PAM8406. Alternative 5W Stereo Audio Amplifier. Key Features. General Description. Applications. Typical Application

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1 Key Features Alternative Output: Class-D or Class-AB Output at THD with a oad and Power Supply at Class D mode 3 Output at THD with a 4 oad and Power Supply Filterless, ow Quiescent Current and No EMI ow THD+N at Fully Output Range Superior ow Noise Efficiency up to 90 with Class D Mode No Pop At Turn-on/off Fully Short Circuit Protection ith Auto Recovery Thermal Shutdown Few External Components to Save the Space and Cost SOP-6/SOP-6(EP) Package Applications CD Ts Mutimedia Speakers AM/FM System DABs General Description The PAM8406 is a audio amplifier with an alternative option between Class-D and Class-AB output which makes PAM8406 very ideally for the applications efficiency-emi compatible. PAM8406 offers low THD+N, high SNR allowing it to achieve high-quality sound reproduction. The fu lly d iffere n tial ou tpu t w ith n ew filte rle ss architecture(class D mode) allows the device to drive the speaker directly, requiring no low-pass output filters and DC blocking capacitors, thus to save the system cost and PCB area. The efficiency of the PAM8406 is up to 90. It can extend the battery life, ideally for portable applications. The PAM8406 is fully protected against faults with short circuit protection and thermal protection. The PAM8406 is available in SOP-6/ SOP- 6(EP) package. Typical Application CC uf uf uf IN Cin Rin IN P PR +OUT_ INR Cin Rin INR PGND -OUT_ SHDN -OUT_R MUTE PGNDR MODE MODE REF GND +OUT_R H: Class D(default) : Class AB uf

2 Block Diagram CURRENT PROTECTION P Pin Configuration & Marking Information Top iew SOP-6/SOP-6(EP) X: Internal Code A: Assembly Code T: Testing Code Y: Year : eek : Internal Code 7 8 9

3 Pin Descriptions Pin Number Pin Name Description +OUT_ eft Channel Positive Output PGND Power GND 3 -OUT_ eft Channel N egative Output 4 P Power MUTE Mute Control Input active low 6 Analog 7 IN eft Channel Input 8 REF Internal analog reference, connect a bypass capacitor from REF to GND 9 MODE High: Class-D; ow: Class-AB INR Right Channel Input GND Analog GND SH DN Shutdown Control Input (active low) 3 PR Power 4 -OUT_R Right Channel Negative Output PGNDR Power GND 6 +OUT_R Right Channel Positive Output 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 oltage Input oltage to D D+0.3 Operation Temperature Range to 8 Maximum Junction Temperature...0 Operation Junction Temperature to Storage Temperature...-6 to 0 Soldering Temperature , sec Recommended Operating Conditions Supply voltage Range.... to. Operation Temperature Range to 8 Junction Temperature Range to Thermal Information Par ameter Sym bol Package Maximum Unit Thermal Resistance (Junction to Ambient) JA SOP-6 C/ Thermal Resis tance (Junction to Case) JC SOP-6 3 C/ 3

4 Electrical Characteristic =, Gain=4dB, R =8, both Class D and Class AB mode,t =, unless otherwise noted. D D A Symbol Parameter Test Condit ions MIN TYP MAX UNIT IN Supply Power.. THD+N=,f=kHz, R = =.0.0 (Class D) =3.6.6 =..3 = THD+N=,f=kHz, R = =3.6.0 (Class D) =..0 = THD+N=,f=kHz, R =4 =3.6. Po Output Power = =.0. THD+N=,f=kHz, R =4 =3.6.4 = =.0.8 THD+N=,f=kHz, R =8 = = =.0.6 THD+N=,f=kHz, R =8 = = =.0,Po=0. ~,R=8 f=khz 0. =3.6,Po=0.0~0.,R=8 0. =.0,Po=0. ~,R =4 0. f=khz Total Harmonic Distortion Plus =3.6,Po=0.0~,R =4 0. THD+N Noise =.0,Po=0. ~,R = 0. (Class D) f=khz =3.6,Po=0.0~,R = (Class D) 0. Gv Gain 4 db PSRR Power Supply R ipple Rejection =.0, Inputs ac-grounded with f=0hz -70 f=khz -6 db Cs Crosstalk =,Po=0.,R =8,Gv=4dB f=khz -9 db SNR Signal-to-noise ratio D D =, THD=,Gv=4dB f=khz 90 db 4

5 Electrical Characteristic =, Gain=4dB, R =8, both Class D and Class AB mode,t =, unless otherwise noted. D D A Symbol Parameter Test Conditions MIN TYP MAX UNIT n Output Noise =, Inputs ac-grounded A-weighting 0 u No A-weighting 0 Efficiency R =8, THD= 90 Class D Mode R =4, THD= 8 F=kHz R =, THD= 80 I Q D D =.0 Quiescent Current (Class D) D D=3.6 No oad 8 ma D D=. 6 D D =.0 Quiescent Current D D=3.6 No oad ma (Class AB) D D=. I MUTE Muting Current D D=.0 MUT E=0.3.4 ma I SD Shutdown Current =. to. sd=0.3 < µa Rdson Static Drain-to-source On-state PMOS 80 I DS=00mA,gs= Resistor NMOS 40 m fsw Switching Frequency =. to. Class D 0 khz os Output Offset oltage Input AC-GND, = m IH Enable Input High oltage D D =.0.4 I Enable Input ow oltage D D= IH MUTE Input High oltage D D=.0.4 I MUTE Input ow oltage D D = IH MODE Input High oltage D D =.0.4 I MODE Input ow oltage D D= OTP OverTemperature Protection 0 OTH Over Temperature Hysterisis No oad, Junction Temperature D D= 30

6 Typical Operating Characteristics (T =) A =, Gain=4dB, R =8, both Class D and Class AB mode,t =, unless otherwise noted. D D A. THD+N vs Output Power. THD+N vs Output Power 0 =3.6 0 = =. = 0. =. = m m m m 0m 0m 0m 00m 00m Class D, R =8, f=khz 0.08 m m m m 0m 0m 0m 00m 00m Class D, R =4, f=khz 3. THD+N vs Output Power 4. THD+N vs Output Power 0 =3.6 0 = 0. =. = =. = m m m m 0m 0m 0m 00m 00m 6 Class D, R =, f=khz 0.0 m m m m 0m 0m 0m 00m 00m Class AB, R =8, f=khz THD+N vs Output Power 6. Frequency Response =. =3.6 = d B g A C IN=uF C =0.47uF IN C IN=0.uF 0.0 m m m m 0m 0m 0m 00m 00m Class AB, R =4, f=khz k k k k 0k Hz 6

7 Typical Operating Characteristics (continued) =, Gain=4dB, R =8, both Class D and Class AB mode,t =, unless otherwise noted. A 7. THD+N vs Frequency (Class D) 8. THD+N vs Output Power (Class AB) Po=0.3 Po= Po=0.3 Po= Po= Po= k k k k 0k k k k k 0k Hz Hz 9.Noise Floor (Class D). Noise Floor (Class AB) d B r A d B r A k k k k 0k k k k k 0k R =4 H,in=./3.3/3.6/4.//. R =4,in=./3.3/3.6/4.// PSRR (Class D). PSRR (Class AB) T T +0 T T T T T T T T T T d B -0 d B k k k k 0k Hz k k k k 0k Hz 7

8 Typical Operating Characteristics (continued) =, Gain=4dB, R =8, both Class D and Class AB mode,t =, unless otherwise noted. A Quiescent Current vs Supply oltage 4. Frequency vs Supply oltage Class D Class A B Sup ply olt age( ) Supply oltage() Rds(on) vs Iload 6. Efficiency vs Output Power(Class D) P MOS NMOS Ilaod(mA ) Po(m) ohm 4ohm 8ohm Output Power vs Power Supply 8ohm 4ohm ohm Supply oltage() 8

9 Application Notes. hen the PAM8406 works in class D mode with C filters, it should be connected with the speaker before it's powered on, otherwise it will be damaged easily.. hen the PAM8406 works without C filters, it's better to add a ferrite chip bead at the outgoing line of speaker for suppressing the possible electromagnetic interference. higher than its operation voltage, which will probably damage the device. Therefore, it's recommended to use either 4 Ni-MH (Nickel Metal Hydride) rechargeable batteries or 3 dry or alkaline batteries. 4. One should not make the input signal too large. arge signal can cause the clipping of output signal when increasing the volume. This will damage the device because of big gain of the PAM The re co mmend ed o pera tin g voltage is.. hen the PAM8406 is powered with 4 battery cells, it should be noted that the voltage of 4 new dry or alkaline batteries is over 6.0, Test Setup for Performance Testing Notes. The AP AUX-00 low pass filter is necessary for class-d amplifier measurement with AP analyzer.. Two µh inductors are used in series with load resistor to emulate the small speaker for effic iency measurement. 9

10 Application Information Maximum Gain As sh own in b lock dia gram (pag e ), the PAM8406 has two internal amplifier stages. The first stage's gain is externally con figurable, 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 x.the output of amplifier serves as the input to amplifier, thus the two a m p l i f i e r s p r o d u c e s i g n a l s i d e n t i c a l i n magnitude, but different in phase by 80. Consequently, the differential gain for the IC is Mode Selection Mute Operation A =0*log [*(R /R )] D f i T h e PA M s e t s m a x i m u m R f= 4 k, minimum R i=8k, so the maximum closed-gain is 4dB. hen mode pin high,it features classd; mode pin low, it s class AB. Mode pin can t be floating. The MUTE pin is an input for controlling the output state of the PAM8406. 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 PAM8406 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 PAM8406 supply current draw will be minimized in idle mode. The SHDN pin can be left floating due to the internal pull-up. Power supply decoupling The PAM8406 is a high performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output THD and PSRR as low as p ossib le. Power su pply decoupling affects low frequ ency 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.0µf, works best, placing it as close as possible to the device D D terminal. For filtering lowerfrequency noise signa ls, a large capacitor of 0µF (ceramic) or greater is recommended, placing it near the audio power amplifier. Input Capacitor (C ) i arge 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 0Hz to 0Hz. Thus, using a large input capacitor may not increase actual system perfor mance. In this case, input capacitor (C i) and input resistance (R i) of the amplifier form a high-pass filter with the corner frequency determined by equation below, f C= R i C i In addition to system cost and size, click and pop perfor mance is affected by the size of the input coupling capacitor, C i. A larger input coupling capacitor requires more charge to reach its quiescent DC voltage (nominally / ). 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 (C ) The Analog Reference Bypass Capacitor (C BYP) is the most critical capacitor and serves several important functions. During start-up or recovery from shutdown mode, C BYP determines the rate at which the amplifie r sta rts up. Th e se cond 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. BYP

PAM8403. Filterless 3W Class-D Stereo Audio Amplifier. Key Features. General Description. Applications. Typical Application

PAM8403. Filterless 3W Class-D Stereo Audio Amplifier. Key Features. General Description. Applications. Typical Application Key Features 3W Output at THD with a 4Ω oad and Power Supply Filterless, ow Quiescent Current and ow EMI ow THD+N Superior ow Noise Efficiency up to 90 Short Circuit Protection Thermal Shutdown Few External