A Product Line of Diodes Incorporated PAM8403H FILTERLESS 3W CLASS-D STEREO AUDIO AMPLIFIER Description Pin Assignments The PAM8403H is a 3W, class-D audio amplifier. It offers low THD+N, allowing it to achieve high quality sound reproduction. The new filterless architecture allows the device to drive the speaker directly, requiring no low-pass output filters, thus saving system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8403H is much better than that of class-AB cousins. It can extend the battery life, ideal for portable applications. The PAM8403H is available in SOP-16 package. Features 3W Output at 10% THD with a 4 Load and 5V Power Supply Filterless, Low Quiescent Current and Low EMI Low THD+N Superior Low 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 Cellular Phones/Speaker Phones PAM8403H Document number: DSxxxxx Rev. 1 - 0 1 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Typical Applications Circuit Pin Descriptions Pin Number Pin Name 1 -OUT_L Function Left Channel Negative Output 2 PGND 3 +OUT_L 4 PVDD Power VDD 5 MUTE Mute Control Inputactive low 6 VDD Analog VDD 7 INL Left Channel Input 8 VREF 9 NC No connected 10 INR Right Channel Input 11 GND Analog GND 12 SHDN Shutdown Control Input (active low) 13 PVDD Power VDD 14 +OUT_R 15 PGND 16 -OUT_R PAM8403H Document number: DSxxxxx Rev. 1 - 0 Power GND Left Channel Positive Output Internal analog reference, connect a bypass capacitor from VREF to GND Right Channel Positive Output Power GND Right Channel Negative Output 2 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Functional Block Diagram Absolute Maximum Ratings (@TA = +25C, 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 Range Input Voltage Operation Temperature Range Maximum Junction Temperature Operation Junction Temperature Storage Temperature Soldering Temperature Rating 6.0 Unit -0.3 to VDD +0.3 -40 to +85 150 -40 to +125 -65 to 150 300, 5sec V C Recommended Operating Conditions (@TA = +25C, unless otherwise specified.) Parameter Supply Voltage Range Operation Temperature Range Junction Temperature Range PAM8403H Document number: DSxxxxx Rev. 1 - 0 Rating 2.5 to 5.5 -40 to +85 -40 to +125 Unit V C C 3 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Thermal Information Package Symbol Max Thermal Resistance (Junction to Ambient) Parameter SOP-16 JA 110 Thermal Resistance (Junction to Case) SOP-16 JC 23 Internal Power Dissipation (@ TA = +25C) SOP-16 PD 90 Note: Unit C/W mW 1. The maximun output current for SOT23-5 package is limited by internal power dissipation capacity as described in Application Information here inafter. Electrical Characteristics (@TA = +25C, VDD = 5V, Gain = 24dB, RL = 8, unless otherwise specified.) Symbol VIN Parameter Test Conditions THD+N GV PSRR Output Power Total Harmonic Distortion Plus Noise VDD = 5.0V 2.25 2.50 W VDD = 5.0V 1.5 1.8 W THD+N = 1%, f = 1kHz, RL = 8 VDD = 5.0V 1.2 1.4 VDD = 5.0V,PO = 0.5W, RL = 8 f = 1kHz 0.15 0.20 % VDD = 5.0V, PO = 1W, RL = 4 f = 1kHz 0.15 0.20 % dB 23 VDD = 5.0V, Inputs AC-grounded with CIN = 0.47F 3.20 W W 24 25 f = 100Hz -59 -50 dB f = 1kHz -58 -50 dB -95 -80 VDD = 5V, PO = 0.5W, RL = 8, GV = 20dB f = 1kHz f = 1kHz VN Output Noise VDD = 5V, Inputs AC-Grounded with CIN = 0.47F IQ Quiescent Current Muting Current ISD Shutdown Current VDD = 2.5V to 5.5V VOS Output Offset Voltage VIN = 0V, VDD = 5V VIH Enable Input High Voltage VDD = 5.0V VIL Enable Input LowVoltage 74 80 dB dB A-weighting 100 200 No A-weighting 150 300 V VDD = 5.0V No load 16 20 mA VDD = 5.0V VMUTE = 0.3V 8 12 mA 20 VSD = 0.3V 10 MUTE Input High Voltage VDD = 5.0V VIL MUTE Input Low Voltage VDD = 5.0V V 0.4 1.5 V V 0.4 4 of 11 www.diodes.com A mV 1.5 VDD = 5.0V VIH Document number: DSxxxxx Rev. 1 - 0 V THD+N =10%,f = 1kHz, RL = 8 VDD = 5V, VORMS = 1V,GV = 20dB PAM8403H Units VDD = 5.0V Crosstalk IMUTE 5.5 THD+N =1%, f = 1kHz, RL = 4 Signal-to-Noise Ration CS SNR Max 2.85 Gain Power Supply Ripple Rejection Typ 2.5 THD+N = 10%,f = 1kHz , RL = 4 PO Min Supply Voltage V November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Typical Performance Characteristics (@TA = +25C, unless otherwise specified.) PAM8403H Document number: DSxxxxx Rev. 1 - 0 5 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Typical Performance Characteristics (cont.) (@TA = +25C, unless otherwise specified.) PAM8403H Document number: DSxxxxx Rev. 1 - 0 6 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Application Information 1. When the PAM8403H 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 PAM8403H 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 recommended operating voltage is 5.5V. When the PAM8403H is powered with four battery cells, it should be noted that the voltage of four new dry or alkaline batteries is over 6.0V, higher than its operation voltage, which will probably damage the device. Therefore, it's recommended to use either four Ni-MH (Nickel Metal Hydride) rechargeable batteries or three dry or alkaline batteries. 4. One should not make the input signal too large. Large signal can cause the clipping of output signal when increasing the volume. This will damage the device because of the big gain of the PAM8403H. 5. When testing the PAM8403H 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 of using speaker as load. Test Setup for Performance Testing Notes: 1. The Audio Precision(AP) AUX-0025 low pass filter is necessary for class-D amplifier measurement with AP analyzer. 2. Two 22H inductors are used in series with load resistor to emulate the small speaker for efficiency measurement. Maximum Gain As shown in block diagram (Page 2), the PAM8403H has two internal amplifier stages. The first stage's gain is externally configurable, while the second stage's is internally fixed. The closed-loop gain of the first stage is set by selecting the ratio of RF to RI while the second stage's gain is fixed at 2x.The output of amplifier 1 serves as the input to amplifier 2, thus the two amplifiers produce signals identical in magnitude, but different in phase by 180. Consequently, the differential gain for the IC is AVD = 20*log [2*(RF/RI)] The PAM8403H sets maximum RF = 142k, minimum RI = 18k, so the maximum closed-gain is 24dB. Mute Operation The MUTE pin is an input for controlling the output state of the PAM8403H. A logic low on this pin disables 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 consumption while not in use, the PAM8403H contains shutdown circuitry to turn off the amplifier's bias circuitry. This shutdown feature turns the amplifier off when logic low is applied to the SHDN pin. By switching the SHDN pin connected to GND, the PAM8403H supply current draw will be minimized in idle mode. The SHDN pin can be left floating due to the internal pull-up. PAM8403H Document number: DSxxxxx Rev. 1 - 0 7 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Application Information (cont.) Power Supply Decoupling The PAM8403H 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 targeting to different types of noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-seriesresistance (ESR) ceramic capacitor, typically 1.0F, works best, placing it as close as possible to the device VDD terminal. For filtering lowerfrequency noise signals, a large capacitor of 20F (ceramic) or greater is recommended, placing it near the audio power amplifier. 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 attenuation. 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 by 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. 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, CBYP determines the rate at which the amplifier starts up. The second function is to reduce noise caused by the power supply coupling into 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) with values of 0.47F to 1.0F 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 (UVLO) The PAM8403H incorporates circuitry designed to detect low supply voltage. When the supply voltage drops to 2.0V or below, the PAM8403H outputs are disabled, and the device comes out of this state and starts to normal function when VDD 2.2V. Short Circuit Protection (SCP) The PAM8403H has short circuit protection circuitry on the outputs to prevent damage to the device when output-to-output or output-to-GND short occurs. 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 PAM8403H prevents the device from damage when the internal die temperature exceeds 140C. There is a 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 30C. This large hystereis will prevent motor boating sound well and the device begins normal operation at this point without extrenal system intervention. PAM8403H Document number: DSxxxxx Rev. 1 - 0 8 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Application Information (cont.) How to Reduce EMI (Electro Magnetic Interference) A simple solution is to put an additional capacitor 1000F 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 in Figure 2. The ferrite filter reduces EMI of around 1MHz and higher. When selecting a ferrite bead, choose one with high impedance at high frequencies, and low impedance at low frequencies. Figure 2. Ferrite Bead Filter to Reduce EMI Ordering Information Part Number PAM8403DR-H PAM8403H Document number: DSxxxxx Rev. 1 - 0 Part Marking PAM8403 XXXYWWLL Package Type Standard Package SOP-16 2500 Units/Tape&Reel 9 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H Marking Information Package Outline Dimensions (All dimensions in mm.) SOP-16 PAM8403H Document number: DSxxxxx Rev. 1 - 0 10 of 11 www.diodes.com November 2012 (c) Diodes Incorporated A Product Line of Diodes Incorporated PAM8403H 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 (c) 2012, Diodes Incorporated www.diodes.com PAM8403H Document number: DSxxxxx Rev. 1 - 0 11 of 11 www.diodes.com November 2012 (c) Diodes Incorporated Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Diodes Incorporated: PAM8403DR-H