IS31AP2010B

IS31AP2010B
[email protected] MONO FILTER-LESS CLASS-D AUDIO POWER AMPLIFIER
April 2013
GENERAL DESCRIPTION
FEATURES
The IS31AP2010B is a high efficiency, [email protected]
mono filter-less Class-D audio power amplifier. A low
noise, filter-less PWM architecture eliminates the
output filter, reduces external component count,
system cost, and simplifying design.


Operating in a single 5.0V supply, IS31AP2010B is
capable of driving 4Ω speaker load at a continuous
average output of 3W@10% THD+N. The
IS31AP2010B has high efficiency with speaker load
compared to a typical class- AB amplifier.



In cellular handsets, the earpiece, speaker phone, and
melody ringer speaker can each be driven by the
IS31AP2010B. The gain of IS31AP2010B is externally
configurable which allows independent gain control
from multiple sources by summing signals from each
function.




IS31AP2010B is available in UTQFN-9 packages. It
operates from 2.7V to 5.5V over the temperature range
of -40°C to +85°C.
5.0V supply at THD+N = 10%
―3W into 4Ω (Typ.)
―1.68W into 8Ω (Typ.)
Efficiency at 5.0V
―85% at 400mW with a 4Ω speaker
―88% at 400mW with an 8Ω speaker
Less than 1μA shutdown current
Optimized PWM output stage eliminates LC output
filter
Fully differential design reduces RF rectification
and eliminates bypass capacitor
Improved CMRR eliminates two input coupling
capacitors
Integrated click-and-pop suppression circuitry
UTQFN-9 package
RoHS compliant and 100% lead(Pb)-free
APPLICATIONS






Wireless or cellular handsets and PDAs
Portable DVD player
Notebook PC
Portable radio
Educational toys
Portable gaming
TYPICAL APPLICATION CIRCUIT
VBattery
B1,B2
CS
1 F
CIN0.1 F
OUT+
RIN150k
Differential
Input
C1
A1
CIN+
0.1 F
VCC
0.1 F
OUTIN-
C3
A3
IS31AP2010B
IN+
RIN+
150k
C2
Shutdown
Control
SDB
GND
A2,B3
100k
Figure 1
Integrated Silicon Solution, Inc. – www.issi.com
Rev.B, 04/10/2013
Typical Application Circuit
1
IS31AP2010B
PIN CONFIGURATION
Package
Pin Configuration (Top View)
UTQFN-9
PIN DESCRIPTION
No.
Pin
Description
A1
IN+
Positive audio input.
A2, B3
GND
Connect to ground.
A3
OUT-
Negative audio output.
B1, B2
VCC
Power supply.
C1
IN-
Negative audio input.
C2
SDB
Enter in shutdown mode when active low.
C3
OUT+
Positive audio output.
Copyright © 2013 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that: a.) the risk of injury or damage has been minimized; b.) the user assume all such risks; and c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances
Integrated Silicon Solution, Inc. – www.issi.com
Rev.B, 04/10/2013
2
IS31AP2010B
ORDERING INFORMATION
Industrial Range: -40°C to +85°C
Order Part No.
Package
QTY/Reel
IS31AP2010B-UTLS2-TR
UTQFN-9, Lead-free
3000
Integrated Silicon Solution, Inc. – www.issi.com
Rev.B, 04/10/2013
3
IS31AP2010B
ABSOLUTE MAXIMUM RATINGS
Supply voltage, VCC
Voltage at any input pin
Junction temperature, TJMAX
Storage temperature range, TSTG
Operating temperature range, TA
-0.3V ~ +6.0V
-0.3V ~ VCC+0.3V
150°C
-65°C ~ +150°C
−40°C ~ +85°C
Note:
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only
and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications is
not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
VCC = 2.7V ~ 5.5V, TA = 25°C, unless otherwise noted. (Note 1)
Symbol
Parameter
VCC
Supply voltage
|VOS|
Output offset voltage
(measured differentially)
ICC
Quiescent current
ISDB
Shutdown current
fSW
Switching frequency
RIN
Input resistor
Gain
Condition
Min.
2.7
VSDB = 0V, AV = 2V/V
10
VCC = 5.5V, no load
2.6
VCC = 2.7V, no load
1.2
VSDB = 0.4V
High-level input voltage
VIL
Low-level input voltage
Max.
Unit
5.5
V
mV
mA
1
250
Gain ≤ 20V/V
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Rev.B, 04/10/2013
μA
kHz
15
RIN = 150kΩ
VIH
Typ.
kΩ
2
V/V
1.4
V
0.4
V
4
IS31AP2010B
ELECTRICAL CHARACTERISTICS
TA = 25°C, Gain = 2V/V, CIN = 2μF, unless otherwise noted. (Note 2)
Symbol
Parameter
Condition
THD+N = 10%
f = 1kHz, RL = 8Ω
THD+N = 10%
f = 1kHz, RL = 4Ω
PO
Output power
THD+N = 1%
f = 1kHz, RL = 8Ω
THD+N = 1%
f = 1kHz, RL = 4Ω
Min.
Typ.
VCC = 5.0V
1.68
VCC = 4.2V
1.2
VCC = 3.6V
0.88
VCC = 5.0V
3.0
VCC = 4.2V
2.0
VCC = 3.6V
1.5
VCC = 5.0V
1.4
VCC = 4.2V
1.0
VCC = 3.6V
0.7
VCC = 5.0V
2.4
VCC = 4.2V
1.68
VCC = 3.6V
1.2
VCC = 4.2V, PO = 0.6W, RL = 8Ω, f = 1kHz
0.18
VCC = 4.2V, PO = 1.1W, RL = 4Ω, f = 1kHz
0.22
Max.
Unit
W
W
W
W
THD+N
Total harmonic
distortion plus noise
VNO
Output voltage noise
VCC = 4.2V, f = 20Hz ~ 20kHz
Inputs AC-grounded
80
μVrms
TWU
Wake-up time
shutdown
VCC = 3.6V
32
ms
SNR
Signal-to-noise ratio
PO = 1.0W, RL = 8Ω, VCC = 4.2V
91
dB
from
Power supply rejection f = 217Hz，RL = 8Ω
PSRR
ratio
Input grounded
VCC = 5.0V
-75
VCC = 4.2V
-70
VCC = 3.6V
-66
%
dB
Note 1: All parts are production tested at TA = 25°C. Other temperature limits are guaranteed by design.
Note 2: Guaranteed by design.
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Rev.B, 04/10/2013
5
IS31AP2010B
TYPICAL PERFORMANCE CHARACTERISTIC
20
20
10
RL = 8Ω
f = 1kHz
10
RL = 4Ω
f = 1kHz
VCC = 5.0V
5
VCC = 5.0V
THD+N(%)
THD+N(%)
5
2
VCC = 4.2V
1
0.5
VCC = 4.2V
1
VCC = 3.6V
0.5
VCC = 3.6V
0.2
0.2
0.1
10m
2
50m
20m
100m
500m
1
2
0.1
10m
3
20m
50m
Output Power(W)
Figure 2
THD+N vs. Output Power
Figure 3
5
1
1
THD+N(%)
THD+N(%)
RL = 8Ω
2
0.5
0.2
VCC = 3.6V
Po = 0.45W
VCC = 5.0V
Po = 0.9W
0.05
0.5
4
3
THD+N vs. Output Power
VCC = 4.2V
Po = 1.1W
0.2
VCC = 5.0V
Po = 1.5W
VCC = 3.6V
Po = 0.8W
0.05
VCC = 4.2V
Po = 0.6W
0.02
50
100
200
500
1k
2k
5k
0.01
20
20k
50
100
Frequency(Hz)
Figure 4
200
500
1k
2k
20k
5k
Frequency(Hz)
THD+N vs. Frequency
Figure 5
+0
THD+N vs. Frequency
+0
RL = 8Ω
Input Grouded
-20
-20
RL = 4Ω
Input Grouded
VCC = 5.0V
-40
-40
PSRR(dB)
PSRR(dB)
2
RL = 4Ω
0.1
0.02
0.01
20
1
10
2
0.1
500m
Output Power(W)
10
5
100m
VCC = 5.0V
VCC = 3.6V
-60
VCC = 3.6V
-60
-80
VCC = 4.2V
-80
-100
20
VCC = 4.2V
50
100
200
500
1k
2k
5k
-100
20k
-120
20
50
100
Frequency(Hz)
Figure 6
PSRR vs. Frequency
Integrated Silicon Solution, Inc. – www.issi.com
Rev.B, 04/10/2013
200
500
1k
2k
5k
20k
Frequency(Hz)
Figure 7
PSRR vs. Frequency
6
IS31AP2010B
200
100
80
100
RL=8Ω
Efficiency(%)
Output Voltage(uV)
VCC = 3.6V~5.0V
RL = 4Ω, 8Ω
70
50
30
20
RL=4Ω
60
40
20
VCC = 5.0V
10
20
50
100
200
500
1k
2k
5k
Frequency(Hz)
Figure 8
Noise
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Rev.B, 04/10/2013
20k
0
0
0.3
0.6
0.9
1.2
1.5
Output Power(W)
Figure 9
Efficiency
7
IS31AP2010B
FUNCTIONAL BLOCK DIAGRAM
Integrated Silicon Solution, Inc. – www.issi.com
Rev.B, 04/10/2013
8
IS31AP2010B
APPLICATION INFORMATION
FULLY DIFFERENTIAL AMPLIFIER
The IS31AP2010B is a fully differential amplifier with
differential inputs and outputs. 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 VCC/2 regardless of the common-mode
voltage at the input. The fully differential IS31AP2010B
can still be used with a single-ended input; however,
the IS31AP2010B should be used with differential
inputs when in a noisy environment, like a wireless
handset, to ensure maximum noise rejection.
ADVANTAGES OF FULLY DIFFERENTIAL
AMPLIFIERS
The fully differential amplifier does not require a
bypass capacitor. This is because any shift in the
mid-supply affects both positive and negative channels
equally and cancels at the differential output.
GSM handsets save power by turning on and shutting
off the RF transmitter at a rate of 217Hz. The
transmitted signal is picked-up on input and output
traces. The fully differential amplifier cancels the signal
much better than the typical audio amplifier.
COMPONENT SELECTION
Figure 10 shows the IS31AP2010B with differential
inputs and input capacitors, and Figure 11 shows the
IS31AP2010B with single-ended inputs. Differential
inputs should be used whenever possible because the
single-ended inputs are much more susceptible to
noise.
VBattery
B1,B2
CS
1 F
CIN0.1 F
OUT+
RIN150k
Differential
Input
C1
A1
CIN+
0.1 F
OUTIN-
C2
A2,B3
100k
Figure 10
Gain 
2  RF  V 
R IN
 
V 
(1)
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
IS31AP2010B to limit noise injection on the
high-impedance nodes.
DECOUPLING CAPACITOR (CS)
IN+
GND
The input resistors (RIN) set the gain of the amplifier
according to Equation (1).
A3
IS31AP2010B
SDB
INPUT RESISTORS (RIN)
C3
RIN+
150k
Shutdown
Control
Single-Ended Input
For optimal performance the gain should be set to
2V/V or lower. Lower gain allows the IS31AP2010B to
operate at its best, and keeps a high voltage at the
input making the inputs less susceptible to noise.
VCC
0.1 F
Figure 11
Differential Input
Integrated Silicon Solution, Inc. – www.issi.com
Rev.B, 04/10/2013
The IS31AP2010B is a high performance Class-D
audio amplifier 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, typically 1μF, placed as close as possible to
the device VCC lead works best. Placing this
decoupling capacitor close to the IS31AP2010B 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.
9
IS31AP2010B
INPUT CAPACITORS (CIN)
The input capacitors and input resistors form a high
pass filter with the corner frequency, fC, determined in
Equation (2).
1
f 
c 2R C
IN
IN
(2)
If summing left and right inputs with a gain of 1V/V, use
RIN1 = RIN2 = 300kΩ.
If summing a ring tone and a phone signal, set the
ring-tone gain to Gain1 = 2V/V, and the phone gain to
Gain2 = 0.1V/V. The resistor values would be
RIN1 = 150kΩ, RIN2 = 3MΩ.
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.
C IN 
1
2R IN f C
(3)
Figure 12
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 (1μF). However, in a GSM phone
the ground signal is fluctuating at 217Hz, but the signal
from the codec does not have the same 217Hz
fluctuation. The difference between the two signals is
amplified, sent to the speaker, and heard as a 217Hz
hum.
SUMMING A DIFFERENTIAL INPUT SIGNAL AND A
SINGLE-ENDED INPUT SIGNAL
Figure 13 shows how to sum a differential input signal
and a single-ended input signal. Ground noise may
couple in through IN- with this method. It is better to
use differential inputs. The gain for each input source
can be set independently by Equations (4) and (5). The
corner frequency of the single-ended input is set by
CIN2, shown in Equation (6).
C IN 2 
SUMMING INPUT SIGNALS
Most wireless phones or PDAs need to sum signals at
the audio power amplifier or just have two signal
sources that need separate gain. The IS31AP2010B
makes it easy to sum signals or use separate signal
sources with different gains. Many phones now use the
same speaker for the earpiece and ringer, where the
wireless phone would require a much lower gain for
the phone earpiece than for the ringer. PDAs and
phones that have stereo headphones require summing
of the right and left channels to output the stereo signal
to the mono speaker.
SUMMING TWO DIFFERENTIAL INPUT SIGNALS
Two extra resistors are needed for summing
differential signals (a total of 5 components). The gain
for each input source can be set independently (see
Equations (4) and (5) and Figure 12).
Gain1 
VO 2  150 k  V 

 
R IN 1
VI 1
V 
Gain 2 
VO 2  150 k

R IN 2
VI 2
V 
 
V 
Summing Two Differential Inputs
1
2RIN 2 f C
(6)
To assure that each input is balanced, the
single-ended input must be driven by a low-impedance
source even if the input is not in use. If summing a ring
tone and a phone signal, the phone signal should use
a differential input signal while the ring tone might be
limited to a single-ended signal. Ring-tone gain is set
to Gain1 = 2V/V, and phone gain is set to Gain2 =
0.1V/V, the resistor values would be RIN1 = 150kΩ, RIN2
= 3MΩ.
The high pass corner frequency of the single-ended
input is set by CIN2. If the desired corner frequency is
less than 20Hz.
So, C IN 2 
1
2 150 k  20 Hz
and C IN 2  53 pF
(4)
(5)
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Rev.B, 04/10/2013
10
IS31AP2010B
Figure 14
Figure 13
Summing Differential Input and Single-Ended Input
Signals
Summing Two Single-Ended Inputs
EMI EVALUATION RESULT
80
dBuV/m
70
SUMMING TWO SINGLE-ENDED INPUT SIGNALS
The gain and corner frequencies (fC1 and fC2) for each
input source can be set independently by Equations (4)
and (5). Resistor, RP, and capacitor, CP, are needed on
the IN+ terminal to match the impedance on the INterminal. The single-ended inputs must be driven by
low impedance sources even if one of the inputs is not
outputting an ac signal.
1
2RIN 1 f C
(7)
1

2RIN 2 f C
(8)
C IN 1 
C IN 2
C p  C IN 1  C IN 2
RP 
R IN 1  R IN 2
R IN 1  R IN 2 
60
50
RE_B
40
30
20
10
(9)
0
30
1000 MHz
100
Figure 15
EMI Evaluation Result
(10)
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Rev.B, 04/10/2013
11
IS31AP2010B
CLASSIFICATION REFLOW PROFILES
Profile Feature
Pb-Free Assembly
Preheat & Soak
Temperature min (Tsmin)
Temperature max (Tsmax)
Time (Tsmin to Tsmax) (ts)
150°C
200°C
60-120 seconds
Average ramp-up rate (Tsmax to Tp)
3°C/second max.
Liquidous temperature (TL)
Time at liquidous (tL)
217°C
60-150 seconds
Peak package body temperature (Tp)*
Max 260°C
Time (tp)** within 5°C of the specified
classification temperature (Tc)
Max 30 seconds
Average ramp-down rate (Tp to Tsmax)
6°C/second max.
Time 25°C to peak temperature
Figure 16
8 minutes max.
Classification Profile
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Rev.B, 04/10/2013
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IS31AP2010B
PACKAGING INFORMATION
UTQFN-9
Note: All dimensions in millimeters unless otherwise stated.
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Rev.B, 04/10/2013
13