MP7770
2 x 45W Stereo Single-Ended
or 90W Mono BTL Class-D Audio Amplifier
The Future of Analog IC Technology
DESCRIPTION
FEATURES
MP7770 is an analog class-D audio amplifier
that can drive either stereo speakers in singleended configuration or a mono speaker in a
bridge-tied-load configuration. It is part of
MPS’s family of fully-integrated audio amplifiers
that dramatically reduce footprint size by
integrating:
•
•
•
•
100mΩ power MOSFETs
•
Startup/Shutdown pop elimination
•
Short-circuit protection circuits
The MP7770 is capable of delivering 45W per
channel into 4Ω speaker in single-ended output
structure, or delivering 90W into 8Ω speaker in
bridge-tied-load output structure under 36V
VDD. MPS’s class D audio amplifiers exhibit the
high fidelity of a Class A/B amplifier at higher
efficiencies. The circuit is based on the MPS’s
proprietary variable-frequency topology, which
delivers excellent linearity, fast response time
and operates from a single power supply.
•
•
•
•
•
•
•
•
•
•
9.5V-to-36V Operation from a Single Supply
±8.5A Peak Current Output
Output Power at 36V and 10%THD:
- Stereo Single-Ended: 2 x 45W into 4Ω Load,
- Bridge-Tied Load: 90W into 8Ω Load
THD+N = 0.03% at 1W, 8Ω
> 90% Efficiency at 10%THD
Low Noise
Switching Frequency of up to 1MHz
Integrated Startup and Shutdown Pop
Elimination Circuit
Programmable UVP
Thermal and Short-Circuit Protection
Output Fault Flag and Thermal Warning
Integrated Power FETs
TSSOP28-EP Package with Exposed Pad
APPLICATIONS
•
•
•
•
•
DVD Receiver
Mini Combo System
Home Theater Systems
Surround Sound Systems
Audio Docking or High-Power Sound Box
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Quality Assurance
“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
MP7770 Rev. 1.02
7/16/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
1
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
TYPICAL APPLICATIONS
CH1
INPUT
CH1
OUTPUT
IN1
SW1
REF1
BST1
TIMER1
PGND1
TIMER2
PGND2
OFF ON
EN
UVP
MP7770
OTW
VDD1
FAULT
VDD2
VDD
AGND1
AGND2
BST2
CH2
OUTPUT
REF2
SW2
CH2
INPUT
IN2
Stereo SE Application Circuit
TIMER1
SW1
TIMER2
BST1
INPUT+
IN1
REF1
REF2
INPUT-
IN2
PGND1
MP7770
EN
OFF ON
OUTPUT
PGND2
VDD
V DD1
UVP
OTW
V DD2
BST2
FAULT
AGND1
SW2
AGND2
Mono BTL Application Circuit
MP7770 Rev. 1.02
7/16/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
2
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
ORDERING INFORMATION
Part Number*
MP7770GF
Package
TSSOP28-EP
Top Marking
See Below
* For Tape & Reel, add suffix –Z (e.g. MP7770GF–Z);
TOP MARKING (MP7770GF)
MP7770: product code of MP7770GF;
MPS: MPS prefix;
Y: year code;
WW: week code:
LLL: lot number;
PACKAGE REFERENCE
EN
BST1
UVP
PGND1
N/C
PGND1
TIMER1
SW1
IN1
SW1
REF1
AGND1
AGND2
VDD1
EXPOSED PAD
ON BOTTOM
REF2
VDD1
VDD2
VDD2
IN2
SW2
TIMER2
SW2
N/C
PGND2
FAULT
PGND2
BST2
OTW
TSSOP28-EP
MP7770 Rev. 1.02
7/16/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
3
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
ABSOLUTE MAXIMUM RATINGS (1)
Supply Voltage VDD ...................................... 40V
BS Voltage .............. (VSW - 0.3V) to (VSW + 6.5V)
VOTW, VFAULT, VUVP, VTIMER, VEN .......–0.3V to +6V
VSW .......................................–0.3V to (VDD + 1V)
VREF, VIN .......................................–0.3V to +34V
AGND to PGND ..........................–0.3V to +0.3V
(2)
Continuous Power Dissipation (TA = 25°C)
............................................................ 3.9 W
Junction Temperature ............................... 150°C
Lead Temperature ....................................260°C
Storage Temperature.............. –65°C to +150°C
Recommended Operating Conditions
(3)
Thermal Resistance
(4)
θJA
θJC
TSSOP28-EP ......................... 32 ....... 6.... °C/W
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-toambient 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) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
Supply Voltage VDD ..........................9.5V to 36V
Operating Junction Temp. (TJ)............................
........................................... -40°C to +125°C
MP7770 Rev. 1.02
7/16/2015
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© 2015 MPS. All Rights Reserved.
4
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
ELECTRICAL CHARACTERISTICS (5, 6)
VDD = 24V, VEN = 5V, TA = 25°C, unless otherwise noted.
Parameters
Standby Current
Quiescent Current
SW ON Resistance
Short-Circuit Current
EN Enable Threshold Voltage
EN Enable Input Current
External Under-Voltage
Detection
External Under-Voltage
Detection Hysteresis Voltage
Thermal Shutdown Trip Point (7)
Thermal Shutdown Hysteresis(7)
Thermal Warning Trip Point(7)
Thermal Warning Hysteresis(7)
Symbol Condition
VEN = 0V,REF=IN=Float
IQ
SW=Low
Sourcing and Sinking
Sourcing and Sinking
VEN Rising
VEN Falling
VEN = 5V
Min
6.2
0.4
2
VUVP
VHys
TJ Rising
Typ
120
3
0.1
8.5
1.4
1.0
5
Max
140
4
0.15
2.2
2.4
2.0
Units
µA
mA
Ω
A
V
V
µA
V
0.3
V
150
20
125
10
°C
°C
°C
°C
Notes:
5) The device is not guaranteed to function outside its operating rating.
6) Electrical Characteristics are for the IC only with no external components except bypass capacitors.
7) Not production tested.
MP7770 Rev. 1.02
7/16/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
5
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
OPERATING SPECIFICATIONS (8)
Circuit of Figure 6, Single-Ended Output Configuration; VDD = 34V, Gain=8.2V/V; VEN = 5V, TA =
25°C, unless otherwise noted.
Parameters
Standby Current
Quiescent Current
Power Output
THD + Noise
Efficiency
Maximum Power Bandwidth
Dynamic Range
Noise Floor
Power Supply Rejection
Symbol Condition
VEN = 0V
Switching, no load
f = 1kHz, THD+N = 10%, 4Ω Load
f = 1kHz, THD+N = 1%, 4Ω Load
f = 1kHz, THD+N = 10%, 8Ω Load
f = 1kHz, THD+N = 1%, 8Ω Load
POUT = 1W, f = 1kHz, 4Ω Load
POUT = 1W, f = 1kHz, 8Ω Load
f = 1kHz, POUT = 41W, 4Ω Load
f = 1kHz, POUT = 22W, 8Ω Load
Min
A-Weighted
VRIPPLE=300mVPP
CR=100μF
f = 1k Hz
f = 217 Hz
Typ
120
29
41
32
22
17
0.05
0.03
91
95
20
102
90
-60
-60
Max
Units
μA
mA
W
W
W
W
%
%
%
%
kHz
dB
μV
dB
dB
Circuit of Figure 7, BTL Output Configuration; VDD = 34V, Gain=15V/V; VEN = 5V, TA = 25°C,
unless otherwise noted.
Parameters
Standby Current
Quiescent Current
Power Output
THD+ Noise
Efficiency
Symbol Condition
VEN = 0V
Switching, no load
f = 1kHz, THD+N = 10%, 6Ω Load
f = 1kHz, THD+N = 1%,6Ω Load
POUT = 1W, f = 1kHz, 6Ω Load
POUT = 1W, f = 1kHz, 8Ω Load
f = 1kHz, POUT = 108W, 6Ω Load
f = 1kHz, POUT = 84W, 8Ω Load
Maximum Power Bandwidth
Dynamic Range
Noise Floor
A-Weighted
Power Supply Rejection
VRIPPLE=300mVPP
f = 1k Hz
f = 217 Hz
Min
Typ
120
32
108
83
0.06
0.04
91
95
20
105
120
-60
-60
Max
Units
μA
mA
W
W
%
%
%
%
kHz
dB
μV
dB
dB
Note:
8) Operating Specifications are for the IC in Typical Application circuit (Figure 6 and Figure 7).
MP7770 Rev. 1.02
7/16/2015
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© 2015 MPS. All Rights Reserved.
6
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
PIN FUNCTIONS
EP on Bottom
Pin #
Name
1
EN
2
3, 12
UVP
N/C
4
TIMER1
5
IN1
6
REF1
7
AGND1
8
AGND2
9
REF2
10
IN2
11
TIMER2
13
FAULT
14
OTW
15
BST2
16, 17
18, 19
PGND2
SW2
20, 21
VDD2
22, 23
VDD1
24, 25
SW1
26,27
PGND1
28
BST1
MP7770 Rev. 1.02
7/16/2015
Description
Enable Input for Amplifier 1. Drive EN1 high to turn on the Amplifier 1, low to turn it
off.
Under-Voltage Protection Reference Input.
Not Connected.
Internal Timer Input for Amplifier 1. A capacitor from TIMER1 to AGND sets the
internal timer which is used for start-up pop elimination.
Inverting Input for Amplifier 1 .
Internal Analog Reference (VDD/2) for Amplifier 1. For SE configuration, connect a
bypass capacitor from REF1 to AGND (10μF).
Analog Ground for Amplifier 1. Connect AGND1 to AGND2. Connect PGND to AGND
at a single point.
Analog Ground for Amplifier 2. Connect AGND2 to AGND1.
Internal Analog Reference (VDD/2) for Amplifier 2. For BTL configuration, connect a
bypass capacitor from REF2 to AGND (10μF).
Inverting Input for Amplifier 2.
Internal Timer Input for Amplifier 2. Use a capacitor from TIMER2 to AGND to set the
internal timer for start-up pop elimination.
Fault Output. A low output at FAULT indicates that the IC has detected an overtemperature or over-current condition. This output is open drain.
Over Temperature Warning. A low output at OTWB indicates that the die temperature
rises above 125°C. This output is open drain.
High-Side MOSFET Bootstrap Input for Amplifier 2. Connect a capacitor from BST2
to SW2 to supplies the gate drive to the internal High-Side MOSFET.
Power Ground for Amplifier 2. Connect PGND2 to PGND1.
Switched Power Output for Amplifier 2.
Power Supply Input for Amplifier 2. Bypass VDD2 to PGND2 with a 1μF X7R
capacitor (in addition to the main bulk capacitor), placed close to the VDD2 and
PGND2 pins.
Power Supply Input for Amplifier 1. Bypass VDD1 to PGND1 with a 1μF X7R
capacitor (in addition to the main bulk capacitor), placed close to the VDD1 and
PGND1 pins.
Switched Power Output for Amplifier 1.
Power Ground for Amplifier 1. Connect PGND1 to PGND2. Connect PGND to AGND
at a single point.
High-Side MOSFET Bootstrap Input for Amplifier 1. A capacitor from BST1 to SW1
supplies the gate drive current to the internal High-Side MOSFET.
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7
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
TYPICAL PERFORMANCE CURVES
Circuit of Figure 6, single-ended output configuration, VDD=34V, VEN=5V, AV=8.2V/V, TA = +25°C,
unless otherwise noted.
MP7770 Rev. 1.02
7/16/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
8
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
TYPICAL PERFORMANCE CURVES (continued)
Circuit of Figure 6, single-ended output configuration, VDD=34V, VEN=5V, AV=8.2V/V, TA = +25°C,
unless otherwise noted.
+0
-20
-20
-10
-40
-40
-60
-80
-100
-120
AMPLITUDE (dBV)
+0
AMPLITUDE (dB)
AMPLITUDE (dBV)
+0
-60
-80
-100
1k
100
10k 30k
60
200 500 1k
FREQUENCY (Hz)
100
40
90
35
50
40
Right to Left
30
Left to Right
10k 20k
0
10
20
FREQUENCY (Hz)
25
20
15
30
40
0
50
P OUT (W)
140
70
60
120
60
50
100
50
40
80
40
30
60
30
20
40
20
10
20
10
0
0
20
30
VDD (V)
40
0
10
20
30 40 50
P OUT (W)
0
10
20
30
VDD (V)
40
Note: Dash line region is thermal limited
70
10
10k 20k
5
10
0
1k
10
20
0
100
30
60
-60
1k
-60
FREQUENCY (Hz)
70
-40
100
-50
-80
20
30k
80
-100
POUT (W)
5k 10k
POUT (W)
AMPLITUDE (dB)
-20
-120
20
-40
FREQUENCY (Hz)
+0
-80
-30
-70
-120
20
-20
60
70
0
0
5
10
15 20 25
P OUT (W)
30
35
Note: Dash line region is thermal limited
MP7770 Rev. 1.02
7/16/2015
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© 2015 MPS. All Rights Reserved.
9
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
TYPICAL PERFORMANCE CURVES (continued)
Circuit of Figure 6, single-ended output configuration, VDD=34V, VEN=5V, AV=8.2V/V, TA = +25°C,
unless otherwise noted.
MP7770 Rev. 1.02
7/16/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
10
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
TYPICAL PERFORMANCE CURVES (continued)
Circuit of Figure 7, bridge-tied-load output configuration, VDD=34V, VEN=5V, AV=15V/V, TA = +25°C,
unless otherwise noted.
MP7770 Rev. 1.02
7/16/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
11
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
TYPICAL PERFORMANCE CURVES (continued)
Circuit of Figure 7, bridge-tied-load output configuration, VDD=34V, VEN=5V, AV=15V/V, TA = +25°C,
unless otherwise noted.
+0
+0
AMPLITUDE (dBV)
-40
-60
-80
-100
AMPLITUDE (dB)
-20
-20
AMPLITUDE (dBV)
+0
-10
-40
-60
-80
-100
60
200 500 1k
5k 10k
30k
-30
-40
-50
-60
-70
-120
-120
-20
60
FREQUENCY (Hz)
200 500 1k
5k 10k
30k
-80
20
FREQUENCY (Hz)
100
1k
10k 20k
FREQUENCY (Hz)
POUT vs. Efficiency
VDD = 34V,
Input Signal Frequency=1kHz
100
140
90
90
120
80
80
70
70
POUT (W)
100
60
50
40
60
30
20
10
10
Note: Dash line region is thermal limited
MP7770 Rev. 1.02
7/16/2015
60
40
20
P OUT (W)
80
50
30
0 0 10 20 30 40 50 60 70 80 90
100
0
40
20
0
10
20
30
VDD (V)
40
0
0
20
40
60
P OUT (W)
80
100
Note: Dash line region is thermal limited
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12
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
FUNCTIONAL BLOCK DIAGRAM
VDD1
REF1
BST1
Reference
VDD
IN1
TIMER1
AAMTM
Modulator
SW1
Control &
Gate Drive
UVP
EN
Control
Processor
PGND1
OTP
OCP
OTW
VDD2
FAULT
BST2
OTW
REF2
VDD
Reference
IN2
TIMER2
AAMTM
Modulator
SW2
Control &
Gate Drive
PGND2
AGND1, 2
Figure 1: Functional Block Diagram
MP7770 Rev. 1.02
7/16/2015
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13
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
OPERATION
The MP7770 is a Class D Audio Amplifier that
drives stereo speakers in single-ended
configuration or a mono speaker in bridge-tiedload configuration. It uses MPS’s patented
Analog Adaptive ModulationTM technology to
convert the audio input signal into pulses.
These pulses drive an internal high-current
output stage and—when filtered through an
external inductor-capacitor filter—reproduce the
input signal across the load. Because of the
switching Class D output stage, power
dissipation in the amplifier is drastically reduced
when compared against Class A, B or A/B
amplifiers, and maintains high fidelity with low
distortion.
REF1 and REF2 are the positive inputs of
two amplifiers. They are set to half the
power supply input voltage (VDD/2) by
internal circuit. The input capacitor
decouples the AC signal at the input.
the
DC
the
CIN
The input resister RIN and the feedback resistor
RFB set the amplifier voltage gain as calculated
by the equation:
AV =
−R FB
R IN
Where:
• Channel 1: RFB=RFB1 and RIN=RIN1
• Channel 2: RFB=RFB2 and RIN=RIN2.
The MP7770 includes four high-power
MOSFETs; For each channel, the output driver
stage uses two 100mΩ N-channel MOSFETs to
deliver pulses to the LC output filter to drive the
load. To enhance the high-side MOSFET (HSFET), the gate is driven to a voltage higher than
the source by the bootstrap capacitor between
SW and BS. When the output is low, the
bootstrap capacitor is charged from VDD through
an internal circuit on the MP7770. The gate of
the HS-FET is driven high by the BST voltage,
forcing the MOSFET gate to a voltage higher
than VDD, thus allowing the MOSFET to turn on
and reducing amplifier power loss.
MP7770 Rev. 1.02
7/16/2015
Pop Elimination
When used in a single-ended output
configuration, the capacitors COUT1 and COUT2
block the DC signal and pass the AC signals to
the load. To insure that the amplifier only
passes low-frequency signals, the time constant
of COUT*RLOAD is large. However, when EN goes
high, the capacitor charges over a long period
and can result in turn-on/turn-off “pop” In typical
amplifiers.
The MP7770 integrates a source-current
function to charge the DC block capacitors
COUT1 and COUT2 and CIN1 and CIN2 at start-up.
Two internally-generated currents flow to the
SW pin (Iinitialization_SW) and the IN pin (Iinitialization_IN)
during start-up, which helps to eliminate turn-on
pop. The rising/falling slew rate of the SW node
start-up current (Iinitialization_SW) is out of audio
band (means rise and falling gradually), can be
adjusted from the timer capacitor CTIMER and the
voltage of SW node; The larger the CTIMER
capacitance, the smaller the slew rate of the
Iinitialization_SW.
After driving the EN pin low, the output SW
immediately switches to high impedance to
eliminate turn-off pop.
Short Circuit/Overload Protection and
Monitoring
The MP7770 is fully-protected against overcurrent and thermal overload conditions as
explained below and \shown in Figure2.
Short Circuit/Overload Protection
The MP7770 has internal overload and shortcircuit protection. The currents in both the highside and low-side MOSFETs (LS-FETs) are
measured and if the current exceeds the short
circuit current limit (typically 8.5A), both
MOSFETs will be turned off for a fixed duration
(around 1ms) before resuming normal operation.
After the fixed duration and the short circuit
condition is removed, the MP7770 will restart
with the start-up sequence that is used for
normal starting to prevent a pop from occurring.
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14
MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER
Over-Temperature Shutdown
Thermal monitoring is also integrated into the
MP7770. If the die temperature rises above
150°C, all switches turn off. The temperature
must fall below 130°C before normal operation
resumes, with the same power-up sequence
used to prevent popping noise.
Over-Temperature Warning Output
The MP7770 includes an open drain, active low
fault indicator output to act as an overtemperature warning (OTW). The OTW pin is
asserted when the die temperature reaches
125°C and goes low until the temperature drops
below 115°C.
Do not apply more than 6V to the OTW pin.
Fault Output
The MP7770 includes an open drain, active low
fault indicator output on the FAULTB pin. A fault
triggers if either the current limit or thermal
shutdown is tripped.
A fault on any channel will cause the FAULTB
pin to pull low. A fault on either channel will
cause the all outputs to go into high impedance.
When the fault goes away, the MP7770 will
resume normal operation.
Normal Operation
No
Overcurrent
detected?
No
No
TEMP>125 °C
?
TEMP>150 °C
?
Yes
Yes
Yes
Disable output,
Fault =L
OTW =L
Disable output ,
Fault =L
No
No
Around 1ms
time out
finished?
Yes
Meet restart
condition (start
up sequence )?
No
No
TEMP