PAM8004DR

A Product Line of Diodes Incorporated PAM8004 FILTERLESS 3W CLASS-D STEREO AUDIO AMPLIFIER Description Pin Assignments The PAM8004 is a 3Wm 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, in order to save system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8004 is much better than that of Class-AB cousins. It can extend the battery life, ideal for portable applications The PAM8004 is available in SOP-16L package. Features Applications  3W Output at 10% THD with a 3Ω Load and  5V Power Supply  2.5W Output at 10% THD with a 4Ω Load and 5V Power Supply  Filterless, Low Quiescent Current and Low EMI  Low THD+N  Superior Low Noise  Short Circuit Protection  Thermal Shutdown  Few External Components to Save the Space and Cost  Pb-Free Package  Portable Speakers  LCD Monitors / TV  Notebook Computers  Portable DVD Players, Game Machines Typical Applications Circuit PAM8004 Document number: DSxxxxx Rev. 1 - 0 1 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 Pin Descriptions Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin Name PVDDL -OUTL PGNDL +OUTL SHDN VREF INL GND VDD INR NC NC +OUTR PGNDR -OUTR PVDDR Function Left Channel Power Supply Left Channel Negative Output Left Channel Power GND Left Channel Positive Output Shutdown Control Input (active low) Internal Analog Reference, Connect a Bypass Capacitor from VREF to GND Left Channel Input Analog Ground Analog Power Supply Right Channel Input Not Connected (Suggest Connect to GND) Not Connected Right Channel Positive Output Right Channel Power GND Right Channel Negative Output Right Channel Power Supply Functional Block Diagram PAM8004 Document number: DSxxxxx Rev. 1 - 0 2 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 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 Operation Temperature Range Junction Temperature Range Rating 2.5 to 5.5 -40 to +85 -40 to +125 Unit V °C °C Thermal Information Parameter Package Symbol Max Thermal Resistance (Junction to Ambient) SOP-16L θJA 110 Thermal Resistance (Junction to Case) SOP-16L θJC 23 Internal Power Dissipation @ TA = +25°C SOP-16L PD 900 PAM8004 Document number: DSxxxxx Rev. 1 - 0 3 of 11 www.diodes.com Unit °C/W mW November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 Electrical Characteristics (@TA = +25°C, VDD = 5V, Gain = 24dB, RL = 8Ω, unless otherwise specified.) Symbol VIN Parameter Test Conditions Output Power Total Harmonic Distortion Plus Noise CS SNR VN η RDS(ON) V 2.5 W W VDD = 5.0V 2.2 1.65 W THD+N = 1%, f = 1kHz, RL = 8Ω VDD = 5.0V 1.3 W VDD = 3.6V, Po = 0.5W, RL = 8Ω VDD = 5.0V, Po = 1W, RL = 4Ω 0.16 f = 1kHz % 0.12 0.17 f = 1kHz % 0.26 Power Supply Ripple Rejection VDD = 5.0V, Inputs AC-Grounded with CIN = 0.47μF, Gv = 6dB f = 1kHz -70 dB Crosstalk VDD = 5V, Po = 0.5W, RL = 8Ω, Gv = 20dB f = 1kHz -93 dB dB Signal-to-Noise VDD = 5V, Gv = 6dB Output Noise VDD = 5V, Inputs AC-Grounded with CIN = 0.47μF, GV = 6dB Efficiency RL = 8Ω, THD = 10% RL = 4Ω, THD = 10% f = 1kHz 86 A-weighting 33 No A-weighting 50 Quiescent Current Shutdown Current Static Drain-to-Source On-State Resistor 4.5 7.0 4.0 6.5 3.7 5.5 1 VDD = 2.5V to 5.5V IDS = 500mA,VGS = 5V % 79 No load VDD = 3.6V µV 87 f = 1kHz VDD = 3.0V ISD Units VDD = 5.0V VDD = 5.0V IQ 5.5 THD+N = 10%, f = 1kHz, RL = 8Ω VDD = 3.6V, Po = 1W, RL = 4Ω PSRR VDD = 5.0V Max THD+N = 1%, f = 1kHz, RL = 4Ω VDD = 5.0V, Po = 0.5W, RL = 8Ω THD+N Typ 2.5 THD+N = 10%, f = 1kHz, RL = 4Ω PO Min Supply Power PMOS NMOS mA µA 0.41 0.27 mΩ fsw Switching Frequency VDD = 3V to 5V 210 kHz VOS Output Offset Voltage VIN = 0V, VDD = 5V 10 mV VIH Enable Input High Voltage VDD = 5.0V VIL OTP OTH Enable Input Low Voltage VDD = 5.0V Over Temperature Protection Over Temperature Hysterisis No Load, Junction Temperature PAM8004 Document number: DSxxxxx Rev. 1 - 0 1.5 0.4 4 of 11 www.diodes.com VDD = 5V 150 30 V °C November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 Typical Performance Characteristics (@TA = +25°C, unless otherwise specified.) PAM8004 Document number: DSxxxxx Rev. 1 - 0 5 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) PAM8004 Document number: DSxxxxx Rev. 1 - 0 6 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 Application Information Maximum Gain As shown in block diagram (Page 2), the PAM8403 has two internal amplifier stages. The first stage’s gain is externally configurable, while the secind 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 A VD  20 * log[ 2 * (R F / R I )] The PAM8403 sets maximum RF = 142kΩ, minimum RI = 18kΩ, so the maximum closed-gain is 24dB. Power Supply Decoupling The PAM8004 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 of noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low equivalentseries-resisitance (ESR) ceramic capacitor, typically 1.0µF, works best, placing it as close as possible to the device VDD terminal. For filtering lower-frequency noise signals, a large capacitor of 20µF (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 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 by equation below. fC  1 2 RI CI In addition to system cost and size, click and pop perfor mance is affected by the size of the input the coupling capacitor, CI. A larger input coupling capacitor requires more charge to reach its quiescent DC voltage (nominally ½ 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 0.1μF 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 leavingshutdown. Under-Voltage Lock-Out (UVLO) The PAM8004 incorporates circuitry designed to detect low supply voltage. When the supply voltage drops to 2.0V or below, the PAM8004 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 PAM8004has 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 out puts are disabled immediately. If the short was removed, the device activates again. Over Temperature Protection Thermal protection on the PAM8004 prevents the device from damage when the internal die temperature exceeds +140°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 and the device begins normal operation at this point without external system intervention. PAM8004 Document number: DSxxxxx Rev. 1 - 0 7 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 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 in Figure 2. 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. Figure 2. Ferrite Bead Filter to Reduce EMI Application Notes 1. When the PAM8804 works with LC filters, it should be connected with the speaker before it’s powered on, otherwise it will damaged easily. 2. When the PAM8004 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 PAM8004 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 that its operation voltage, which will probably damage the device. Therefore, its 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 big gain of the PAM8004. 5. When testing the PAM8804 without LC filters by using resistor instead of speakers 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 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. PAM8004 Document number: DSxxxxx Rev. 1 - 0 8 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 Ordering Information Part Number PAM8004DR Part Marking PAM8004 XATYWWLL Package Type Standard Package SOP-16L 2500 Units/Tape&Reel Marking Information PAM8004 Document number: DSxxxxx Rev. 1 - 0 9 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 Package Outline Dimensions (All dimensions in mm.) SOP-16 PAM8004 Document number: DSxxxxx Rev. 1 - 0 10 of 11 www.diodes.com November 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM8004 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 PAM8004 Document number: DSxxxxx Rev. 1 - 0 11 of 11 www.diodes.com November 2012 © Diodes Incorporated