APA4838

APA4838 Stereo 2.8W Audio Power Amplifier with DC Volume Control and Selectable Gain Features • • • • • • • Operating Voltage : 4.5V to 5V Stereo switchable bridged/single-ended power amplifiers DC Volume Control Interface , 0dB to –78dB with precision scale Supply Current , IDD = 15mA at Stereo BTL Low Shutdown Current , IDD = 0.7µA Bridge-Tied Load (BTL) or Single-Ended-(SE) Modes Operation Output Power at 1% THD+N , VDD=5V General Description The APA4838 is a monolithic integrated circuit , which provides DC volume control , and a stereo bridged audio power amplifiers capable of producing 2.8W (2.3W) into 3Ω with less than 10% (1.0%) THD+N. APA4838 includes a DC volume control , stereo bridge-tied and single-ended audio power amplifiers , stereo docking outputs , and a selectable gain control , that makes it optimally fittable for notebook PC , multimedia monitors , and other portable applications. The attenuator range of the volume control in APA4838 is from 0dB (DC_Vol=0.8VDD) to –78dB (DC_Vol=0V) with 31 steps. Both of the depop circuitry and the thermal shutdown protection circuitry are integrated in APA4838 , that reduces pops and clicks noise during power up or shutdown mode operation , and protects the chip from being destroyed by over temperature failure. To simplify the audio system design , APA4838 combines a stereo bridgetied loads (BTL) mode for speaker drive and a stereo single-end (SE) mode for headphone drive into a single chip , where both modes are easily switched by the HP Sense input control pin signal. Besides the low supply current design to increase the efficiency of the amplifiers , APA4838 also features a shutdown function which keeps the supply current only 0.7µA (typ). • – 2.3W/Ch (typ) into a 3 Ω Load – 2.0W/Ch (typ) into a 4 Ω Load – 1.2W/Ch (typ) into a 8 Ω Load Output Power at 10% THD+N , VDD=5V • • • • • • – 2.8W/Ch (typ) into a 3 Ω Load – 2.3W/Ch (typ) into a 4 Ω Load – 1.5W/Ch (typ) into a 8Ω Load Single-ended mode at 1.0% THD+N – 95mW/Ch (typ) into 32Ω Load Depop Circuitry Integrated Thermal shutdown protection and over current protection circuitry High supply voltage ripple rejection PC99 Compliant 28-pin TSSOP-P (with enhanced thermal pad) power package available Pin Description GN D Shutdown G ain Select M ode M ute VDD DC V ol GN D Right Dock Right In 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Right O ut + V DD Right O ut Right G ain 2 Right G ain 1 GN D BY PA SS HP Sense GN D Left G ain 1 Left G ain 2 Left O ut V DD Left O ut + Applications • • • Notebook and Desktop Computers Multimedia Monitors Portable Applications Beep In Left In Left Dock GN D ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders. Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 1 www.anpec.com.tw APA4838 Ordering and Marking Information APA4838 H a n d lin g C o d e T em p. R an g e P ac ka ge C od e P ackage C ode R : T S S O P -P Tem p. R ange I : -4 0 to 8 5 ° C H a n d lin g C o d e TU : Tube TR : Tape & R eel A P A 4838 R : A P A 4838 XXXXX X X X X X - D a te C o d e Block Diagram Gain Select 20KΩ 20KΩ Left Gain1 Mode Mute HP Sense DC_Vol Left Dock 20KΩ Left Audio Input 200KΩ 200KΩ Right Audio Input 20KΩ 20KΩ Mode Control Left Gain2 20KΩ 10KΩ 0.068µF 10KΩ - Left Out + Bias + Bias + + Right Out 20KΩ + Power Management 10KΩ 10KΩ 20KΩ Right Gain1 Right Gain2 Click and Pop Suppression Circuitry 20KΩ 2 0.33µF Beep In 0.33µF Right In Right Dock 20KΩ Shutdown VDD GND Beep Detect Bypass Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 + - + Volume Control 31 steps Left In 20KΩ 20KΩ + Left Out 20KΩ - Right Out 0.068µF 20KΩ www.anpec.com.tw APA4838 Absolute Maximum Ratings (Over operating free-air temperature range unless otherwise noted.) Symbol VDD VIN TA TJ TSTG TS VESD PD Parameter Rating Supply Voltage -0.3 to 6 Input Voltage Range, HP sense, Shutdown, -0.3 to VDD+0.3 Mute, Mode, Gain Select Operating Ambient Temperature Range -40 to 85 Maximum Junction Temperature Internally Limited*1 Storage Temperature Range -65 to +150 Soldering Temperature,10 seconds 260 Electrostatic Discharge -2000 to 2000*2 Power Dissipation Internally Limited Unit V V °C °C °C °C V W Note: 1.APA4838 integrated internal thermal shutdown protection when junction temperature ramp up to 150°C 2.Human body model: C=100pF, R=1500Ω, 3 positives pulse plus 3 negative pulses 3.Machine model: C=200pF, L=0.5µF, 3 positive pulses plus 3 negative pulses Recommended Operating Conditions Min. Supply Voltage, VDD High level threshold voltage, VIH Low level threshold voltage, VIL Common mode input voltage, VICM Shutdown, Mute, Mode, Gain Select HP Sense Shutdown, Mute, Mode, Gain Select HP Sense VDD-1.0 4.5 2 4 1.0 3 Max. 5.5 Unit V V V V Thermal Characteristics Symbol R THJA Parameter Thermal Resistance from Junction to Ambient in Free Air TSSOP-P* 45 K/W Value Unit * 5 in2 printed circuit board with 2oz trace and copper pad through 9 25mil diameter vias. The thermal pad on the TSSOP_P package with solder on the printed circuit board. Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 3 www.anpec.com.tw APA4838 Electrical Characteristics Electrical Characteristics for Entire IC The following specifications apply for VDD= 5V unless otherwise noted. Limits apply for TA= 25°C Symbol VDD IDD ISD Parameter Supply Voltage Quiescent Power Supply Current Shutdown Current Test Conditions Min. 4.5 APA4838 Typ. Max. 5.5 15 0.7 25 2.0 Unit V mA µA VIN=0V, IO=0A VPIN 2= VDD Electrical Characteristics for Volume Attenuators The following specifications apply for VDD= 5V. Limits apply for TA= 25°C Symbol CRANGE AM Parameter Attenuator Range Mute Attenuation Test Conditions Gain with VPIN 7=5V Attenuation with VPIN 7=0V VPIN 5=5V, Bridged Mode VPIN 5=5V, Single-Ended Mode Min. APA4838 Typ. Max. ±0.5 -65 -78 -70 -70 Unit dB dB Electrical Characteristics for BTL Mode Operation The following specifications apply for VDD= 5V unless otherwise noted. Limits apply for TA= 25°C Symbol VOS PO Parameter Output Offset Voltage Output Power Test Conditions THD+N PSRR XTALK SNR VN VIN=0V THD=1%, f=1kHz RL=3Ω RL=4Ω RL=8Ω THD=10%, f=1kHz RL=8Ω Total Harmonic Distortion + Noise AVD=2, f=1kHz RL=4Ω , PO =1.5W RL=8Ω , PO=1W VRIPPLE=100mVRms CB=2.2µF, Power Supply Rejection Ratio RL=8Ω, f=1kHz CB=2.2µF, f=1kHz, RL=8Ω Channel Separation VDD=5V, PO =1.1W, RL=8Ω,A-Wtd Signal-to-Noise Ratio Filter RL=8Ω,A-Wtd Filter Output Noise Voltage APA4838 Typ. 5 2.3 2.0 1.2 1.5 0.07 0.07 70 90 95 30 Unit mV W % dB dB dB µV Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 4 www.anpec.com.tw APA4838 Electrical Characteristics (Cont.) Electrical Characteristics for SE Mode Operation (Cont.) The following specifications apply for VDD= 5V unless otherwise noted. Limits apply for TA= 25°C Symbol VOS PO THD+N PSRR XTALK SNR VN Parameter Output Offset Voltage Output Power VIN=0V THD=1%, THD=10%, Test Conditions f=1kHz, RL=32Ω f=1kHz, RL=32Ω APA4838 Typ. 5 95 110 0.05 0.07 52 90 102 20 Unit mV mW % % dB dB dB µV Total Harmonic Distortion AV= 1 , VOUT=1VRMS, RL=10kΩ, f=1kHz plus Noise PO =75mW, RL=32Ω, AV= 1, f=1kHz Power Supply Rejection VRIPPLE=100mVRMS , f=120Hz, CB=2.2µF Ratio Channel Separation CB=2.2µF, RL=8Ω , f=1kHz Signal-to-Noise Ratio PO =75mW, RL=32Ω, A-Wtd Filter Output Noise Voltage RL=32Ω, A-Wtd Filter Pin Description Pin Name GND Shutdown Gain Select Mode Mute VDD DC_Vol Right Dock Right In Beep In Left In Left Dock Left Out + Left Out Left Gain 2 Left Gain 1 HP Sense No 1, 8, 14, 20, 23 2 3 4 5 6, 16, 27 7 9 10 11 12 13 15 17 18 19 21 I/O Ground connection for circuitry. I Shutdown mode control signal input, place entire IC in shutdown mode when held high, Idd=0.7uA I Gain select input pin, logic high will switch the amplifier to external gain mode, and logic low will switch to internal unity gain. I Mode select input pin, fixed gain when logic L and gain adjustable mode when logic H. I Mute control input pin, active H. Supply voltage input pin I Volume control function input pin. O Right docking output pin I Right channel audio input pin I Beep signal input pin I Left channel audio input pin O Right docking output pin O Left channel positive output pin O Left channel negative output pin Connect pin 2 of the external gain setting resistor for left channel Connect pin 1 of the external gain setting resistor for left channel I Headphone sense control pin 5 www.anpec.com.tw Description Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 APA4838 Pin Description (Cont.) Pin Name Bypass Right Gain 1 Right Gain 2 Right Out Right Out + No 22 24 25 26 28 I/O Bypass pin Connect pin 1 of the external gain setting resistor for right channel Connect pin 2 of the external gain setting resistor for right channel O Right channel negative output pin O Right channel positive output pin Description Truth Table for Logic Inputs Mute 0 0 0 0 0 0 0 0 1 Gain HP Mode Select Sense 0 0 0 0 1 1 1 1 X 0 0 1 1 0 0 1 1 X 0 1 0 1 0 1 0 1 X Gain Mode of Power Amplifier Unity Gain Setting Unity Gain Setting Unity Gain Setting Unity Gain Setting External Gain Setting External Gain Setting External Gain Setting External Gain Setting - DC Vol. Control Fixed Level Fixed Level Adjustable Adjustable Fixed Level Fixed Level Adjustable Adjustable - BTL Output Vol. Fixed Muted Vol. Adjustable Muted Vol. Fixed Muted Vol. Adjustable Muted Muted SE Output Vol. Fixed Vol. Adjustable Vol. Fixed Vol. Adjustable Muted Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 6 www.anpec.com.tw APA4838 Typical Application Circuit VDD 1 µF VDD R_var DC Vol Control VDD 100KΩ Internal gain select 3 20KΩ 20KΩ HP Sense 100KΩ 21 5 Mute Mode 4 13 7 19 18 To Control Pin on Headphone Jack Mode Control 20KΩ 10KΩ 10KΩ - Left Out 0.068µ F Left Dock Left Audio Input 20KΩ 20KΩ 200KΩ Beep In Right Audio Input 200KΩ Right In Left In + 0.33µ F 11 Bias 10 20KΩ + 0.33µ F 20KΩ Right Dock VDD Bias 28 9 20KΩ 1,8,14,20,23 GND 0.1µ F 0.1µ F 0.1µ F 2.2µ F Bypass 22 10KΩ Click and Pop Suppression Circuitry 2 24 Shutdown 20KΩ 20KΩ Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 7 - Power Management + 6,16,27 10KΩ 20KΩ 0.068µ F 25 + - Beep Detect + + Volume Control 31 steps 12 + 20KΩ 20KΩ 17 + 220µ F 1KΩ Control Pin Pin Ring 15 + Left Out To HP sense Circuit + Right Out Tip Sleeve + Headphone Jack 20KΩ 26 + 220µ F 1KΩ - Right Out www.anpec.com.tw APA4838 Application Information Volume Control Table Gain (dB) Low 0 -1 -2 -3 -4 -5 -6 -8 -10 -12 -14 -16 -18 -20 -22 -24 -26 -28 -30 -32 -34 -36 -38 -40 -42 -44 -46 -48 -50 -52 -78 77.5% 75.0% 72.5% 70.0% 67.5% 65.0% 62.5% 60.0% 57.5% 55.0% 52.5% 50.0% 47.5% 45.0% 42.5% 40.0% 37.5% 35.0% 32.5% 30.0% 27.5% 25.0% 22.5% 20.0% 17.5% 15.0% 12.5% 10.0% 7.5% 5.0% 0.0% Voltage Range (% of Vdd) High 100.00% 78.5% 76.25% 73.75% 71.25% 68.75% 66.25% 63.75% 61.25% 58.75% 56.25% 53.75% 51.25% 48.75% 46.25% 43.75% 41.25% 38.75% 36.25% 33.75% 31.25% 28.75% 26.25% 23.75% 21.25% 18.75% 16.25% 13.75% 11.25% 8.75% 6.25% Recommended 100.000% 76.875% 74.375% 71.875% 69.375% 66.875% 64.375% 61.875% 59.375% 56.875% 54.375% 51.875% 49.375% 46.875% 44.375% 41.875% 39.375% 36.875% 34.375% 31.875% 29.375% 26.875% 24.675% 21.875% 19.375% 16.875% 14.375% 11.875% 9.375% 6.875% 0.000% Low 3.875 3.750 3.625 3.500 3.375 3.250 3.125 3.000 2.875 2.750 2.625 2.500 2.375 2.250 2.125 2.000 1.875 1.750 1.625 1.500 1.375 1.250 1.125 1.000 0.875 0.750 0.625 0.500 0.375 0.250 0.000 Voltage Range (Vdd=5V) High 5.000 3.938 3.813 3.688 3.563 3.438 3.313 3.188 3.063 2.938 2.813 2.688 2.563 2.438 2.313 2.188 2.063 1.938 1.813 1.688 1.563 1.438 1.313 1.188 1.063 0.937 0.812 0.687 0.562 0.437 0.312 Recommended 5.000 3.844 3.719 3.594 3.469 3.344 3.219 3.094 2.969 2.844 2.719 2.594 2.469 2.344 2.219 2.094 1.969 1.844 1.719 1.594 1.469 1.344 1.219 1.094 0.969 0.844 0.719 0.594 0.469 0.344 0.000 Copyright  ANPEC Electronics Corp. Rev. A.1 - Feb., 2003 8 www.anpec.com.tw APA4838 Typical Characteristics THD+N vs. Frequency 10 VDD=5V RL=3Ω Po=1.8W BTL Av=2 Av=4 Av=8 THD+N vs. Output Power 10 VDD=5V RL=3Ω Av=2 BTL f=20KHz THD+N (%) THD+N (%) 1 1 0.1 0.1 f=20Hz f=1KHz 0.01 20 100 1k 20k 0.01 10m 100m 1 3 Frequency (Hz) Output Power (W) THD+N vs. Frequency 10 VDD=5V RL=4Ω Po=1.5W BTL THD+N vs. Output Power 10 VDD=5V RL=4Ω Av=2 BTL THD+N (%) 1 Av=2 Av=4 Av=8 1 0.1 THD+N (%) f=20KHz 0.1 f=1KHz f=20Hz 0.01 20 100 1k 20k 0.01 100m 500m 1 3 Frequency (Hz) Output Power (W) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 9 www.anpec.com.tw APA4838 Typical Characteristics (Cont.) THD+N vs. Frequency 10 VDD=5V RL=8Ω Po=1.0W BTL THD+N vs. Output Power 10 VDD=5V RL=8Ω Av=2 BTL THD+N (%) THD+N (%) 1 Av=2 Av=4 Av=8 1 f=20KHz 0.1 0.1 f=1KHz f=20Hz 0.01 20 100 1k 20k 0.01 10m 100m 1 2 Frequency (Hz) Output Power (W) THD+N vs. Frequency 10 VDD=5V RL=8Ω Po=250mW SE THD+N vs. Output Power 10 VDD=5V RL=8Ω Av=1 SE THD+N (%) Av=1 Av=2 Av=4 THD+N (%) 1 1 f=20KHz 0.1 0.1 f=1KHz f=20Hz 0.01 20 100 1k 20k 0.01 10m 100m 500m Frequency (Hz) Output Power (W) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 10 www.anpec.com.tw APA4838 Typical Characteristics (Cont.) THD+N vs. Frequency 10 VDD=5V RL=16Ω Po=150mW SE THD+N vs. Output Power 10 VDD=5V RL=16Ω Av=1 SE THD+N (%) Av=1 Av=2 THD+N (%) 1 1 f=20KHz 0.1 Av=4 0.1 f=20Hz f=1KHz 0.01 20 100 1k 20k 0.01 10m 100m 300m Frequency (Hz) Output Power (W) THD+N vs. Frequency 10 VDD=5V RL=32Ω Po=75mW SE THD+N vs. Output Power 10 VDD=5V RL=32Ω Av=1 SE THD+N (%) 1 1 THD+N (%) f=20Hz f=20KHz 0.1 Av=1 Av=2 Av=4 0.1 f=1KHz 0.01 20 100 1k 20k 0.01 10m 50m 100m 200m Frequency (Hz) Output Power (W) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 11 www.anpec.com.tw APA4838 Typical Characteristics (Cont.) THD+N vs. Frequency 10 VDD=5V RL=10KΩ Vo=1VRMS SE THD+N vs. Output Swing 10 VDD=5V RL=10KΩ Av=1 SE THD+N (%) Av=1 THD+N (%) 1 1 0.1 Av=2 Av=4 0.1 f=20Hz f=20KHz f=1KHz 0.01 20 100 1k 20k 0.01 100m 500m 2 3 Frequency (Hz) Output Swing (VRHS) Crosstalk vs. Frequency +0 -20 -40 -60 -80 R-ch to L-ch VDD=5V RL=8Ω Po=1.0W Av=2 BTL Crosstalk vs. Frequency VDD=5V RL=32Ω -20 Po=75mW Av=2 SE +0 Crosstalk (dB) Crosstalk (dB) -40 -60 -80 -100 R-ch to L-ch L-ch to R-ch -100 L-ch to R-ch -120 20 100 1k 20k -120 20 100 1k 20k Frequency (Hz) Frequency (Hz) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 12 www.anpec.com.tw APA4838 Typical Characteristics (Cont.) Noise Floor vs. Frequency 100 Noise Floor vs. Frequency 100 No Filter Noise Floor (µVRMS) Noise Floor (µVRMS) No Filter A-Weight 10 10 A-Weight VDD=5V RL=8Ω Av=2 BTL 1 20 100 1k 20k VDD=5V RL=32Ω Av=1 SE 1 20 100 1k 20k Frequency (Hz) Frequency (Hz) Supply Current vs. Supply Voltage 25 2 1 .8 Power Dissipation vs. Output Power Power Dissipation (W) Supply Current (mA) 20 1 .6 1 .4 1 .2 1 0 .8 0 .6 0 .4 0 .2 0 0 0 .5 1 1 .5 RL=8Ω RL=3Ω 15 BTL RL=4Ω 10 SE 5 No Load VDD=5V Av=2 BTL 0 1 1 .5 2 2 .5 3 3 .5 4 4 .5 5 5 .5 2 2 .5 Supply Voltage (V) Output Power (W) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 13 www.anpec.com.tw APA4838 Typical Characteristics (Cont.) Power Dissipation vs. Output Power 0 .2 5 4 0 -4 -8 Gain vs. Voltage, 5V, SE Power Dissipation (W) 0 .2 RL=8Ω -1 2 Output Gain (dB) VDD=5V Av=2 SE -1 6 -2 0 -2 4 -2 8 -3 2 -3 6 -4 0 -4 4 -4 8 -5 2 -5 6 -6 0 -6 4 -6 8 -7 2 -7 6 -8 0 0 .1 5 RL=16Ω 0 .1 0 .0 5 RL=32Ω 0 0 0 .0 5 0 .1 0 .1 5 0 .2 0 .2 5 0 .3 0 .3 5 0 .4 VDD=5V AV=1 SE 0 0 .5 1 1 .5 2 2 .5 3 3 .5 4 4 .5 5 Output Power (W) DC Vol Input Voltage (V) Output Power vs. Supply Voltage 2 .2 5 2 160 140 Output Power vs. Supply Voltage Output Power (W) 1 .5 THD+N=10% Output Power (mW) 120 100 THD+N=10% 1 THD+N=1% 80 60 40 20 0 RL=32Ω Av=1 SE THD+N=1% 0 .5 RL=8Ω Av=2 BTL 0 2 .5 3 3 .5 4 4 .5 5 5 .5 2 .5 3 3 .5 4 4 .5 5 5 .5 Supply Voltage (V) Supply Voltage (V) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 14 www.anpec.com.tw APA4838 Typical Characteristics (Cont.) Output Power vs. Load Resistance 3 2.5 VDD=5V Av=2 BTL Output Power vs. Load Resistance 800 700 VDD=5V Av=1 SE 2 1.5 1 0.5 THD+N=1% Output Power (mW) Output Power (W) 600 500 400 300 200 100 0 THD+N=10% THD+N=1% THD+N=10% 0 48 16 24 32 40 48 56 64 48 16 24 32 40 48 56 64 Load Resistance (Ω) Load Resistance (Ω) PSRR vs. Frequency +0 6 PSRR vs. Frequency +0 VDD=5V Vin=100mVRMS RL=8Ω -20 Cbypass=2.2µF Av=1 SE Ripple Rejection Ratio (dB) -20 -40 Ripple Rejection Ratio (dB) VDD=5V Vin=100mVRMS RL=8Ω Cbypass=2.2µF Av=2 BTL -40 Gain Adjustable Gain Adjustable -60 -60 -80 Fixed Gain Mode -80 Fixed Gain Mode -100 20 100 1k 20k -100 20 100 1k 20k Frequency (Hz) Frequency (Hz) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 15 www.anpec.com.tw APA4838 Typical Characteristics (Cont.) Gain vs. Frequency +12 +10 +8 +6 +4 +2 -0 20 100 1k 20k VDD=5V RL=8Ω Av=2V/V BTL Cf=0.068µF Cf=0.22µF Cf=0.1µF Gain (dB) Frequency (Hz) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 16 www.anpec.com.tw APA4838 Application Descriptions BTL Operation The APA4838 output stage (power amplifier) has two pairs of operational amplifiers internally, allowed for different amplifier configurations for each channel. Gain 1 Gain 2 BTL Operation (Cont.) A BTL amplifier design has a few distinct advantages over the SE configuration, as it provides differential drive to the load, thus doubling the output swing for a specified supply voltage. Four times the output power is possible as compared -Out to a SE amplifier under the same conditions. A BTL configuration, such as the one used in APA4838, also Volum e Control Am plifier output signal OP1 creates a second advantage over SE amplifiers. RL +Out Since the differential outputs, +Right Out, -Right Out, +Left Out, and -Left Out, are biased at half-supply, no need DC voltage exists across the load. This eliminates the need for an output coupling capacitor which is required in a single supply, SE configuration. Single-Ended Operation Consider the single-supply SE configuration shown Application Circuit. A coupling capacitor is required to block the DC offset voltage from reaching the load. These capacitors can be quite large (approximately 33µF to 1000µF) so they tend to be expensive, occupy valuable PCB area, and have the additional drawback of limiting low-frequency performance of the system (refer to the Output Coupling Capacitor). The rules described still hold with the addition of the following relationship: 1 ≤ 1 1kΩ with rail-to-rail output and output coupling capacitor is required when using these outputs. Tip Headphone Jack Figure 2: HP Sense input selection by phonejack plug Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 18 www.anpec.com.tw APA4838 Application Descriptions (Cont.) Docking Output Signal (Cont.) Typical values for the output coupling capacitors are 0.33µF to 1.0µF. If polarized coupling capacitors are used, connect their ’+’ terminals to the respective output pin. The Right Dock and Left Dock channel outputs signal are also used to driving internal volume control amplifier. Input Capacitor, Ci 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 a high-pass filter with the corner frequency determined in the follow equation: FC(highpass)= 1 2πRiCi (3) As other power amplifiers, proper supply bypassing is critical for low noise performance and high power supply rejection. The capacitors located on the bypass and power supply pins should be as close to the device as possible. The effect of a larger half supply bypass capacitor will improve PSRR due to increased halfsupply stability. Typical application employ a 5V regulator with 1.0µF and a 0.1µF bypass as supply filtering. This does not eliminate the need for bypassing the (4) supply nodes of the APA4838. The selection of bypass capacitors, especially Cbypass, is thus dependent upon desired PSRR requirements, click and pop performance. To avoid start-up pop noise occurred, the bypass voltage should rise slower than the input bias voltage and the relationship shown in equation (5) should be maintained. 1 1 200V 10ms , Itr > 100mA Carrier Tape & Reel Dimensions Po E P P1 D t F W Bo Ao Ko D1 T2 J C A B T1 A pp lication A 330 ± 1 B 100 ref D 1.5 +0.1 C 13 ± 0.5 D1 1.5 min J 2 ± 0.5 Po 4.0 ± 0.1 T1 16.4 ± 0.2 P1 2.0 ± 0.1 T2 2 ± 0.2 Ao W 16 ± 0.3 Bo P 12 ± 0.1 Ko E 1.75 ± 0.1 t TSSOP- 28 F 7.5 ± 0.1 6.9 ± 0.1 10.2 ± 0.1 1.8 ± 0.1 0.3 ± 0.05 (mm) Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 28 www.anpec.com.tw APA4838 Cover Tape Dimensions Application TSSOP- 28 Carrier Width 16 Cover Tape Width 21.3 Devices Per Reel 2000 Customer Service Anpec Electronics Corp. Head Office : 5F, No. 2 Li-Hsin Road, SBIP, Hsin-Chu, Taiwan, R.O.C. Tel : 886-3-5642000 Fax : 886-3-5642050 Taipei Branch : 7F, No. 137, Lane 235, Pac Chiao Rd., Hsin Tien City, Taipei Hsien, Taiwan, R. O. C. Tel : 886-2-89191368 Fax : 886-2-89191369 Copyright  ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 29 www.anpec.com.tw