LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET KEY FEATURES DESCRIPTION The LX1702 family provides very low quiescent current consumption through the use of a proprietary output modulation scheme. This technology enables filterless operation in many applications. The LX1702 features on board, low Rdson, complementary output MOSFET’s that reduces the need for external components. The LX1702 is offered in a small footprint, low profile, 4mm x 4mm 16pin MLPQ. IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com PRODUCT HIGHLIGHT Speaker Out 1 PVDD PVSS3 OUT1- IN1- OUT2+ Speaker Out 2 Portable Speakers Portable DVD PMP / PMC Notebook PC PVSS2 EN IN1- Part LX1702 VSS IN1+ PVDD PVDD2 IN2- IN1+ APPLICATIONS OUT2- VDD IN2+ VDD PVDD1 OUT1+ PVSS1 No Output Filter Required Low EMI Design Low Quiescent Current: 4mA Low Shutdown Current: 1µA Wide Supply Voltage Range: 2.5-5.5 Volt 1W Output Power into 8Ω Load with THD<1% @ 5.0V THD+N as low as 0.1% Small Form Factor...16-pin MLP Package only 4x4mm Built-in Clock Frequency Built-in Feedback Loop, Keep High Audio Fidelity Fixed 20dB Gain Full 20-20KHz Audio Bandwidth Shutdown Function Internal Thermal Shutdown High Efficiency: over 85% through Modulation Scheme and Class-D Operation Built-in De-Pop Circuit WWW . Microsemi .C OM The LX1702 family represents a new generation of a fully integrated audio stereo class-D amplifier from Microsemi. This CMOS stereo class-D amplifier series is optimized for low voltage, low power operation and minimum system cost. The products are ideal for use in battery powered applications where low power consumption is desirable such as portable speakers, DVDs, PMP, and other low power systems. IN2ENABLE IN2+ PACKAGE ORDER INFO TA (°C) LQ Plastic MLPQ 4mm x 4mm 16-Pin RoHS Compliant / Pb-free LX1702 0 to 70 LX1702CLQ Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1702CLQ-TR) Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET 1 OUT1- PVSS3 16 15 14 13 12 OUT2PVDD2 e10 OUT2+ IN1- 4 9 PVSS2 5 THERMAL DATA 6 7 8 EN 11 3 VSS 2 IN2+ VDD IN1+ IN2- 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. PVSS1 WWW . Microsemi .C OM Positive Supply Voltage (VDD, PVDD) ........................................................... -0.3 to 6.5V Analog Input Voltage (IN1+, IN1-, IN2+, IN2-).................................. -0.3 to VDD + 0.3V Digital Input Voltage (EN, MUTE) ..................................................... -0.3 to VDD + 0.3V Operating Temperature Range (TA) ................................................................0°C to +70°C Maximum Operating Junction Temperature (TJ) ....................................................... 150°C Storage Temperature Range.........................................................................-65°C to 150°C Package Peak Temp. for Solder Reflow (40 seconds maximum exposure) ... 260°C (+0 -5) PVDD1 PACKAGE PIN OUT OUT1+ ABSOLUTE MAXIMUM RATINGS LQ PACKAGE (Top View) LQ Plastic MLPQ 16-Pin 4mm x 4mm RoHS / Pb-free 100% Matte Tin Lead Finish THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 24.6°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. FUNCTIONAL PIN DESCRIPTION Name Description VSS Negative supply to analog stage (ground) IN1- Negative audio input channel 1 IN1+ Positive audio input channel 1 EN Enable pin, active high IN2- Negative audio input channel 2 IN2+ Positive audio input channel 2 VDD Analog positive power supply Negative supply to Negative output stage (ground) for channel1 OUT1+ Positive audio (PWM) output for channel 1 PVDD1 & PVDD2 PACKAGE DATA PVSS1 PVSS2 PVSS3 Positive supply to Positive output stage for channel 1 OUT1- Negative audio (PWM) output for channel 1 OUT2+ Positive audio (PWM) output channel 2 OUT2- Negative audio (PWM) output channel 2 Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET SYSTEM CHARACTERISTICS Parameter Symbol Supply Current: Quiescent Supply Current: Shutdown Mode IQQ IQQSD Test Conditions Min LX1702 Typ Output Power @ 8 Ohms PQ Power Efficiency Total Harmonic Distortion @ 50% of Maxim Power Η THD_N VDD = PVDD = 5V, Fin = 1kHz, RL = 8Ω 0.1 90 dB VN VDD = PVDD = 5V, F = 1kHz, PO = 0.5W, A-weighted Input Grounded A-weighted 20 to 20kHz 100 µVRMS FLO 3dB relative to 1kHz 20 VDD = PVDD = 2.5 to 5.5V, RL = 8Ω, PO = 200mW @ 20 ~ 80kHz, Filter less Input Reffered, VDD = PVDD = 2.5V to 5.5V VDD = PVDD = 2.5V to 5.5V 55 55 SNR Output Noise Floor Frequency Response Lower Corner Frequency Frequency Response Power Supply Rejection Ratio Common Mode Rejection Ratio Gain PSRR CMRR GSYS 1.2 1.6 0.45 0.6 85 5 1 Units No Load Disable Pin Active VDD = PVDD = 5V, Fin THD+N = 1% = 1kHz THD+N = 10% THD+N = 1% VDD = PVDD = 3.3V, Fin = 1kHz THD+N = 10% VDD = PVDD = 5V, Fin = 1kHz Signal To Noise Ratio 2.5 Max W % % 20K 3 60 60 20 mA µA WWW . Microsemi .C OM The following specifications apply over the operating ambient temperature 0 < TA < 70°C except where otherwise noted and the following test conditions: PVDD = VDD = 5.0V, PVSS = VSS = 0V, RL = 8Ω Hz dB dB dB dB ELECTRICALS Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET ELECTRICAL CHARACTERISTICS Parameter Symbol Supply Voltage Oscillator Frequency Supply Current: Quiescent Supply Current: Shutdown Mode Power Supply Rejection Ratio Input Resistance Output DC Offset Static Drain-to-Source ONResistance Stage Gain Thermal Junction Shutdown Thermal Shutdown Hysteresis Enable Threshold Under Voltage Threshold Level Test Conditions Min VDD PVDD fSW VDD = PVDD = 2.5 ~ 5.5V VDD = PVDD = 5V No Load IQQ VDD = PVDD = 3.3V IQQSD Disable Pin Active PSRR VDD = PVDD = 2.5V to 5.5V RIN VDD = PVDD = 2.5V ~ 5.5V Single Ended VOFF Input Shorted to GND P Channel VDD = PVDD = 5V N Channel P Channel VDD = PVDD = 3.3V RDSON N Channel P Channel VDD = PVDD = 2.5V N Channel GH VDD = PVDD = 2.5V to 5.5V TJ EN VDD LX1702 Typ 2.5 55 Max 5.5 200 2.5 2 0.5 60 18 -50 5 4 2 +50 400 400 550 550 9 2.1 1.8 10 150 25 2.25 2.0 Units V kHz mA µA dB KΩ mV WWW . Microsemi .C OM The following specifications apply over the operating ambient temperature 0 < TA < 70°C except where otherwise noted and the following test conditions: PVDD = VDD = 5.0V, PVSS = VSS = 0V, RL = 8Ω mΩ 900 900 11 2.4 2.2 V/V °C °C V V SIMPLIFIED BLOCK DIAGRAM LX1702 Triangle Wave Generator PVDD2 PVDD1 DRIVER VINP OUTP Dynamic Pulse Generation VINN OUTN DRIVER PVSS1 VSS De-pop signal ground Generation LP LP ELECTRICALS VDD PVSS2 EN Figure 1 – LX1702 Simplified Block Diagram (Half Circuit) Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET SYSTEM TEST SETUP WWW . Microsemi .C OM Output1Audio Precision System One IN1- Output1+ IN1+ Output2- IN2- Output2+ GND VBAT + Power Supply - 2nd Order RC LPF C1 TP1OUT1- OUT1+ LX1702 Input1Audio Precision System One 2nd Order RC LPF TP1+ GND Input1+ 2nd Order RC LPF TP2- Input2- OUT2IN2+ OUT2+ 2nd Order RC LPF TP2+ Input2+ LX1702 Evaluation Kit Figure 2 – Typical Evaluation Test Setup Circuit Default Settings: Equipments: Audio Precision SYSTEM 1 Oscilloscope, Power Supply ~ +5V; Supply Voltage: 2.5V / 3.3V / 5.0V 3 corner voltages On-Board passive LPF: 40kHz cut off frequency (-6dB) AP settings: 10Hz ~ 22KHz BPF APPLICATIONS Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET APPLICATION CIRCUITS WWW . Microsemi .C OM R1 470 TP9 R2 470 C11 2200pF C12 4700pF For Test Purposes Only TB2 OUTR+ OUTR- R3 470 TB1 C19 4700pF VIN C1 47µF INR- PVSS3 TP7 R5 470 PVDD2 VIN OUT2+ For Test Purposes Only TP8 TB3 J2 C5 0.47µF JP2 C13 2200pF C14 4700pF C8 1µF PVSS2 IN1- TP11 R6 470 EN C4 0.47µF IN1+ For Test Purposes Only OUT2- LX1702 Part VSS JP1 VDD IN2+ C3 0.47µF OUT1- PVSS1 J1 INR+ PVDD1 OUT1+ C2 1µF C10 2200pF TP6 C7 1µF TP2 IN2- RTN TP10 TP5 TP1 +VIN R4 470 TP1 C6 0.47µF OUTLVIN ENABLE INL+ OUTL+ TP4 INL- C15 4700pF R8 470 APPLICATIONS R7 470 TP12 C16 2200pF For Test Purposes Only Figure 3 – Typical LX1702 Application Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX1702 TM ® 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET FUNCTIONAL DESCRIPTION FILTERLESS 3-LEVEL CLASS-D MODULATION The LX1702 output stage is configured as a full H-bridge push-pull driver. The speaker must be driven differentially from the OUTP and OUTN pins. Each side of the speaker is driven by a 200KHz switching signal that transitions between VDD and GND. With zero input voltage, the duty cycle at each output is around 50% and the signals are inphase with each other. In this case, there is basically no differential voltage across the speaker. When the input signal goes positive, the duty cycle at OUTP increases above 50% and the duty cycle at OUTN decreases below 50%. This causes a net positive current to flow into the speaker. A negative input voltage causes the OUTN duty cycle to increase and the OUTP duty cycle to decrease which causes a net negative current to flow into the speaker. The differential voltage across the speaker has a fundamental frequency of twice the 200KHz switching frequency. The speaker itself serves as the low pass filter which then recreates the audio signal. This type of modulation can be described as driving +VDD, -VDD, and 0V across the speaker which is why it is referred to as 3-Level modulation. Classical, 2-Level modulation drives either +VDD or –VDD across the speaker at all times. This scheme requires an L-C filter between the amplifier’s outputs and the speaker in order to keep the output current low. LOW-EMI OUTPUT STAGE WITH SLEW RATE LIMITING AND ACTIVE OVERSHOOT CLAMPING With 3-Level modulation, the carrier frequency drives a full amplitude common-mode signal to the speaker wires. This can cause high EMI radiation. One way to combat this would be to filter the outputs with LC filters or ferrite beads located close to the amplifier. In the LX1702, the output stage has been carefully designed to minimize EMI radiation so that these types of filters are not required. Slew rate limiting is used to keep the outputs from switching too quickly. Active overshoot clamping is used to minimize the inductive overshoot which occurs at each transition. These two techniques allow the LX1702 to easily meet FCC standards for radiated emissions when driving up to 3 meters of speaker wire. WWW . Microsemi .C OM GENERAL DESCRIPTION The LX1702 is a filterless, low-EMI, class-D audio power amplifier. It offers high performance (THD+N is just 0.1% @ 1W), high efficiency (>85% @ 0.6W), and best in class EMI radiation (just 20dBµV/m). The internal signal path is completely differential to minimize commonmode noise pickup. The inputs may be driven single-ended or differentially and they may be direct or AC coupled. The LX1702 may be operated with just a single decoupling capacitor. DIFFERENTIAL SIGNAL PATH, WIDE DYNAMIC RANGE, AND BUILT-IN THERMAL OVERLOAD PROTECTION The fully differential signal path uses Pulse Width Modulation and multiple feedback loops to provide high performance and low distortion. This is all fully-integrated to eliminate the need for any external feedback components or filters. The gain is fixed by internal resistors at 20dB. The differential signal path and internal voltage boosters allow for wide dynamic range. In fact, the LX1702 can be operated from supplies as low as 2.5V and as high as 5.5V. The output power will be limited by the available supply voltage. An internal thermal sensing circuit shuts down the outputs when the junction temperature exceeds about 150°C to provide thermal overload protection. APPLICATIONS Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET THD+N VS. POWER PVDD=VDD=5.0V, RL = 8OHM Fin=1KHz, 10~22KHz BPF 20 10 5 % THD+N VS. FREQUENCY 100 50 % 0.2 0.1 0.05 2 1 0.5 0.2 0.1 0.05 0.02 0.01 0.005 0.02 0.01 0.005 0.002 0.001 0.002 0.001 20 200m PVDD=VDD=5V, RL=8OHM POUT=1W, 10 ~ 22KHz BPF 20 10 5 2 1 0.5 60m 100m 500m 1 2 5 50 100 200 W THD VS. POWER VS. VIN VIN = 2.5V, 3.5V, 4.5V, 5.5V, RL = 8OHM 20 500 Hz 1k 2k 5k 10k 20k SIGNAL TO NOISE +0 -5 100 50 WWW . Microsemi .C OM 100 50 -10 -15 10 -20 5 -25 PVDD=VDD=5.0V RL=8OHM NO Input, 1 ~22KHz BPF Non A-weighted -30 2 -35 1 -40 0.5 -45 0.2 dBr -50 -55 0.1 -60 0.05 -65 % -70 0.02 -75 0.01 -80 0.005 -85 -90 0.002 0.001 -95 60m 100m 200m 500m W 1 2 5 -100 20 50 CHANNEL CROSSTALK +0 -5 -10 PVDD=VDD=5.0V, RL = 8OHM POUT = 1W, 10 ~ 22KHz BPF -20 -25 -30 -35 -40 -45 -50 -60 -65 -70 -75 -80 -85 -90 -95 50 100 200 500 1k 2k 5k 10k 20k 500 1k +0 -5 -10 -15 -20 -25 -30 -35 -40 -45 dBr -50 -55 -60 -65 -70 -75 -80 -85 -90 -95 -100 20 50 100 200 500 1k 2k 5k 10k 20k Hz Hz Copyright © 2005 Rev. 1.0, 2006-10-11 200 GRAPHS -55 -100 20 Hz CMRR -15 dB 100 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET FREQUENCY RESPONSE PSRR +0 -5 -10 -15 WWW . Microsemi .C OM +6 +5.5 +5 +4.5 +4 +3.5 +3 +2.5 +2 +1.5 +1 +0.5 -0 dBr -0.5 -1 -1.5 -2 -2.5 -3 -3.5 -4 -4.5 -5 -5.5 -6 PVDD=VDD=5.0V, RL = 8OHM Input Shorted, ?V = 1VP-P -20 -25 -30 -35 -40 dBr -45 -50 -55 -60 -65 -70 -75 -80 -85 -90 -95 -100 20 20 50 100 200 500 1k 2k 5k 10k 20k 50k 80k 5k 10k 20k 50k 80k 50 100 200 500 1k 2k 5k 10k 20k Hz Hz GAIN RESPONSE +30 +29 PVDD=VDD=5.0V, RL = 8OHM +28 +27 Pout=1W, 10 ~ 80KHz BPF +26 +25 +24 +23 +22 +21 +20 +19 +18 +17 +16 dBr +15 +14 +13 +12 +11 +10 +9 +8 +7 +6 +5 +4 +3 +2 +1 +0 20 50 100 200 500 1k 2k Hz GRAPHS Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 9 LX1702 ® TM 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET PACKAGE DIMENSIONS 16-Pin MLPQ Plastic (4x4mm EP / 114x114Cu Exposed Pad) D b E2 L D2 E e A A1 K Dim A A1 A3 b D E e D2 E2 K L MILLIMETERS MIN MAX 0.80 1.00 0 0.05 0.18 0.30 0.23 0.38 4.00 BSC 4.00 BSC 0.65 BSC 2.55 2.80 2.55 2.80 0.20 0.30 0.50 INCHES MIN MAX 0.031 0.039 0 0.002 0.007 0.012 0.009 0.015 0.157 BSC 0.157 BSC 0.026 BSC 0.100 0.110 0.100 0.110 0.008 0.012 0.020 WWW . Microsemi .C OM LQ 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. A3 MECHANICALS Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 10 LX1702 TM ® 1W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET NOTES WWW . Microsemi .C OM NOTES PRODUCTION DATA – Information contained in this document is proprietary to Microsemi and is current as of publication date. This document may not be modified in any way without the express written consent of Microsemi. Product processing does not necessarily include testing of all parameters. Microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 2005 Rev. 1.0, 2006-10-11 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 11