set by the
input resistors (RI) as the following equation:
GAIN=2 ×
150kΩ (1)
RI
The maximum output voltage swing is limited by
the power supply. To achieve the maximum
output power of the MP1740 amplifier, set the
amplifier gain such that the maximum peak-topeak input signal results in at least the maximum
peak-to-peak output voltage swing. Lower gain
allows the MP1740 to operate at its best,
because a higher voltage at the input for the
same output power making the inputs less
susceptible to noise. So setting voltage gain to
2V/V may achieve optimal performance.
2. Input Coupling Capacitors (CI)
The MP1740 is a mono BTL Class-D amplifier
with differential inputs and outputs. This device
can still be used with a single-ended input; but for
some noisy environment (such as a wireless
handset) the MP1740 should be used with
differential inputs to ensure maximum noise
rejection.
The fully differential amplifier allows the inputs to
be biased at voltage other than mid-supply. The
input coupling capacitors are not required if the
design uses a differential source that is biased
from 0.5 V to VCC - 0.8 V (as shown in
Recommended Operating Conditions). If the
input signal is not biased within the
recommended common-mode input range or if
using a single-ended source, the input coupling
capacitors are used to pass only the AC audio
signal to the input of the amplifier as a high pass
filter. The input capacitors create a high-pass
filter with the input resistor. Choose an input
coupling capacitor such that the corner frequency
MP1740 Rev. 1.0
1/5/2012
fC is less than the desired pass-band frequency.
The formula for the corner frequency is:
fC =
1
(2)
2πRICI
Speakers in wireless handsets usually can’t
respond well to low frequencies, so for this
application the corner frequency can be set to
block the low frequencies.
The input coupling capacitance is calculated as:
CI =
1
(3)
2πRIfC
If the corner frequency is within the audible band,
the capacitors should have a tolerance of ±10%
or better, because any mismatch in capacitance
causes an impedance mismatch at the corner
frequency and below.
3. Power Supply Decoupling Capacitor (CS)
The class-D audio amplifier requires adequate
power supply decoupling to ensure the efficiency
is high and total harmonic distortion (THD) is low.
To carry the higher frequency transient current,
spikes, or digital hash on the line, a good low
ESR ceramic capacitor is necessary. Place a 1μF
decoupling capacitor as close as possible to the
device VCC lead. It is very important for the
efficiency of the class-D amplifier, because any
resistance or inductance in the trace between the
capacitor and the device may cause a loss. A
10μF or greater capacitor placed near the audio
power amplifier would also help for filtering lowerfrequency noise.
4. Input Resistors (RI)
In fully differential amplifiers, please use the
matching input resistors. Matching is very
important for the balance of the output on the
reference voltage (more important than overall
tolerance). The higher matching, the batter
CMRR and PSRR performance. Therefore, it is
recommended to use 1% precision resistors or
better to keep the performance optimized. Place
the input resistors as close to the MP1740 as
possible to limit noise injection on the highimpedance nodes.
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MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
TYPICAL APPLICATION CIRCUIT
To Battery
Cs
Cs
AVCC
PVCC
RI
Differential
Input
IN+
INP
OUT+
VON
OUT-
MP1740
RI
IN-
VOP
INN
EN
EN
AGND
PGND
Figure 2—MP1740 Application Schematic with Differential Input
(input DC-biased voltage is within the recommended common-mode voltage range)
To Battery
Cs
Cs
AVCC
CI
Differential
Input
PVCC
RI
IN+
INP
CI
RI
INEN
VOP
OUT+
VON
OUT-
MP1740
INN
EN
AGND
PGND
Figure 3—MP1740 Application Schematic with Differential Input
(input DC-biased voltage is out of the recommended common-mode voltage range)
To Battery
Cs
Cs
AVCC
CI
Single-ended
Input
PVCC
RI
INP
CI
RI
EN
VOP
OUT+
VON
OUT-
MP1740
INN
EN
AGND
PGND
Figure 4—MP1740 Application Schematic with Single-Ended Input
MP1740 Rev. 1.0
1/5/2012
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MP1740 –3W HIGH EFFCIENCY MONO CLASS-D AUDIO AMPLIFIER
PACKAGE INFORMATION
WLCSP
PIN 1 ID
MARKING
1.00
REF
1.50
1.60
3
2
1
A
0.50
BSC
1.50
1.60
PIN 1 ID
INDEX AREA
B
0.28
0.34
TOP VIEW
C
BOTTOM VIEW
0.38
REF
0.21
0.27
1.00
REF
0.57
0.67
SIDE VIEW
NOTE:
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) BALL COPLANARITY SHALL BE 0.05 MILLIMETER MAX.
3) JEDEC REFERENCE IS MO-211, VARIATION DD.
4) DRAWING IS NOT TO SCALE.
1.00
0.50
1.00
0.25
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MP1740 Rev. 1.0
1/5/2012
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