LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET KEY FEATURES DESCRIPTION Filter Free Operation 15W +15W Output Power @ 4Ω load: THD+N < 1% High Efficiency > 85% Full Audio Bandwidth: 20Hz to 20KHz Low Distortion < 0.15% @ 30% Max Power, 1KHz High Signal-to-Noise Ratio: 90dB Wide Supply Voltage Range 5.0V ~ 15V Low Quiescent Current < 30mA Turn ON/OFF POP Free Standby / Mute Feature Built-in Under Voltage Lockout Thermal Protection Short Circuit Protection The part features on–board H-bridge output stages with low RDSON. External bootstrap capacitors are all that is required to provide the gate drive to the all-NFET output stage since onboard bootstrap diodes are provided. The LX1708 also features Mute and Standby modes, over-current protection, POP-free turn-on and turn-off, undervoltage lockout, over-voltage protection, and over-temperature protection. The LX1708 is offered in a small footprint, low profile surface mountable 32-pin Micro Lead Quad Package (MLPQ) in 7mm x 7 mm. WWW . Microsemi .C OM The LX1708 is part of a new generation of fully integrated stereo class-D amplifiers from Microsemi. This CMOS audio amplifier is optimized for highly efficient operation and minimum system cost. The stereo BTL (Bridge-tied-load) configuration uses 3-level PWM modulation. This allows eliminating the LC filter to reduce the system cost and simplify the system design. The LX1708 outputs 15W into each of two channels with better than 85% efficiency. APPLICATIONS LCD TV Car Navigation Computer: Portable Sound System IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com PRODUCT HIGHLIGHT STBY 5V TMON ROSC V5V STBY N.C. STATUS AVSS1 PVSS1N OUT1N OUT2N BOOT2N BOOT1N PVDD1 PVDD PVDD1 LX1708 BOOT1P PVDD2 PVDD2 PVDD BOOT2P OUT1P MUTE N.C. TCTRL IN1P OUT2P VREF PVSS1P IN1N AVSS2 PVSS2N PVSS2P IN2P IN2N IN2N IN2P IN1P MUTE LX1708 IN1N PACKAGE ORDER INFO TA (°C) LQ Plastic MLPQ 32-Pin 7mmx7mm RoHS Compliant / Pb-free -40 to 85 LX1708ILQ Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1708ILQ-TR) Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1708 TM ® 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT PVDD1 PVDD1 BOOT1N OUT1N PVSS1N 31 30 29 28 27 26 25 1 24 TCTRL IN1P 2 23 TMON IN1N 3 22 AVSS2 N.C. 4 21 ROSC N.C. 5 20 VREF IN2N 6 19 AVSS1 IN2P 7 18 V5V MUTE 8 17 STATUS 12 13 14 15 16 PVDD2 BOOT2N OUT2N PVSS2N OUT2P 11 PVDD2 10 BOOT2P 9 WWW . Microsemi .C OM BOOT1P 32 STBY PVSS2P THERMAL DATA OUT1P 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. PVSS1P Analog Supply Voltage (PVDD) ................................................................. -0.3V to 16.5V Supply Voltage (V5V) ......................................................................................... -0.3 to 6V STBY to VSS......................................................................................-0.3V to V5V + 0.3V IN1P/M, IN2P/M .................................................................................-0.3V to V5V +0.3V Maximum Operating Junction Temperature .............................................................. 150°C Storage Temperature Range.........................................................................-65°C to 150°C Package Peak Temp. for Solder Reflow (40 seconds maximum exposure) ... 260°C (+0 -5) LQ PACKAGE (Top View) Pb-free 100% Matte Tin Lead Finish LQ Plastic MLPQ 32-Pin 7mm x 7mm THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 15.5°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. PACKAGE DATA Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 LX1708 ® TM 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET FUNCTIONAL PIN DESCRIPTION # Of Pins PVSS1P PVSS1N PVSS2P PVSS2N Power Ground PVDD1 PVDD2 Description 4 Power Ground for the two H-bridge output drivers. Power Supply 4 Power Supply for the two H-bridge output drivers. Operating voltage is from 4.5 up to 15V. Current draw will be up to 3.2A at 2X15W into 8ohms or up to 4.5A at 2X15W into 4 ohms. These are peak currents when the part is run at maximum rated power on both channels. V5V Power Supply 1 Analog Power Supply for the analog signal processing section. Operating voltage is from 4.5 up to 5.5V. AVSS1 AVSS2 Analog Ground 2 Analog Ground for the analog signal processing section. Should be at the same voltage as PVSS. Also used to bias the substrate. IN1N IN1P IN2N IN2P Analog Input 4 Differential analog audio inputs for each channel. The common mode voltage will be set by the LX1708 to around 2.25V. OUT1N OUT1P OUT2N OUT2P Digital Output 4 Differential high power audio outputs for each channel. Each output will swing between PVDD and PVSS. These outputs are driven by an on-chip H-bridge output driver which uses low Rdson NFETs. BOOT1N BOOT1P BOOT2N BOOT2P Digital Output 4 Bootstrap voltage pins which provide the high voltage needed to drive the upper NFET. A bootstrap capacitor should be placed between the respective output and these pins. VREF Analog Output 1 2.25V reference voltage which serves as a local “GND” reference. An external compensation capacitor of at least 1uF should be connected between this pin and AVSS. CMOS Input 1 STBY CMOS Input 1 Logic level control which places the chip into sleep mode when high. The logic threshold will be at ½ of V5V. STATUS CMOS Output 1 Digital monitoring pin which is used to flag internal fault states. This pin will be synchronized with the internal clock to prevent glitches. See the STATUS flag table for a summary of which conditions will force this pin to go high. ROSC Analog Input 1 Frequency control pin. A resistor between this pin and GND will set the oscillation frequency for the Class-D modulator. TCTRL CMOS Input 1 Test purpose only, Connect to AVSS1 TMON Analog I/O 1 Test purpose only, left open. 2 No Connect N.C. PACKAGE DATA MUTE Logic level control which mutes the audio signal when high. This will be a four level pin to allow testing of the low gain mode as follows: From 0 to ¼ of V5V, the gain will be normal. From ¼ of V5V to ½ of V5V, the gain will be low Above ½ of V5V, the gain will be muted. The STATUS pin will go under any of the following conditions: STBY is high. This indicates that the chip is in “stand-by” mode. V5V is below the UVLO threshold. The outputs will be forced into the low state. PVDD is below the PVDD UVLO threshold. The outputs will be forced into the low state. PVDD is above the over-voltage threshold which is about 17.8V. The outputs will be forced into the low state. The die temperature is above about 140°C. This indicates that the part has gone in to gain foldback. A short circuit at the output has caused the output devices to shut off due to excessive temperature. Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 WWW . Microsemi .C OM Name Page 3 LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET Parameter ` Symbol Test Conditions Min LX1708 Typ Max Units OSCILLATOR Oscillator Frequency FOSC Temperature Stability POWER SUPPLY Supply Voltage UVLO UVLO Hysteresis +5V Supply UVLO UVLO Hysteresis Stand-By Current Operating Current Stand-By Current Operating Current Power Supply Rejection Ratio 1 Reference Voltage GAIN Stage Gain @ 0dB Volume Mute Gain @ minimum volume OFFSET PVDD PVDD PVDD V5V V5V V5V IQQ IQQ IQQ5V5 IQQ5V5 PSRR VREF G GMUTE Output DC Offset VOFF INPUT STAGE Input Resistance Common Mode Voltage RIN VCM Varies with ROSC resistor value, value shown is for default conditions. R = 25K TA = 0°C to 70°C TA = -40°C to 125°C 5.0 300 KHz 5 8 % % 2.25 V V mV V V mV µA mA µA mA dB V f = 1KHz Mute active, Input shorted 20 0.01 V/V V/V Measured Differentially. OUT1- to OUT1+ OUT2- to OUT2+ 100 mV 22 2.25 KΩ V 280 mΩ 150 °C 25 °C V5V 2 V Start-up Voltage 12 4.50 500 4.5 Start-up Voltage For PVDD, STBY high For PVDD, STBY low, Mute high For 5V5, STBY high For 5V5, STBY low, Mute high For PVDD C bypass = 1µF 4.25 250 10 10 10 7 15 4.90 5.5 4.50 50 30 15 55 WWW . Microsemi .C OM ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the operating ambient temperature -40°C < TA < 85°C except where otherwise noted and the following test conditions: PVDD = 12V, PVSS = AVSS = 0V, V5V = 5V, ROSC = 25KΩ OUTPUT STAGE MOSFET On Resistance RDSON IDS = 200mA THERMAL Thermal Shut Off Junction Temperature Hystersis MUTE / STBY / MASTER MUTE Threshold Mute Mode STBY Threshold STBY To Output Enable Power On Reset Delay After Power on Reset Pulse, Not Quick Mode 0.20 V5V 2 V 16384 0.30 Clocks mS 3.8 Note 1: Not ATE Tested ELECTRICALS Note: Functionality over the -40°C to +85°C operating range is assured by design characterization and correlation. Caution: Power Up/Down Sequencing Power-on: Apply V5V w/STBY=V5V. Then apply PVDD. Then bring STBY low. Power-off: Bring STBY high such that STBY=V5V. Then shut off PVDD. Then shut off V5V. Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX1708 ® TM 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET Parameter ` Symbol Test Conditions Min LX1708 Typ Max Units AUDIO CHARACTERISTICS Output Power Stereo PO Total Harmonic Distortion Stereo Power Efficiency Channel Crosstalk Audio Bandwidth THD+N VXTALK BW High Low Stage Gain Stereo Mute Output VMUTE Signal to Noise Ratio SNR Output Noise Floor VN Common Mode Rejection Ratio Output Short Circuit Protection CMRR TSENSE THD+N < 1% THD+N <10% POUT = 50% of Maximum Power, FIN = 1KHz with diodes POUT = 50% of Maximum Power, FIN = 1KHz No diodes POUT = 1W, FIN = 20Hz~20KHz POUT = Max, THD+N < 1% POUT = 1W, F = 1KHz POUT = 1W, F = 20-20KHz VIN = 200mVRMS, F = 20Hz~20KHz VIN = 2VRMS, F = 20Hz~20Khz Input short, system muted, stereo 12 15 20 0.01 -60 FIN = 1KHz @ 20Hz-20KHz non A-weighted 90 dB 200 µVRMS dB °C W 0.2 % 0.7 0.4 90 -60 3 Input short, non A-weighted @ 20Hz-20KHz 55 Thermal Shutdown Mode 150 % dB dB WWW . Microsemi .C OM SYSTEM MODULE CHARACTERISTICS Unless otherwise specified, the following specifications apply over the operating ambient temperature -40°C < TA < 85°C except where otherwise noted and the following test conditions: PVDD = 12V, PVSS = AVSS = 0V, V5V = 5V, ROSC = 25KΩ, RL = 4Ω. V/V dB ELECTRICALS Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET PVDD2 V5V WWW . Microsemi .C OM PVDD1 SIMPLIFIED BLOCK DIAGRAM BOOT1P OUT1P IN1P + IN1N - PWM BOOT1N PVDD OUT1N LPF From H-Bridge LPF Clock BOOT2P LPF From H-Bridge LPF OUT2P IN2P + IN2N - PWM BOOT2N PVDD V5V OUT2N De-POP BLOCK DIAGRAM PVSS4 PVSS3 PVSS2 PVSS1 AVSS1 AVSS2 Figure 1 – Simplified Block Diagram Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET JP5 +5V TB3 JP3 PVDD +V GND GND IN1IN1+ TB1 OUT1OUT1+ RL OUT1- LX1708 IN2- OUT2+ IN2+ IN1IN2- OUT2RL OUT2+ IN2+ TB2 OUT2- System One IN1+ OUT1+ GND J2 Audio Precision Power Supply VNEG J1 Dual Single JP4 AGND GND CTR GND VCOM NORM TB4 Power Supply WWW . Microsemi .C OM +5V STBY TEST SYSTEM SET-UP Audio Precision System One SQUK SNOR MQUK MNOR 20dB 14dB LX1725 Evaluation Module JP6 MUTE JP7 Oscilloscope Figure 2 – System Test Set-up Diagram Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET APPLICATION CIRCUITS VIN CR1 1N5817 C1 47µF 25V RTN R8 470 TB1 R9 470 C23 4.7nF TP4 RT-P C24 2.2nF CR2 1N5817 OUTR+ +5V +5V TP2 1P C2 22µF 6.3V RTN OUTR- TP3 1N TEST PURPOSE TB1 VIN VIN TP1 GND R6 470 C4 0.47µF C6 0.47µF OUT1N PVSS1N STATUS R1 25K C11 1µF C12 1µF TP6 STATUS PVSS2N OUT2N L RCA Jack BOOT2N M V5V PVDD2 MUTE +5V VREF AVSS1 IN2P JP2 HEADER 2 J2 ROSC Part LX1708 N/C IN2N PVDD2 INLINL+ AVSS2 U1 N/C C5 0.47µF C22 2.2nF TCTRL TMON IN1N JP1 HEADER 1 PVSS2P OUT2P BOOT2P INR- PVDD1 STBY IN1P C3 0.47µF INR+ BOOT1N RCA Jack PVDD1 SW1 SLEEP C21 4.7nF C9 1µF PVSS1P OUT1P BOOT1P C8 1µF +5V TP5 RT-N C10 1µF C7 1µF J1 R7 470 +5V N Header 3x2 C14 1µF TP7 GND C15 1µF C13 1µF C16 1µF VIN TP8 2P TEST PURPOSE TP10 LEFT-N VIN TP9 2N R2 470 C17 4.7nF CR8 1N5817 R3 470 C18 2.2nF OUTL- CR7 1N5817 TEST PURPOSE R4 470 C19 4.7nF TP1 LEFT-P R5 470 C20 2.2nF Note 1: CR1, CR2, CR7, CR8 can be used for lower distortion performance. Figure 3 – Typical Application Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 APPLICATIONS OUTL+ Copyright © 2004 Rev.1.2, 2007-01-05 WWW . Microsemi .C OM TEST PURPOSE +VIN LX1708 ® TM 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET FUNCTIONAL DESCRIPTION The LX1708 drives each output between PVDD and PVSS using an all-NFET, bootstrapped, H-bridge driver for each channel. High efficiency is obtained by forcing all transistors to operate either completely on or completely off as required for a true class-D amplifier. The entire signal path from input to output is differential to reject any sources of common-mode noise or distortion. Even the triangle wave operates differentially. Filterless class-D modulation operates such that with no input signal, the outputs switch at 300KHz and are in-phase with each other. Because the two signals are identical, the differential signal to the speaker is zero. As a direct result, there is no requirement for a low-pass LC filter to present a high impedance at the modulation frequency. This allows a cheaper and simpler audio amplifier to be designed . As the input signal goes positive, the duty cycle to the positive output increases while the duty cycle of the negative output decreases. This produces a net positive current flow into the load. A negative signal reduces the positive output duty cycles and increases the negative output duty cycle. The differential signal actually appears at twice the modulation frequency and alternates between +PVDD, 0, and –PVDD which allows the parasitic inductance of the load to effectively filter the switching signal so that only the audio band portion remains. Because each speaker is driven by an in-phase signal, the common mode voltage to the speaker switches at the full PVDD amplitude at 300KHz. This is a possible source of EMI radiation. Typically, a ferrite bead is placed with a small common-mode filter capacitor to reduce EMI generation by filtering the edges of the output signals. NOISE-FREE TURN-ON AND OFF Copyright © 2004 Rev.1.2, 2007-01-05 AC-COUPLING AND BOOTSTRAP CAPACITORS Input AC-coupling capacitors should be used to block any input DC and low frequency components below the desired low frequency corner. Since the input resistance to the LX1708 is 25Kohms, a 20Hz low frequency corner can be achieved with a 0.32µF AC-coupling capacitor. 1µF bootstrap capacitors are required at each output to supply the gate drive voltage for the upper level NFET in each half-bridge. THERMAL OVERLOAD PROTECTION The LX1708 protects itself by monitoring its operating temperature in two different ways. A general thermal protection scheme monitors the overall die temperature. Above 140°C, the amplifier gain is reduced by 6dB so that the audio signal is still amplified, but the on-chip power dissipation is halved. When the die temperature then goes below 110°C, the amplifier gain is restored. Above 150°C, the LX1708 forces all outputs to PVSS so that no power is dissipated until the chip cools down to 110°C. A dynamic thermal protection scheme operates by placing temperature sensors near each of the output devices. When a differential temperature rise of about 60°C occurs above the core die temperature, which indicates a local short circuit condition, the outputs are disabled to protect the part. This provides short circuit protection for differential shorts and shorts to ground. Since the outputs go low to PVSS, shorts to PVDD are NOT protected. Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 9 APPLICATIONS Noise-free turn-on and off is accomplished by carefully sequencing the signal path when the amplifier is enabled or disabled. Prior to turn-on, the outputs are initially both at PVSS so there is no differential signal. The internal error amplifier is held in a reset condition so that the internal loop compensation components are “ready to go”. When the outputs begin to toggle, the audio signal path is muted for about 1.6mS. Following that time, the internal mute signal is de-asserted and the audio input signal is allowed to drive the pulse-width–modulator which then adjusts the output duty cycle as necessary to drive the speaker. At turn-off, the internal mute signal is asserted to silence the input audio signal. The outputs continue switching in this muted condition for about 0.6mS prior to being pulled low. Once the outputs are forced low, the error amplifier is reset so that the part is ready to being a new power-up sequence. This scheme basically limits the pop noise at turn-on or off to be no larger than the differential offset voltage of the error amplifier. WWW . Microsemi .C OM FILTERLESS CLASS-D MODULATION LX1708 ® TM 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET OSCILLATOR The value of R1 decides the switching frequency, smaller value gives the system faster switching. See Figure 4, SW Frequency vs. R1 SW Freq. vs. ROSC 1,400k SW Freq. (Hz) 1,200k 1,000k 800k 600k 400k 200k 0k 5K 17.5K 30K 42.5K ROSC (ohm) Figure 4 – SW Frequency vs. R1 BOOTSTRAP CAPACITORS C8, C9, C14, and C15 are bootstrap capacitors for internal NMOSFETs gate drive voltage, they work together with internal diodes to boost the PVDD voltage doubled, over the threshold voltage of VGS. If BOOT1P, BOOT1N, BOOT2P, and BOOT2N are probed, 2x PVDD voltages on the PWM waveform will be observed. Those capacitors should be placed as close to the IC as possible. BYPASSING CAPACITORS C7, C10, C11, C12, C13, and C16 are bypassing capacitors for input supplies and internal reference voltage (2.5V), nominal value is 1µF. These capacitors should be placed as close to the IC as possible also, to guarantee low ripples and noise. Copyright © 2004 Rev.1.2, 2007-01-05 PCB DESIGN GUIDELINES One of the key efforts in implementing the MLP package on a pc board is the design of the land pattern. The MLP has rectangular metallized terminals exposed on the bottom surface of the package body. Electrical and mechanical connection between the component and the pc board is made by screen printing solder paste on the pc board and then reflowing the paste after placement. To guarantee reliable solder joints it is essential to design the land pattern to the MLP terminal pattern, exposed PAD, and Thermal PAD via. There are two basic designs for PCB land pads for the MLP: Copper Defined style (also known as Non Solder Mask Defined (NSMD)) and the Solder Mask Defined style (SMD). The industry has had some debate on the merits of both styles and although Microsemi recommends the Copper Defined style land pad (NSMD). Both styles are acceptable for use with the MLP package. NSMD pads are recommended over SMD pads due to the tighter tolerance on copper etching than solder masking. NSDM by definition also provides a larger copper pad area and allows the solder to anchor to the edges of the copper pads thus providing improved solder joint reliability. EXPOSED PAD PCB DESIGN The construction of the Exposed Pad MLP enables enhanced thermal and electrical characteristics. In order to take full advantage of this feature the exposed pad must be physically connected to the PCB substrate with solder. The exposed pad is internally connected to the die substrate potential which is VNEG so it is very important that the PCB substrate potential be connected to VNEG as well. The thermal pad (D2th) should be greater than D2 of the MLP whenever possible; however adequate clearance (Cpl > 0.15mm) must be met to prevent solder bridging. If this clearance cannot be met, then D2th should be reduced in area. The formula would be: D2TH > D2 only if D2TH < Gmin – (2 x Cpl). Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 10 WWW . Microsemi .C OM APPLICATION NOTE/PCB DESIGN GUIDLINE LX1708 ® TM 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET THERMAL PAD VIA DESIGN There are two types of on-board thermal PAD designs: one is using thermal vias to sink the heat to the other layer with metal traces. Based on the Jedec Specification (JESD 51-5) the thermal vias should be designed like Figure 5. Another one is the no via thermal PAD which is using the same copper PAD as heat sink, this type of thermal PAD is good for a two layer board, since the bottom side is filled with all other kinds of trace also, it’s hard to use the whole plane for the heat sink. But you still can use vias to sink the heat to the bottom layer by the metal traces, then layout a NMSD on which a metal heat sink is put to sink the heat to the air. The LX1708 is supplied in an MLPQ – 7mm x 7mm, 32 pin package. θJA = 15.5°C/W for the package by itself in still air. When running at a continuous 20W output power, the on-chip power dissipation will be 3.5W assuming 85% efficiency. With no reduction in the thermal resistance, the die temperature will rise 103 about ambient. θJC is about 4° C/W. if the exposed pad is properly connected to a heat sink, then the temperature rise will be reduced to around 16°C under these conditions. So the via type thermal PAD is suggested. ~0.85mm ~0.025mm ~0.355mm Zmin ~7.45mm D2th ~5.15mm 1.2mm Gmin ~6.00mm 0.305mm Micro Lead Quad Land Pattern for Four Package Land Pattern Layer Board with Vias Figure 5 – Comparison of land pattern theory Ø 0.3mm 5.00mm Figure 6 – Recommended Land Pad with Vias for LQ32 (7mm2) Zmin=D + aaa+ 2(0.2) (where pkg body tolerance aaa=0.15) (where 0.2 is outer pad extension) Gmin=D-2(Lmax)-2(0.05) (where 0.05 is inner pad extension) (Lmax=0.05 for this example) D2th max = Gmin-2(CpL) (where CpL=0.2) Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 11 WWW . Microsemi .C OM APPLICATION NOTE/PCB DESIGN GUIDLINE (CONTINUED) LX1708 ® TM 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET PRINTED CIRCUIT BOARD FOR THE LXE1708 WWW . Microsemi .C OM Figure 7 – Inner Layer 1 Figure 8 – Bottom Layer Figure 10 – Inner Layer 2 Figure 9 – Top Layer Figure 11 – Top Component Layer Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 12 LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET LX1708 EVAL KIT BILL OF MATERIALS Part Description Manufacturer & Part # Case Reference Designators Qty 1 Microsemi IC Controller LX1708 Class-D Audio Amplifier MICROSEMI LX1708ILQ MLPQ-32 U1 1 2 Diode, Schottky MICROSEMI UPS5817 Powermite CR1, CR2, CR7, CR8 N/U 3 Jack, PCB Mount, RCA KEYSTONE 901 J1, J2 2 4 Header, 2 Position Vertical 3M 929450-01-02-1 JP1 – JP7 6 5 Header, 3 Position, 2 Row Vertical 0.1” Centers 3M JP3 1 6 Switch, SPDT, PCB Mount Subminiature C&K GT11MSAKE SW1 1 TB1, TB2, TB3, TB4 4 SMT TP1, TP7 2 SMT TP2, TP3, TP4, TP5, TP6, TP8, TP9, TP10, TP11 9 Case Reference Designators Qty 7 Terminal Block, 2 Position BLOCKMASTER 301-021-1000 8 Terminal, Compact, Test Point KEYSTONE 5016 9 Terminal, Subminiature, KEYSTONE 5015 10 PCB, LX1708 Evaluation Board MICROSEMI SGE2874-X1 CAPACITORS Line Item Part Description Manufacturer & Part # 11 Capacitor, Elect., 47µF, 35V, 20%, KS Type PANASONIC ECEA1VKS470i Thru C1 1 12 Capacitor, Elect., 22µF, 10V, 20%, KS Type PANASONIC ECEA1AkS220i Thru C2 1 13 Capacitor, Ceramic, .47µF, 16V, 10% PANASONIC ECJ2YB1C474K 0805 C3, C4, C5, C6 4 14 Capacitor, Ceramic, X5R, 1µF, 25V, 10%, PANASONIC ECJ-2FB1E105K 0805 15 Capacitor, Ceramic, 4700pF, 50V, 10%, PANASONIC ECJ-1VB1H472K 0603 16 Capacitor, Ceramic, 2200pF, 50V, 10% PANASONIC ECJ-1VB1H222K 0603 C7, C8, C9, C10, C11, C12, C13, C14, C15, C16 C17, C19, C21, C23 C18, C20, C22, C24 10 4 4 RESISTORS Line Item 17 18 Part Description Resistor, 25.5K Ohm, 1/10W, 1% Resistor 470 Ohm, 1/10W, 5% Copyright © 2004 Rev.1.2, 2007-01-05 Manufacturer & Part # PANASONIC PANASONIC Reference Designators Qty 0603 R1 1 0603 R2, R3, R4, R5, R6, R7, R8, R9 8 Case ERJ3EKF2552V ERJ3GSYJ471 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 13 WWW . Microsemi .C OM MISCELLANEOUS COMPONENTS Line Item LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET THD VS PWR @ 4 OHM NO DIODES THD+N VS. FREQUENCY GAIN RESPONSE WWW . Microsemi .C OM THD VS PWR @ 4 OHM WITH DIODES 100 50 20 PVDD = 12V, V5V = 5V PO = 1W, 10Hz ~ 22KHz BPF Load 4 10 5 2 Without Diodes 1 0.5 % 0.2 0.1 0.05 With Diodes 0.02 0.01 0.005 0.002 0.001 20 See Note 1 on Schematic 50 100 200 500 1k 2k 5k 10k 20k Hz CHARTS Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 14 LX1708 TM ® 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET NOISE FLOOR & SIGNAL-TO-NOISE RATIO CHANNEL CROSSTALK WWW . Microsemi .C OM OUTPUT POWER BANDWIDTH @ 1% THD EFFICIENCY @ 4 OHM LOAD 100% Without LC Filter 90% 80% With LC Filter Efficiency (%) 70% 60% 50% 40% 30% 20% 10% 0% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Power/CH (W) CHARTS Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 15 LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET IQQ VS. FREQUENCY PSRR (AC) WWW . Microsemi .C OM 40 35 30 IQQ (mA) 25 20 15 10 5 0 150k 250k 350k 450k 550k 650k 750k 850k 950k 1,050k 1,150k SW Freq. (Hz) POWER VS. SUPPLY VOLTAGE IQQ VS. SUPPLY 20 35 18 30 16 14 With LC Filter 4OHM Resistor Load Power/CH (W) IQQ (mA) 25 20 15 Without LC Filter 4OHM Speaker Load 10 R=4ohm; FIN = 1kHz THD+N <= 1% 12 10 8 6 Without LC Filter NO Load 5 4 2 0 5 6 7 8 9 10 Supply (V) 11 12 13 14 15 0 5 6 7 8 9 10 11 12 13 14 15 Supply Voltage (V) CHARTS Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 16 LX1708 15+15W Stereo Filterless Class-D Amplifier ® TM P RODUCTION D ATA S HEET PACKAGE DIMENSIONS WWW . Microsemi .C OM LQ 32-Pin MLPQ Plastic (7x7mm EP) D E2 b L D2 E e MILLIMETERS MIN MAX 0.80 1.00 0 0.05 0.25 REF 0.23 0.38 7.00 BSC 5.00 5.25 7.00 BSC 5.00 5.25 0.65 BSC 0.45 0.65 INCHES MIN MAX 0.031 0.039 0 0.002 0.010 0.009 0.015 0.276 BSC 0.197 0.207 0.276 BSC 0.197 0.207 0.026 0.018 0.026 Note: A A1 Dim A A1 A3 b D D2 E E2 e L 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 © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 17 LX1708 TM ® 15+15W Stereo Filterless Class-D Amplifier P RODUCTION D ATA S HEET NOTES WWW . Microsemi .C OM 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 pre-production form only and may not have completed Microsemi’s Quality Assurance process for Release to Production. Microsemi reserves the right to change or discontinue this proposed product at any time. Copyright © 2004 Rev.1.2, 2007-01-05 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 18