ETC LX1722CDB

AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
KEY FEATURES
DESCRIPTION
A complete audio amplifier module is
available to quickly evaluate the LX1721
or LX1722 stereo controller. Simply
connect the amplifier to the power source,
audio signal, and speakers. Reference
designs support a variety of requirements
including
multi
channel
systems,
subwoofers, satellite / subwoofer combinations and various speaker loads (2Ω,
4Ω, 8Ω). The versatile amplifier solution
can easily be adjusted for frequency
response, optimized for efficiency and
performance, or designed to minimize
PCB area and component count. The
LX1721/1722 is available in a space
saving 44-pin QSOP package.
(Continued Next Page)
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
PRODUCT HIGHLIGHT
! Integrated Switching Class-D
Stereo Controller IC
! Full 20Hz-20kHz Audio
Bandwidth
! High Fidelity (LX1721) Or
High Power (LX1722)
Versions Available
! Single Supply Operation
! THD+N <0.06% Typical
(1Wrms, 1kHz, 4Ω)
! Maximum Efficiency 80%85%
! Output Power >60Wrms per
Channel (LX1722, 4Ω, 1%
THD+N)
! PSRR –70dB Typical
! Differential Input To Minimize
Noise Effects
! Supports Multi-Channel
Systems
! Complete LXE1721or
LXE1722 Amplifier Evaluation
Module Available
! 44-Pin QSOP Package
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The LX1721/1722 is a monolithic high
performance Class-D stereo controller IC
designed for high efficiency or space
constrained audio requirements such as
portable or battery operated products,
automotive amplifiers, and multi-channel
multimedia computer and video game
applications. This high frequency, full
audio bandwidth switching power
amplifier controller offers dramatically
improved performance over Linfinity’s
previous generation amplifier products.
Enhancements include higher output
power, better SNR, lower noise floor, and
reduced THD. Combined with output
power MOSFET’s and an output filter, the
LX1721/1722 is a complete Class-D audio
solution.
7V - 25V
Channel
1
IN +
IN -
FETs
Left
FETs
Right
Output Power vs. Supply Voltage
1kHz, 4Ω, THD+N=1%
LX1722
Stereo
Channel 2
IN +
IN -
2Ω, 4Ω, 8Ω
CLOCK
LX1711
Channel 3
Mono
FETs
IN +
IN -
Subwoofer
2.1 Audio Amplifier
Configuration
APPLICATIONS
! Multimedia Speakers
! Surround Sound Game
Systems
! Notebook Computers
! Desktop Computers
! Automotive Amplifiers And
Head units
! Battery Operated Equipment
(Megaphone, Public Address
System)
! Portable Audio (Boom Box)
! Wireless Speakers
! High Power Subwoofer
! Automotive Audio Systems
! Home Theatre
LX1721 / 22
PACKAGE ORDER INFO
TJ (°°C)
VDD
0 to 70
0 to 70
7V – 15V
7V – 25V
DB
Plastic QSOP
44-Pin
LX1721CDB
LX1722CDB
Note: Available in Tape & Reel.
Append the letter “T” to the part number. (i.e. LX1722CDBT)
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
PACKAGE PIN OUT
DB
44-PIN QSSOP PACKAGE
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
LFAOUT
50°°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
1
44
LFBK-
CPWM
LFBK+
RPWM
LISN
LMUTE
VDD
LEAOUT
CN
LEAIN
PVDD
VREF
PGND
CLOCK
LN+
GND
LP+
V25
LP-
LIN+
LN-
LIN-
RN-
LAMPOUT
RP-
RIN+
RP+
RIN-
RN+
RAMPOUT
PGND
SLEEP
CP
STATUS
PVDD
RMUTE
NC
REAIN
RISN
REAOUT
RFAOUT
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THERMAL DATA
RFBK+
22
23
RFBK-
DB PACKAGE
(Top View)
DESCRIPTION (CONTINUTED)
The stereo output controller is available in either an
LX1722 high power version (>65Wrms, 4Ω) with a supply
voltage range of 7V-25V or an LX1721 high fidelity
version (better SNR performance) with a supply voltage
range of 7V-15V. The current rating of the external
MOSFET’s, the available supply voltage, and speaker load
primarily limits the maximum output power. The amplifier
provides high fidelity performance and is designed to
operate over the full 20Hz to 20kHz audio band. Signal
distortion measurements yield
THD+N levels of 0.06%(1kHz, 1Wrms). Efficiency is
greater than 80% typical, which eliminates the need for
heatsinks in most applications. The AudioMAX™ solution
requires a single supply voltage, simplifying input power
requirements where a dual supply may not be available. To
minimize potential environmental noise issues and ease the
integration of the amplifier into a variety of applications,
features such as a balanced/differential audio input and a high
power supply rejection ratio help reduce the effects of noise
from the audio signal or power supply.
PACKAGE DATA
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
PIN NAME
DESCRIPTION
PIN NAME
Left Feedback Amplifier Output
LFBK-
PWM Capacitor Connection
LFBK+
RPWM
LMUTE
LEAOUT
LEAIN
VREF
PWM Resistor Connection
Left Mute Input (Active High)
Left Error Amplifier Output
Left Inverting Input of Error Amplifier
5V Reference
LISN
VDD
CN
PVDD
PGND
CLOCK
Input / Output Clock for Synch Operation
LN+
GND
Low Current Ground
LP+
V25
2.5V Reference
LP-
LIN+
Left Positive Audio Input
LN-
LIN-
Left Negative Audio Input
RN-
LAMPOUT
Left Input Amplifier Output
RP-
RIN+
Right Positive Audio Input
RP+
RIN-
Right Negative Audio Input
RN+
LFAOUT
CPWM
SLEEP
STATUS
RMUTE
REAIN
Right Input Amplifier Output
Sleep Input (active low)
UVLO Indicator (Open Collector Output)
Right Mute Input (Active High)
Right Inverting Input of Error Amplifier
PGND
CP
PVDD
NC
RISN
REAOUT
Right Error Amplifier Output
RFBK+
RFAOUT
Right Feedback Amplifier Output
RFBK-
RAMPOUT
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FUNCTIONAL PIN DESCRIPTION
DESCRIPTION
Left Feedback Amplifier Inverting Input
Left Feedback Amplifier Non-Inverting
Input
Left Current Limit Sense Input
Analog Supply Voltage
Supply Decoupling for NFET Drivers
Output Driver Supply Voltage
Output Driver High Current Ground
Left Drive for NFET on Positive Half of
Bridge
Left Drive for PFET on Positive Half of
Bridge
Left Drive for PFET on Negative Half of
Bridge
Left Drive for NFET on Negative Half of
Bridge
Right Drive for NFET on Negative Half of
Bridge
Right Drive for PFET on Negative Half of
Bridge
Right Drive for PFET on Positive Half of
Bridge
Right Drive for NFET on Positive Half of
Bridge
Output Driver High Current Ground
Supply Decoupling for PFET Drivers
Output Driver Supply Voltage
No Connect
Right Current Limit Sense Input
Left Feedback Amplifier Non-Inverting
Input
Right Feedback Amplifier Inverting Input
ABSOLUTE MAXIMUM RATINGS
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into negative out of the
specified terminal.
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
PACKAGE DATA
Supply Voltage (PVDD, VDD)..............................................................................................................................-0.3V to 30V
SLEEP , STATUS, R/LFBK+, R/LFBK-................................................................................................. -0.3V to VDD +0.3V
R/LISN......................................................................................................................................... PVDD –2 to PVDD to +0.3V
RPWM, CPWM, R/LMUTE....................................................................................................................-0.3V to VREF +0.3V
R/LIN+, R/LIN-, R/LAMPOUT ..............................................................................................................-0.3V to VREF +0.3V
R/LEAIN, R/LEAOUT, R/LFAOUT......................................................................................................-0.3V to VREF + 0.3V
CLOCK ........................................................................................................................................................ -0.3V to CN +0.3V
Operating Junction Temperature Plastic ...........................................................................................................................125°C
Storage Temperature Range............................................................................................................................... -65°C to 150°C
Lead Temperature (Soldering, 10 seconds).......................................................................................................................300°C
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
Parameter
Symbol
Test Conditions
Min
LX1721 / 1722
Typ
Max
Units
Evaluation Module (See Figure 2)
Supply Voltage
LX1721
LX1722
Power Supply Rejection Ratio
Output Power (Per Channel)
VDD
PSRR
PO
Efficiency
Total Harmonic Distortion Plus Noise
Signal-To-Noise Ratio
THD+N
SNR
7
15
7
25
VIN = 15V, VRIPPLE = 1VRMS, 20Hz
to 20kHz
VIN = 15V, RL=4Ω, THD+N=1%,
10Hz to 22kHz
VIN = 25V, RL=4Ω, THD+N=1%,
10Hz to 22kHz
VIN = 15V, fIN = 1kHz, PO = 10W
-70
V
dB
25
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ELECTRICAL CHARACTERISTICS
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C < TA < 70°C.
Test conditions: RPWM = 34.8k, CPWM = 100pF, VDD = PVDD = 15V
W
60
82
VIN = 15V, fIN = 1kHz, PO = 20W
85
fIN = 1kHz, PO = 1W
.06
fIN = 20Hz to 20kHz, PO = 1W
%
.2
RL = 4Ω, PO = 1W
%
81
dBr
335
kHz
Oscillator Section
Oscillator Frequency
FOSC
Charge Current
ICHG
(varies with VDD pin voltage)
-110
µA
Discharge Current
IDIS
(varies with VDD pin voltage)
110
µA
Oscillator Peak Voltage
VPK
(varies with VDD pin voltage)
3.4
V
Oscillator Valley Voltage
VVAL
Voltage Stability
(varies with VDD pin voltage)
1.6
VDD = 8V to 25V
0.6
2
%
1.0
2
%
TA = 0OC to 70OC
Temperature Stability
O
O
TA = -40 C to 125 C
V
1.5
%
‘mV
Error Amplifier
Input Offset Voltage
VIO
5
DC Open Loop Gain
AOL
60
dB
Unity Gain Bandwidth
UGBW
7
‘mHz
High Output Voltage
VOH
IOUT = -100µA
Low Output Voltage
VOL
IOUT = +100µA
50
‘mV
VIN = 1V to VREF
1
µA
3.535
V/V
VREF –1
V
Input Common Mode Range
Input Bias Current
IIN
Stage Gain
Set by Internal Resistors
3.465
Output Voltage, High
VOH
IOUT = -100µA
3.85
Output Voltage, Low
VOL
IOUT = +100µA
Input Impedance
Copyright  2000
Rev. 0.1b,2001-09-19
3.5
V
1.3
42
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
‘mV
‘kΩ
Page 4
ELECTRICALS
Input Amplifier
AudioMAX™
L I N F I N I T Y
D I V I S I O N
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
P RELIMINARY
Units
Feedback Amplifier
Stage Gain
LX1721
LX1722
Set by Internal Resistors
Set by Internal Resistors
89
56
91
57
388
93
58
190
210
500
250
230
mV
‘ns
‘ns
4
4
4
‘cycles
2
2
2
‘cycles
± 50
5
10
‘mV
‘mV
‘mV
‘mV
‘mV
Input Impedance
Current Limit Comparator
Voltage Sense Threshold
Blanking Pulse Delay
Response Time
IUM Pulses required to Current Limit
Latch
Consecutive Clear Pulses required to
reset IUM counter
Reference Voltage Section
Excluding blanking pulse
Initial Accuracy
Voltage Stability
5.000
± 25
2
4
0.5
5
TA = 0OC to 70OC
TA = -40OC to 125OC
VDD = 9V to 15V
IOUT = 0 to 20mA
Temperature Stability
Line Regulation
Load Regulation
Under voltage Lockout Section
Start Threshold Voltage
UV Lockout Hysteresis
UVLO Delay To Output Enable
Supply Current
0.5
Operating Current
V
V
clkcyc
25
µA
5.0
‘mV
1.2
62,500
1.45
1.6
clkcyc
V
1.6
1.7
1.8
V
ISINK = 3mA
ISINK = 75mA
ISOURCE = 3mA, CN = 5.2V
applied externally
ISOURCE = 75mA, CN = 5.2V
applied externally
30
1.5
100
2.0
‘mV
V
30
100
‘mV
1.5
2.0
V
ISINK = 3mA
ISINK = 75mA
ISOURCE = 3mA, CP = 5.2V
(applied externally)
ISOURCE = 75mA, CP = 5.2V
(applied externally)
30
1
100
1.5
‘mV
V
30
100
‘mV
1
1.5
V
Mute Threshold
Output Drivers for N-Channel MOSFETs
VOL
NFET Drivers, High Level Voltage
VOH
Output Drives For P-Channel MOSFETs
PFET Drivers, Low Level Voltage
VOL
PFET Drivers, High Level Voltage
VOH
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
ELECTRICALS
2.9
Sleep to Output Enable
Sleep Threshold
Mute Section
NFET Drivers, Low Level Voltage
kΩ
6.5
6.5
62,500
SLEEP Input = 0V, TA = 25OC
SLEEP Input = 2V, VIN = 15V,
No MOSFETs connected
Sleep Current
‘mV/V
‘mV/V
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Parameter
ELECTRICAL CHARACTERISTICS (CONTINUED)
LX1721 / 1722
Symbol
Test Conditions
Min
Typ
Max
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
10 SLEEP
VDD 25
PVDD
LISN 27
CLOCK 28
RPWM
5
CPWM
6
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BLOCK DIAGRAM
+
-
SYNC
OSC
UVLO
&
REFERENCE
5V
Reference
220mV
1
VREF
4
V25
24 CN
CLK
24 PVDD
5V
Reference
CURRENT SENSE
26 CP
LEAOUT 14
23 LP+
LEAIN 13
LAMPOUT
FAULT
TIMER
ERROR AMP
9
LIN-
8
LIN+
7
OUTPUT
DRIVERS
&
LOGIC
CLK
S
Q
R
Q
22 LN+
21 LN20 LP-
15 LFAOUT
MUTE
MUX
INPUT AMP
17 LFBK-
MUTE
16 LFBK+
2.5V
FEEDBACK AMP
LMUTE 11
2.5V
FIGURE 1 – LX1721 / 22 SIMPLIFIED BLOCK DIAGRAM (LEFT CHANNEL CIRCUIT SHOWN)
BLOCK DIAGRAM
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
Frequency Synchronization
Two or more LX1721 / LX1722 oscillators can be configured for
synchronous operation. One unit, the master, is programmed for
the desired frequency with the RPWM and CPWM as usual.
Additional units will be slave units, and their oscillators will be
disabled by leaving the RPWM pin disconnected. The CLOCK pin
and the CPWM pin of the slave units should be tied to the CLOCK
pin and the CPWM pin of the master unit respectively. In this
configuration, the CLOCK pins of the slave units begin receiving
instead of transmitting clock pulses. Also, the CPWM pins quit
driving the PWM capacitor in the slave units. Note that for
optimum performance, all slave units should be located within a
few inches of the master unit.
Oscillator Configuration (RPWM and CPWM selection)
The oscillator is programmed by the external timing components
RPWM and CPWM. For a nominal frequency of 333kHz, RPWM and
CPWM should be set to 49.9kOhms and 100pF respectively. Note
that in order to keep the slope of the PWM ramp voltage
proportional to the supply voltage, both the ramp peak and valley
voltages, and the charge and discharge currents are proportional to
the supply voltage. This keeps the frequency relatively constant
while keeping the slope of the PWM ramp proportional to the
voltage on the VDD pin. For operating frequencies other than
333kHz, the frequency can be approximated by the following
equation:
Frequency =
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APPLICATION INFORMATION
1
(0.577)( RPWM )(CPWM ) + 320ns
APPLICATION
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 7
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
100
dx=-18.20 W
dy=-0.17812 %
FIGURE 2 – THD+N VS. OUTPUT POWER
50
20
10
5
VIN = 15V
fIN = 1kHz
RL = 4Ω
2
1
THD+N (%)
0.5
0.24563
0.2
0.1
0.06751
0.05
0.02
0.01
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CHARACTERISTIC CURVES
0.005
0.002
0.001
100m
200m
500m
.91611
2
5
10
19.12
20
50
100
Output Power (W)
100
dx=58.73
W
dy=0.47633 %
FIGURE 3 – THD+N VS. OUTPUT POWER
50
20
10
5
VIN = 25V
fIN = 1kHz
RL = 4Ω
2
1
THD+N (%)
0.5
0.53924
0.2
0.1
0.0629
0.05
0.02
0.01
0.005
0.002
0.001
100m
200m
500m
1 1.225
2
5
10
5059.95
20
100
Output Power (W)
100
dx=-36.99 W
dy=-0.22386 %
FIGURE 4 – THD+N VS. OUTPUT POWER
50
20
10
5
2
VIN = 15V
fIN = 1kHz
RL = 2Ω
1
THD+N (%)
0.5
0.26783
0.2
0.1
GRAPHS
0.05
0.04397
0.02
0.01
0.005
0.002
0.001
100m
Copyright  2000
Rev. 0.1b,2001-09-19
200m
500m
1 1.252
2
5
Output Power (W)
10
20
38.24
50
100
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 8
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
dx=108.8
100
W
FIGURE 5 – THD+N VS. OUTPUT POWER
dy=0.48800 %
50
20
10
5
2
VIN = 25V
fIN = 1kHz
RL = 2Ω
THD+N(%)
1
0.5
0.53924
0.2
0.1
0.05
0.05123
0.02
0.01
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CHARACTERISTIC CURVES (CONTINUED)
0.005
0.002
0.001
100m
200m
500m
1.136
1
2
5
10
20
50
109.9
100
200 300
Output Power (W)
100
dx=-4.8988 kHz
dy=-0.17080 %
FIGURE 6 – THD+N VS. FREQUENCY
50
20
10
5
2
VIN = 15V
RL = 4Ω
PO = 1W RMS
1
THD+N (%)
0.5
0.2
0.19402
0.1
0.05
0.02322
0.02
0.01
0.005
0.002
0.001
20
50
100126.2
200
500
1k
2k
5.025k
5k
10k
20k
Frequency (Hz)
100
dx=-4.8988 kHz
dy=-0.11937 %
FIGURE 7 – THD+N VS. FREQUENCY
50
20
10
5
2
VIN = 25V
RL = 4Ω
PO = 1W RMS
1
THD+N (%)
0.5
0.2
0.1798
0.1
0.06044
0.05
GRAPHS
0.02
0.01
0.005
0.002
0.001
20
50
100126.2
200
500
1k
2k
5.025k
5k
10k
20k
Frequency (Hz)
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 9
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
+10
dx=-17.869 kHz
dy=-0.155 dB
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CHARACTERISTIC CURVES (CONTINUED)
FIGURE 8 – FREQUENCY RESPONSE
+8
+6
Voltage Amplification (dBr)
+4
VIN = 15V
RL = 4Ω
PO = 1W RMS
+2
+0
-0.965
-1.119
-2
-4
-6
-8
-10
10
18.220
50
dx=-17.869 kHz
+10
100
200
500
1k
2k
Frequency (Hz)
5k
10k
17.8875k
20k
50k
80k
dy=+0.170 dB
FIGURE 9 – FREQUENCY RESPONSE
+8
+6
Voltage Amplification (dBr)
+4
VIN = 25V
RL = 4Ω
PO = 1W RMS
+2
+0
-1.436
-1.606
-2
-4
-6
-8
-10
10
18.220
50
100
200
500
1k
2k
5k
10k
17.8875k
20k
50k
80k
Frequency (Hz)
+10
dx=-2.9880 kHz
dy=+3.205 dB
FIGURE 10 – NOISE FLOOR FFT
+0
-10
-20
-30
-40
VIN = 15V
RL = 4Ω
10Hz – 22kHz Bandwidth
A-weighted
dBV
-50
-60
-70
-80
-90
-94.916
-100
-98.12
GRAPHS
-110
-120
-130
-140
-150
20
50
100
200
500
.973932k
1k
2k
3.96192k 5k
10k
20k
Frequency (Hz)
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 10
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
CHARACTERISTIC CURVES (CONTINUED)
dx=-2.9880 kHz
dy=-1.969 dB
W W W. Microsemi .COM
+10
FIGURE 11 – NOISE FLOOR FFT
+0
-10
-20
-30
-40
-50
VIN = 25V
RL = 4Ω
10Hz – 22kHz Bandwidth
A-Weighted
dBV
-60
-70
-80
-90
-94.11
-96.079
-100
-110
-120
-130
-140
-150
20
50
100
200
.973932k
1k
500
2k
3.96192k5k
10k
20k
Frequency (Hz)
FIGURE 12 – EFFICIENCY VS. OUTPUT
POWER
90%
85%
Efficency (%)
80%
75%
70%
VIN = 15V
fIN = 1kHz
65%
60%
55%
50%
45%
0
5
10
15
20
25
30
Output Power (W)
8Ω
4Ω
2Ω
FIGURE 13 – POWER SUPPLY REJECTION
RATIO (PSSR)
Power Supply Rejection Ratio (PSRR)
0
-10
-30
PO = 1W RMS
RL = 4Ω
-40
-50
GRAPHS
Amplitude (dB)
-20
-60
-70
-80
-90
-100
10
100
1000
10000
100000
Frequency (Hz)
15V+1,Left
Copyright  2000
Rev. 0.1b,2001-09-19
15V+1,Right
15V-1,Left
15V-1,Right
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 11
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
LISN
R16
Q1
LFBK+
R8
24.3K 1%
C25
220pF
5.1/1W
JP1
Vcc
Vcc
2
1
PGND
Teminal 2
Vcc Vcc
PGND
+ C1
1000µF
25V
L1
Vcc
R6
0.020/1W
C2
0.1uF/25V
OUTL+
LISN
R9
5.1/1W
15uH
Q2
C29
0.68uF/50V
LFBKLFBK+
PGND
R10
U1
C7
1
100pF
2
3
GND
C9
18pF
R5 34.8k 1%
4
5
R2 56.2k 1%
C10 150pF
6
7
+
C13 1uF/10V,TANT
8
9
C14 0.1uF/25V
LIN+
LIN-
RIN+
RIN-
C3
LIN+
10
0.47uF
11
LIN-
12
C4 0.47uF
C5 0.47uF
RIN+
13
14
RINC6
15
0.47uF
16
17
18
19
_MUTE
R4 56.2k 1%
C12150pF
20
21
22
LFBK-
CPWM
LFBK+
RPWM
LISN
_LMUTE
LEAOUT
VDD
CN
LEAIN
PVDD
VREF
PGND
CLOCK
LN+
GND
LP+
V25
LP-
LIN+
LN-
LIN-
RN-
LAMPOUT
RP-
RIN+
RP+
RIN-
RN+
RAMPOUT
SLEEP
PGND
CP
STATUS
PVDD
_RMUTE
NC
REAIN
RISN
REAOUT
RFBK+
RFAOUT
RFBK-
44
43
42
41
40
39
38
C16
0.1uF/25V
LN+
36
LP+
35
LP-
34
LN-
33
RN-
32
RP-
31
RP+
30
RN+
28
27
26
25
C30
0.68uF/50V
5.1/1W
OUTL15uH
R17
R11
5.1/1W
LFBKQ4
24.3K 1%
R18
RFBK-
R12
24.3K 1%
PGND
C20 4.7uF/25V,TANT
L3
C21
47uF/25V
C22
0.1uF/25V
OUTRR13
15uH
Vcc
24
5.1/1W
23
C27
220pF
5.1/1W
Q6
C32
0.68uF/50V
R21
15/1W
PGND
LX1721-01CDB
10k
C26
220pF
Q5
C11 18pF
R3
C31
0.47uF/50V
L2
PGND
C17 4.7uF/25V,TANT
Vcc
C18
+47uF/25V
C19
PGND
0.1uF/25V
37
29
C15
10uF/25V
+
+
SLEEP
Q3
Vcc
LFAOUT
+
10k
+
R1
R20
15/1W
W W W. Microsemi .COM
APPLICATION
R14
Q7
RFBK+
RFBK-
C33
0.68uF/50V
5.1/1W
C34
0.47uF/50V
L4
OUTR+
15uH
R19
R15
R7
0.020/1W
APPLICATION
Vcc
Vcc
RFBK+
RISN
Q8
24.3K 1%
5.1/1W
C28
220pF
RISN
GND
PGND
FIGURE 14 – TYPICAL CLASS-D STEREO SWITCHING AMPLIFIER CIRCUIT APPLICATION
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 12
AudioMAX™
L I N F I N I T Y
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
D I V I S I O N
P RELIMINARY
DB
44-Pin Quarter Size Outline Package (QSOP)
44
Dim
23
A
B
C
D
E
F
G
L
M
P
R
ZD
*LC
R
E
1
P
22
B
F
ZD
D
E
Note:
INCHES
MIN
MAX
0.096
0.104
0.011
0.020
0.091
0.0125
0.698
0.706
0.291
0.299
0.0315 BSC
0.004
0.012
0.016
0.050
0°
8°
0.396
0.414
0.025
0.035
0.033 REF
0.004
* Lead Coplanarity
A
G
MILLIMETERS
MIN
MAX
2.44
2.64
0.28
0.51
0.23
0.32
17.73
17.93
7.40
7.60
0.80 BSC
0.10
0.30
0.40
1.27
0°
8°
10.11
10.51
0.63
0.89
0.51 REF
0.10
W W W. Microsemi .COM
MECHANICAL DIMINSIONS
C
L
M
Dimensions do not include mold flash or protrusions; these shall not exceed 0.15mm (.006”) on any side. Lead dimension shall not include
solder coverage.
MECHANICALS
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 13
AudioMAX™
L I N F I N I T Y
D I V I S I O N
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
P RELIMINARY
W W W. Microsemi .COM
NOTES
NOTES
Preliminary Data – Information contained in this document is pre-production data and is
proprietary to LinFinity. It may not be modified in any way without the express written
consent of LinFinity. Product referred to herein is offered in sample form only and
LinFinity reserves the right to change or discontinue this proposed product at any time.
Copyright  2000
Rev. 0.1b,2001-09-19
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 14