A Product Line of Diodes Incorporated PAM8603E FILTERLESS 3W CLASS-D STEREO AUDIO AMPLIFIER WITH DC VOLUME CONTROL and HEADPHONE OUTPUT Description Pin Assignments The PAM8603E is a 3W, class-D audio amplifier with headphone amplifier. Advanced 64-step DC volume control minimizes external components and allows speaker volume control and headphone volume control. It offers low THD+N, to produce high-quality sound reproduction. The new filterless architecture allows the device to drive the speaker directly, without low-pass output filters which will save 30% system cost and 75% PCB area. With the same numbers of external components, the efficiency of the PAM8603E is much better than Class-AB cousins. It can extend the battery life thus be ideal for portable applications. The PAM8603E is available in a SSOP-24 and SOP-24 package. 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 • Headphone Output Function • Superior Low Noise • Low pop noise • Efficiency up to 90% • 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 • VoIP/Speaker Phones PAM8603E Document number: DSxxxxx Rev. 1 - 1 1 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Typical Applications Circuit Pin Descriptions Pin Number Package Name 1 +OUT_L 2 PGNDL 3 PGNDL 4 -OUT_L 5 PVDDL 6 MUTE 7 VDD 8 INL 9 Ear In L 10 VDC 11 VOLUME 12 Ear Out L 13 Ear Out R 14 VREF 15 LINE/EAR 16 Ear IN R 17 INR 18 GND 19 SHDN 20 PVDDR 21 -OUT_R 22 PGNDR 23 PGNDR 24 +OUT_R PAM8603E Document number: DSxxxxx Rev. 1 - 1 Function Left Channel Positive Output Left Channel Power GND Left Channel Power GND Left Channel Negative Output Left Channel Power Supply Mute Control Input（active low） Analog VDD Left Channel Input Left Earphone input Analog Reference for Gain Control Section DC Volume Control to Set the Gain of Class-D Left Earphone Output Right Earphone Output Internal Analog Reference, Connect a Bypass Capacitor from VREF to GND Line/ Earphone Detect Right Earphone Input Right Channel Input Analog GND Shutdown Control Input (active low) Right Channel Power Supply Right Channel Negative Output Right Channel Power GND Right Channel Power GND Right Channel Positive Output 2 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E 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 -0.3 to VDD +0.3 150 -65 to +150 300, 5 sec Unit V °C Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Parameter Supply Voltage Range Ambient Operation Temperature Range Junction Temperature Range Rating 2.5 to 5.5 -20 to +85 -20 to +125 Unit V °C °C Thermal Information Parameter Thermal Resistance (Junction to Ambient) PAM8603E Document number: DSxxxxx Rev. 1 - 1 Package SSOP-24 SOP-24 Symbol θJA 3 of 17 www.diodes.com Max 96 79.2 Unit °C/W November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Electrical Characteristics (@TA = +25°C, VDD = 5V, Gain = Maximum, RL = 8Ω, unless otherwise specified.) Symbol VDD Parameter Test Conditions Min Supply Voltage Typ 2.5 5.5 V 15 mA 10 30 mV No Load VOS Output Offset Voltage No Load RDS(ON) Static Drain-to-Source On-State Resistor IDS = 0.5mA, VGS = 5V Output Power THD+N = 10%, f = 1KHz THD+N Total Harmonic Distortion Plus Noise RL = 8Ω, PO = 0.85W, f = 1KHz 0.08 RL = 4Ω, PO = 1.75W, f = 1KHz 0.08 PSRR Power Supply Ripple Rejection Inputs AC-GNG, f = 1KHz, VPP = 200mV CS Channel Separation PO = 1W, f = 1KHz fOSC Oscillator Frequency PO η VN Efficiency Output Noise SNR Signal-to-Noise Ratio Earphone Stage IQ Quiescent Current 1.55 2.85 0.21 0.17 1.7 3.0 RL = 8Ω, THD = 10% 85 89 RL = 4Ω, THD = 10% 80 83 f = 20-20kHz, THD = 1% 180 260 75 No Load 4.5 2.5 Output Offset Voltage No Load PO Output Power THD+N = 10%, f = 1KHz, RL = 32Ω THD+N Total Harmonic Distortion Plus Noise RL = 32Ω, PO = 10mW, f = 1KHz PSRR Power Supply Ripple Rejection Channel Separation A-Weighting No A-Weighting f = 1kHz dB 7.5 mA V PO = 1W, f = 1KHz -85 dB Shutdown Current ISHDN = 0V VSH SHDN Input High VSL SHDN Input Low VMH MUTE Input High VML OTP OTH MUTE Input Low Document number: DSxxxxx Rev. 1 - 1 µV dB ISHDN PAM8603E % 70 4.5 Over Temperature Protection Over Temperature Hysterisis kHz Inputs AC-GNG, f = 1KHz, VPP = 200mV VMUTE = 0V IMUTE dB 300 % Mute Current SNR Signal-to-Noise Ratio Control Section UVLO Under Voltage Lock-Out dB 0.02 THD = 1%, f = 120-20kHz Noise % mW 30 40 92 VN W -95 250 Inputs AC-Grounded Ω 65 200 VOS CS P MOSFET N MOSFET RL = 8Ω RL = 4Ω Units 10 Quiescent Current IQ Max Inputs AC-Grounded A-Weighting No A-Weighting µV dB 2 V 7.5 mA 1 µA 1.4 0.6 1.4 0.6 No Load, Junction Temperature 4 of 17 www.diodes.com VDD = 5.0V 140 30 V V °C November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Typical Performance Characteristics (@TA = +25°C, unless otherwise specified.) Class D Output PAM8603E Document number: DSxxxxx Rev. 1 - 1 5 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) Class D Output PAM8603E Document number: DSxxxxx Rev. 1 - 1 6 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) Earphone Output PAM8603E Document number: DSxxxxx Rev. 1 - 1 7 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) PAM8603E Document number: DSxxxxx Rev. 1 - 1 8 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) PAM8603E Document number: DSxxxxx Rev. 1 - 1 9 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) STEP 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 32 PAM8603E Document number: DSxxxxx Rev. 1 - 1 Gain (dB) Class D -75 -40 -34 -28 -22 -16 -10 -7.5 -5 -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 Gain (dB) Earphone -75.0 -40.0 -38.0 -36.0 -34.0 -32.0 -30.0 -29.0 -28.0 -27.0 -26.0 -25.0 -24.0 -23.0 -22.2 -21.4 -20.6 -19.8 -19.0 -18.2 -17.4 -16.6 -15.9 -15.2 -14.5 -13.8 -13.1 -12.4 -11.7 -11.0 -10.4 -9.8 STEP 10 of 17 www.diodes.com 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 64 Gain (dB) Class D 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 Gain (dB) Earphone -9.2 -8.6 -8.0 -7.4 -6.8 -6.2 -5.7 -5.2 -4.7 -4.2 -3.7 -3.2 -2.7 -2.2 -1.8 -1.4 -1.0 -0.6 -0.2 0.2 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 2.9 3.1 3.3 3.5 November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Application Information Test Setup for Performance Testing (Class-D) 1. When the PAM8603E works with LC filters, it should be connected with the speaker before it's powered on, otherwise it will be damaged easily. 2. When the PAM8603E works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker for suppressing the possible electromagnetic interference. 3. The absolute maximum rating of the PAM8603E operation voltage is 6.0V. When the PAM8603E is powered with 4 battery cells, it should be noted that the voltage of 4 new dry or alkaline batteries is over 6V, higher than its maximum operation voltage, which probably make the device damaged. Therefore, it's recommended to use either 4 Ni-MH (Nickel Metal Hydride) rechargeable batteries or 3 dry or alkaline batteries. 4. 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 PAM8603E has big gain, it will make the device damaged. 5. When testing the PAM8603E without LC filters by using resistor instead of speaker as the output load, the test results, e.g. THD or efficiency, will be worse than those using speaker as load. Notes: 1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement with 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 PAM8603E. A logic low on this pin diables the outputs, and a logic high on this pin 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. Shutdown Operation In order to reduce power comsuption while not in use, the PAM8603E contains shutdown circuitry to turn off the amplifier’s bias circuitry. The amplifieris turned off when logic low is placed on the SHDN pin. By switching the SHDN pin connected to GND, the PAM8603E supply current draw will be minimized in the idle mode. The SHDN pin can be left floating due to the internal pull-up For the best power on/off pop performance, the amplifier should be placed in the Mute mode prior to turning on/off the power supply. PAM8603E Document number: DSxxxxx Rev. 1 - 1 11 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Application Information (cont.) Power Supply Decoupling The PAM86003E is a high performance CMOS audio amplifer that requires adequate power supply decoupling to ensure the output THD and PSRR are as low as possible. Power supply decoupling affects low frequency on the power supply leads. For higher frey response optimum decoupling is achieved by using two capacitors of different types that target different types of noise 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 possilbe 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. Input Capacitor (CI) Large inout capacitors are both expensive and space hungry for portable designs. Clearly, a certain sized capacitors is needed to couple in low frequencies without severe attentuation. But in many cases the speakers used in portable systems, whether intenal 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 capcitor (CI) and input resisitance (RI) of amplifier form a high-pass filter with the corner frequency determined equatiion below, fC = 1 2ΠR 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 (norminally ½ VDD). This charge comes from the internal circuit via the feedback and is apt to create pops upon device enable. This minimizing the capacitor size based on necessary low frequency response, turn-on pops can be minimized. Analog Reference Bypass Capacitor (CBYP) The Analog Reference Bypass Capacitor (CBYP) is the most critical caoacitor and serves several important functions. During start-up or recovery from shutdown mode, CBYP determines the rate at which the amplifier starts up. The second function is to reduce noise produced by the power supply caused by coupling in to 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 poping noise from power on/off and entering and leaving shutdown. Under Voltage Lock-Out (UVLO) The PAM8603E incorporates circuitry designed to detect when the supply voltage is low. When the supply voltage drops to 1.8V or below, the PAM8603E outputs are disabled and the device comes out of this state and starts normal function once VDD ≥2.0V. Short Circuit Protection (SCP) The PAM8603E has short circuit protection circuitry on the outputs that prevents the device from damage when output-to-output and output-toGND 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 PAM8603E 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. PAM8603E Document number: DSxxxxx Rev. 1 - 1 12 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Application Information (cont.) 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 1. The ferrite filter reduces EMI 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 1. Ferrite Bead Filter to reduce EMI 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, worse yet, 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 PAM8603E 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 in 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. PCB Layout Example Figure 2. Top Layer PAM8603E Document number: DSxxxxx Rev. 1 - 1 Figure 3. Bottom Layer 13 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Ordering Information Part Number PAM8603ENHR PAM8603EDHR Package Type SSOP-24 SOP24 Standard Package 2500 Units/Tape & Reel 1000 Units/Tape & Reel Marking Information PAM8603E Document number: DSxxxxx Rev. 1 - 1 14 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Package Outline Dimensions (All dimensions in mm.) SSOP-24 PAM8603E Document number: DSxxxxx Rev. 1 - 1 15 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E Package Outline Dimensions (cont.) (All dimensions in mm.) SOP-24 PAM8603E Document number: DSxxxxx Rev. 1 - 1 16 of 17 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8603E 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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Copyright © 2012, Diodes Incorporated www.diodes.com PAM8603E Document number: DSxxxxx Rev. 1 - 1 17 of 17 www.diodes.com November 2012 © Diodes Incorporated