NATIONAL SEMICONDUCTOR LM4890 Manual(1)
Contents
1. using Equation 2 and add the output voltage Using this method the minimum supply voltage would be where 219 are extrapolated from the Dropout Volt age vs Supply Voltage curve in the Typical Performance Characteristics section Vopeak V 2R Po 2 5V is a standard voltage which in most applications is cho sen for the supply rail Extra supply voltage creates head room that allows the LM4890 to reproduce peaks in excess of 1W without producing audible distortion At this time the designer must make sure that the power supply choice along with the output impedance does not violate the conditions explained in the Power Dissipation section Once the power dissipation equations have been addressed the required differential gain can be determined from Equa tion 3 V PoR p Veena Vine Avp 2 From Equation 3 the minimum is 2 83 use Ayp Since the desired input impedance is 20 and with an gain of 3 a ratio of 1 5 1 of R to bw results in an allocation of Rin 20 and R 30 The final design step is to address the bandwidth requirements which must be stated as a pair of 3 dB frequency points Five times away from a 3 dB point is 0 17 dB down from passband response which is better than the required 0 25 dB specified f 100Hz 5 20Hz 20kHz 5 100kHz www nat2. vs Power Out Vpp 3 3V 80 1kHz Ay 2 10 CH L L D J LL SSS m 0 05 0 02 SSC 10m 20m 50m 100m 200m 500m 1 0 01 POWER OUT IN WATTS 20019242 80 1kHz 2 10 0 1 TOTAL HARMONIC DISTORTION IN 0 01 WH 10m 20m 50m100m200m 500m 1 2 vs Power Out Vp 2 6V R 80 1kHz Av 2 TOTAL HARMONIC DISTORTION IN www national com 1 0 1 mm Hr 0 05 EE 10m 20m 50m 100m 200m 500m 1 0 01 POWER OUT IN WATTS 20019243 POWER OUT IN WATTS TOTAL HARMONIC DISTORTION IN 76 20019291 THD N vs Power Out Vp 2 6V 40 1kHz Ay 2 10 c 10m 20m 50m 100m 200m 500m 1 POWER OUT IN WATTS 20019244 Typical Performance CharacteristicS continued Power Supply Rejection Ratio PSRR Av 2 Power Supply Rejection Ratio PSRR A 2 Vpp SV V ipple 200mvp p Vpp 5V V ripple 200mvp p 80 Rin 100 80 Rin Float LEVEL dB LEVEL dB FREQUENCY Hz FREQUENCY Hz 20019245 20019273 Power Supply Rejection Ratio PSRR A 4 Power Supply Rejection Ratio PSRR A 4 Vpp 5 Vrippte 200mvp p Voo 9V 200 80 Rin 100 80 Float 0 TT 10 CID C
3. 2 R 80 gt gt 2 22 5 5 80 Bottom 2 AMBIENT TEMPERATURE C Supply Voltage V 20019299 20019252 www national com 14 Typical Performance CharacteristicS continued DIE TEMPERATURE 25 C AMBIENT C OFFSET VOLTAGE mV Supply Current mA Max Die Temp at Pomax 9 bump microSMD Maximum Die Temperature 1509 14 eee 5 609 wes 0 50 100 150 200 250 500 PCB HEATSINK AREA mm 20019286 Output Offset Voltage Maximum Von AN to 5V Typical Won AN to SV TEMPERATURE C 200192B7 Shutdown Hysterisis Voltage O L 0 1 2 3 Shutdown Voltage V 20019279 15 O o pad Lu lt L re N Lu oO 2 He lt DE LO gt Supply Current mA SUPPLY CURRENT MA Max Die Temp at Pomax 8 bump microSMD 200 a Maximum Die Temperature 150 C 140 120 100 80 gt gt lt a gt e lt gt lt DI DOW oL Cao Note 13 0 50 100 150 200 250 500 PCB HEATSINK AREA mm 20019287 Supply Current vs Shutdown Voltage Shutdown Voltage V 20019253 Shutdown Hysterisis Voltage SHUTDOWN VOLTAGE V 20019280 www national com O687IN1
4. TEMPERATURE C 200192B6 Frequency Response Noise Floor vs Input Capacitor Size 2 Jr _ E s 9 33 coramic E LLL LLL 2 amp LL LU CIE 3 3 s LL LU L i MET 5 E LLL LEE o UU LIUM 20 50100200 500 1k 2k 5k 10k 20k 20 50100200 500 1k 2k 5k 10k 20k Frequency Hz Frequency Hz 20019254 20019256 17 www national com O687IN1 Application Information BRIDGED CONFIGURATION EXPLANATION As shown in Figure 1 the LM4890 has two operational amplifiers internally allowing for a few different amplifier configurations The first amplifier s gain is externally config urable while the second amplifier is internally fixed in a unity gain inverting configuration The closed loop gain of the first amplifier is set by selecting the ratio of R to while the second amplifier s gain is fixed by the two internal 20kQ resistors Figure 1 shows that the output of amplifier one serves as the input to amplifier two which results in both amplifiers producing signals identical in magnitude but out of phase by 180 Consequently the differential gain for the IC is 2 By driving the load differentially through outputs 1 and Vo2 an amplifier configuration commonly referred to as bridged mode is established Bridged mode operation is different from the classical single ended amplifier configura tion where one side of the load is connected t
5. 0681 01 PSRR vs DC Output Voltage Vpp 5V Ay 4 Vourpc V 20019297 PSRR vs DC Output Voltage Vpp 3V Av 2 Vourpc V 20019294 PSRR vs DC Output Voltage V 200192A4 www national com LM4890 Typical Performance Characteristics continued PSRR Distribution Vpp 5V PSRR Distribution Vpp 217Hz 200mvp p 217Hz 200mvp p 30 25 and 80 C 30 25 and 80 C 200192B4 200192B5 Power Supply Rejection Ration vs Power Supply Rejection Ration vs Bypass Capacitor Size Bypass Capacitor Size Vpp 5V Input Grounded 100 Output Load 80 Vpp Input Grounded 100 Output Load 80 0 5 GLOD CU 0 e EHI 1o 15 Lt C all _15 HL 20 Bum 20 CLUE Um 25 5s LI pillil HHH LL T S 35 EI S 35 1 ao A CU 750 240 LLL E D 45 a 50 50 1 S N pillil 55 E 55 All lIIIII eg Uu 60 JO 65 Tt 65 70 minal 70 TI 75 80 L iil 20 100 1k 10k 100k 20 100 1k 10k 100k FREQUENCY Hz FREQUENCY Hz 200192A7 200192A8 Top Trace No Cap Next Trace Down 1pf Top Trace No Cap Next Trace Down 11 Next Trace Down 211 Bottom Trace
6. LM4890 Typical Performance Characteristics continued Open Loop Frequency Response 5V No Load GAIN dB FREQUENCY 20019281 Gain Phase Response Ay 2 Vpp 5V 80 Load 500pF PHASE 20 100 10K 100K 1M 10M 100 FREQUENCY Hz 200192B2 Phase Margin vs Ay 2 Capacitance to gnd on each output 1000 1500 CAPACITANCE pF 2000 200192A5 www national com GAIN dB GAIN dB PHASE Open Loop Frequency Response No Load PHASE E _ B III N IN 10k 100k 1M FREQUENCY 20019282 Gain Phase Response A 4 Vpp 5V 80 Load 500 PHASE 10K 100K 1 FREQUENCY Hz 200192 3 Phase Margin vs C 4 gnd each output 2000 1500 500 1000 200192A6 Typical Performance CharacteristicS continued Phase Margin and Limits vs Application Variables Rin 22KQ RF22k RLopen 0 01 RF220k RL8Q 0 pF 250 RF22k RLopen 0 pF RF220k RL8Q 0 01 uF A d RF22k RL80 0 01 uF RF220k RLopen 0 pF RF 22k RL80 O pF RF220k RLopen 1000 pF Unstable Operation Area Measured Phase Margin 5 6 Volts T 20 to 85 C and connected across outputs in differential mode 20019298 Wake Up Time NE NE Vpp to 5V T E gt
7. 2006 National Semiconductor Corporation National Semiconductor LM4890 Boomer Audio Power Amplifier Series 1 Watt Audio Power Amplifier General Description The 1 4890 is an audio power amplifier primarily designed for demanding applications in mobile phones and other por table communication device applications It is capable of delivering 1 watt of continuous average power to an 80 BTL load with less than 1 distortion THD N from 5Vpc power supply Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components The LM4890 does not require output coupling capacitors or bootstrap capacitors and therefore is ideally suited for mobile phone and other low voltage appli cations where minimal power consumption is a primary re quirement The 1 4890 features a low power consumption shutdown mode which is achieved by driving the shutdown pin with logic low Additionally the LM4890 features an internal ther mal shutdown protection mechanism LM4890 contains advanced pop amp click circuitry which eliminates noises which would otherwise occur during turn on and turn off transitions The 1 4890 is unity gain stable and can be configured by external gain setting resistors Connection Diagrams 8 Bump micro SMD V 1 8 N 11 O O 7 GND 2 6 Von Bypass 3 Q Q Q 5 Shutdown 4 V2 20019223 Top View Order Number LM4890IBP
8. Tel 81 3 5639 7560
9. Vos Output Offset Voltage x 7 5 mv 8 5 1 0 N z 5 215 ground 66 f 1kHz Shut Down Time 8 Q load ms Electrical Characteristics Vpp Notes 1 2 8 The following specifications apply for the circuit shown Figure 1 unless otherwise specified Limits apply for T4 25 Symbol Parameter Conditions lbp Quiescent Power Supply Current mA 0 1 0 45 9 mamay jo Se gt D 45 lt 3 D min 180 ms max OS Twu Wake up time www national com 4 Electrical Characteristics Vp Notes 1 2 8 The following specifications apply for the circuit shown in Figure 1 unless otherwise specified Limits apply for T4 25 C Continued LM4890 ze Conditions pn Limits P Tsp THD N PSRR Power Supply Rejection Ratio Viipple sine p p Note 14 Input terminated with 10 ohms to 217Hz ground 62 f 2 1kHz Electrical Characteristics 2 6V Notes 1 2 8 The following specifications apply for for the circuit shown in Figure 1 unless otherwise specified Limits apply for T4 25 1 4890 Unit Symbol Parameter Conditions Typical ere Note 6 Notes 7 9 Ipp Quiescent Power Supply Current Vin OV No Load mA max Po Output Power 80 THD 1 max f 1 kHz 0 2 W Output
10. 4 71 Next Trace Down 211 Bottom Trace 4 71 LM4890 vs LM4877 Power Supply Rejection Ratio LM4890 vs LM4877 Power Supply Rejection Ratio Vpp 5V Input Grounded 100 Vpp Input Grounded 100 Output Load 80 200mV Ripple Output Load 80 200mV Ripple HH m s BEI bx HH LII x Gc ER HH LL HH OU NI LI M BHI rl 20 100 1k 10k 100k 20 100 1k 10k 100k FREQUENCY Hz FREQUENCY Hz 20019288 20019289 LM4890 Bottom Trace LM4890 Bottom Trace LM4877 Top Trace LM4877 Top Trace www national com 12 Typical Performance CharacteristicS continued Power Derating Curves 670mW POWER DISSIPATION W 0 7 E mus 0 6 N ae MSOP N NN 240 mm Heatsink AMBIENT TEMPERATURE C 20019283 Ambient Temperature in Degrees C Note 670mW for 5V 80 Power Derating 9 bump pSMD 670mW POWER DISSIPATION W x _ PCB Heatsink T LIN IN LL NS nahen IN 20 40 60 80 100 120 140 160 C 20019285 Ambient Temperature Degrees Note 670mW for 5V 80 POWER OUT mW Power Output vs Supply Voltage S ZEIT sss 2 3 2 3 4 3 6 3 8 4 4 2 4 4 4 6 4 8 5 SUPPLY VOLTAGE V 200192A1
11. 1 20019236 View Order Number LM4890MM See NS Package Number MUA08A Small Outline SO Package 1 8 SHUTDOWN Vo2 2 7 BYPASS GND 3 IN Vpp 4 5 N Vol 20019235 Top View Order Number LM4890M See NS Package Number www national com 9 Bump micro SMD Marking X oj P 200192C2 Pin 1 Top View X Date Code T Die Traceability G Boomer Family P LM4890IBL 10 Pin LLP Marking ZXYTT L4890 200192C6 Top View Z Assembly Plant Date Code M for Malacca XY Digit Date Code TT Die Traceability L4890 LM4890LD MSOP Marking VK Pin 1 20019271 View G Boomer Family 90 LM4890MM SO Marking XY LM 48 90 M Pin 1 20019272 Top View XY Date Code TT Die Traceability Bottom 2 lines Part Number Connection Diagrams continued 9 Bump micro SMD 9 Bump micro SMD Marking X G IN n A8 Pin 1 V 20019200 x Top View X Date Code Shutdown T Die Traceability G Boomer Family 8 LM4890ITL 200192C1 Top View Order Number LM4890ITL LM4890ITLX See NS Package Number TLA09AAA Typical Application 10k RL 2 an 20019201 FIGURE 1 Typical Audio Amplifier Application Circuit 3 www national com O687IN1 LM4890 Absolute Maximum Ratings Note 2 0 4 9 Bump micro SMD Note 12 180 C W If Military Aerospace specified devices are required De MSOP 56 please contact the National Semiconductor Sales Office 0
12. 4 MSOP 190 Distributors for availability specifications 0 4 LLP 220 C W Supply Voltage Note 11 6 0V Soldering Information Storage Temperature 65 150 See 1112 microSMD Wafers Level Chip Scale Input Voltage 0 3V to Vpp 0 3V Package Power Dissipation Note 3 Internally Limited See AN 1187 Leadless Leadframe Package LLP ESD Susceptibility Note 4 2000V Junction Temperature 150 C Operating Ratings Thermal Resistance o SOP 35 C W Temperature Range 0 4 SOP 150 C W Tmin lt TA lt Tmax 40 C lt TA lt 85 8 Bump micro SMD Note 12 220 C W S ppiy Voiage SE pp oo Electrical Characteristics Vpp DN Notes 1 2 8 The following specifications apply for the circuit shown in Figure 1 unless otherwise specified Limits apply for T4 25 C LM4890 Unit nits Conditions Typical Limit rimis Hm enn Resistor Output to GND Note 10 Output Power 80 THD 2 max f 1 kHz EM Wake up time 220 10 2 ms Thermal Shutdown Temperature gan 190 Total Harmonic Distortion Noise 0 4 Wrms f 1kHz e 55 Power Supply Rejection Ratio Vue 200mV sine 62 f dB min Note 14 Input Terminated with 10 ohms to 217Hz Note 6 Notes 7 9 lbp Quiescent Power Supply Current Vin OV OA No Load Shutdown Voltage Vm
13. Power 40 THD 1 max f 1 kHz 0 22 W uA max THD N Total Harmonic Distortion Noise P 0 1Wrms f 1kHz 96 Power Supply Rejection Ratio Viipple 200mV sine p p dB Note 14 Input Terminated with 10 ohms to ground Note 1 All voltages are measured with respect to the ground pin unless otherwise specified Note 2 Absolute Maximum Ratings indicate limits beyond which damage to the device may occur Operating Ratings indicate conditions for which the device is functional but do not guarantee specific performance limits Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific performance limits This assumes that the device is within the Operating Ratings Specifications are not guaranteed for parameters where no limit is given however the typical value is a good indication of device performance Note 3 The maximum power dissipation must be derated at elevated temperatures and is dictated by and the ambient temperature TA The maximum allowable power dissipation is PpyAx TJMAx T A 0jA or the number given in Absolute Maximum Ratings whichever is lower For the LM4890 see power derating curves for additional information Note 4 Human body model 100 pF discharged through a 1 5 resistor Note 5 Machine Model 220 240 pF discharged through all pins Note 6 Typicals are measured at 25 C and represent the param
14. 0IBP LM4890IBPX NS Package Number BPA08DDB X1 1 361 0 03 X2 1 361 0 03 0 850 0 10 www national com 26 Physical Dimensions inches millimeters unless otherwise noted Continued P 0278 gt 9 d 9X 092250 1 DIMENSIONS ARE IN MILLIMETERS 5 DIMENSIONS IN FOR REFERENCE ONLY SYMM 1 mel 9 Bump micro SMD Order Number LM4890IBL LM4890IBLX NS Package Number BLAO9AAB X1 1 514 0 03 X2 1 514 0 03 0 945 0 10 Huuu 8X 040 193 006 14 90 151 MSOP Order Number LM4890MM NS Package Number MUA08A 27 www national com 068tIN1 LM4890 Physical Dimensions inches millimeters unless otherwise noted Continued 0 189 0 197 4 800 5 004 8 7 5 5 0 228 0 244 5 791 6 198 0 010 wax 0 254 LEAD 1 1 2 3 4 IDENT 0 150 0 157 3 810 3 988 0 053 0 069 1 346 1 753 8 0 004 0 010 ALL LEADS 0 102 0 254 t Ah I mam SEATING 0 004 4 PLANE 0 102 la 014 0 008 0 010 ALL LEAD TIPS em 0 356 0 050 2 Ki 20 014 0 020 TYP ALL LEADS 406 1 270 TYP 0 008 typ TYP ALL LEADS 0 203 MOBA REV H SO Order Number LM4890M NS Package Number www national com 28 Physical Dimensions inches millimeters unless otherwise noted Continued 2 3 3 10X 0 5 TB ul H H DIMENSIONS ARE IN MILLIMETERS eb DIMENSIONS IN FOR REFERE
15. 3 Demo Boards en Number Part Description RetDesgmaor _ 1 208 001 1 8 Mono Reference Design Board _ ho femsa Ip swenayon mwCapwrivio bh Ja wech e 2 lt 472911207 001 Res 20K Ohm 1 10W 5 R1 R2 R3 210007039 002 Jumper Header Vertical Mount 2X1 0 100 J2 PCB LAYOUT GUIDELINES Single Point Power Ground Connections This section provides practical guidelines for mixed signal The analog power traces should be connected to the digital PCB layout that involves various digital analog power traces through a single point link A Pi filter can be helpful ground traces Designers should note that these are only in minimizing High Frequency noise coupling between the rule of thumb recommendations and the actual results will analog and digital sections It is further recommended to put depend heavily on the final layout digital and analog power traces over the corresponding digi tal and analog ground traces to minimize noise coupling GENERAL MIXED SIGNAL LAYOUT RECOMMENDATIONS Placement of Digital and Analog Components mE All digital components and high speed digital signals traces Power and Ground Circuits should be located as far away as possible from analog For 2 layer mixed signal design it is important to isolate the components and circuit traces digital power and ground trace paths from the analog power and ground trace paths Star trace routing techniques brin
16. LM4890IBPX See NS Package Number BPA08DDB Boomer is a registered trademark of National Semiconductor Corporation 05200192 July 2006 Key Specifications m PSRR at 217Hz 5V Fig 1 62dB typ m Power Output at 5 0V amp 1 THD 1W typ B Power Output at 3 3V amp 196 THD 400mW typ B Shutdown Current 0 1pA typ Features m Available in space saving packages micro SMD MSOP SOIC and LLP m Ultra low current shutdown mode BTL output can drive capacitive loads m Improved pop 8 click circuitry eliminates noises during turn on and turn off transitions 2 2 5 5V operation m No output coupling capacitors snubber networks or bootstrap capacitors required m Thermal shutdown protection m Unity gain stable m External gain configuration capability Applications m Mobile Phones m PDAs m Portable electronic devices 8 bump micro SMD Marking X T lo E Pin 1 20019270 Top View X Date Code T Die Traceability G Boomer Family LM4890IBP www national com L 068rIN1 LM4890 Connection Diagrams Continued 9 Bump micro SMD IN Shutdown 200192C1 Top View Order Number LM4890IBL LM4890IBLX See NS Package Number BLA09AAB LLP Package SHUTDOWN BYPASS GND 200192C7 Top View Order Number LM4890LD See NS Package Number LDA10B Mini Small Outline MSOP Package SHUTDOWN Vo2 2 BYPASS GND 5 6 IN Von 4 5 N
17. Low gain configurations require large input signals to obtain a given output power Input signals equal to or greater than 1Vrms are available from sources such as audio codecs Please refer to the section Audio Power Amplifier Design for a more com plete explanation of proper gain selection Besides gain one of the major considerations is the closed loop bandwidth of the amplifier To a large extent the band width is dictated by the choice of external components shown in Figure 1 The input coupling capacitor Cin forms a first order high pass filter which limits low frequency re sponse This value should be chosen based on needed frequency response for a few distinct reasons Selection Of Input Capacitor Size Large 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 100Hz to 150Hz Thus using a large input capacitor may not increase actual system perfor mance In addition to system cost and size click and pop perfor mance is effected by the size of the input coupling capacitor A larger input coupling capacitor requires more charge to reach its quiescent DC voltage nominally 1 2 This charge comes from the output via the feedback and is apt to create pops
18. MONIC DISTORTION IN 76 Vpp TOTAL HARMONIC DISTORTION IN 76 THD N vs Frequency 10 20 50100 200 500 1k 2k 5k 10k 20k FREQUENCY IN Hz 20019237 THD N vs Frequency at Vpp 3 3V 80 R PWR 150mW Ay 2 TOTAL HARMONIC DISTORTION IN 76 THD N vs Frequency at Vpp R 80 PWR 250mW A 2 10 0 1 TOTAL HARMONIC DISTORTION IN 76 0 001 20 50 100200 500 1k 2k vs Frequency 2 6V R 80 PWR 100mW A 2 10 5 2 1 0 5 0 2 REO 0 1 KEN 0 05 FRR 0 02 0 01 0 005 0 002 H 0 001 k 2k Sk 10k 20k FREQUENCY IN Hz 20019239 FREQUENCY IN Hz TOTAL HARMONIC DISTORTION IN 76 10 0 5 SS Dr 0 2 L 0 1 NULL 0 05 0 02 H 0 01 0 005 Sa 0 002 DUO HHR LIL 20 50 100 200 500 1k 2k 5k 10k 20k FREQUENCY IN Hz 20019238 20019290 THD N vs Frequency 2 6V R 40 PWR 100mW A 2 10 0 5 0 2 NUT 0 1 0 05 0 02 H 0 01 0 005 1 0 002 H 0 001 EHE CEDE 20 50 100 200 500 1k 2k 10k 20k FREQUENCY IN Hz 20019240 www national com O687IN1 LM4890 Typical Performance Characteristics continued TOTAL HARMONIC DISTORTION IN THD N vs Power Out Vpp 5V 80 1kHz Av 2 10 POWER OUT WATTS 200192C9 TOTAL HARMONIC DISTORTION IN 76 vs Power Out
19. NCE ONLY 10X 0 25 m 8X 0 5 RECOMMENDED LAND PATTERN 1 1 RATIO WITH PKG SOLDER PADS 0 25 0 8 MAX TUN 0 2 0 1 PIN 1 INDEX AREA ALL LEADS Ze Cr f f 7 f V gt v v v bey 10X 0 50 1 10 0 2550 05 e 9 c9 e9 F ex 9 8 2X LDA10B Rev B LLP Order Number LM4890LD NS Package Number LDA10B m 0 215 lt S 9X 05550 DIMENSIONS ARE IN MILLIMETERS gt 94 o DIMENSIONS IN FOR REFERENCE ONLY LAND PATTERN RECOMMENDATION T B id 0 125 TOP SIDE COATING 0 050 x1 BUMP A1 CORNER SILICON H 0 942 0 335 9X 305 TLA09XXX Rev C 9 Bump micro SMD Order Number LM4890ITL LM4890ITLX NS Package Number TLA09AAA 1 514 0 03 X2 1 514 0 03 0 600 0 075 29 www national com 068tIN1 LM4890 1 Watt Audio Power Amplifier Notes National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications For the most current product information visit us at www national com LIFE SUPPORT POLICY NATIONAL S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION As used h
20. Power Derating 8 bump SMD 670mW POWER DISSIPATION W AMBIENT TEMPERATURE C 20019284 Ambient Temperature in Degrees C Note 670mW for 5V 80 Power Derating 10 Pin LD Pkg 670mW N RRRRRE OR 0 20 40 60 80 100 120 140 160 AMBIENT TEMPERATURE C 200192C8 Ambient Temperature in Degrees C Note 670mW for 5V 80 POWER DISSIPATON W Power Output vs Temperature LLL ws T POWER OUTPUT mW 0 40 20 0 20 40 60 80 100 TEMPERATURE C 200192A2 13 www national com O687IN1 LM4890 Typical Performance Characteristics continued Power Dissipation vs Output Power Power Dissipation vs Output Power Vpp 5V 1kHz 80 THD lt 1 0 Vpp 3 3V 1kHz 80 THD lt 1 0 0 7 0 285 0 6 0 28 0 275 os c c 0 27 0 4 0 265 Ha Ha 2 03 E 0 26 o o 0 255 0 2 gt 2 0 25 0 245 0 0 24 0 0 5 1 15 2 0 0 2 0 4 0 6 0 8 Output Power W Output Power W 20019248 20019249 Power Dissipation vs Output Power Output Power Vpp 2 6V 1kHz vs Load Resistance N 2 lt qi a 5 Qo 5 o 0 0 1 02 03 04 05 4 8 12 16 20 24 28 32 Output Power W Load Resistance 0 20019250 20019274 Supply Current Clipping Dropout Voltage vs Ambient Temperature vs Supply Voltage E ES
21. Supply Rejection Ratio PSRR A 2 Vpp 3 3V V rippie 200mvp p 2 6V 200mvp p 80 Rin 1002 80 109 III sc III LII 10 III LLLI 10 II 15 III I III T 15 20 Il 20 III 25 T 11111 25 10 230 III T 81111111 2X5 II i III 8111111 40 LE 40 T 81111111 T Il LE a45 LLULLU UL UL E RR L s 50 I I Hill m 50 LIE Dell Lu 255 ELLE LL III 81111 2 60 I gt 60 8111111 65 E III LLLI 70 III 80111111 70 III E 8111111 75 Il T pL LLLI III 80 80 255 ell 85 Il 90 III UI 90 III 95 III E 80111111 95 100 108 LL 20 100 1k 10k 100k 20 100 1k 10k 100k FREQUENCY Hz FREQUENCY Hz 20019246 20019247 www national com 10 Typical Performance Characteristics continued PSRR dBr PSRR dBr PSRR vs DC Output Voltage Vpp 5V Av 2 PSRR dBr Vourpc V PSRR vs DC Output Voltage 5V Av 10 20019296 Vourpc V PSRR vs DC Output Voltage 200192A3 Vourpc V 20019295 PSRR dBr PSRR dBr PSRR dBr
22. U 15 TO 20 25 30 HHH 8 35 LL 5 UI TT lt 210 HL III E 8011111 f 2 5H HL E LLLI alll s50 HHL III jll 55 HHE 65 TIC 70 RE BEI 75 Wu BENI 80 Eli 20 100 10k 100k FREQUENCY Hz FREQUENCY Hz 200192A9 200192B8 9 www national com 068 1 1 4890 Typical Performance Characteristics continued Power Supply Rejection Ratio PSRR A 2 Power Supply Rejection Ratio A 2 Vpp 7 3V V ripple 200mvp p Vpp Vrippie 200mvp p 80 Rin 100 80 Rin Float LEVEL dB LEVEL dB 80 20 100 500 2k 10k 50k 5 0 200 1k 5k 20k 100k 20 100 FREQUENCY Hz FREQUENCY Hz 200192C5 20019293 Power Supply Rejection Ratio PSRR A 4 Power Supply Rejection Ratio PSRR A 4 Vpp 200mvp p Vpp 200mvp p 80 Rin 100 80 Rin Float BEI 111 L p H P 5 lt 1111111 HHI m m HHH UI l J mu H ill i li 20 100 1k 10k 100k FREQUENCY Hz FREQUENCY Hz 200192B1 200192B9 Power Supply Rejection Ratio PSRR A 2 Power
23. erein 1 Life support devices or systems are devices or systems which a are intended for surgical implant into the body or b support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user BANNED SUBSTANCE COMPLIANCE 2 A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness National Semiconductor follows the provisions of the Product Stewardship Guide for Customers CSP 9 111C2 and Banned Substances and Materials of Interest Specification 5 9 11152 for regulatory environmental compliance Details may be found www national com quality green Lead free products are RoHS compliant National Semiconductor National Semiconductor Americas Customer Europe Customer Support Center Support Center Fax 49 0 180 530 85 86 Email new feedback nsc com Email europe support 9 nsc com Tel 1 800 272 9959 Deutsch Tel 49 0 69 9508 6208 English Tel 44 0 870 24 0 2171 www national com Frangais Tel 33 0 1 41 91 8790 National Semiconductor National Semiconductor Asia Pacific Customer Japan Customer Support Center Support Center Fax 81 3 5639 7507 Email ap support 9 nsc com Email jpn feedback nsc com
24. etric norm Note 7 Limits are guaranteed to National s AOQL Average Outgoing Quality Level Note 8 For micro SMD only shutdown current is measured in a Normal Room Environment Exposure to direct sunlight will increase Isp by a maximum of 2 Note 9 Datasheet min max specification limits are guaranteed by design test or statistical analysis Note 10 ROUT is measured from each of the output pins to ground This value represents the parallel combination of the 10k ohm output resistors and the two 20k ohm resistors Note 11 If the product is in shutdown mode and Vpp exceeds 6V to a max of 8V Vpp then most of the excess current will flow through the ESD protection circuits If the source impedance limits the current to a max of 10 ma then the part will be protected If the part is enabled when Vpp is greater than 5 5V and less than 6 5V no damage will occur although operational life will be reduced Operation above 6 5V with no current limit will result in permanent damage Note 12 All bumps have the same thermal resistance and contribute equally when used to lower thermal resistance All bumps must be connected to achieve specified thermal resistance Note 13 Maximum power dissipation PpyAx in the device occurs at an output power level significantly below full output power PpyAx can be calculated using Equation 1 shown in the Application section It may also be obtained from the power dissipation graphs Note 14 is a functi
25. g Avoiding Typical Design Layout Problems ing individual traces back to a central point rather than daisy Avoid ground loops or running digital and analog traces chaining traces together in a serial manner can have a parallel to each other side by side on the same PCB layer major impact on low level signal performance Star trace When traces must cross over each other do it at 90 degrees routing refers to using individual traces to feed power and Running digital and analog traces at 90 degrees to each ground to each circuit or even device This technique will other from the top to the bottom side as much as possible will require a greater amount of design time but will not increase minimize capacitive noise coupling and cross talk the final price of the board The only extra parts required will be some jumpers 25 www national com O687IN1 LM4890 Physical DIMENSIONS inches millimeters unless otherwise noted SYMM 0 17 EE i i 0 5 DIMENSIONS ARE IN MILLIMETERS DIMENSIONS IN FOR REFERENCE ONLY 0 5 X3 LAND PATTERN RECOMMENDATION SYMM TOP SIDE COATING 050 Note Unless otherwise specified 1 Epoxy coating 2 63Sn 37Pb eutectic bump 3 Recommend non solder mask defined landing pad 4 Pin 1 is established by lower left corner with respect to text orientation pins are numbered counterclockwise 5 Reference JEDEC registration MO 211 variation BC 8 Bump micro SMD Order Number LM489
26. ional com O687IN1 LM4890 Application Information Continued As stated the External Components section in con junction with Cj create a highpass filter gt 1 2 20 kO 20Hz 0 397yF use 0 91 The high frequency pole is determined by the product of the desired frequency pole and the differential gain Ayp Shutdown With a 3 f 100kHz the resulting GBWP 300kHz which is much smaller than the LM4890 GBWP of 2 5MHz This calculation shows that if a designer has a need to design an amplifier with a higher differential gain the LM4890 can still be used without running into bandwidth limitations 20019224 FIGURE 2 HIGHER GAIN AUDIO AMPLIFIER The LM4890 is unity gain stable and requires no external components besides gain setting resistors an input coupling Capacitor and proper supply bypassing in the typical appli cation However if a closed loop differential gain of greater than 10 is required a feedback capacitor C4 may be needed as shown in Figure 2 to bandwidth limit the amplifier This feedback capacitor creates a low pass filter that elimi www national com 20 nates possible high frequency oscillations Care should be taken when calculating the 3dB frequency in that an incor rect combination of R4 and will cause rolloff before 20kHz A typical combination of feedback resistor and pacitor that will not produce audio band high frequenc
27. ns no connect and ground pins should also be directly connected to this copper pad heatsink area The area of the copper pad heatsink can be determined from the LD Power Derating graph If the multiple layer copper heatsink areas are used then these inner layer or backside copper heatsink areas should be connected to each other with 4 2 x 2 vias The diameter for these vias should be between 0 013 inches and 0 02 inches with a 0 050inch pitch spacing Ensure efficient thermal conductivity by plating through and solder filling the vias Further detailed information concerning PCB Application Information continued SHUTDOWN OUTPUT IMPEDANCE For R 20k ohms Zou between Out and GND 1 6 Zour between Out2 and GND 10kII 40k 10kIIR 8 3kQ Zou between Out1 and Out2 40kll 10k 10klIR 11 7 3dB roll for these measurements is 600kHz PROPER SELECTION OF EXTERNAL COMPONENTS Proper selection of external components in applications us ing integrated power amplifiers is critical to optimize device and system performance While the LM4890 is tolerant of external component combinations consideration to compo nent values must be used to maximize overall system qual ity The LM4890 is unity gain stable which gives the designer maximum system flexibility The LM4890 should be used in low gain configurations to minimize THD N values and maximize the signal to noise ratio
28. o ground A bridge amplifier design has a few distinct advantages over the single ended configuration as it provides differential drive to the load thus doubling output swing for a specified supply voltage Four times the output power is possible as compared to a single ended amplifier under the same con ditions This increase in attainable output power assumes that the amplifier is not current limited or clipped In order to choose an amplifier s closed loop gain without causing ex cessive clipping please refer to the Audio Power Amplifier Design section A bridge configuration such as the one used in the LM4890 also creates a second advantage over single ended amplifi ers Since the differential outputs Vo1 and Vo2 are biased at half supply no net DC voltage exists across the load This eliminates the need for an output coupling capacitor which is required in a single supply single ended amplifier configura tion Without an output coupling capacitor the half supply bias across the load would result in both increased internal IC power dissipation and also possible loudspeaker damage EXPOSED DAP PACKAGE PCB MOUNTING CONSIDERATIONS FOR THE LM4890LD The LM4890LD s exposed DAP die attach paddle package LD provides a low thermal resistance between the die and the PCB to which the part is mounted and soldered The LM4890LD package should have its DAP soldered to the grounded copper pad heatsink under the LM4890LD the NC pi
29. on of system gain Specifications apply to the circuit in Figure 1 where Ay 2 Higher system gains will reduce PSRR value by the amount of gain increase A system gain of 10 represents a gain increase of 14dB PSRR will be reduced by 14dB and applies to all operating voltages 5 www national com 0681 01 LM4890 External Components Description Figure 1 Components Functional Description 1 Rin Inverting input resistance which sets the closed loop gain in conjunction with This resistor also forms Kd high pass filter with Cu at lt 1 2 RNC e Cin Input coupling capacitor which blocks the DC voltage at the amplifier s input terminals Also creates highpass filter with at f 1 2x Ri CiN Refer to the section Proper Selection of External Components for an explanation of how to determine the value of Cj 3 Feedback resistance which sets the closed loop gain in conjunction with Ry 4 Cs Supply bypass capacitor which provides power supply filtering Refer to the section Power Supply Bypassing for information concerning proper placement and selection of the supply bypass capacitor Cpvypass 5 Lepage Bypass pin capacitor which provides half supply filtering Refer to the section Proper Selection of External Components for information concerning proper placement and selection of www national com 6 Typical Performance Characteristics at Vop 5V 80 R and PWR 250mW Ay 2 TOTAL HAR
30. upon device enable Thus by minimizing the capacitor size based on necessary low frequency response turn on pops can be minimized Besides minimizing the input capacitor size careful consid eration should be paid to the bypass capacitor value Bypass capacitor Cgypass is the most critical component to mini mize turn on pops since it determines how fast the LM4890 turns on The slower the LM4890 s outputs ramp to their quiescent DC voltage nominally 1 2 the smaller the turn on pop Choosing Cpypass equal to 1 0uF along with a small value of CiN in the range of 0 1uF to 0 39uF should 19 produce a virtually clickless and popless shutdown function While the device will function properly no oscillations or motorboating with Cgypass equal to 0 11 the device will be much more susceptible to turn on clicks and pops Thus a value of Cgypass equal to 1 0UF is recommended in all but the most cost sensitive designs AUDIO POWER AMPLIFIER DESIGN A 1W 8Q Audio Amplifier Given Power Output 1 Wrms Load Impedance 80 Input Level 1 Vrms Input Impedance 20 Bandwidth 100 Hz 20 kHz 0 25 dB A designer must first determine the minimum supply rail to obtain the specified output power By extrapolating from the Output Power vs Supply Voltage graphs in the Typical Per formance Characteristics section the supply rail can be easily found A second way to determine the minimum sup ply rail is to calculate the required
31. y rolloff is Rs 20kQ and C 25pf These components result in a 3dB point of approximately 320 kHz Application Information continued Shutdown 20019229 FIGURE 3 DIFFERENTIAL AMPLIFIER CONFIGURATION FOR LM4890 C 4 pot stuffed 20019225 FIGURE 4 REFERENCE DESIGN BOARD and LAYOUT micro SMD 21 www national com O687IN1 LM4890 Application Information Continued LM4890 micro SMD BOARD ARTWORK Silk Screen Top Layer NATIONAL SEMICONDUCTOR LM4890 BOOMER micro SMD T e E GND VDD 20019257 20019258 Bottom Layer Inner Layer 20019259 20019260 Inner Layer Ground 20019261 www national com 22 Application Information Continued CA 11 Shutdown not stuffed 20019268 FIGURE 5 REFERENCE DESIGN BOARD and PCB LAYOUT GUIDELINES 8 SO Boards 23 www national com O687IN1 LM4890 Application Information continued LM4890 SO DEMO BOARD ARTWORK INPUT NAT L Silk Screen IONAL SEMICONDUCTOR M4890 BOOMER SOIC GND VDD Top Layer 20019262 Bottom Layer 20019263 www national com 20019264 24 LM4890 MSOP DEMO BOARD ARTWORK Silk Screen NATIONAL SEMICONDUCTOR LM4890 BOOMER MSOP e opp C 2000 GND VDD 20019265 Top Layer 20019266 Bottom Layer 20019267 Application Information continued Mono LM4890 Reference Design Boards Bill of Material for all
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NATIONAL SEMICONDUCTOR LM4890 Manual(1)