PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Key Features General Description n 1.0W/2.0W@<1% THD Output with a 8 Ω / 4 Ω The PAM8012 is a 2.0W mono filterless class-D amplifier with high PSRR and differential input that reduce noise. n n n n n n n n Load at 5V Supply Maximum Output Power Can Be Set by One External Resistor Minimized ON/OFF Pop Noise Superior Low Noise High PSRR Supply Voltage from 2.5V to 5.5 V Auto Recovering Short Circuit Protection Over Temperature Protection 9 Ball, 1.3mm x 1.3mm, 0.4mm Pitch WCSP and eMSOP10 Packages Features like 90% efficiency and small PCB area make the PAM8012 Class-D amplifier ideal for cellular handsets. The filterless architecture requires no external output filter, fewer external components, less PCB area and lower system costs, and simplifies application design. Applications The PAM8012 features anti-saturation function which detect output signal clip due to the over input level and keep the output non-saturation automatically to get the excellent sound quality. n n n The maximum output power without clip can be set by one resistor at PL pin that to prevent the speaker to be damaged.. Wireless or Cellular Handsets and PDAs Portable Navigation Devices General Portable Audio Devices The PAM8012 features short circuit protection and over temperature protection. The PAM8012 is available in tiny WCSP9 (1.3mm x 1.3mm) and eMSOP10 packages. Typical Application Circuit VDD 1 μF 10μF VDD 0.1 μF IN+ Input 0.1 μF IN- OUT+ ON EN OFF PAM8012 RPL PL 1 μF OUT- 1 μF VREF GND Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 1 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Block Diagram VDD IN+ Rin Rf PWM Modulator Rin IN- + Rf Gate Drive OUT+ Gate Drive OUT- Anti-Sat EN Bias PL Power Limit SCP OTP UVLO Startup Protection OSC VREF VREF GND Pin Configuration & Marking Information 9 Ball 0.4mm pitch WCSP Top View of PCB OUT+ OUT- GND A1 A2 A3 VDD EN PL B1 B2 B3 VREF IN+ IN- C1 C2 C3 9 Ball 0.4mm pitch WCSP Top View of Marking BI YW BI: Product Code of PAM8012 Y: Year W: Week Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 2 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Top View eMSOP10 PGND 1 10 OUT+ OUT- 2 9 VDD PL 3 8 EN IN- 4 7 VREF IN+ 5 6 AGND X: Internal Code Y: Year W: Week Absolute Maximum Ratings 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. Supply Voltage, VDD...................................6.0V Input Voltage,IN+,IN-...............-0.3V to VDD+0.3V Minimum load resistance, R L......................3.2 Ω Storage Temperature.....................-65°C to 150 °C Maximum Junction Temperature..................150°C Soldering Temperature....................260°C,10 sec Recommended Operating Conditions Supply voltage Range........................ 2.5V to 5.5V Ambient Temperature Range............-40 °C to 85 °C Junction Temperature Range......... -40°C to 125°C Thermal Information Parameter Symbol Thermal Resistance (Junction to ambient) θJA Thermal Resistance (Junction to case) Package Maximum WCSP9 1.3x1.3 100 eMSOP10 60 WCSP9 1.3x1.3 40 eMSOP10 30 Unit °C/W θJC °C/W Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 3 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Electrical Characteristic T A=25 °C, VDD=5.0V, RL =8 Ω , unless otherwise noted. Symbol VDD Po Pa ra me te r Test Conditions Supply V oltage Output Power Total Harmonic Distortion Plus THD+N Noise RPL=110K Ω,f=1kHz, R=4Ω VDD=5.0V 2.0 RPL=110K Ω,f=1kHz, R=8Ω VDD=5.0V 1.0 SNR Vn Signal to Noise Ratio THD=1% , f=1KHz Output Noise Cin=0.1uF, Inputs acgrounded RL=8Ω UNIT 5.5 V W % 0.08 VDD=5.0V ,P o=1.0W,R=8Ω f=217Hz, Inputs ac-grounded with Cin=0.1µF MAX 0.08 f=1kHz VDD=3.6V ,P o=1.0W,R=4Ω VDD=3.6V ,P o=0.5W,R=8Ω AC Power Supply Ripple Rejection TYP 2.5 VDD=5.0V ,P o=2.0W,R=4Ω PSRR MIM 0.08 f=1kHz % 0.08 VDD=5.0V -75 VDD=3.6V -75 VDD=5.0V 95 VDD=3.6V 95 No A-weighting 60 A -wei ghting 40 dB µV 90 η Peak E fficiency IQ Quiescent Current VEN=5.0V,VDD=5.0V,PL=0V No Load Isd Shutdown Current VDD=2.5V to 5.5V ,V EN=0V No Load |VOS| Offset Voltage VDD=5V RIN Input Resistor VDD=5V 31 KΩ GV Closed Loop Gain VDD=5V 18 dB f SW Switching Frequency VDD=5V 250 K Hz TON Turn-on Time VDD=5V 45 mS OTP Over Temperature P rotecti on VDD=5V No Load 150 ℃ OTH Over Temperature Hysterisis VDD=5V No Load 40 ℃ VENH High-level EN voltage VDD=5V VENL Low-level EN voltage VDD=5V Maximum Attenuation Range Anti-saturation Active,from +18dB to -8dB AR f=1kHz RL=4Ω % 87 4.2 -20 mA 1 uA 20 mV 1.4 V 0.4 26 V dB Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 4 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Typical Operating Characteristics T A=25 °C, V DD=5V, unless otherwise noted. 1. THD+N VS Output Power 2. THD+N VS Output Power 20 20 RL =8 Ω 10 5 Vin=5V 5 2 % 0.5 Vin=5V 2 Vin=4.2V 1 % R L=4 Ω 10 Vin=4.2V 1 0.5 Vin=3.6V 0.2 Vin=3.6V 0.2 0.1 0.1 0.04 1m 2m 5m 10m 20m 50m 100m 200m 500m 1 0.05 1m 2 2m 5m 10m 20m 50m W 3. THD+N VS Frequency 500m 1 2 4 4. THD+N VS Frequency 10 10 RL =8 Ω 5 100m 200m W 5 2 RL =4 Ω 2 1 1 Po=1W 0.5 Po=1W 0. 5 % Po=0.5W % Po=0.5W 0.2 0. 2 0.1 0. 1 0.05 0.0 5 Po=0.3W Po=0.3W 0.02 0.0 2 0.01 0.007 20 50 100 200 500 1k 2k 5k 10k 0.0 1 20 20k 50 100 Hz 500 1k 2k 5k 10k 20k Hz 5. Frequency Response 6. Frequency VS Supply Voltage 255 + 20 Cin=1uF + 19 200 253 + 18 + 17 251 + 16 + 15 249 Cin=0.47uF + 14 d B r + 13 A + 11 247 245 + 12 + 10 243 Cin=0.1uF + 9 241 + 8 239 + 7 + 6 237 + 5 + 4 20 50 100 200 500 1k 2k 5k 10k 20 k 235 50 k Hz 2.0 3.0 4.0 5.0 6.0 Supply Voltage(V) Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 5 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Typical Operating Characteristics T A=25 °C, V DD=5V, unless otherwise noted. 7. Efficiency VS Output Power 8. Efficiency VS Output Power 100 100 RL =8 Ω 90 R L=4 Ω 90 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 0 0.5 1 Out put P ower(W) 1. 5 2 0 0. 5 9. PSRR VS Frequency +0 TT TT TT TT R L=8 Ω T TT - 10 -20 - 20 -30 - 30 -40 d B 1. 5 2 2. 5 Ou tp ut P ower(W ) 3 3. 5 10. PSRR VS Frequency +0 -10 1 T RL =4 Ω - 40 d B -50 - 50 -60 - 60 -70 - 70 -80 - 80 -90 - 90 - 100 - 100 20 50 100 200 500 1k 2k 5k 10k 20 20 k 50 100 200 500 2k 5k 10 k 20k 12. R PL VS Output Power 11. Rdson VS Load Current 300 1. 2 250 1 200 0. 8 150 0. 6 100 0. 4 Vin=4.2V RL =8 Ω 0. 2 PMOS(mΩ) 50 1k Hz Hz NMOS(mΩ) 0 0 0 500 1000 1500 0 2000 20 40 60 80 100 120 140 RPL(kΩ) Load Current(mA) Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 6 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Test Setup for Performance Testing PAM8012 Demo Board Load +OUT Input AP System One Generator AP Low Pass Filter GND -OUT AP System Two Analyzer AUX-0025 VDD Power Supply Notes 1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement with AP analyzer. 2. Two 33µH inductors are used in series with load resistor to emulate the small speaker for efficiency measurement. Application Information Anti-saturation The Anti-saturation feature provides continuous automatic gain adjustment to the amplifiier through an internal circuit. This feature enhances the perceived audio loudness and at the same time prevents speaker damage from occurring. The Anti-saturation works by detecting the output. The gain changes depending on the supply voltage , and the attack and release time. The gain changes constantly as the audio signal increases and/or decreases. The gain step size for the Anti-saturation is 0.4 dB. If the audio signal has near-constant amplitude, the gain does not change. Table 1 shows the Anti-saturation variable description. Table 1. PAM8012 Anti-saturation Variable Description VARIABLE Gain DE SCRIP TI ON V alue The pre-set gain of the device when the Anti-saturation is inactive. 18dB The fixed gain is also the initial gain when the device c omes out of (Max imum) shutdown mode or when the Anti-s aturation is disabled Attack Time The minimum time between two gain dec rements . 128uS Release Time The minimum time between two gain increments. 256mS PL Terminal Function The voltage value of PL sets the PAM8012 maximum output by an external resistor. Refer to t able 2 for anti-saturation and power limit selection. Table 2. PAM8012 Anti-saturation and Power Limit Variable Description VDD EN VDD/2 0 PL: OFF Anti-sat: OFF PL: OFF Anti-sat: OFF Rpl 30K<Rpl<120K PL: ON Anti-sat: ON PL: ON Anti-sat: OFF Open PL: OFF Anti-sat: ON PL: ON Anti-sat: OFF Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 7 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Application Information Input Capacitors (Ci ) audio power amplifier is recommended. In the typical application, an input capacitor, Ci, is required to allow the amplifier to bias the input signal to the proper DC level for optimum operation. In this case, Ci and the minimum input impedance Ri form is a high-pass filter with the corner frequency determined in the follow equation: How to Reduce EMI fc = Most applications require a ferrite bead filter for EMI elimination shown at Figure 1. The ferrite filter reduces EMI around 1MHz and higher. When selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at low frequencies. 1 2pRiCi Fe rrit e Be ad It is important to consider the value of Ci as it directly affects the low frequency performance of the circuit. For example,the specification calls for a flat bass response are down to 150Hz. Equation is reconfigured as followed: Ci = OUT+ 20 0p F Fe rrit e Bea d OUT- 1 2p Rifc 20 0p F Figure 1: Ferrite Bead Filter to Reduce EMI When input resistance variation is considered, the Ci is 34nF, so one would likely choose a value of 33nF. A further consideration for this capacitor is the leakage path from the input source through the input network (Ci , Ri + Rf ) to the load. This leakage current creates a DC offset voltage at the input to the amplifier that reduces useful headroom, especially in high gain applications. For this reason, a low-leakage tantalum or ceramic capacitor is the best choice. When polarized capacitors are used, the positive side of the capacitor should face the amplifier input in most applications as the DC level is held at V DD/2, which is likely higher than the source DC level. Please note that it is important to confirm the capacitor polarity in the application. Shutdown operation In order to reduce power consumption while not in use, the PAM8012 contains shutdown circuitry that is used to turn off the amplifier’s bias c ircuitr y. This shutdown featur e tur ns the amplifier off when logic low is placed on the EN pin. By switching the EN pin connected to GND, the PAM8012 supply current draw will be minimized in idle mode. Short Circuit Protection (SCP) The PAM8012 has short circuit protection circuitry on the outputs to prevent the device from damage when output-to-output shorts or output-to-GND shorts occur. When a short circuit o cc urs , the dev ice i mmed iatel y goe s into shutdown state. Once the short is removed, the device will be reactivated. Decoupling Capacitor (C S ) The PAM8012 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output total harmonic distortion (THD) as low as possible. Power supply decoupling also prevents the oscillations causing by long lead length between the amplifier and the speaker. The optimum decoupling is achieved by using two different types of capacitors that target on different types of noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low equivalentseries-resistance (ESR) ceramic capacitor, typically 1 μF, is placed as close as possible to VDD pin for the best operation. For filtering lower fr e q ue nc y n oi s e s i gn a ls , a l ar g e c e r am i c c apacitor of 10μF or greater placed near the Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 8 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Over Temperature Protection (OTP) Power Supply Line Thermal protection on the PAM8012 prevents the device from damage when the internal die temperature exceeds 150°C. There is a 15 °C tolerance on this trip point from device to device. Once the die temperature exceeds the set point, the device will enter the shutdown state and the outputs are disabled. This is not a latched fault. The thermal fault is cleared once the temperature of the die decreased by 40°C . This large hysteresis will prevent motor boating sound well and the device begins normal operation at this point with no external system interaction. It is recommended that all the trace could be routed as short and thick as possible. For the power line layout, just imagine water stream, any barricade placed in the trace (shown in figure 2) could result in the bad performance of the amplifier. POP and Click Circuitry Components Placement The PAM8012 contains circuitry to minimize turnon and turn-off transients or “click and pops”, where turn-on refers to either power supply turnon or device recover from shutdown mode. When the device is turned on, the amplifiers are internally muted. An internal current source ramps up the internal reference voltage. The device will remain in mute mode until the reference voltage reach half supply voltage, 1/2 VDD. As soon as the reference voltage is stable, the device will begin full operation. For the best power-off pop performance, the amplifier should be set in shutdown mode prior to removing the power supply voltage. Decoupling capacitors as previously described, the high-frequency 1 μF decoupling capacitors should be placed as close to the power supply terminals VDD as possible. Large bulk power supply decoupling capacitors (10 μF or greater) should be placed near the PAM8012 on the VDD terminal. Figure 2: Power Line Input resistors and capacitors need to be placed very close to input pins. Output filter - The ferrite EMI filter should be placed as close to the output terminals as possible for the best EMI performance, and the capacitors used in the filters should be grounded to system ground. PCB Layout Guidelines Grounding It is recommended to use plane grounding. Noise currents in the output power stage need to be returned to output noise ground and nowhere else. When these currents circulate elsewhere, they may get into the power supply, or the signal ground, etc, even worse, they may form a loop and radiate noise. Any of these instances results in degraded amplifier performance. The output noise ground that the logical returns for the output noise currents associated with class D switching must tie to system ground at the power exclusively. Signal currents for the inputs, reference need to be returned to quite ground. This ground only ties to the signal components and the GND pin. GND then ties to system ground. Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 9 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Ordering Information PAM8012 X X X Number of pins Package Type Pin Configuration Pin Configuration A: B: A1: OUT+ 1. PGND A2: OUT- 2. OUT- A3: GND 3. PL B1: VDD 4. IN- B2: EN Number of pins Z: WCSP9 N: 9 S: eMSOP10 M: 10 5. IN+ B3: PL 6. AGND C1: VREF 7. VREF C2: IN+ 8. EN C3: IN- Package Type 9. VDD 10.OUT+ Part Num ber PAM8012AZN PA M8012BSM Marking BI YW Package Type MOQ WCSP9(1.3mm x 1.3mm) 3,000 Units/ Tape & Reel eMSOP10 2,500 Units/ Tape & Reel P8012 XXXYW Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 10 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Outline Dimensions WCSP9 TOP VIEW BOTTOM VIEW 0. 80 1 .24 1 .32 0. 40 3 1. 24 1. 32 0.80 2 0 .40 1 C PIN A1 CORNER B A 9 X 0. 300 0. 200 SIDE V IEW 0 .42 0 .34 0 .72MAX 0. 30 0. 24 WCSP9 9- Ball Wafer Level Chip Scale Package Unit: Millimeter SEATING PLANE Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 11 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Outline Dimensions eMSOP10 Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 12 PAM8012 Mono 2.0W Anti-saturation Class D Audio Power Amplifier with Power Limit Datasheet Revision History Date Revision Description Comment 03/10/2011 Advanced 08/30/2011 Preliminary 09/19/2011 Rev1.0 Initially released. 02/06/2012 Rev1.1 Add eMSOP10 package and update the "RPL vs Po" curve. 05/23/2012 Rev1.2 Update the "Pin Configuration" of eMSOP10 package and thermal info; Add "Datas heet Revision History" form. 06/06/2012 Rev1.3 Update "Table 2" in "Application Information" Initially Version. Add silic on test data. Power Analog Microelectronics, Inc 06/2012 Rev1.3 www.poweranalog.com 13