CM8603D Ultra Low EMI, 2×3.0W Filterless Stereo Class-D Audio Power Amplifier Feature n n n n n n n n n n n n 1.8 V to 5.5Vsingle supply Up to 3.0W/Ch at 5.5V, 3 ohms No output filter required for inductive loads 3mA/Ch quiescent current at 5.5V Up to 88% Power efficiency Less than 0.2uA/Ch shutdown current Differential signal processing improved CMRR “click and pop” suppression circuitry Micro-power shutdown mode Minimum external components Thermal shutdown Differential 300kHz PWM allows BTL to increase output power and eliminate LC output filter General Description The CM8603D is a single supply, high efficiency 2 3.0W switching stereo audio amplifier. A low noise, filterless PWM architecture eliminate the output filter, reducing external component count, board area consumption, system cost, and simplifying design. The CM8603D is designed to meet the demands of notebook PC and other portable communication devices. Operating on a single 5V supply, it is capable of driving a 3 W speaker load at a continuous average output of 3.0W with less than 1% THD+N. Its flexible power supply requirements allow operation from 1.8 V to 5 .5V. The CM8603D has high efficiency with speaker loads compared to a typical Class AB amplifier. With a 3V supply driving an 8 W speaker, the IC"s efficiency for a 100mW power level is 80%, reaching 88% at 400mW output power. The CM8603D features a low-power consumption shutdown mode. Shutdown may be enabled by driving the SD pin to a logic low (AGND). The gain of the CM8603D is set 24 dB in the chip. In addition to these features, a fast startup time and small package size make the CM8603D class-D amplifier an ideal choice for notebook PC. Applications n n n n n Notebook PC Portable DVD Player Portable electronic devices Wireless or cellular handsets PDAs 8R LINN R Left Input PWM LINP 8R 8R SOP16 Block Diagram OSC R Right Input HBridge PWM RINP BYPASS CBYP SD LOUTN LOUTP R Package RINN HBridge ROUTN ROUTP R 8R Bias Circuitry Protect Circuits AVDD PVDD PGND AGND 深圳市宏达科技有限公司 0755-61588823/13530382140 业务：曾先生 1/8 To Battary CS Typical Application 10 uF VDD LEFT AUDIO OUTPUT+ 0.1 uF LEFT AUDIO INPUT- 1 PVDD PGND 2 LOUTP LOUTN 3 0.1 uF 4 RIGHT AUDIO INPUT+ 0.1 uF 5 RIGHT AUDIO INPUT- 0.1 uF 6 7 LEFT AUDIO INPUT+ RIGHT AUDIO OUTPUT+ 8 SD LINN 16 15 AVDD RINP AGND 12 RINN BYPASS 11 ROUTP ROUTN 10 PVDD TO SYSTEM CONTROL 13 LINP PGND LEFT AUDIO OUTPUT- 14 0.1 uF VDD 1 uF RIGHT AUDIO OUTPUT- 9 VDD 10 uF Terminal Functions Terminal Pin Number I/O INLP 4 3 5 6 14 I Left channel positive input I Left channel negative input I Right channel positive input I Right channel negative input I Shutdown terminal (active low) 15 2 10 7 13 1,9 12 8,16 11 O Left channel negative differential output O Left channel positive differential output O Right channel negative differential output O Right channel positive differential output I Analog supply (must be same voltage as PVDD) I Power supply (must be same voltage as AVDD) I Analog ground I Power ground I Capacitance for power up delay INLN INRP INRN SD OUTLN OUTLP OUTRN OUTRP AVDD PVDD AGND PGND BYPASS 深圳市宏达科技有限公司 Description 0755-61588823/13530382140 业务：曾先生 2/8 CM8603D Recommended Operating Conditions Symbol Parameter Conditions AVDD PVDD VIH Power Supply Voltage High-level input voltage SD VIL Low-level input voltage TA TJ SD Operating free-air temperature range Operating junction temperature range Storage temperature range Tstg AVDD=PVDD=5.0V Electrical Characteristics Min. Typ. Max. Unit 1.8 5.5 V 2.0 AVDD 0 1.2 V -40 -40 85 150 ℃ ℃ -65 150 ℃ Max. Unit 25 mV TA=25℃，AVDD＝PVDD＝5.0V，AV=24dB (unless otherwise noted) Symbol |Vos| PSRR CMRR IDD Parameter Output offset voltage (measured differentially) Power supply rejection ratio Common mode rejection ratio Quiescent power supply current (per channel) ISD Shutdown current RSD Resistance Zi fSW PO from SD pin to AGND Input impedance Switch frequency Output power (per channel) Conditions Total Harmonic Distortion + Noise 深圳市宏达科技有限公司 Typ. AVDD=PVDD=2.5 to 5.5V -75 -60 dB Input shorted together, AVDD=PVDD=2.5 to 5.5V -60 -55 dB AVDD=PVDD=5.0V, No load or output filter AVDD=PVDD=3.6V, No load or output filter AVDDpVDD=2.5V, No load or output filter 4.5 6.0 3.5 5.0 2.0 3.0 0.3 1 V SD =0V, AVDD=PVDD=2.5 to 5.5V AVDD=PVDD=2.5 to 5.5V 225 mA uA 300 kΩ 45 kΩ 275 AVDD=PVDD=5.0V, f=1kHz, THD=10% 1.5 2.3 3 AVDD=PVDD=5.5V, f=1kHz,THD=10% AVDD=PVDD=5.0V PO=1.0W,RL=8 Ω , f=1kHz, L=33uH,C=1uF AVDD=PVDD=5.0V PO=2.0W,RL=4 Ω , f=1kHz,L=10uH,C=1.2uF AVDD=PVDD=3.6V, PO=1.13W,RL=4 Ω , f=1kHz,L=10uH,C=1.2uF 3.5 RL=8 Ω RL=4 Ω RL=3 Ω RL=3 Ω THD+N Min. Inputs ac grounded, AV=6dB, AVDD=PVDD=2.5 to 5.5V 325 kHz W 0.03 0.22 0.32 0755-61588823/13530382140 业务：曾先生 % 3/8 CM8603D Symbol Parameter SNR Signal to Noise ratio Twu Wake up time TSD Shutdown time Bom Maximum output power bandwidth Crosstalk Conditions AVDD=PVDD=5V, PO=1.0W,RL=8 Ω , f=1kHz, L=33uH,C=1uF AVdd=5.0V THD=5% Min. Typ. Max. Unit 70 dB 15 us 170 us 20 kHz -68 dB Application Information General Amplifier Function The CM8603D features a filterless modulation scheme. The differential outputs of the device switch at 275 kHz from PVDD to PGNG. When there is no input signal applied, the two outputs( LOUTP and LOUTN，or ROUTP and ROUTN) switch with a 50% duty cycle, with both outputs in phase. Because the outputs of the CM8603D are differential, the two signals cancel each other. This results in no net voltage across the speaker, thus there is no load current during an idle state, conserving power. With an input signal applied, The duty cycle (pulse width) of the CM8603D output changes. For increasing output voltages, the duty cycle of LOUTP and ROUTP increases, while the duty cycle of LOUTN and ROUTN decreases. For decreasing output voltages, the converse occurs, the duty cycle of LOUTP and ROUTP decreases, while the duty cycle of LOUTN and ROUTN increases. The difference between the two pulse widths yields the differential output voltage. Power Dissipation and Efficiency In general terms, efficiency is considered to be the ratio of useful work output divided by the total energy required to produce it with the difference being the power dissipated, typically, in the IC. The key here is "useful" work. For audio systems, the energy delivered in the audible bands is considered useful including the distortion products of the input signal. Sub-sonic (DC) and super-sonic components (>22 kHz) are not useful. The difference between the power flowing from the power supply and the audio band power being transducer is dissipated in the MCD4230 and in the transducer load. The amount of power dissipation in the CM8603D is very low. This is because the on resistance of the switches used to from the output waveforms if typically less than 0.25 Ω . This leaves only the transducer load as a potential "sink" for the small excess of input power over audio band output power. The CM8603D dissipates only a fraction of the excess power requiring no additional PCB area or copper plane to act as a heat sink. Input Resistance 深圳市宏达科技有限公司 0755-61588823/13530382140 业务：曾先生 4/8 CM8603D Each gain setting is achieved by varying the input resistance of the amplifier, which can range from its smallest value to over 16 times that value. The -3dB frequency can be calculated using Equation 1: f −3 dB = 1 2π CiZi Zf IN Input Signal (1) Ci Zi Input Capacitance In the typical application an input capacitor, Ci, is required ti allow the amplifier t bias the input signal to the proper dc level for optimum operation. In the case, Ci and the input impedance of the amplifier, Zi, form a high-pass filter with the corner frequency determined in Equation 2: f c ( highpass ) = 1 2π CiZi (2) -3dB The value of Ci is important, as it directly affects the bass (low frequency) performance of the circuit. Consider the example where Zi is 45 k Ω and the specification calls for a flat bass response down to 80 Hz. Equation 2 is reconfigured as Equation 3: fc 1 (3) 2π fc ∗ Zi In the example, Ci is 0.05uF, so one would likely choose a value in range of 0.1uF to 1uF. A further consideration for this capacitor is the leakage path from the input source through the input network (Ci) and the feedback network to the load. This leakage current creates a dc offset voltage at the input to the amplifier that reduces useful headroom, especially in the 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 there is held at Vdd/2, which is likely higher than the source dc level. Note that it is important to confirm the capacitor polarity in the application. Ci should be 10 times smaller than the bypass capacitor to reduce clicking and popping noise from power on/off and entering an leaving shutdown. After sizing Ci for a given cutoff frequency, size the bypass capacitor up to 10 times that of the input capacitor. Ci = Ci ≤ 1 CBYP 10 (4) Power Supply Decoupling, Cs The CM8603D is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output total harmonic distortion (THD) is as low as possible. Power supply decoupling also prevents oscillations for long lead lengths between the amplifier and the speaker. The optimum decoupling is achieved by using two capacitors of different types that target different types of noise in the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low 深圳市宏达科技有限公司 0755-61588823/13530382140 业务：曾先生 5/8 CM8603D equivalent-series-resistance (ESR) ceramic capacitor, typically 0.1uF placed as close as possible to the device VDD lead works best. For filtering lower-frequency noise signals, a larger aluminum electrolytic capacitor of 10uF or greater placed near the audio power amplifier is recommended. Mid-Rail Bypass Capacitor, CBYP The mid-rail bypass capacitor, CBYP, is the most critical capacitor and 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 produced by the power supply caused by coupling into the output drive signal, This noise is from the mid-rail generation circuit internal to the amplifier, which appears as degraded PSRR and THD+N. Bypass capacitor, CBYP, values of 0.47uF to 1uF ceramic or tantalum low ESR capacitors are 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. To have minimal pop, CBYP should be 10 times larger than Ci. CBYP ≥ 10Ci (5) Shutdown mode The CM8603D employs a shutdown mode of operation designed to reduce supply current, IDD, to the absolute minimum level during periods of nonuse for battery-power conservation. The SD input terminal should be held high during normal operation when the amplifier is in use. Pulling SD low causes the outputs to mute and the amplifier to enter a low-current state. IDD( SD )=0.1uA. The device has an internal resistor connected between the AGND and changes when the SD SD pins. The purpose of the resistor is to eliminate any unwanted state pin is floating. The CM8603D will enter the shutdown state when the floating or if not floating, when the SD pin is left SD pin voltage has cross the threshold. To minimize the supply current while in the shutdown state, the SD pin is not driven to AGND or left floating. If the SD pin is not driven to AGND, the amount of additional resistor current due to the internal shutdown resistor can be found. When to Use an Output Filter Design the CM8603D without the filter if the traces from amplifier to speaker are short. Notebook PCs and powered speakers where the speaker is in the same enclosure as the amplifier are good applications for Class-D without a filter. A ferrite bead filter can often be used if the design is falling radiated emissions without a filter, and the frequency sensitive circuit is greater than 1MHz. If choosing a ferrite bead, choose one with high impedance at high frequencies, but very low impedance at low frequencies. Over Temperature Protect A temperature sensor is built in the device to detect the temperature inside the device. When a high temperature around 150℃ and above is detected the switching output signals are disabled to protect the device from over temperature. Automatic recovery circuit enables the device to come back to normal operation when the internal temperature of the device is below around 120℃. 深圳市宏达科技有限公司 0755-61588823/13530382140 业务：曾先生 6/8 CM8603D EVALUATION CIRCUIT Without Filter With Filter 深圳市宏达科技有限公司 0755-61588823/13530382140 业务：曾先生 7/8 CM8603D Packa ge Information 深圳市宏达科技有限公司 0755-61588823/13530382140 业务：曾先生 8/8