PAM8302S8R

PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable DESCRIPTION The PAM8302 is a 2 Watt, 8-pin, class D audio amplifier with Enable function, it offers low THD+N (0.10%), allowing it to produce high-quality sound reproduction. The PAM8302 runs off of a 5 Volt supply at much higher efficiencies than their class AB cousins, making it ideal for many portable applications. The PAM8302 only requires very few external components (as few as two tiny capacitors), results in significant cost and board space savings. The PAM8302 is available in a SOP8 package. FEATURES 2 Watts @ 10% THD output into a 4 load at 5V Support speakers or earphone (4 to 32 ). With Enable function. Superior low noise without input. Supply voltage from 2.5V to 5.5V. 85% efficiency above. Short Circuit Protection. Less output capacitor and inductor to save the space and cost. Low THD+N Low quiescent current < 10 mA APPLICATIONS Notebook Computers. PDAs/ GPS Navigator/ e-Dictionary Portable DVD Players, Game Machines. Cellular Phones, VoIP Phones, Screen Phones MP3 or PMP Players. Portable Speaker System, Portable Amplifier LCD monitor / TV. Bluetooth Car-Kit TYPICAL APPLICATION CIRCUIT Vdd 33 H VDD 0.47 F Input 10K IN +OUT 0.47 F Speaker 33 H Enable GND -OUT 0.47 F Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. 1 PAM8302 data sheet, Rev. 0.1 CONFIDENTIAL INFORMATION PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable TOP MARKING & PIN CONFIGURATION 8 7 6 5 Absolute Maximum Ratings: Supply voltage: *6V Input voltage: -0.3V to VDD +0.3V Operation Temperature range: 40OC to 85OC Operation junction temperature: -40OC to 125OC Storage Temperature: -65OC to 150OC Maximum Junction Temperature: 150OC Soldering temperature: 250 OC, 10 secretary A Y WW AYWW 1 2 3 4 Weekly Year Assembly Location SOP8 Recommended operating Conditions: Supply voltage Range: 2.5V to 5.5V Operation Temperature Range: -40OC to 85OC Junction Temperature Range: -40OC to 125OC Pin Description Pin No. 1 2 3 4 5 6 7 8 Pin Name IN_R VDD EN GND NC GND +OUT -OUT Description Right channel audio input. Supply voltage, need a 1uF ceramic decouple capacitor very close bet ween this pin to GND pin. Chip enable, high active. GNDChip ground. Not connected Chip ground. Non-inverted output Inverted output Thermal Information: Thermal Resistance ( SOP8: DIP8 JA JC): 90 OC/W O C/W *Note: Without input signal. ORDERING INFORMATION Ordering Number Package Shipping 2,500 Units/ Reel PAM8302S8R SOP-8 ELECTRONIC SPECIFICATIONS PARAMETER Vdd Range Vdd Quiescent current SW On Resistance SW Frequency PSRR Gain SNR Input impedance E ach channel V DD = 5V No Input Signal VDD = 2.5V to 5.5V VDD = 2.5V to 5.5V, 0 input resistor VDD = 5V, Po = 1.5W, 8 Load 100 0.4 500 -45 10 60 kHz dB V/V dB K CONDITION MIN 2.5 TYP 5 MAX 5.5 10 UNITS V mA Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. 2 CONFIDENTIAL INFORMATION PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable BLOCK DIAGRAM Vdd C1 Input Signal 1F Enable 1 Bit Speaker Controller Over Current TEST CIRCUIT FOR GRAPHS PAM8302 Demo Board +OUT Input AP System One Generator GND -OUT VDD Load AP Low Pass Filter AUX-0025 AP System One Analyzer Power Supply Notes: 1.The AP AUX-0025 low pass filter is necessary for every class D amplifier measurement done by AP analyzer. 2.A 33 H inductor is used in series with load resistor to emulate the small speaker for efficiency measurement. Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. 3 CONFIDENTIAL INFORMATION PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable (%) 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 (W) (%) 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 (W) Ap Ap 1 600u 100m 200m 500m 600u 100m 200m 500m 1m 2m 5m 10m 20m 50m 1m 2m 5m 10m 20m 50m 2 3 1 THD+N vs. Output Power 8 , 1kHz, VDD = 5V (%) 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 20 (Hz) 20k 0% 0 Efficiency 100% THD+N vs. Output Power 4 , 1kHz, VDD = 5V Efficiency VS Output Power Ap 80% 60% 40% 20% 1 Power 2 2 3 3 50 100 200 500 1k 2k 5k 1 10k THD+N vs. Frequency 8 , 500mW output, VDD = 5V 1.4 1.2 Power Dissipation -W 1.0 0.8 0.6 0.4 0.2 0.0 (dBr) +0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 20 Power Dissipation vs. Output Power 4 , 1kHz, VDD = 5V 0 0.5 1 Output Power -W 1.5 2 (Hz) 50 100 200 500 1k 2k 5k 10k 20k Power Dissipation vs. Output Power 4 , 1kHz, VDD = 5V C lass AB = Blue line PAM8202 = Magenta line Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. FFT Noise Floor (16k FFT) 4 CONFIDENTIAL INFORMATION PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable OPERATION INFORMATION Calculating Output Power of BTL amplifier Output power is related to supply voltage and the saturation Vsupply Vsat voltage (Vsat). The Maximum peak-to-peak output voltage on one side of BTL amplifier output is Vp-p = ( Vsupply - 2 X Vsat ) Vp-p 22 Vpk-pk Vrms = Vsat Vsupply One side Maximum output power of a BTL amplifier with 1% THD is Pout (1%) = 4 X Vrms2/ Rload Maximum output power of a BTL amplifier with 10% THD is Pout (10%) = Pout (1%) X 1.25 Output Power vs. Vp-p BTL Output Power 5.0 Output Power @THD 10% 4.0 4 3.0 2.0 8 1.0 0.0 0 1 2 3 4 Vdd - Vsat (V) 5 6 Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. 5 CONFIDENTIAL INFORMATION PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable Vdd C1 C2 33 H 0.47 F Input 10K IN VDD +OUT 0.47 F Speaker 33 H Enable GND -OUT 0.47 F F ig. 1 Setting Amplifier voltage gain It is very important to know the maximum output level (0dB) of the signal source connected to a power amplifier in order to prevent hard clipping during operation. Gain (max) = Vsupply/ Vin (p-p) Insufficient voltage gain will cause low output level and maybe not enough to drive speaker properly. On the other hand, the distortion will be very high if the voltage gain is too high in an audio system. There is a 10k input resistor integrated in side IN (input) node, and since the integrated feedback resistor is 100k , so the maximum voltage gain of PAM8302 is limited at 10V/V (100k/10k, one output). With an external input resistor (Rin) placed between signal source & input node, the voltage gain will be Gain = 100k/ (10k + Rin) = Vsupply/ Vin (p-p) Actual voltage gain is two times of this calculation because of BTL connection. Decouple capacitor PAM8302 is a high performance, high speed class D amplifier, and it requires a 1 F, X7R ceramic decouple capacitor (C1) placed very close between VDD & GND pins to ensure the total harmonic distortion plus noise (THD+N) performance is as designed. This is also very important for efficiency and lowering noise floor. Another 100 F to 1000 F main decouple capacitor (C2) should be placed close to supply pin for low frequency Ecoupling. Input capacitor Input capacitor (Cin) blocks the DC voltage between signal source & amplifier to ensure the DC balancing will not be broken between two systems. It also form a high-pass-filter (HPF) with input resistors (Rin + 10k), the lower corner frequency (FCL) is determine by equation below. Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. 6 CONFIDENTIAL INFORMATION PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable FCL = 1/ [2 X Cin X (Rin + 10k)] FCL is the lower corner on frequency response curve. Cin is very important consider to the lower frequency performance. The Cin should not be too large with small speakers as the load, because such small speakers usually can not response with lower frequency, delivering too much low frequency energy into a small speaker which usually got resonant frequency (Fs) around 150Hz is meaningless and dangerous. This will easily over drive the small speakers. The movement of speaker cone will be too much under such condition and this also creates unnecessary distortion on mid-to high frequency range because the speaker is now operating in non-linear area. Speakers can only generate heat but not low frequency sound when it is over driven, the will cause speaker or amplifier failure in some cases. Cin should have 10% tolerance or less because the tolerance can cause the input impedance mismatch at FCL and below. Output filter The L and C on each output node of PAM8302 form the low-pass-filter (LPF), the higher corner frequency (FCH) is determine by equation below. FCH = 1/ [2 X sqr (L X C)] FCH is the higher corner on frequency response curve. Important Notice The L-C filters (-12dB/Oct) gives twice much attenuation and lower impedance (means lower insertion loss) compare to those R-C filters (-6dB), but remember, the FCH above is also the resonant frequency of this LC network. The quality factor (Q) of this resonant network can be very high, depended on the Q of L and C. The high resonant Q which is usually caused by open-load can generate a very high voltage on speaker terminal, and the impedance of the L-C network can be very low, thus induces large amount of current flows from output stage of PAM8302. This always causes part failure. So Do Not test open-load on any class D amplifier with output filters. LC filter calculator with output load impedance and cut-off frequency 1 f= 2 LC , XL= 2 fL , XC= 1 2 fC Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. 7 CONFIDENTIAL INFORMATION PAM8302 Tiny Package 2 Watt Class-D Audio Amplifiers With Enable OUTLINE DIMENSION SOP8 5.80 - 6.20 0.35 - 0.49 1.27 TYP. 3.80 - 4.00 45 0.19 - 0.25 0 - 0.15 0.40 - 0.90 1.35 - 1.75 0 ~8 4.80 - 5.00 Note: Package outline exclusive of mold flash and metal burr. Power Analog Microelectronics, Inc. CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M. CONFIDENTIAL INFORMATION