LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
DESCRIPTION
KEY FEATURES
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The MSC-LX1792 offers a patent pending, low voltage, low power, and high efficiency amplifier for driving a high impedance speaker such as a hearing aid receiver. The core of the amplifier is built upon Microsemi’s patented LX1790 class D amplifier.
The LX1790 consists of a preamplifier followed by a fixed gain class D amplifier. The input resistor and feedback resistor is external in the LX1792 making it possible to set the gain arbitrarily, up to approximately 40dB. The feedback resistor can also be potentiometer to facilitate volume control.
! Low Operating Current: 120µA Typical ! Low Operating Voltage: 0.9V minimum ! Gain set by external resistors ! 3 Output Switch Resistance Settings: 48, 24 & 16 Ω ! 5uVrms input referred noise. APPLICATIONS ! Hearing Aid applications ! High impedance speaker /Transducer applications
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
PRODUCT HIGHLIGHT
CLOCK
DIN
PRE AMP
Σ
CMP
HBRIDGE
SPEAKER
PACKAGE ORDER INFO
LX1792 LX1792
TJ (°C) 10 to 55
J
Ceramic Dip 14-Pin LX1792CJ
LM
Plastic MLPM 8-Pin LX1792CLM
DU
Plastic MSOP 8-Pin LX1792CDU
BD
Bare Die LX1792BD
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 1
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
ABSOLUTE MAXIMUM RATINGS Input Logic Supply Voltage (VDD).......................................-0.3V to +3.0V Operating Temperature Range ................................................10°C to 55°C
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal.
PACKAGE PIN OUT
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VSS OUTN IMPSEL
1 2 3 4
8 7 6 5
LM PACKAGE
(Top View)
VDD OUTP PREOUT IN
VSS OUTN IMPSEL
1 2 3 4
8 7 6 5
DU PACKAGE
(Top View)
VDD OUTP PREOUT IN
SETTINGS PIN IMPSEL IMPSEL=VSS 16Ω IMPSEL=VDD 24Ω IMPSEL=Floating 48Ω
OUTN VSS
1 2 3 4 5
14 13 12 11 10 9 8
(Top View)
OUTP VDD
1
6 7
IMPSEL
PREOUT IN
J PACKAGE
FUNCTIONAL PIN DESCRIPTION PIN NAME VDD VSS IN OUTP OUTN PREOUT IMPSEL PIN NO 14 PIN J PIN NO 8 PIN LM PIN NO 8 PIN DU 8 1 5 7 2 6 3 Supply Voltage Ground Analog Audio Input Positive Output Voltage Negative Output Voltage Pre amplifier output Output Resistance Select. See Settings table below for selections. DESCRIPTION
(EVALUATION SAMPLES)
PACKAGE DATA PACKAGE DATA
13 2 8 14 1 9 6
8 1 5 7 2 6 3
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 2
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
RECOMMENDED OPERATING CONDITIONS Parameter Symbol Test Conditions Min 0.9 0 LX1792 Typ Max 1.5 Units
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!
OPERATING CONDITIONS
Supply Voltage Ground
VDD VSS
V V
ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the operating ambient temperature TA=25°C except where otherwise noted. Test conditions: VDD=1.3V, VSS=0V, Circuit connected as application schematic on page 5,Output loaded with 200Ohm in series with 60mH. Parameter
Switch Output Resistance @ Low Drive Switch Output Resistance @ Med Drive Switch Output Resistance @ High Drive Quiescent Current @ Low Drive Quiescent Current @ Med Drive Quiescent Current @ High Drive 3dB Bandwidth – min Frequency 3dB Bandwidth – max Frequency Output Switching Frequency Gain1 Power Supply Rejection Ratio Total Harmonic Distortion Input Referred Noise Output clock frequency Max absolute DC Offset OutN-OutP
()
Symbol
ROUT-L ROUT-M ROUT-HI IDDQL IDDQM IDDQH FMIN FMAX FCLK A1 PSRR THD1 VN-20 No load
Test Conditions
Min
LX1792 Typ
48 24 16 110 120 130
Max
Units
Ω 19
µA
R1=50k, R2=1000k, Fin=1kHz 10
40
100
Hz KHz
200 32 37 45 0.3 0.5 4 3 140 200 0.5 300 5 0
KHz dB dB % µVrms KHz mV
R1=50k, R2=500k R1=25k, R2=500k Input Reference R1=50k, R2=500k R1=50k, R2=500k, Vin=5mVrms, Fin=1kHz R1=25k, R2=500k, Vin=5mVrms, Fin=1kHz R1=50k, R2=500k, 100Hz-10kHz, No weighting R1=25k, R2=500k, 100Hz-10kHz, No weighting No input signal
FCLK VOFF-NP
E ELECTRICALS
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 3
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
CHARTS
W W W. Microsemi . COM
Note: Graphs show distortion with no load outputs
CHARTS CHARTS
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 4
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
CHARTS (CONTINUED)
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LX1790 H-bridge on impedance
30 25 Ron [Ohm] 20 15 10 5 0 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 Supply voltage
Figure 2 – H-Bridge Impedance vs. Supply Voltage (Lowest Impedance Setting)
CHARTS CHARTS
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 5
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
W W W. Microsemi . COM
APPLICATION SCHEMATIC
Transducer/Speaker
Battery 0.9-1.5 V
C2
VSS
VDD
OUTN
MSC-LX1792
OUTP
Volume cntrl potentiometer
CIN R1 R2
IMPsel
PREOUT
NC
IN
Microphone
SUGGESTED EXTERNAL APPLICATION COMPONENTS Component Suggested value Description
CIN C2 R1 R2 RX/CX
100nF > 25k Ohm
Input AC coupling capacitor, must be present For best performance this should be as close as possible to the supply pins Input resistor > 25k Ohms Preamplifier feedback resistor If the audio source (for example a microphone) has a low power supply rejection an additional filter for the supply to this have to be added.
APPLICATION APPLICATION
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 6
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
MECHANICAL – 8 PIN MLPQ PACKAGE OUTLINE
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LM
8-Pin Plastic MLP-Micro Exposed Pad
A K J B E H I G
Dim A B C D E F G H I J K
F
MILLIMETERS MIN MAX 2.90 3.10 2.90 3.10 0.65 0.75 0.15 0.25 1.841 BSC 0.27 0.43 0.65 BSC 1.22 BSC 0 0.10 0.21 0.37 0 0.10
INCHES MIN MAX 0.114 0.122 0.114 0.122 0.025 0.029 0.005 0.009 0.075 BSC 0.010 0.016 0.025 BSC 0.048 BSC 0 0.003 0.008 0.014 0 0.003
C D
Internally Connected together, but isolated from all other terminals
J
14-Pin Ceramic Dip
A
Dim
B
1
L
C F J
K H G D
A B C D F G H J K L M
M
MILLIMETERS MIN MAX 19.30 19.94 5.59 7.11 5.08 0.38 0.51 1.02 1.77 2.54 BSC 2.03 0.20 0.38 3.18 5.08 7.37 7.87 15°
INCHES MIN MAX 0.760 0.785 0.220 0.280 0.200 0.015 0.020 0.040 0.070 0.100 BSC 0.080 0.008 0.015 0.125 0.200 0.290 0.310 15°
MECHANICAL MECHANICAL
Note:
1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage.
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 7
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
MECHANICALS
7-PIN BARE DIE
W W W. Microsemi . COM
DU
A
8-Pin MSOP
Dim A B C D G H J K L M N P MILLIMETERS MIN MAX 2.85 3.05 2.90 3.10 – 1.10 0.25 0.40 0.65 BSC 0.38 0.64 0.13 0.18 0.95 BSC 0.40 0.70 3° 0.05 0.15 4.75 5.05 INCHES MIN MAX .112 .120 .114 .122 – 0.043 0.009 0.160 0.025 BSC 0.015 0.025 0.005 0.007 0.037 BSC 0.016 0.027 3° 0.002 0.006 0.187 0.198
B
H
G P M C N K
D
L
Dim X Y
Note:
MILLIMETERS MIN MAX 1.15 1.78
INCHES MIN MAX 0.045 0.070
1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage.
MECHANICAL MECHANICAL
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 8
LX1792
INTEGRATED PRODUCTS
Low Voltage, Low Power, AudioMite™ Class-D Audio Amplifier P RELIMINARY S PECIFICATION
NOTES
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NOTES NOTES
Preliminary Data – Information contained in this document is pre-production data and is proprietary to Microsemi. It may not be modified in any way without the express written consent of Microsemi. Product referred to herein is offered in sample form only and Microsemi reserves the right to change or discontinue this proposed product at any time.
Copyright 2001 Rev. 0.3,2002-05-08
Microsemi
INTEGRATED PRODUCTS 5973 Avenida Encinas, Suite 101, Carlsbad 92008, Fax (760) 431-0541
Page 9
