LX1704 ® TM 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET The LX1704 family represents a new generation of a fully integrated audio stereo Class-D amplifier from Microsemi. This CMOS stereo ClassD 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. The LX1704 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 part features on board, low Rdson, complementary output MOSFET’s that reduces the need for external components. The LX1704 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 No Output Filter Required Low EMI Design Low Quiescent Current: 4mA Low Shutdown Current: 1µA Wide Supply Voltage Range: 2.5 - 5.5 Volt 2W Output Power into 4Ω Load with THD<1% @ 5.0V THD+N as Low as 0.1% Small Form Factor...16 pin MLP Package Only 4 x 4mm Built-in Clock Frequency Built-in Feedback Loop, Keep High Audio Fidelity Fixed 20dB Gain Full 20 - 20kHz Audio Bandwidth Shut-down Function Internal Thermal Shutdown High Efficiency: over 85% through Modulation Scheme and Class-D Operation Built-in De-Pop Circuit WWW . Microsemi .C OM KEY FEATURES DESCRIPTION APPLICATIONS VDD Portable Speakers Portable DVD PMP / PMC Notebook PC PVDD OUT2+ Speaker Out 2 PVSS2 EN IN1VSS IN1- IN2+ IN1+ OUT2- PVDD2 Part LX1704 IN2- IN1+ PVSS3 OUT1- VDD PVDD1 OUT1+ PVSS1 IN2ENABLE IN2+ TA (°C) LQ LX1704 PACKAGE ORDER INFO Plastic MLPQ 4mm x 4mm 16-Pin RoHS Compliant / Pb-free -40 to 85 LX1704ILQ Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1704ILQ-TR) Copyright © 2009 Rev.1.4, 2009-02-23 Page 1 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET OUT1- PVSS3 15 14 13 IN1+ 3 IN1- 4 IN2- 6 Plastic MLPQ 16-Pin 4mm x 4mm 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. 7 12 OUT2- 11 PVDD2 e10 OUT2+ 9 PVSS2 8 EN 2 VSS VDD MSC 1704 xxxx 5 THERMAL DATA LQ 16 1 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) ............................................................ -40°C to +85°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) RoHS / Pb-free 100% matte Tin Lead Finish xxxx = date/lot code 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 PVSS1 PVSS2 PVSS3 Negative Supply to Negative Output Stage (ground) for Channel1 OUT1+ Positive Audio (PWM) Output for Channel 1 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 © 2009 Rev.1.4, 2009-02-23 PACKAGE DATA PVDD1 & PVDD2 Page 2 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W 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 Output Power @ 4 Ohms Power Efficiency Total Harmonic Distortion @ 50% of Maxim Power Signal To Noise Ratio Output Noise Floor Frequency Response Lower Corner Frequency Min LX1704 Typ Η THD_N VDD = PVDD = 5V, Fin = 1kHz, RL = 4Ω 0.1 % 90 dB VN VDD = PVDD = 5V, F = 1kHz, PO = 1W, Aweighted Input Grounded A-weighted 20 to 20kHz FLO 3dB relative to 1kHz 20 VDD = PVDD = 2.5 to 5.5V, RL = 4Ω, PO = 200mW @ 20 to 80kHz, Filter less Input Referred, VDD = PVDD = 2.5V to 5.5V VDD = PVDD = 2.5V to 5.5V 55 55 SNR PSRR CMRR GSYS 5 1 Units 2.4 3.3 0.9 1.2 85 PQ 2.5 Max 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 Frequency Response Power Supply Rejection Ratio Common Mode Rejection Ratio Gain Test Conditions W % 100 µVRMS 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 = 4Ω Hz dB dB dB dB ELECTRICALS Copyright © 2009 Rev.1.4, 2009-02-23 Page 3 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET ELECTRICAL CHARACTERISTICS Parameter 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 Indicator Junction Under Voltage Threshold Level Enable Threshold Symbol Test Conditions VDD PVDD fSW VDD = PVDD = 2.5 to 5.5V VDD = PVDD = 5V IQQ No Load VDD = PVDD = 3.3V IQQSD Disable Pin Active PSRR VDD = PVDD = 2.5V to 5.5V RIN VDD = PVDD = 2.5V to 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 VDD EN Min LX1704 Typ 2.5 5.5 200 2.5 2 55 Max 5 4 1 60 18 -50 +50 350 350 470 470 9 1.8 2.10 10 150 2.0 2.25 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 = 4Ω mΩ 600 600 11 2.2 2.40 V/V °C V V ELECTRICALS Copyright © 2009 Rev.1.4, 2009-02-23 Page 4 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET SIMPLIFIED BLOCK DIAGRAM WWW . Microsemi .C OM LX1704 Triangle Wave Generator PVDD2 PVDD1 DRIVER VINP OUTP Dynamic Pulse Generation VINN OUTN DRIVER PVSS1 VDD VSS De-pop signal ground Generation LP LP PVSS2 EN Figure 1 – LX1704 Simplified Block Diagram (Half Circuit) BLOCK DIAGRAM Copyright © 2009 Rev.1.4, 2009-02-23 Page 5 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W 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+ LX1704 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+ LX1704 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 © 2009 Rev.1.4, 2009-02-23 Page 6 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W 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 TP5 TP1 TB1 C19 4700pF VIN C1 47µF JP1 C4 0.47µF INR- VDD IN1+ PVSS3 OUT1- For Test Purposes Only TP7 OUT2- LX1704 Part 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 C3 0.47µF VSS J1 INR+ PVDD1 PVSS1 IN2+ C2 1µF C10 2200pF TP6 C7 1µF TP2 OUT1+ RTN IN2- +VIN TP10 R4 470 TP1 C6 0.47µF OUTLVIN ENABLE INL+ OUTL+ TP4 INL- R8 470 C15 4700pF APPLICATIONS R7 470 TP12 C16 2200pF For Test Purposes Only Figure 3 – Typical LX1704 Application Copyright © 2009 Rev.1.4, 2009-02-23 Page 7 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 TM ® 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET FUNCTIONAL DESCRIPTION FILTERLESS 3-LEVEL CLASS-D MODULATION The LX1704 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 LC 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 LX1704, 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 LX1704 to easily meet FCC standards for radiated emissions when driving up to 3 meters of speaker wire. WWW . Microsemi .C OM GENERAL DESCRIPTION The LX1704 is a filterless, low-EMI, class-D audio power amplifier. It offers high performance (THD+N is just 0.1% @ 2W), high efficiency (>85% @ 1.2W), 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 LX1704 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 LX1704 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 © 2009 Rev.1.4, 2009-02-23 Page 8 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET THD+N VS. FREQUENCY GAIN RESPONSE NOISE FLOOR WWW . Microsemi .C OM THD+N VS. POWER CHANNEL CROSSTALK IQQ VS. SUPPLY VOLTAGE 3.5 3 PVDD=VDD; NO INPUT 4 OHM LOAD IQQ (mA) 2.5 2 NO LOAD 1.5 GRAPHS 1 0.5 0 2.5 3 3.5 4 4.5 5 5.5 Supply Voltage (V) Copyright © 2009 Rev.1.4, 2009-02-23 Page 9 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET 900 PSRR WWW . Microsemi .C OM SUPPLY CURRENT VS OUTPUT POWER PVDD = VDD = 5V; RL = 4 OHMS; BOTH CHANNELS DRIVEN 800 700 Current (mA) 600 500 400 300 200 100 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Output Power (mW) OUTPUT POWER VS SUPPLY VOLTAGE 3500 PVDD = VDD; FIN = 1kHZ; RL = 4 OHMS 3000 Power/CH (mW) 2500 THD + N = 10% 2000 1500 THD + N = 1% 1000 500 0 2.5 3 3.5 4 4.5 5 5.5 Supply Voltage (V) GRAPHS Copyright © 2009 Rev.1.4, 2009-02-23 Page 10 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 ® TM 2W Filter less Stereo Class-D Amplifier P RODUCTION D ATA S HEET PACKAGE DIMENSIONS 16-Pin MLPQ Plastic (4mm x 4mm EP / 114x114Cu Exposed Pad) D b E2 L D2 E e A A1 A3 K or Pin 1 Indicator 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. MECHANICALS Copyright © 2009 Rev.1.4, 2009-02-23 Page 11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570 LX1704 TM ® 2W 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 © 2009 Rev.1.4, 2009-02-23 Page 12 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, 800-877-6458, Fax: 714-893-2570