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LM4890MBD

LM4890MBD

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    -

  • 描述:

    BOARD EVALUATION LM4890M

  • 数据手册
  • 价格&库存
LM4890MBD 数据手册
LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 LM4890 1 Watt Audio Power Amplifier Check for Samples: LM4890 FEATURES DESCRIPTION • The LM4890 is an audio power amplifier primarily designed for demanding applications in mobile phones and other portable communication device applications. It is capable of delivering 1 watt of continuous average power to an 8Ω BTL load with less than 1% distortion (THD+N) from a 5VDC power supply. 1 2 • • • • • • • • Available in Space-Saving Packages: DSBGA, VSSOP, SOIC, and WSON Ultra Low Current Shutdown Mode BTL Output Can Drive Capacitive Loads Improved Pop & Click Circuitry Eliminates Noises During Turn-On and Turn-Off Transitions 2.2 - 5.5V Operation No Output Coupling Capacitors, Snubber Networks or Bootstrap Capacitors Required Thermal Shutdown Protection Unity-Gain Stable External Gain Configuration Capability APPLICATIONS • • • Mobile Phones PDAs Portable Electronic Devices KEY SPECIFICATIONS • • • • PSRR at 217Hz, VDD = 5V (Fig. 1): 62dB(typ.) Power Output at 5.0V & 1% THD: 1W(typ.) Power Output at 3.3V & 1% THD: 400mW(typ.) Shutdown Current: 0.1μA(typ.) 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 applications where minimal power consumption is a primary requirement. The LM4890 features a low-power consumption shutdown mode, which is achieved by driving the shutdown pin with logic low. Additionally, the LM4890 features an internal thermal shutdown protection mechanism. The LM4890 contains advanced pop & click circuitry which eliminates noises which would otherwise occur during turn-on and turn-off transitions. The LM4890 is unity-gain stable and can be configured by external gain-setting resistors. 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2001–2013, Texas Instruments Incorporated LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Connection Diagrams Top View Top View Figure 1. 8 Bump DSBGA Package See Package Number YPB0008 Figure 2. 9 Bump DSBGA Package See Package Number YZR0009 Top View Top View Figure 3. WSON Package See Package Number NGZ0010B Figure 4. Mini Small Outline (VSSOP) Package See Package Number DGK0008A Top View Top View Figure 5. Small Outline (SOIC) Package See Package Number D0008A 2 Figure 6. 9 Bump DSBGA Package See Package Number YZR0009AAA Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Typical Application Rf CS 1PF Audio Input VDD 20k RIN 20k 15pF VOUT1 - A1 CIN 0.39PF 10k 20k RL 8: SW 20k 250k 500k CBYPASS 1PF 250k Bias A2 Shutdown Control 10k VOUT2 + VIH VIL GND Figure 7. Typical Audio Amplifier Application Circuit These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 3 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Absolute Maximum Ratings (1) (2) Supply Voltage (3) 6.0V −65°C to +150°C Storage Temperature −0.3V to VDD +0.3V Input Voltage Power Dissipation (4) Internally Limited (5) 2000V ESD Susceptibility Junction Temperature Thermal Resistance 150°C θJC (SOIC) 35°C/W θJA (SOIC) 150°C/W θJA (8 Bump DSBGA, (6)) 220°C/W θJA (9 Bump DSBGA, (6)) 180°C/W θJC (VSSOP) 56°C/W θJA (VSSOP) 190°C/W θJA (WSON) Soldering Information (1) (2) (3) (4) (5) (6) 220°C/W See AN-1112 (SNVA009) "DSBGA Wafers Level Chip Scale Package." See AN-1187 (SNOA401) "Leadless Leadframe Package (WSON)." 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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication of device performance. If Military/Aerospace specified devices are required, please contact the TI Sales Office/ Distributors for availability and specifications. If the product is in shutdown mode and VDD exceeds 6V (to a max of 8V VDD), 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 VDD 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. The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature TA. The maximum allowable power dissipation is PDMAX = (TJMAX–TA)/θJA or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4890, see power derating curves for additional information. Human body model, 100 pF discharged through a 1.5 kΩ resistor. 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. Operating Ratings Temperature Range TMIN ≤ TA ≤ TMAX −40°C ≤ TA ≤ 85°C 2.2V ≤ VDD ≤ 5.5V Supply Voltage 4 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Electrical Characteristics VDD = 5V (1) (2) (3) The following specifications apply for the circuit shown in Figure 7 unless otherwise specified. Limits apply for TA = 25°C. Parameter IDD Test Conditions Quiescent Power Supply Current LM4890 Typical (4) Limit (5) (6) Units (Limits) VIN = 0V, Io = 0A, No Load 4 8 mA (max) VIN = 0V, Io = 0A, 8Ω Load 5 10 mA (max) 0.1 2.0 µA (max) ISD Shutdown Current VSDIH Shutdown Voltage Input High 1.2 V (min) VSDIL Shutdown Voltage Input Low 0.4 V (max) VOS Output Offset Voltage 50 mV (max) 9.7 kΩ (max) 7.0 kΩ (min) 1.0 0.8 W 170 220 ms (max) ROUT-GND Resistor Output to GND VSHUTDOWN = 0V 7 (7) 8.5 Po Output Power (8Ω) TWU Wake-up time TSD Thermal Shutdown Temperature THD+N Total Harmonic Distortion + Noise PSRR Power Supply Rejection Ratio TSDT Shut Down Time (1) (2) (3) (4) (5) (6) (7) (8) THD = 2% (max); f = 1 kHz (8) 170 Po = 0.4 Wrms; f = 1kHz Vripple = 200mV sine p-p Input Terminated with 10 ohms to ground 8 Ω load 150 °C (min) 190 °C (max) 0.1 % 62 (f = 217Hz) 66 (f = 1kHz) 55 dB (min) 1.0 ms (max) All voltages are measured with respect to the ground pin, unless otherwise specified. 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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication of device performance. For DSBGA only, shutdown current is measured in a Normal Room Environment. Exposure to direct sunlight will increase ISD by a maximum of 2µA. Typicals are measured at 25°C and represent the parametric norm. Limits are specified to TI's AOQL (Average Outgoing Quality Level). Datasheet min/max specification limits are specified by design, test, or statistical analysis. 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. PSRR is a function of system gain. Specifications apply to the circuit in Figure 7 where AV = 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. Electrical Characteristics VDD = 3V (1) (2) (3) The following specifications apply for the circuit shown in Figure 7 unless otherwise specified. Limits apply for TA = 25°C. Parameter IDD Quiescent Power Supply Current Test Conditions LM4890 Typical (4) Limit (5) (6) Units (Limits) VIN = 0V, Io = 0A, No Load 3.5 7 mA (max) VIN = 0V, Io = 0A, 8Ω Load 4.5 9 mA (max) VSHUTDOWN = 0V 0.1 2.0 µA (max) ISD Shutdown Current VSDIH Shutdown Voltage Input High 1.2 V(min) VSDIL Shutdown Voltage Input Low 0.4 V(max) (1) (2) (3) (4) (5) (6) All voltages are measured with respect to the ground pin, unless otherwise specified. 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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication of device performance. For DSBGA only, shutdown current is measured in a Normal Room Environment. Exposure to direct sunlight will increase ISD by a maximum of 2µA. Typicals are measured at 25°C and represent the parametric norm. Limits are specified to TI's AOQL (Average Outgoing Quality Level). Datasheet min/max specification limits are specified by design, test, or statistical analysis. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 5 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Electrical Characteristics VDD = 3V(1)(2)(3) (continued) The following specifications apply for the circuit shown in Figure 7 unless otherwise specified. Limits apply for TA = 25°C. Parameter VOS Output Offset Voltage ROUT-GND Resistor Output to Gnd (7) Test Conditions Limit (5) Wake-up time Output Power (8Ω) TSD Thermal Shutdown Temperature THD+N Total Harmonic Distortion + Noise Po = 0.15Wrms; f = 1kHz PSRR Power Supply Rejection Ratio (8) Vripple = 200mV sine p-p Input terminated with 10 ohms to ground THD = 1% (max); f = 1kHz (6) Units (Limits) 50 mV (max) 9.7 kΩ (max) 7.0 kΩ (min) 120 180 ms (max) 0.31 0.28 W 150 °C(min) 190 °C(max) 45 dB(min) 8.5 Po (8) Typical 7 TWU (7) LM4890 (4) 170 0.1 % 56 (f = 217Hz) 62 (f = 1kHz) 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. PSRR is a function of system gain. Specifications apply to the circuit in Figure 7 where AV = 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. Electrical Characteristics VDD = 2.6V (1) (2) (3) The following specifications apply for for the circuit shown in Figure 7 unless otherwise specified. Limits apply for TA = 25°C. Parameter Test Conditions LM4890 Typical (4) Limit (5) (6) Units (Limits) IDD Quiescent Power Supply Current VIN = 0V, Io = 0A, No Load 2.6 mA (max) ISD Shutdown Current VSHUTDOWN = 0V 0.1 µA (max) P0 Output Power (8Ω) Output Power (4Ω) THD = 1% (max); f = 1 kHz THD = 1% (max); f = 1 kHz 0.2 0.22 W W THD+N Total Harmonic Distortion + Noise Po = 0.1Wrms; f = 1kHz 0.08 % 44 (f = 217Hz) 44 (f = 1kHz) dB PSRR (1) (2) (3) (4) (5) (6) (7) 6 Power Supply Rejection Ratio (7) Vripple = 200mV sine p-p Input Terminated with 10 ohms to ground All voltages are measured with respect to the ground pin, unless otherwise specified. 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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication of device performance. For DSBGA only, shutdown current is measured in a Normal Room Environment. Exposure to direct sunlight will increase ISD by a maximum of 2µA. Typicals are measured at 25°C and represent the parametric norm. Limits are specified to TI's AOQL (Average Outgoing Quality Level). Datasheet min/max specification limits are specified by design, test, or statistical analysis. PSRR is a function of system gain. Specifications apply to the circuit in Figure 7 where AV = 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. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 External Components Description (See Figure 7) Components Functional Description 1. RIN Inverting input resistance which sets the closed-loop gain in conjunction with Rf. This resistor also forms a high pass filter with CIN at fC= 1/(2π RINCIN). 2. CIN Input coupling capacitor which blocks the DC voltage at the amplifier's input terminals. Also creates a highpass filter with RIN at fc = 1/(2π RINCIN). Refer to the section, Proper Selection of External Components, for an explanation of how to determine the value of CIN. 3. Rf Feedback resistance which sets the closed-loop gain in conjunction with RIN. 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, CBYPASS. 5. CBYPAS 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 CBYPASS. S Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 7 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics 8 THD+N vs Frequency at VDD = 5V, 8Ω RL, and PWR = 250mW, AV = 2 THD+N vs Frequency at VDD = 3.3V, 8Ω RL, and PWR = 150mW, AV = 2 Figure 8. Figure 9. THD+N vs Frequency at VDD = 3V, RL = 8Ω, PWR = 250mW, AV = 2 THD+N vs Frequency at VDD = 2.6V, RL = 8Ω, PWR = 100mW, AV = 2 Figure 10. Figure 11. THD+N vs Frequency at VDD = 2.6V, RL = 4Ω, PWR = 100mW, AV = 2 THD+N vs Power Out at VDD = 5V, RL = 8Ω, 1kHz, AV = 2 Figure 12. Figure 13. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Typical Performance Characteristics (continued) THD+N vs Power Out at VDD = 3.3V, RL = 8Ω, 1kHz, AV = 2 THD+N vs Power Out at VDD = 3V, RL = 8Ω, 1kHz, AV = 2 Figure 14. Figure 15. THD+N vs Power Out at VDD = 2.6V, RL = 8Ω, 1kHz, AV = 2 THD+N vs Power Out at VDD = 2.6V, RL = 4Ω, 1kHz, AV = 2 Figure 16. Figure 17. Power Supply Rejection Ratio (PSRR) at AV = 2 VDD = 5V, Vripple = 200mvp-p RL = 8Ω, RIN = 10Ω Power Supply Rejection Ratio (PSRR) at AV = 2 VDD = 5V, Vripple = 200mvp-p RL = 8Ω, RIN = Float Figure 18. Figure 19. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 9 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 10 Power Supply Rejection Ratio (PSRR) at AV = 4 VDD = 5V, Vripple = 200mvp-p RL = 8Ω, RIN = 10Ω Power Supply Rejection Ratio (PSRR) at AV = 4 VDD = 5V, Vripple = 200mvp-p RL = 8Ω, RIN = Float Figure 20. Figure 21. Power Supply Rejection Ratio (PSRR) at AV = 2 VDD = 3V, Vripple = 200mvp-p, RL = 8Ω, RIN = 10Ω Power Supply Rejection Ratio (PSRR) at AV = 2 VDD = 3V, Vripple = 200mvp-p, RL = 8Ω, RIN = Float Figure 22. Figure 23. Power Supply Rejection Ratio (PSRR) at AV = 4 VDD = 3V, Vripple = 200mvp-p, RL = 8Ω, RIN = 10Ω Power Supply Rejection Ratio (PSRR) at AV = 4 VDD = 3V, Vripple = 200mvp-p, RL = 8Ω, RIN = Float Figure 24. Figure 25. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Typical Performance Characteristics (continued) Power Supply Rejection Ratio (PSRR) at AV = 2 VDD = 3.3V, Vripple = 200mvp-p, RL = 8Ω, RIN = 10Ω Power Supply Rejection Ratio (PSRR) at AV = 2 VDD = 2.6V, Vripple = 200mvp-p, RL = 8Ω, RIN = 10Ω Figure 26. Figure 27. PSRR vs DC Output Voltage VDD = 5V, AV = 2 0 0 -10 -10 -20 -20 PSRR (dBr) PSRR (dBr) 10 PSRR vs DC Output Voltage VDD = 5V, AV = 4 10 -30 -40 -50 -30 -40 -50 -60 -60 -70 -70 -80 -80 -6 -4 -2 0 2 4 -6 6 -4 -2 V OUTDC (V) 2 Figure 28. Figure 29. PSRR vs DC Output Voltage VDD = 5V, AV = 10 PSRR vs DC Output Voltage VDD = 3V, AV = 2 10 0 0 -10 -10 -20 -20 PSRR (dBr) PSRR (dBr) 10 0 4 6 V OUTDC (V) -30 -40 -50 -30 -40 -50 -60 -60 -70 -70 -80 -80 -6 -4 -2 0 2 4 6 -3 -2 -1 0 V OUTDC (V) V OUTDC (V) Figure 30. Figure 31. 1 2 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 3 11 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) PSRR vs DC Output Voltage VDD = 3V, AV = 4 10 0 0 -10 -10 PSRR (dBr) PSRR (dBr) PSRR vs DC Output Voltage VDD = 3V, AV = 10 1 0 -20 -30 -40 -20 -30 -40 -50 -50 -60 -3 -2 -1 0 1 2 3 -60 -3 -2 -1 0 V OUTDC (V) 12 2 Figure 32. Figure 33. PSRR Distribution VDD = 5V 217Hz, 200mvp-p, -30, +25, and +80°C PSRR Distribution VDD = 3V 217Hz, 200mvp-p, -30, +25, and +80°C (dBr) -80 1 -70 -60 3 V OUTDC (V) (dBr) -50 -40 -85 -80 -75 -70 -65 -60 -55 -50 -45 -40 Figure 34. Figure 35. Power Supply Rejection Ration vs Bypass Capacitor Size VDD = 5V, Input Grounded = 10Ω, Output Load = 8Ω Power Supply Rejection Ration vs Bypass Capacitor Size VDD = 3V, Input Grounded = 10Ω, Output Load = 8Ω Figure 36. Top Trace = No Cap, Next Trace Down = 1µf Next Trace Down = 2µf, Bottom Trace = 4.7µf Figure 37. Top Trace = No Cap, Next Trace Down = 1µf Next Trace Down = 2µf, Bottom Trace = 4.7µf Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Typical Performance Characteristics (continued) LM4890 vs LM4877 Power Supply Rejection Ratio VDD = 5V, Input Grounded = 10Ω Output Load = 8Ω, 200mV Ripple LM4890 vs LM4877 Power Supply Rejection Ratio VDD = 3V, Input Grounded = 10Ω Output Load = 8Ω, 200mV Ripple Figure 38. LM4890 = Bottom Trace LM4877 = Top Trace Figure 39. LM4890 = Bottom Trace LM4877 = Top Trace Power Derating Curves (PDMAX = 670mW) Power Derating - 8 bump DSBGA (PDMAX = 670mW) Note: (PDMAX = 670mW for 5V, 8Ω) Figure 40. Ambient Temperature in Degrees C Power Derating - 9 bump DSBGA (PDMAX = 670mW) Note: (PDMAX = 670mW for 5V, 8Ω) Figure 41. Ambient Temperature in Degrees C Power Derating - 10 Pin LD Pkg (PDMAX = 670mW) 0.8 POWER DISSIPATON (W) 0.7 2 480mm 0.6 2 120mm 0.5 0.4 0mm 2 0.3 0.2 0.1 NOTE 13 0 0 Note: (PDMAX = 670mW for 5V, 8Ω) Figure 42. Ambient Temperature in Degrees C 20 40 60 80 100 120 140 160 AMBIENT TEMPERATURE (°C) Note: (PDMAX = 670mW for 5V, 8Ω) Figure 43. Ambient Temperature in Degrees C Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 13 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 14 Power Output vs Supply Voltage Power Output vs Temperature Figure 44. Figure 45. Power Dissipation vs Output Power VDD = 5V, 1kHz, 8Ω, THD ≤ 1.0% Power Dissipation vs Output Power VDD = 3.3V, 1kHz, 8Ω, THD ≤ 1.0% Figure 46. Figure 47. Power Dissipation vs Output Power VDD = 2.6V, 1kHz Output Power vs Load Resistance Figure 48. Figure 49. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Typical Performance Characteristics (continued) Supply Current vs Ambient Temperature Clipping (Dropout) Voltage vs Supply Voltage Figure 50. Figure 51. Max Die Temp at PDMAX (9 bump DSBGA) Max Die Temp at PDMAX (8 bump DSBGA) Figure 52. Figure 53. Output Offset Voltage Supply Current vs Shutdown Voltage Figure 54. Figure 55. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 15 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) Shutdown Hysterisis Voltage VDD = 5V 4 Shutdown Hysterisis Voltage VDD = 3V 4 SUPPLY CURRENT (MA) 2 OFF ON 1 0 3 2 OFF 0 0 1 2 0 3 1 Shutdown Voltage (V) Figure 57. Open Loop Frequency Response VDD = 5V, No Load Open Loop Frequency Response VDD = 3V, No Load Figure 58. Figure 59. Gain / Phase Response, AV = 2 VDD = 5V, 8Ω Load, CLOAD = 500pF Gain / Phase Response, AV = 4 VDD = 5V, 8Ω Load, CLOAD = 500pF 30 0 -90 10 -180 5 0 20 10 0 -5 -10 -10 -15 -15 10K 100K 1M 10M 100M -180 5 -5 1K -90 15 GAIN (dB) 15 0 25 PHASE (°) 20 GAIN (dB) 3 Figure 56. 25 -20 100 1K 10K 100K 1M 10M 100M FREQUENCY (Hz) FREQUENCY (Hz) Figure 60. 16 2 SHUTDOWN VOLTAGE (V) 30 -20 100 ON 1 PHASE (°) Supply Current (mA) 3 Figure 61. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Typical Performance Characteristics (continued) Phase Margin vs CLOAD, AV = 2 VDD = 5V, 8Ω Load Capacitance to gnd on each output Phase Margin vs CLOAD, AV = 4 VDD = 5V, 8Ω Load Capacitance to gnd on each output 100 100 80 80 PHASE (°) 120 PHASE (°) 120 60 50 deg Stability Limit 40 50 deg Stability Limit 40 20 0 60 20 0 500 1000 1500 0 2000 0 CAPACITANCE (pF) Figure 62. 1000 500 1500 CAPACITANCE (pF) 2000 Figure 63. Phase Margin and Limits vs Application Variables, RIN = 22KΩ Figure 64. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 17 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) Wake Up Time (TWU) Frequency Response vs Input Capacitor Size Figure 65. Figure 66. Noise Floor Figure 67. 18 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 APPLICATION INFORMATION BRIDGED CONFIGURATION EXPLANATION As shown in Figure 7, the LM4890 has two operational amplifiers internally, allowing for a few different amplifier configurations. The first amplifier's gain is externally configurable, 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 Rf to RIN while the second amplifier's gain is fixed by the two internal 20kΩ resistors. Figure 7 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 AVD= 2 *(Rf/RIN) By driving the load differentially through outputs Vo1 and Vo2, an amplifier configuration commonly referred to as “bridged mode” is established. Bridged mode operation is different from the classical single-ended amplifier configuration where one side of the load is connected to 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 conditions. This increase in attainable output power assumes that the amplifier is not current limited or clipped. In order to choose an amplifier's closedloop gain without causing excessive 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 amplifiers. 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, singleended amplifier configuration. 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 pins, 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 layout, fabrication, and mounting an WSON package is available from TI's Package Engineering Group under application note AN1187. POWER DISSIPATION Power dissipation is a major concern when designing a successful amplifier, whether the amplifier is bridged or single-ended. A direct consequence of the increased power delivered to the load by a bridge amplifier is an increase in internal power dissipation. Since the LM4890 has two operational amplifiers in one package, the maximum internal power dissipation is 4 times that of a single-ended amplifier. The maximum power dissipation for a given application can be derived from the power dissipation graphs or from Equation 1. PDMAX = 4*(VDD)2/(2π2RL) (1) It is critical that the maximum junction temperature TJMAX of 150°C is not exceeded. TJMAX can be determined from the power derating curves by using PDMAX and the PC board foil area. By adding additional copper foil, the thermal resistance of the application can be reduced, resulting in higher PDMAX. Additional copper foil can be added to any of the leads connected to the LM4890. Refer to the Application Information on the LM4890 reference design board for an example of good heat sinking. If TJMAX still exceeds 150°C, then additional changes must be made. These changes can include reduced supply voltage, higher load impedance, or reduced ambient temperature. Internal power dissipation is a function of output power. Refer to the Typical Performance Characteristics curves for power dissipation information for different output powers and output loading. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 19 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com POWER SUPPLY BYPASSING As with any amplifier, proper supply bypassing is critical for low noise performance and high power supply rejection. The capacitor location on both the bypass and power supply pins should be as close to the device as possible. Typical applications employ a 5V regulator with 10 µF tantalum or electrolytic capacitor and a ceramic bypass capacitor which aid in supply stability. This does not eliminate the need for bypassing the supply nodes of the LM4890. The selection of a bypass capacitor, especially CBYPASS, is dependent upon PSRR requirements, click and pop performance (as explained in the section, Proper Selection of External Components), system cost, and size constraints. SHUTDOWN FUNCTION In order to reduce power consumption while not in use, the LM4890 contains a shutdown pin to externally turn off the amplifier's bias circuitry. This shutdown feature turns the amplifier off when a logic low is placed on the shutdown pin. By switching the shutdown pin to ground, the LM4890 supply current draw will be minimized in idle mode. While the device will be disabled with shutdown pin voltages less than 0.5VDC, the idle current may be greater than the typical value of 0.1µA. (Idle current is measured with the shutdown pin grounded). In many applications, a microcontroller or microprocessor output is used to control the shutdown circuitry to provide a quick, smooth transition into shutdown. Another solution is to use a single-pole, single-throw switch in conjunction with an external pull-up resistor. When the switch is closed, the shutdown pin is connected to ground and disables the amplifier. If the switch is open, then the external pull-up resistor will enable the LM4890. This scheme ensures that the shutdown pin will not float thus preventing unwanted state changes. SHUTDOWN OUTPUT IMPEDANCE For Rf = 20k ohms: ZOUT1 (between Out1 and GND) = 10k||50k||Rf = 6kΩ ZOUT2 (between Out2 and GND) = 10k||(40k+(10k||Rf)) = 8.3kΩ ZOUT1-2 (between Out1 and Out2) = 40k||(10k+(10k||Rf)) = 11.7kΩ The -3dB roll off for these measurements is 600kHz PROPER SELECTION OF EXTERNAL COMPONENTS Proper selection of external components in applications using integrated power amplifiers is critical to optimize device and system performance. While the LM4890 is tolerant of external component combinations, consideration to component values must be used to maximize overall system quality. 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. 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 complete 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 bandwidth is dictated by the choice of external components shown in Figure 7. The input coupling capacitor, CIN, forms a first order high pass filter which limits low frequency response. 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 attenuation. 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 performance. 20 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 In addition to system cost and size, click and pop performance is effected by the size of the input coupling capacitor, CIN. A larger input coupling capacitor requires more charge to reach its quiescent DC voltage (nominally 1/2 VDD). This charge comes from the output 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. Besides minimizing the input capacitor size, careful consideration should be paid to the bypass capacitor value. Bypass capacitor, CBYPASS, is the most critical component to minimize 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 1/2VDD), the smaller the turn-on pop. Choosing CBYPASS equal to 1.0µF along with a small value of CIN, (in the range of 0.1µF to 0.39µF), should produce a virtually clickless and popless shutdown function. While the device will function properly, (no oscillations or motorboating), with CBYPASS equal to 0.1µF, the device will be much more susceptible to turn-on clicks and pops. Thus, a value of CBYPASS equal to 1.0µF is recommended in all but the most cost sensitive designs. AUDIO POWER AMPLIFIER DESIGN A 1W/8Ω Audio Amplifier Given: Power Output 1 Wrms Load Impedance 8Ω Input Level 1 Vrms Input Impedance 20 kΩ 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 Performance Characteristics section, the supply rail can be easily found. A second way to determine the minimum supply rail is to calculate the required Vopeak using Equation 2 and add the output voltage. Using this method, the minimum supply voltage would be (Vopeak + (VODTOP + VODBOT)), where VODBOT and VODTOP are extrapolated from the Dropout Voltage vs Supply Voltage curve in theTypical Performance Characteristics. (2) 5V is a standard voltage which in most applications is chosen for the supply rail. Extra supply voltage creates headroom 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 Equation 3. (3) (4) Rf/RIN = AVD/2 From Equation 3, the minimum AVD is 2.83; use AVD = 3. Since the desired input impedance is 20 kΩ, and with an AVD gain of 3, a ratio of 1.5:1 of Rf to RIN results in an allocation of RIN = 20 kΩ and Rf = 30 kΩ. 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. fL = 100Hz/5 = 20Hz fH = 20kHz * 5 = 100kHz As stated in the External Components Description section, RIN in conjunction with CIN create a highpass filter. CIN ≥ 1/(2π*20 kΩ*20Hz) = 0.397µF; use 0.39µF Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 21 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com The high frequency pole is determined by the product of the desired frequency pole, fH, and the differential gain, AVD. With a AVD = 3 and fH = 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. Figure 68. 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 application. However, if a closed-loop differential gain of greater than 10 is required, a feedback capacitor (C4) may be needed as shown in Figure 68 to bandwidth limit the amplifier. This feedback capacitor creates a low pass filter that eliminates possible high frequency oscillations. Care should be taken when calculating the -3dB frequency in that an incorrect combination of R3 and C4 will cause rolloff before 20kHz. A typical combination of feedback resistor and capacitor that will not produce audio band high frequency rolloff is R3 = 20kΩ and C4 = 25pf. These components result in a -3dB point of approximately 320 kHz. 22 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Figure 69. DIFFERENTIAL AMPLIFIER CONFIGURATION FOR LM4890 Figure 70. REFERENCE DESIGN BOARD and LAYOUT - DSBGA Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 23 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com LM4890 DSBGA BOARD ARTWORK Silk Screen Top Layer Bottom Layer Inner Layer VDD Inner Layer Ground 24 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Figure 71. REFERENCE DESIGN BOARD and PCB LAYOUT GUIDELINES - VSSOP and SOIC Boards LM4890 SOIC DEMO BOARD ARTWORK Figure 72. Silk Screen Figure 73. Top Layer Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 25 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com Figure 74. Bottom Layer LM4890 VSSOP DEMO BOARD ARTWORK Figure 75. Silk Screen Figure 76. Top Layer Figure 77. Bottom Layer Table 1. Mono LM4890 Reference Design Boards 26 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 LM4890 www.ti.com SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 Table 1. Mono LM4890 Reference Design Boards Bill of Material for all 3 Demo Boards (continued) Bill of Material for all 3 Demo Boards Item Part Number 1 551011208-001 LM4890 Mono Reference Design Board Part Description Qty 1 Ref Designator 10 482911183-001 LM4890 Audio AMP 1 U1 20 151911207-001 Tant Cap 1uF 16V 10 1 C1 21 151911207-002 Cer Cap 0.39uF 50V Z5U 20% 1210 1 C2 25 152911207-001 Tant Cap 1uF 16V 10 1 C3 30 472911207-001 Res 20K Ohm 1/10W 5 3 R1, R2, R3 35 210007039-002 Jumper Header Vertical Mount 2X1 0.100 2 J1, J2 PCB LAYOUT GUIDELINES This section provides practical guidelines for mixed signal PCB layout that involves various digital/analog power and ground traces. Designers should note that these are only "rule-of-thumb" recommendations and the actual results will depend heavily on the final layout. GENERAL MIXED SIGNAL LAYOUT RECOMMENDATIONS Power and Ground Circuits For 2 layer mixed signal design, it is important to isolate the digital power and ground trace paths from the analog power and ground trace paths. Star trace routing techniques (bringing individual traces back to a central point rather than daisy chaining traces together in a serial manner) can have a major impact on low level signal performance. Star trace routing refers to using individual traces to feed power and ground to each circuit or even device. This technique will require a greater amount of design time but will not increase the final price of the board. The only extra parts required will be some jumpers. Single-Point Power / Ground Connections The analog power traces should be connected to the digital traces through a single point (link). A "Pi-filter" can be helpful in minimizing High Frequency noise coupling between the analog and digital sections. It is further recommended to put digital and analog power traces over the corresponding digital and analog ground traces to minimize noise coupling. Placement of Digital and Analog Components All digital components and high-speed digital signals traces should be located as far away as possible from analog components and circuit traces. Avoiding Typical Design / Layout Problems Avoid ground loops or running digital and analog traces parallel to each other (side-by-side) on the same PCB layer. When traces must cross over each other do it at 90 degrees. Running digital and analog traces at 90 degrees to each other from the top to the bottom side as much as possible will minimize capacitive noise coupling and cross talk. Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 27 LM4890 SNAS138L – SEPTEMBER 2001 – REVISED MAY 2013 www.ti.com REVISION HISTORY Changes from Revision K (May 2013) to Revision L • 28 Page Changed layout of National Data Sheet to TI format .......................................................................................................... 27 Submit Documentation Feedback Copyright © 2001–2013, Texas Instruments Incorporated Product Folder Links: LM4890 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LM4890M/NOPB ACTIVE SOIC D 8 95 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 LM48 90M LM4890MM/NOPB ACTIVE VSSOP DGK 8 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 G90 LM4890MMX/NOPB ACTIVE VSSOP DGK 8 3500 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 G90 LM4890MX/NOPB ACTIVE SOIC D 8 2500 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 LM48 90M (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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