A Product Line of Diodes Incorporated PAM8603M 3W FILTERLESS STEREO CLASS-D AUDIO AMPLIFIER WITH DC VOLUME CONTROL Description Pin Assignments The PAM8603M is a 3W, sterero, Class-D audio amplifier with DC volume control. It offers low THD+N, allowing it to produce highquality sound reproduction. The new filterless architecture allows the device to drive the speaker directly, requiring no low-pass output filters, which saves the system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8603M is much better than class-AB cousins. It can extend the battery life thus ideal for portable applications. The PAM8603M is available in SSOP-24 and SOP-18 packages. Features 3W Output at 10% THD with a 4Ω Load and 5V Power Supply Filterless, Low Quiescent Current and Low EMI Low THD+N 64-Step DC Volume Control from -75dB to +24dB Superior Low Noise Efficiency up to 89% Short Circuit Protection Thermal Shutdown Few External Components to Save the Space and Cost Pb-Free Package Applications LCD Monitors/TV Projectors Notebook Computers Portable Speakers Portable DVD Players, Game Machines Cellular Phones/Speaker Phones PAM8603M Document number: DSxxxxx Rev. 1 - 1 1 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Typical Applications Circuit Pin Descriptions Pin Name +OUTL PGNDL -OUTL PVDDL MUTE VDD INL NC VDC VOLUME VREF INR GND SHDN PVDDR -OUTR PGNDR +OUTR Package Name SSOP-24 SOP-18 1 1 2, 3 2 4 3 5 4 6 5 7 6 8 7 9, 12, 13, 15, 16 8 10 9 11 10 14 11 17 12 18 13 19 14 20 15 21 16 22, 23 17 24 18 PAM8603M Document number: DSxxxxx Rev. 1 - 1 Function Left Channel Positive Output Left Channel Power GND Left Channel Negative Output Left Channel Power Supply Mute Control Input (active low) Analog Power Supply Left Channel Input No Connection Analog reference for gain control section. DC volume control to set the gain of Class-D. Internal analog reference, connect a bypass capacitor from VREF to GND. Right Channel Input Analog Ground Shutdown Control Input (active low) Right Channel Power Supply Right Channel Negative Output Right Channel Power GND Right Channel Positive Output 2 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Functional Block Diagram Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. All voltages are with respect to ground. Parameter Supply Voltage Input Voltage Maximum Junction Temperature Storage Temperature Soldering Temperature Rating 6.0 Unit V -0.3 to VDD +0.3 150 -65 to +150 300, 5sec °C Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Parameter Supply Voltage Range Ambient Temperature Range Junction Temperature Range Rating 2.8 to 5.5 -40 to +85 -40 to +125 Unit V °C °C Thermal Information Parameter Thermal Resistance (Junction to Ambient) Thermal Resistance (Junction to Case) PAM8603M Document number: DSxxxxx Rev. 1 - 1 Package SSOP-24 SOP-18 SSOP-24 SOP-18 Symbol θJA θJC 3 of 14 www.diodes.com Max 96 70 18 16 Unit °C/W November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Electrical Characteristics (@TA = +25°C, VDD = 5V, Gain = 20dB, unless otherwise specified.) Symbol VDD Parameter Test Conditions Min Supply Power THD+N = 10%, f = 1kHz, RL = 4Ω THD+N = 1%, f = 1kHz, RL = 4Ω PO Output Power THD+N = 10%, f = 1kHz, RL = 8Ω THD+N = 1%, f = 1kHz, RL = 8Ω VDD = 5.0V, Po = 0.5W, RL = 8Ω THD+N Total Harmonic Distortion Plus Noise Power Supply Ripple Rejection VDD = 5.0V, Po = 1W, RL = 4Ω Crosstalk VDD = 5.0V, Po = 0.5W, RL = 8Ω, f = 1kHz VDD = 5V, VO_RMS = 1V, f = 1kHz VN Output Noise VDD = 5V, Inputs AC-Grounded with CIN = 0.47μF Dyn Dynamic Range VDD = 5V, THD = 1%, f = 1kHz η Efficiency IQ Quiescent Current IMUTE ISD RDS(ON) VDD = 3.6V 1.55 1.8 VDD = 5.0V 2.35 2.6 VDD = 3.6V 1.25 1.5 VDD = 5.0V 1.55 1.8 VDD = 3.6V 0.75 0.9 VDD = 5.0V 1.15 1.4 VDD = 3.6V 0.5 0.72 f = 100Hz f = 1kHz 0.3 0.15 0.3 0.11 0.25 -59 -58 -50 -50 150 No A-weighting 120 300 f = 1kHz 90 102 85 89 80 85 IDS = 500mA,VGS = 5V PMOS NMOS 200 % % dB dB 98 No load dB µV dB % 13.5 20 8.5 15 2.7 5 mA 1 µA 240 180 500 350 mΩ 260 300 kHz 10 50 mV Switching Frequency VDD = 3V to 5V VIN = 0V, VDD = 5V VIH SD/MUTE Input High VDD = 5V 1.45 VIL SD/MUTE Input Low VDD = 5V 0.65 Over Temperature Protection Over Temperature Hysterisis No Load, Junction Temperature, VDD = 5V 135 30 4 of 14 www.diodes.com W 0.25 Output Offset Voltage Document number: DSxxxxx Rev. 1 - 1 W 0.11 fsw PAM8603M W 0.15 VOS OTP OTH W A-weighting VDD = 5.0V VDD = 2.5V to 5.5V, VSD = 0.3V V -80 VDD = 3.6V Shutdown Current Units 5.5 -95 RL = 8Ω, THD = 10% VDD = 5.0V, VMUTE = 0.3V Max -58 85 RL = 4Ω, THD = 10% Muting Current Static Drain-to-Source On-State Resistor 3.2 f = 1kHz VDD = 5.0V, Inputs AC-Grounded Signal-to-Noise CS SNR VDD = 5.0V 2.85 f = 1kHz VDD = 3.6V, Po = 0.5W, RL = 8Ω VDD = 3.6V, Po = 1W, RL = 4Ω PSRR Typ 2.8 mA V °C November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Typical Performance Characteristics (@TA = +25°C, unless otherwise specified.) PAM8603M Document number: DSxxxxx Rev. 1 - 1 5 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) PAM8603M Document number: DSxxxxx Rev. 1 - 1 6 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) PAM8603M Document number: DSxxxxx Rev. 1 - 1 7 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Table 1. DC Volume Control Step 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 PAM8603M Document number: DSxxxxx Rev. 1 - 1 Gain (dB) -75 -40 -34 -28 -22 -16 -10 -7.5 -5.0 -2.5 0 1.5 3.0 4.0 4.4 4.8 5.2 5.6 6.0 6.4 6.8 7.2 7.6 8.0 8.4 8.8 9.2 9.6 10.0 10.4 10.8 11.2 Step 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 8 of 14 www.diodes.com Gain (dB) 11.6 12.0 12.4 12.8 13.2 13.6 14.0 14.4 14.8 15.2 15.6 16.0 16.4 16.8 17.2 17.6 18.0 18.4 18.8 19.2 19.6 20.0 20.4 20.8 21.2 21.6 22.0 22.4 22.8 23.2 23.6 24.0 November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Application Information 1. When the PAM8603M works with LC filters, it should be connected with the speaker before it is powered on, otherwise it will be damaged easily. 2. When the PAM8603M works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker to suppress the possible electromagnetic interference. 3. The input signal should not be too high. If too high, it will cause the clipping of output signal when increasing the volume. Because the DC volume control of the PAM8603M has big gain, it will make the device damaged. 4. When testing the PAM8603M without LC filters by using resistor instead of speaker as the output load, the test results, e.g. efficiency, will be worse than those using speaker as load. Test Setup for Performance Testing Notes: 1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement done by AP analyzer. 2. Two 22µH inductors are used in series with load resistor to emulate the small speaker for efficiency measurement. Mute Operation The MUTE pin is an input for controlling the output state of the PAM8603M. A logic low on this pin disables the outputs, and a logic high enables the outputs. This pin may be used as a quick disable or enable of the outputs without a volume fade. Quiescent current is listed in the electrical characteristic table. The MUTE pin can be left floating due to the internal pull-up. For better power-off pop performance, the amplifier should be placed in the mute mode prior to removing the power supply. Shutdown Operation In order to reduce power consumption while not in use, the PAM8603M contains shutdown circuitry to turn off the amplifier's bias circuitry. The amplifier is turned off when logic low is placed on the SHDN pin. By switching the SHDN pin connected to GND, the PAM8603M supply current draw will be minimized in idle mode. The SHDN pin can be left floating due to the pull-up. Power Supply Decoupling The PAM8603M is a high performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output THD and PSRR as low as possible. Power supply decoupling affects low frequency response. Optimum decoupling is achieved by using two capacitors of different types that target different noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series resistance (ESR) ceramic capacitor, typically 1.0µF, placed as close as possible to the device VDD terminal works best. For filtering lower-frequency noise signals, a large capacitor of 10µF (ceramic) or greater placed near the audio power amplifier is recommended. PAM8603M Document number: DSxxxxx Rev. 1 - 1 9 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Application Information (cont.) Input Capacitor (CI) Large input capacitors are both expensive and space hungry for portable designs. Clearly, a certain sized capacitor is needed to couple in low frequencies without severe attenu ation. But in many cases the speakers used in portable systems, whether internal or external, have little ability to reproduce signals below 100Hz to 150Hz. Thus, using a large input capacitor may not increase actual system performance. In this case, input capacitor (CI) and input resistance (RI) of the amplifier form a high-pass filter with the corner frequency determined equation below, fC 1 2R I CI In addition to system cost and size, click and pop performance is affected by the size of the input coupling capacitor, CI. A larger input coupling capacitor requires more charge to reach its quiescent DC voltage (nominally 1/2 VDD). This charge comes from the internal circuit via the feedback and is apt to create pops upon device enable. Thus, by minimizing the capacitor size based on necessary low frequency response, turn-on pops can be minimized. The Analog Reference Bypass Capacitor (CBYP) The Analog Reference Bypass Capacitor (CBYP) is the most critical capacitor and serves several important functions. During start-up or recovery from shutdown mode, C determines the rate at which the amplifier starts up. The second function is to reduce noise produced by the power supply coupling in the output drive signal. This noise is from the internal analog reference to the amplifier which appears as degraded PSRR and THD+N. A ceramic bypass capacitor (CBYP) of 0.47μF to 1.0μF is recommended for the best THD and noise performance. Increasing the bypass capacitor reduces clicking and popping noise from power on/off and entering and leaving shutdown. Under Voltage Lock-Out The PAM8603M incorporates circuitry to detect low supply voltage. When the supply voltage drops to 1.8V or below, the PAM8603M outputs are disable. The device resumes to normal functional once VDD ≥ 2.0V. Short Circuit Protection (SCP) The PAM8603M has short circuit protection circuitry on the outputs to prevent the device from damage when output-to-output or output-to-GND short. When a short circuit is detected on the outputs, the outputs are disabled immediately. If the short was removed, the device activates again. Over Temperature Protection Thermal protection on the PAM8603M prevents the device from damage when the internal die temperature exceeds +135°C. There is a 15 degree tolerance on this trip point from device to device. Once the die temperature exceeds the thermal set point, the device outputs are disabled. This is not a latched fault. The thermal fault is cleared once the temperature of the die is reduced by 30°C. This large hysteresis will prevent motor boating sound well. The device begins normal operation at this point without external system interaction. How to Reduce EMI (Electro Magnetic Interference) A simple solution is to put an additional capacitor 1000µF at power supply terminal for power line coupling if the traces from amplifier to speakers are short (< 20cm). Most applications require a ferrite bead filter as shown at Figure 3. The ferrite filter reduces EMI of around 1 MHz and higher. When selecting a ferrite bead, choose one with high impedance at high frequencies, and low impedance at low frequencies (MH2012HM221-T). Figure 3. Ferrite Bead Folter to reduce EMI PAM8603M Document number: DSxxxxx Rev. 1 - 1 10 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Application Information (cont.) PCB Layout Guidelines Grounding At this stage it is paramount to notice the necessity of separate grounds. Noise currents in the output power stage need to be returned to output noise ground and nowhere else. Were these currents to circulate elsewhere, they may get into the power supply, the signal ground, etc, even worse, they may form a loop and radiate noise. Any of these cases results in degraded amplifier performance. The logical returns for the output noise currents associated with Class-D switching are the respective PGND pins for each channel. The switch state diagram illustrates that PGND is instrumental in nearly every switch state. This is the perfect point to which the output noise ground trace should return. Also note that output noise ground is channel specific. A two channel amplifier has two seperate channels and consequently must have two seperate output noise ground traces. The layout of the PAM8603M offers separate PGND connections for each channel and in some cases each side of the bridge. Output noise grounds must be tied to system ground at the power exclusively. Signal currents for the inputs, reference, etc need to be returned to quite ground. This ground is only tied to the signal components and the GND pin, and GND then tied to system ground. Ordering Information Part Number PAM8603MNHR PAM8603MDER PAM8603MDET Part Marking PAM8603M XXXYWWLL PAM8603M XXXYWWLL PAM8603M XXXYWWLL Package Type Standard Package SSOP-24 2500 Units/Tape&Reel SOP-18 1000 Units/Tape&Reel SOP18 40 Units/Tube Marking Information PAM8603M Document number: DSxxxxx Rev. 1 - 1 11 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Package Outline Dimensions (All dimensions in mm.) SSOP-24 PAM8603M Document number: DSxxxxx Rev. 1 - 1 12 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M Package Outline Dimensions (cont.) (All dimensions in mm.) SOP-18 PAM8603M Document number: DSxxxxx Rev. 1 - 1 13 of 14 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603M IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. 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