ETC EUA2510

芯美电子
EUA2510
2.7W Boosted Class-D
Audio Power Amplifier
DESCRIPTION
The EUA2510 integrates a current-mode boost converter
with a high efficiency mono, Class D audio power amplifier
to provide 2.7W/10% THD or 2W/1% THD continuous
power into a 4Ω speaker when operating on a 3.3V power
supply with boost voltage (PV1) of 5V. The Class D
amplifier is a low noise, filterless PWM architecture that
eliminates the output filter, reducing external component
count, board area consumption, system cost, and simplifying
design.
The EUA2510’s boost converter, operating at a fixed
frequency of 600KHz, generates a high voltage rail which is
used to supply the Class-D amplifier. The EUA2510 features
a low-power consumption shutdown mode. Shutdown may
be enabled by driving the Shutdown pin to a logic low
(GND).
The gain of the Class D is externally configurable which
allows independent gain control from multiple sources by
summing the signals. Output short circuit and Thermal
shutdown protection prevent the device from damage during
fault conditions. Superior click and pop suppression
eliminates audible transients during power-up and shutdown.
FEATURES
z
z
z
z
z
z
z
z
z
2.7W/10% THD into a 4Ω Load with a 3.3V Supply
Fully Differential Inputs
Externally Configurable Gain on Class D
2.7V - 5V operation (VDD)
Independent Boost and Amplifier Shutdown Pins
0.5µA Shutdown Current
Integrated Pop and Click Suppression Circuitry
3mm × 4mm TDFN-14 Package
RoHS compliant and 100% lead(Pb)-free
APPLICATIONS
z
z
z
z
Mobile Phones
GPS
Portable media
Handheld games
Typical Application Circuit
Figure1.
DS2510
Ver1.0
Feb. 2008
1
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芯美电子
EUA2510
Pin Configurations
Package Type
Pin Configurations
TDFN-14
Pin Description
PIN
TDFN-14
VO1
1
Amplifier Output
GND1
2
GND
PV1
3
Amplifier Power Input
VO2
4
Amplifier Output
5
Boost Regulator Active Low Shutdown
6
Signal Ground (Booster)
FB
7
Feedback point that connects to external resistive divider.
SW
8
Drain of the Internal FET Switch
GND3
9
Power Ground (Booster)
VDD
10
Power Supply
SD
BOOST
GND2
SD
DESCRIPTION
AMP
IN-
11
Amplifier Active Low Shutdown
12
Amplifier Inverting Input
IN+
13
Amplifier Non-Inverting Input
GND
14
GND
DS2510
Ver1.0
Feb. 2008
2
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芯美电子
EUA2510
Ordering Information
Order Number
Package Type
Marking
Operating Temperature range
EUA2510JIR1
TDFN-14
xxxxx
A2510
-40 °C to 85°C
EUA2510
□ □ □ □
Lead Free Code
1: Lead Free 0: Lead
Packing
R: Tape & Reel
Operating temperature range
I: Industry Standard
Package Type
J: TDFN
DS2510
Ver1.0
Feb. 2008
3
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芯美电子
EUA2510
Absolute Maximum Ratings
▓
▓
▓
▓
▓
▓
Supply Voltage, VDD -------------------------------------------------------------------------------------------6V
Input Voltage ------------------------------------------------------------------------------------ -0.3 V to VINA +0.3V
Junction Temperature Range, TJ ------------------------------------------------------------------------------- 150°C
Storage Temperature Rang, Tstg --------------------------------------------------------------------- -65°C to 150°C
ESD Susceptibility -------------------------------------------------------------------------------------------2kV
Thermal Resistance
θJA (TDFN) --------------------------------------------------------------------------------------------------- 47°C/W
Recommended Operating Conditions
Min
Max
Unit
Supply voltage, VDD
2.7
5
V
Operating free-air temperature, TA
-40
85
°C
Electrical Characteristics VDD=3.3V
The following specifications apply for VDD =3.3V,PV1=5V,AV=6dB (Ri=150kΩ), RL=15µH+8Ω+15µH ,fIN=1kHz,
unless otherwise specified. Limits apply for TA=25℃.
Symbol
Parameter
Quiescent Power Supply
Current
Shutdown Current
IDD
I(SD)
VSDIH
Shutdown Voltage Input
High
VSDIL
Shutdown Voltage Input
Low
TWU
Wake-up Time
VOS
Output Offset Voltage
THD+N
DS2510
(SD - AMP ) = (SD - BOOST ) =GND
(SD - AMP )
(SD - BOOST )
(SD - BOOST )
(SD - AMP )
Total Harmonic Distortion
+ Noise
Output Noise
Ver1.0
Feb. 2008
EUA2510
Unit
Min.
Typ. Max.
VIN=0, RLOAD=∞
Output Power
PO
εOS
Conditions
RL=15µH+4Ω+15µH ,THD+N=1% (max),
f=1kHz,22kHz,BW VDD=3.3V
RL=15µH+8Ω+15µH ,THD+N=1% (max),
f=1kHz,22kHz,BW VDD=3.3V
RL=15µH+4Ω+15µH,THD+N=10%(max),
f=1kHz,22kHz,BW
VDD=2.7V
VDD=3.3V
RL=15µH+8Ω+15µH,THD+N=10%(max),
f=1kHz,22kHz,BW
VDD=2.7V
VDD=3.3V
Po=500mW, f=1kHz, RL=15µH+8Ω+15µH
VDD=2.7V
Po=500mW, f=1kHz, RL=15µH+8Ω+15µH
VDD=3.3V
VDD=3.3V,f=20Hz~20kHz
Inputs to AC GND, No weighting
input referred
VDD=3.3V,f=20Hz~20kHz
Inputs to AC GND, A weighting
input referred
7.6
mA
1
µA
1.3
1.3
V
V
0.35
0.35
V
V
11.4
ms
4
mV
2.2
1.4
2.1
2.7
W
1.7
1.7
0.189
%
0.186
%
61
µVRMS
44
µVRMS
4
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EUA2510
Electrical Characteristics VDD=3.3V
The following specifications apply for VDD =3.3V,PV1=5V,AV=6dB (Ri=150kΩ), RL=15µH+8Ω+15µH ,fIN=1kHz,
unless otherwise specified. Limits apply for TA=25℃.
Symbol
AV
PSRR
CMRR
η
VFB
UVLO
IOL
DS2510
Parameter
Conditions
EUA2510
Max.
Min.
Typ.
Unit
300 kΩ /Ri
V/V
-75.4
dB
-68
dB
-51
dB
Gain
VRIPPLE=200mVP-P Sine
f=RIPPLE=217Hz
Power Supply Rejection Ratio VRIPPLE=200mVP-P Sine
f=RIPPLE=1Hz
VRIPPLE=200mVP-P Sine
f=RIPPLE=10Hz
Common Mode Rejection
Ratio
VRIPPLE=200mVP-P, f=RIPPLE=217Hz
-52
dB
Efficiency
PO=1W, f=1kHz, RL=15µH+8Ω+15µH
VDD=3.3V
77
%
FB Regulation Voltage
Boost Converter Switching
Frequency
Class D Switching Frequency
Under Voltage Lockout
Output Current Limit
Ver1.0
Feb. 2008
1.20
1.25
1.30
V
450
600
750
kHz
200
2.2
1700
250
2.4
2200
300
2.6
2700
kHz
V
mA
5
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EUA2510
Typical Operating Characteristics
DS2510
Ver1.0
Figure2.
Figure3.
Figure4.
Figure5.
Figure6.
Figure7.
Feb. 2008
6
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芯美电子
EUA2510
Figure8.
Figure9.
Power Dissipation vs Output Power VDD=2.7V
Power Dissipation vs Output Power VDD=3.3V
0.7
1.0
0.6
POWER DISSIPATION(W)
POWER DISSIPATION(W)
0.8
0.5
RL=4 ohm
0.4
0.3
RL=8 ohm
0.2
0.6
RL=4 ohm
0.4
RL=8 ohm
0.2
0.1
0.0
0.0
0.0
0.2
0.4
0.6
0.8
1.0
0.0
1.2
0.2
0.4
Figure10.
Power Dissipation vs Output Power VDD=4.2V
1.0
1.2
1.4
1.6
Power Supply Current vs Output Power VDD=2.7V
700
600
Power SUPPLY CURRENT(mA)
0.8
POWER DISSIPATION(W)
0.8
Figure11.
1.0
0.6
RL=4 ohm
0.4
RL=8 ohm
0.2
0.0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Feb. 2008
RL=4 ohm
400
300
RL=8 ohm
200
100
0.0
0.2
0.4
0.6
0.8
OUTPUT POWER(W)
Figure13.
Figure12.
Ver1.0
500
0
1.8
OUTPUT POWER(W)
DS2510
0.6
OUTPUT POWER(W)
OUTPUT POWER(W)
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1.0
芯美电子
EUA2510
Power Supply Current vs Output Power VDD=4.2V
Power Supply Current vs Output Power VDD=3.3V
800
800
700
POWER SUPPLY CURRENT(mA)
700
Power Supply Current(mA)
RL=4 ohm
600
500
400
RL=8 ohm
300
200
100
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
500
400
300
RL=8 ohm
200
100
1.6
0.0
0.2
0.4
0.6
0.8
1.0
1.2
OUTPUT POWER(W)
OUTPUT POWER(W)
Figure14.
Figure15.
Figure16.
Figure17.
Supply Current vs. Supply Voltage
RL=no load (Boost Converter+Class D)
9
1.4
1.6
1.8
Feedback Voltage vs. Temperature
1.255
Feedback Voltage (V)
8
POWER SUPPLY CURRENT(mA)
RL=4 ohm
0
0.0
7
6
5
4
3
2
1.25
1.245
1.24
1.235
1
1.23
0
2.7
3.0
3.3
3.6
3.9
4.2
4.5
-40
4.8
POWER SUPPLY VOLTAGE(V)
Ver1.0
Feb. 2008
10
60
110
Temperature (℃)
Figure18.
DS2510
600
Figure19.
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160
芯美电子
EUA2510
Switching Duty Cycle vs. Temperature
RDS(ON) vs. Temperature (Boost Converter)
300
73.2
250
73
200
RDS(ON) (mΩ)
Duty Cycle (%)
73.4
72.8
72.6
150
100
72.4
Vin=3.3V
72.2
72
-40
50
Vin=3.3V
Vin=4.5V
-10
20
50
80
110
Vin=4.5V
0
-40
140
-20
0
20
40
60
80
100
120
Temperature (℃)
Temperature (℃)
Figure20.
Figure21.
Output Power vs. Efficiency
RL=4 ohm (Boost Converter+Class D)
RDS(ON) vs. VIN (Boost Converter)
250
100
90
200
VDD=5V
80
EFFICIENCY(%)
RDS(ON) (mΩ)
70
150
100
VDD=3.3V
VDD=2.7V
60
50
40
30
20
50
10
0
0.00
0
2.5
3
3.5
4
4.5
0.25
0.50
5
0.75
1.00
1.25
1.50
1.75
2.00
OUTPUT POWER(W)
VIN (V)
Figure23.
Figure22.
Output Power vs. Efficiency
RL=8 ohm(Boost Converter+Class D)
100
1600
VDD=5.0V
90
Max Load Current (mA)
1400
80
70
EFFICIENCY(%)
Max Load Current vs. Vin
Vout=5V
VDD=2.7V
60
VDD=3.3V
50
40
30
1200
1000
800
600
400
20
200
10
0
0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
2.5
1.4
Figure24.
DS2510
Ver1.0
Feb. 2008
3
3.5
4
4.5
Vin (V)
OUTPUT POWER(W)
Figure25.
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5
芯美电子
EUA2510
Application Information
Fully Differential Amplifier
The EUA2510 integrates a boost converter with a high
efficiency mono, class-D audio power amplifier. The fully
differential amplifier consists of a differential amplifier
and a common-mode amplifier. The differential amplifier
ensures that the amplifier outputs a differential voltage on
the output that is equal to the differential input times the
gain. The common-mode feedback ensures that the
common-mode voltage at the output is biased around
VDD/2 regardless of the common-mode voltage at the
input. The fully differential class-D can still be used with
a single-ended input; however, the class-D should be used
with differential inputs when in a noisy environment, like
a wireless handset, to ensure maximum noise rejection.
Operating Ratings
The boost converter takes a low supply voltage (VDD),
and increase it to a higher output voltage (PV1). PV1 is
the power supply for the Class D amplifier. The Class D
amplifier operating rating is 2.5V≤(PV1)≤5.5V when
being used without the Boost. Note the output voltage
(PV1) has to be more than VDD.
Setting the Boost
Output Voltage
An external feedback resistor divider is required to divide
the output voltage down to the nominal 1.25V reference
voltage. The current drawn by the resistor network should
be limited to maintain the overall converter efficiency.
The maximum value of the resistor network is limited by
the feedback input bias current and the potential for noise
being coupled into the feedback pin. Selecting R2 in the
range of 10kΩ to 50 kΩ. The boost converter output
voltage s determined by the relationship:
 R 
=V
× 1 + 1 
V
OUT
FB 
R 

2
The nominal VFB voltage is 1.25V
Inductor Selection
The inductor selection determines the output ripple
voltage, transient response, output current capability, and
efficiency. Its selection depends on the input voltage,
output voltage, switching frequency, and maximum output
current. For most applications, a 4.7µH inductor is
recommended for 600KHz.The inductor maximum DC
current specification must be greater than the peak
inductor current required by the regulator. The peak
inductor current can be calculated:
Output Capacitor
Low ESR capacitors should be used to minimized the
output voltage ripple. Multilayer ceramic capacitors (X5R
and X7R) are preferred for the output capacitors because
of their lower ESR and small packages. Tantalum
capacitors with higher ESR can also be used. The output
ripple can be calculated as:
×D
I
OUT
+I
× ESR
∆V =
OUT
O
×C
F
O
SW
Choose an output capacitor to satisfy the output ripple and
load transient requirement. A 4.7µF to 10µF ceramic
capacitor is suitable for most application.
Schottky Diode
In selecting the Schottky diode, the reverse break down
voltage, forward current and forward voltage drop must
be considered for optimum converter performance. The
diode must be rated to handle 2A, the current limit of the
EUA2510. The breakdown voltage must exceed the
maximum output voltage. Low forward voltage drop, low
leakage current, and fast reverse recovery will help the
converter to achieve the maximum efficiency.
Selecting Input Capacitor (CS1) for Boost
Converter
An input capacitor is required to serve as an energy
reservoir for the current which must flow into the coil
each time the switch turns ON. This capacitor must have
extremely low ESR, so ceramic is the best choice. A
nominal value of 4.7µF is recommended, but larger values
can be used. Since this capacitor reduces the amount of
voltage ripple seen at the input pin, it also reduces the
amount of EMI passed back along that line to other
circuitry.
Maximum Output Current
The output current capability of the EUA2510 is a
function of current limit, input voltage, operating
frequency, and inductor value. The output current
capability is governed by the following equation:
V
×V
× (V
−V )
IN
OUT
IN
OUT
OUT
=
+ 1/2 ×
I
V
L×V
× FREQ
L(PEAK)
IN
OUT
Ver1.0
Feb. 2008
)
∆I L =inductor ripple current
∆I L =
I
DS2510
(
=I
+ 1 / 2 × ∆I
L
L
L - AVG
Where:
IL=MOSET current limit
I L - AVG =average inductor current
I


VIN ×  VO + VDIODE − V  − VIN 
IN 


 × F
L ×  VO + V

DIODE  S
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EUA2510
VDIODE = Schottky diode forward voltage, typically,
0.6V
FS = switching frequency, 600KHz.
I
I
= OUT
L - AVG
1− D
D = MOSFET turn-on ratio:
V
IN
D = 1−
V
OUT + V
DIODE
Figure 27. Typical Application Schematic With
Differential Input and Input Capacitors
Class D Requirements
Figure 26 shows the class-D typical schematic with
differential inputs and Figure 27 shows the class-D with
differential inputs and input capacitors, and Figure 28
shows the class-D with single-ended inputs. Differential
inputs should be used whenever possible because the
single-ended inputs are much more susceptible to noise.
Table 1. Typical Component Values
REF DES
VALUE
RI
150kΩ ( ± 0.5%)
CS
1µF (+22%,-80%)
CI (1)
3.3nF ( ± 10%)
(1) CI is only needed for single-ended input or if VICM is not
between 0.5 V and VDD – 0.8 V. CI = 3.3 nF (with RI = 150
kΩ) gives a high-pass corner frequency of 321 Hz.
Figure 28. Typical Application Schematic With
Single-Ended Input
Input Resistors (RI)
The input resistors (RI) set the gain of the amplifier
according to equation (1).
Gain =
Figure 26. Typical Application Schematic With
Differential Input for a Wireless Phone
DS2510
Ver1.0
Feb. 2008
2 × 150k Ω
RI
 V  ---------------------------------(1)
 
V
Resistor matching is very important in fully differential
amplifiers. The balance of the output on the reference
voltage depends on matched ratios of the resistors. CMRR,
PSRR, and cancellation of the second harmonic distortion
diminish if resistor mismatch occurs. Therefore, it is
recommended to use 1% tolerance resistors or better to
keep the performance optimized. Matching is more
important than overall tolerance. Resistor arrays with 1%
matching can be used with a tolerance greater than 1%.
Place the input resistors very close to the class-D to limit
noise injection on the high-impedance nodes.
For optimal performance the gain should be set to 2 V/V
or lower. Lower gain allows the class-D to operate at its
best, and keeps a high voltage at the input making the
inputs less susceptible to noise.
11
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EUA2510
Decoupling Capacitor (CS)
The EUA2510 is a high-performance class-D audio
amplifier with boost converter that requires adequate
power supply decoupling to ensure the efficiency is high
and total harmonic distortion (THD) is low. For higher
frequency transients, spikes, or digital hash on the line, a
good low equivalent-series-resistance (ESR) ceramic
capacitor, typically1 µF, placed as close as possible to the
device VDD lead works best. Placing this decoupling
capacitor close to the EUA2510 is very important for the
efficiency of the class-D amplifier, because any resistance
or inductance in the trace between the device and the
capacitor can cause a loss in efficiency. For filtering
lower-frequency noise signals, a 10µF or greater capacitor
placed near the audio power amplifier would also help,
but it is not required in most applications because of the
high PSRR of this device.
Input Capacitors (CI)
The class-D does not require input coupling capacitors if
the design uses a differential source that is biased from
0.5 V to VDD – 0.8 V (shown in Figure 31). If the input
signal is not biased within the recommended common
−mode input range, if needing to use the input as a high
pass filter (shown in Figure 32), or if using a single-ended
source (shown in Figure 33), input coupling capacitors are
required.
The input capacitors and input resistors form a high-pass
filter with the corner frequency, fc, determined in equation
(2).
1
f =
--------------------------------------------(2)
c
2 πR I C I
The value of the input capacitor is important to consider
as it directly affects the bass (low frequency) performance
of the circuit. Speakers in wireless phones cannot usually
respond well to low frequencies, so the corner frequency
can be set to block low frequencies in this application.
Equation (3) is reconfigured to solve for the input
coupling capacitance.
(
)
1
C =
I
2 πR I f c
(
)
Layout Considerations
For high frequency boost converter, it requires very
careful layout of components in order to get stable
operation, low noise and good regulation. Some
guidelines are recommended: Place power components as
close together as possible, keeping their traces short,
direct, and wide. Avoid interconnecting the ground pins
of the power components using vias through an internal
ground plane. Instead, keep the power components close
together and route them in a “star” ground configuration
using component-side coper, then connect the star ground
to internal ground using multiple vias.
For Class-D amplifier, to maintain the highest output
voltage swing and corresponding peak output power, the
PCB traces that connect the output pins to the load and the
supply pins to the power supply should be as wide as
possible to minimize trace resistance.
The use of power and ground planes will give the best
THD+N performance. While reducing trace resistance, the
use of power planes also creates parasite capacitors that
help to filter the power supply line.
The inductive nature of the transducer load can also result
in overshoot on one or both edges, clamped by the
parasitic diodes to GND and VDD in each case. From an
EMI stand- point, this is an aggressive waveform that can
radiate or conduct to other components in the system and
cause interference. It is essential to keep the power and
output traces short and well shielded if possible. Use of
ground planes, beads, and micro-strip layout techniques
are all useful in preventing unwanted interference.
As the distance from the EUA2510 and the speaker
increase, the amount of EMI radiation will increase since
the output wires or traces acting as antenna become more
efficient with length. What is acceptable EMI is highly
application specific. Ferrite chip inductors placed close to
the EUA2510 may be needed to reduce EMI radiation.
The value of the ferrite chip is very application specific.
--------------------------------------------(3)
If the corner frequency is within the audio 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.
For a flat low-frequency response, use large input
coupling capacitors (1 µF). However, in a GSM phone the
ground signal is fluctuating at 217 Hz, but the signal from
the codec does not have the same 217 Hz fluctuation. The
difference between the two signals is amplified, sent to
the speaker, and heard as a 217 Hz hum.
DS2510
Ver1.0
Feb. 2008
12
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EUA2510
Package Information
TDFN-14
SYMBOLS
A
A1
b
E
D
D1
E1
e
L
DS2510
Ver1.0
Feb. 2008
MILLIMETERS
MIN.
MAX.
0.70
0.80
0.00
0.05
0.20
0.35
2.90
3.10
3.90
4.10
1.65
3.25
0.50
0.30
0.50
INCHES
MIN.
0.028
0.000
0.008
0.114
0.153
MAX.
0.031
0.002
0.014
0.122
0.161
0.065
0.128
0.020
0.012
0.020
13
联系电话：１５９９９６４４５７９　８３１５１７１５