Transcript
NOT RECOMMENDED FOR NEW DESIGN
AudioMAX
TM
LX1720
SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC T
H E
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N F I N I T E
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O W E R
O F
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N N O VA T I O N
R O D U C T I O N
DESCRIPTION Its high efficiency (>92%) eliminates the need for heat sinks — even while delivering more than 10WRMS across 8 ohms per channel (20WRMS stereo) with 0.1 ohm SO-8 power FETs. The LX1720's output power is limited only by external FETs and available supply voltage. While offering breakthrough performance capabilities for notebooks, the LX1720 is equally attractive for multimedia systems or to drive full-size home theatre speakers.
PRODUCT HIGHLIGHT
E F F I C I E N C Y C O M PA R I S O N 100
H E E T
■ Integrated Switching (Class-D) Stereo Power Amplifier Controller IC ■ Delivers >10WRMS Across 8Ω /Channel (20WRMS stereo) ■ Output Power Limited Only By External FETs And Available Supply Voltage ■ Will Drive A Wide Range Of Speakers ■ High Efficiency (>92%) ■ Due To High Efficiency, Power FETs Do Not Require Heatsinking ■ Audio Bandwidth Of 20Hz to 20kHz ■ Wide Input Voltage Range Of 7V-15V ■ Low Output Signal Distortion <1% ■ High Operating Frequency (350kHz) Helps To Reduce Output Filter Size ■ Compact Design Minimizes EMI / RFI
OF THE
APPLICATIONS / BENEFITS
CLASS-D AMPLFIER
Notebook Computers:
■ Replaces existing internal low power linear amplifier with a high efficiency Class-D amplifier ■ Enables the use of virtually any external speaker without amplification ■ Precious battery life is extended ■ Fully protected power topology can withstand shorts or external speaker failures without damage, overheating or posing fire hazard
- Average Power Out for 20sec. approx. 512mW - Across 8.6 Ohm Load
Linfinity's LX1720 Class-D Amplifier
80
Efficiency (%)
S
K E Y F E AT U R E S
IMPORTANT: For the most current data, consult LinFinity's web site: http://www.linfinity.com.
Desktop Computers:
60
40
■ Output power capability of up to 20WRMS per channel in an area less than 3"x3", without using expensive heatsinks ■ Greatly reduced power supply requirements when compared to a linear solution of same power capabilities ■ Any speakers can be used including conventional home stereo speakers ■ Very light weight circuitry will not add to the overall weight of the system ■ Multimedia amplifier can be directly incorporated on the motherboard using surface mount components
Highly Integrated Linear Amplifier
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A T A
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The LX1720 is a highly-integrated, Switching Class-D Stereo Power Amplifier Controller IC with power and size features that make it ideal for multimedia computer applications, as well as other applications where high fidelity sound is required. With input voltage ranging from 7V15V, the LX1720 is designed to operate over the full 20Hz to 20kHz audio range. Signal distortion measurements using industry standard 1kHz signal yields THD + noise levels < 1% (10 watts output).
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Audio sample from "Hold On Tight" by Electric Light Orchestra
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APPLICATION NOTE AN-11
Seconds
available on our web site or call 1-800-LMI-7011
PA C K A G E O R D E R I N F O TJ (°C)
Maximum VDD
0 to 70
15V
SSOP DB Plastic 44-pin LX1720-01CDB
Note: Available in Tape & Reel. Append the letter "T" to part number. (i.e. LX1720-01CDBT)
Copyright © 1999 Rev. 1.0 9/99
LINFINITY MICROELECTRONICS INC. 11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570
1
PRODUCT DATABOOK 1996/1997
AudioMAX
LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P
R O D U C T I O N
A B S O L U T E M A X I M U M R AT I N G S
D
A T A
S
H E E T PA C K A G E P I N O U T S
(Note 1)
RISLISIS+ RPWM CPWM CN N.C. CT RT RBIAS GND AGND INPUT (R) INPUT (L) SLEEP EAIN (R) N.C. EAOUT (R) FAOUT (R) EAOUT (L) EAIN (L) FAOUT (L)
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35
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32
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31
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30
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27
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20
25
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Supply Voltage (PVDD, VDD) ...................................................................... -0.3V to 18V RPWM .................................................................................................... -0.3V to VCN+0.3V INPUT (R), INPUT (L) .......................................................................... -0.3V to VCN+0.3V FBK+(R), FBK-(R), FBK+(L), FBK-(L), SLEEP .............................................. -0.3V to VDD MUTE (R), MUTE (L) .................................................................................... -0.3V to 6.0V EAOUT (R), EAOUT (L) ....................................................................... -0.3V to VCN+0.3V CPWM, CT ............................................................................................. -0.3V to VCN+0.3V IS+, LIS-, RIS+ ................................................................................................ VDD-2 to VDD Operating Junction Temperature Plastic (DB Package) ............................................................................................ 125ºC Storage Temperature Range ...................................................................... -65°C to 150°C Lead Temperature (Soldering, 10 seconds) ............................................................ 300°C Note 1. 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.
T H E R M A L D ATA
DB PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
65°C/W
FBK- (R) FBK+ (R) N.C. VDD CP PVDD PGND P- (R) N- (R) N+ (R) P+ (R) P- (L) N- (L) N+ (L) P+ (L) PGND PVDD FBK- (L) FBK+ (L) GND MUTE (L) MUTE (R)
DB PACKAGE (Top View)
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.
FUNCTIONAL PIN DESCRIPTION
Pin Name RISLISIS+
Description
Pin Name
Description
Right Channel Current Sense Input
FAOUT (R)
Output of Right Feedback Amp
Left Channel Current Sense Input
EAOUT (L)
Left Channel Error Amplifier Output
Positive Current Sense Input
RPWM
PWM Resistor Connection
CPWM
PWM Capacitor Connection
CN CT
Oscillator Timing Capacitor Connection Oscillator Timing Resistor
O
RT
Supply Decoupling for NFET Drivers
RBIAS
Bias Setting Resistor for Error Amps
GND
Ground (2-pins)
EAIN (L)
FAOUT (L)
FBK+(R), FBK-(R) CP
Supply Decoupling for PFET Drivers
VDD
Analog Supply Voltage
PGND P+(R), N+(R), P-(R), N-(R)
INPUT (R)
Right Channel Input
P+(L), N+(L),
INPUT (L)
Left Channel Input
EAIN (R)
Right Channel Feedback Inputs
Output Driver Supply Voltage (2-pins)
Audio Input Ground
EAOUT (R)
Output of Left Feedback Amp
PVDD
AGND
SLEEP
Inverting Input of Left Channel Error Amp
IC Power Ground for the Output Drivers (2-pins) Right Channel Gate Drive Outputs Left Channel Gate Drive Outputs
P-(L), N-(L) FBK+(L), FBK-(L)
Sleep Input Inverting Input of Right Channel Error Amp
MUTE (R),
Right Channel Error Amplifier Output
MUTE (L)
Left Channel Feedback Inputs Mute Inputs
NOT RECOMMENDED FOR NEW DESIGN
2
Copyright © 1999 Rev. 1.0 9/99
TM
PRODUCT DATABOOK 1996/1997
AudioMAX
TM
LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P
R O D U C T I O N
D
A T A
S
H E E T
ELECTRICAL CHARACTERISTICS (Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 70°C. Test conditions: RT = 30k, CT = 100pF, VDD = PVDD = 15V.)
Parameter
Symbol
Test Conditions
Min.
LX1720 Typ.
Max.
Units
Oscillator Section 280
330 2.5 200 1 1 2
380
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Oscillator Frequency Oscillator Peak Voltage Oscillator Valley Voltage Oscillator Max. Frequency Voltage Stability Temperature Stability
2
kHz V mV MHz % %
Error Amplifiers
Input Offset Voltage DC Open Loop Gain Unity Gain Bandwidth High Output Voltage Low Output Voltage Input Common Mode Range Input Bias Current
5 60 7
IOUT = -100µA IOUT = +100µA
4
50 5 1
1
mV dB MHz V mV V µA
Input Amplifiers Stage Gain Input Impedance
Set by Internal Resistors
3.465
3.5 42
3.535
V/V kΩ
Feedback Amplifiers
High Output Voltage Low Output Voltage Common Mode Rejection Input Common Mode Range Input Impedance Stage Gain LX1720-01
IOUT = -250µA IOUT = +250µA
4
50
70
0
Set by Internal Resistors
89
VDD
388 91
93
V mV dB V kΩ mV/V
Current Limit Comparators Voltage Sense Threshold Comparator Response Time
200
220 500
240
mV nsec
PWM Comparators
CPWM Delay To Output
250
nsec
RPWM = 75k
75 20
µA Ω
ISINK = 3mA ISINK = 75mA ISOURCE = 3mA ISOURCE = 75mA, CN = 5.2V (applied externally)
30 1 30 1
100 1.5 100 1.5
mV V mV V
ISINK = 3mA ISINK = 75mA ISOURCE = 3mA ISOURCE = 75mA, CP = 5.2V (applied externally)
30 1 30 1
100 1.5 100 1.5
mV V mV V
PWM Current Generator
O
CPWM Charge Current Impedance of Internal Discharge FET
Output Drivers For The N-Channel MOSFETs Ext. NFET Drivers, Low Level Voltage
VOL
Ext. NFET Drivers, High Level Voltage
VOH
Output Drivers For The P-Channel MOSFETs Ext. PFET Drivers, Low Level Voltage
VOL
Ext. PFET Drivers, High Level Voltage
VOH
NOT RECOMMENDED FOR NEW DESIGN Copyright © 1999 Rev. 1.0 9/99
3
PRODUCT DATABOOK 1996/1997
AudioMAX
LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P
R O D U C T I O N
D
A T A
S
H E E T
ELECTRICAL CHARACTERISTICS Parameter
Symbol
(Continued)
Test Conditions
Min.
LX1720 Typ.
Max.
Units
Undervoltage Lockout Section 6.3
Start Threshold Voltage UV Lockout Hysteresis UVLO Delay To Output Enable
6.5 500 976
6.7
V mV clkcyc
Supply Current
1.2
20 5 976 1.45
1.6
µA mA clkcyc V
1.6
1.7
1.8
V
SLEEP Input = 0V, TA = 25°C SLEEP Input = 2V, VIN = 15V, No MOSFETs Connected
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bs ol et e
Sleep Current Operating Current Sleep To Output Enable Sleep Threshold
Mute Section
O
Mute Threshold
NOT RECOMMENDED FOR NEW DESIGN
4
Copyright © 1999 Rev. 1.0 9/99
TM
PRODUCT DATABOOK 1996/1997
AudioMAX
TM
LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P
R O D U C T I O N
D
A T A
S
H E E T
BLOCK DIAGRAM R T
O S C
C T
P G N D
C L K
P V D D
S L E E P V
R B IA S V D D
R E G
U V L O V R E F B IA S
P - (R )
bs ol et e
C N
E A O U T (R ) E A IN (R )
S
F B K + (R )
Q
E rro r A m p
Q
R
F B K - (R )
O U T D R IV A N P R O T E C IR C U
IN P U T (R ) M U T E (R )
N - (R )
P + (R )
C L K
F e e d b a c k A m p
F A O U T (R )
C P
In p u t A m p
P U E R D C T IT
T
N + (R )
S
IO N R Y
P - (L )
V D D
V D D
N - (L )
C L K
R P W M C P W M
S
E A O U T (L )
R
Q
E A IN (L )
E rro r A m p
F B K + (L )
Q
P + (L )
N + (L )
C L K
O
F B K - (L )
M U T E (L )
L IS -
IN P U T (L )
R IS -
IS +
F A O U T (L )
F e e d b a c k A m p
In p u t A m p
FIGURE 1 — LX1720 Block Diagram
NOT RECOMMENDED FOR NEW DESIGN Copyright © 1999 Rev. 1.0 9/99
5
PRODUCT DATABOOK 1996/1997
AudioMAX
LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P
R O D U C T I O N
D
A T A
S
H E E T
T Y P I C A L A P P L I C AT I O N V
IN
= 7 V T O
1 5 V R 6
R C
1 9
C
1 8
C
C
1 7
5
1 6
IS + P V D D
L IS -
R IS Q
1
P - (R )
L
L 1
2
P
R
Q
3
Q
4
P + (R )
IN P U T (L )
N + (R )
S L E E P
S L E E P
R M U T E
R M U T E
L M U T E
L M U T E
C
C
R
7
2 1
R
C
C
(R )
Q
6
N - (L )
L
R
1 0
F A O U T (L )
F B K + (R )
F B K + (R )
F B K - (L )
F B K - (L )
F B K + (L )
F B K + (L )
C P W M
F B K - (R )
7
N + (L )
Q
8
4
C
6
C
8
3
L
5
C
3
6
5
F B K -(L )
1 1
L 7
R
C
4
F B K + (L )
L 8
C
7
1 2
A G N D
For detailed application information please refer to
APPLICATION NOTE AN-11 N
T
C
C C
P W M
O
F B K - (R )
Q
P + (L )
E A IN (L )
C
4
1 0
C
E A O U T (L )
C
F B K + (R )
2 2
9
L
3
2
F A O U T (R )
R
2 3
R
E A IN
R
5
E A O U T (R )
8
L
Q
P - (L )
2
9
C
2 0
C
1
F B K -(R )
P G N D
L E F T IN
IN P U T (R )
G N D
2 5
T
C
1
C
L X 1 7 2 0
C
R
R T
R
C N
2 4
2
R P W M
C T
C
R IG H T IN
Q
N - (R )
C P
P W M
L E F T
C
R IG H T
bs ol et e
V D D
available on our web site or call 1-800-LMI-7011
FIGURE 2 — Typical Class-D Stereo Switching Amplifier Circuit Application
NOT RECOMMENDED FOR NEW DESIGN PRODUCTION DATA - Information contained in this document is proprietary to LinFinity, and is current as of publication date. This document may not be modified in any way without the express written consent of LinFinity. Product processing does not necessarily include testing of all parameters. Linfinity reserves the right to change the configuration and performance of the product and to discontinue product at any time.
6
Copyright © 1999 Rev. 1.0 9/99
TM
