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LM4864MM

LM4864MM

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    VSSOP8

  • 描述:

    IC AMP AUDIO PWR .725W AB 8VSSOP

  • 数据手册
  • 价格&库存
LM4864MM 数据手册
LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 LM4864 725mW Audio Power Amplifier with Shutdown Mode Check for Samples: LM4864 FEATURES DESCRIPTION 1 • • 23 • • • VSSOP, SOIC, PDIP , and WSON Packaging No Output Coupling Capacitors, Bootstrap Capacitors, or Snubber Circuits are Necessary Thermal Shutdown Protection Circuitry Unity-Gain Stable External Gain Configuration Capability (1) APPLICATIONS • • • Cellular phones Personal computers General purpose audio KEY SPECIFICATIONS • (1) (2) PO at 1% THD+N with VDD = 5V, 1kHz – LM4864LD, 4Ω load 625 mW (typ) – LM4864LD, 8Ω load 725 mW (typ) – LM4864M & LM4864N (1), 8Ω load 675 mW (typ) – LM4864MM, 8Ω load (2) 300 mW (typ) – LM4864, 16Ω load 550 mW (typ) – Shutdown current 0.7 µA (typ) The LM4864 is a bridged audio power amplifier capable of delivering 725mW of continuous average power into an 8Ω load with 1% THD+N from a 5V power supply. Boomer® audio power amplifiers were designed specifically to provide high quality output power from a low supply voltage while requiring a minimal amount of external components. Since the LM4864 does not require output coupling capacitors, bootstrap capacitors or snubber networks, it is optimally suited for low-power portable applications. The LM4864 features an externally controlled, low power consumption shutdown mode, and thermal shutdown protection. The closed loop response of the unity-gain stable LM4864 can be configured by external gain-setting resistors. The device is available in multiple package types to suit various applications. Not recommended for new designs. Contact TI Audio Marketing. The DGK0008BA package is thermally limited to 595 mW of power dissipation at room temperature. Referring to Figure 21 in Typical Performance Characteristics, the power dissipation limitation for the package occurs at 300 mW of output power. This package limitation is based on 25°C ambient temperature and θJA = 210°C. For higher output power possibilities refer to POWER DISSIPATION. 1 2 3 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. Boomer is a registered trademark of Texas Instruments. All other 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 © 1999–2013, Texas Instruments Incorporated LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com Typical Application Figure 1. Typical Audio Amplifier Application Circuit Connection Diagram Figure 2. VSSOP, SOIC, and PDIP Package- Top View See Package Number DGK0008A, D0008A or P0008E (3) Figure 3. WSON Package- Top View See Package Number NGY0010A (3) 2 Not recommended for new designs. Contact TI Audio Marketing. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 Figure 4. DIE LAYOUT (B-STEP) 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. Absolute Maximum Ratings (1) (2) Supply Voltage 6.0V −65°C to +150°C Storage Temperature −0.3V to VDD + 0.3V Input Voltage Power Dissipation (3) Internally limited ESD Susceptibility (4) 2000V ESD Susceptibility (5) 200V Junction Temperature Soldering Information Thermal Resistance (1) (2) (3) (4) (5) (6) 150°C Small Outline Package Vapor Phase (60 sec.) 215°C Infrared (15 sec.) 220°C θJC (VSSOP) 56° C/W θJA (VSSOP) 210°C/W θJC (SOIC) 35°C/W θJA (SOIC) 170°C/W θJC (PDIP)* 37°C/W θJA (PDIP)* 107°C/W θJA (WSON) (6) 63°C/W θJC (WSON) (6) 12°C/W 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 specified 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 Texas Instruments Sales Office/ Distributors for availability and specifications. 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 the Absolute Maximum Ratings, whichever is lower. For the LM4864, TJMAX = 150°C. The typical junction-to-ambient thermal resistance, when board mounted, is 230°C/W for package number DGK0008A, 170°C/W for package number D0008A and is 107°C/W for package number P0008E*. Human body model, 100pF discharged through a 1.5kΩ resistor. Machine Model, 220pF – 240pF discharged through all pins. The NGY0010A package has its exposed-DAP soldered to an exposed 1.2in2 area of 1oz printed circuit board copper. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 3 LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com Operating Ratings TMIN ≤ TA ≤ TMAX Temperature Range −40°C ≤ TA ≤ +85°C 2.7V ≤ VDD ≤ 5.5V Supply Voltage Electrical Characteristics VDD = 5V (1) (2) The following specifications apply for VDD = 5V, for all available packages, unless otherwise specified. Limits apply for TA = 25°C Symbol Parameter Conditions (6) LM4864 Typical (3) Limit (4) (5) Units (Limits) IDD Quiescent Power Supply Current VIN = 0V, IO = 0A ISD Shutdown Current VPIN1 = VDD 3.6 6.0 0.7 5 VOS Output Offset Voltage VIN = 0V μA (max) 5 50 mV (max) PO Output Power THD = 1% (max); f = 1 kHz; RL = 4Ω; LM4864LD (7) 625 mW (min) THD = 1% (max); f = 1 kHz; RL = 8Ω; LM4864LD (7) 725 mW (min) THD = 1% (max); f = 1 kHz; RL = 8Ω; LM4864MM (8) 300 THD = 1% (max); f = 1 kHz; RL = 8Ω; LM4864M and LM4864N* 675 300 mA (max) mW (min) mW (min) THD+N = 1%; f = 1 kHz; RL = 16Ω; 550 THD+N Total Harmonic Distortion+Noise PO = 300 mWrms; AVD = 2; RL = 8Ω; 20 Hz ≤ f ≤ 20 kHz, BW < 80kHz 0.7 % PSRR Power Supply Rejection Ratio VDD = 4.9V–5.1V 50 dB (1) (2) (3) (4) (5) (6) (7) (8) 4 mW 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 specified for parameters where no limit is given, however, the typical value is a good indication of device performance. 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. The quiescent power supply current depends on the offset voltage when a practical load is connected to the amplifier. The NGY0010A package has its exposed-DAP soldered to an exposed 1.2in2 area of 1oz printed circuit board copper. The DGK0008BA package is thermally limited to 595 mW of power dissipation at room temperature. Referring to Figure 21 in Typical Performance Characteristics, the power dissipation limitation for the package occurs at 300 mW of output power. This package limitation is based on 25°C ambient temperature and θJA = 210°C. For higher output power possibilities refer to POWER DISSIPATION. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 Electrical Characteristics VDD = 3V (1) (2) The following specifications apply for VDD = 3V, for all available packages, unless otherwise specified. Limits apply for TA = 25°C Symbol Parameter Conditions IDD Quiescent Power Supply Current VIN = 0V, IO = 0A ISD Shutdown Current VPIN1 = VDD VOS Output Offset Voltage VIN = 0V PO Output Power THD+N Total Harmonic Distortion+Noise PSRR Power Supply Rejection Ratio (1) (2) (3) (4) (5) (6) (6) LM4864 Typical (3) Limit (4) (5) Units (Limits) 1.0 3.0 mA (max) 0.3 2.0 μA (max) 5 mV THD = 1% (max); f = 1 kHz; RL = 8Ω 200 mW THD = 1% (max); f = 1 kHz; RL = 16Ω 175 mW PO = 100 mWrms; AVD = 2; RL = 8Ω; 20 Hz ≤ f ≤ 20 kHz, BW < 80 kHz 1.5 % VDD = 2.9V–3.1V 50 dB 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 specified for parameters where no limit is given, however, the typical value is a good indication of device performance. 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. The quiescent power supply current depends on the offset voltage when a practical load is connected to the amplifier. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 5 LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com External Components Description (See Figure 1) Components Functional Description 1. Ri Inverting input resistance which sets the closed-loop gain in conjunction with RF. This resistor also forms a high pass filter with Ci at fc = 1/(2π RiCI). 2. Ci Input coupling capacitor which blocks the DC voltage at the amplifier's input terminals. Also creates a highpass filter with Ri at fc = 1/(2π RiCi). Refer to PROPER SELECTION OF EXTERNAL COMPONENTS for an explanation of how to determine the value of Ci. 3. RF Feedback resistance which sets the closed-loop gain in conjunction with Ri. 4. CS Supply bypass capacitor which provides power supply filtering. Refer to POWER SUPPLY BYPASSING section for information concerning proper placement and selection of the supply bypass capacitor. 5. CB Bypass pin capacitor which provides half-supply filtering. Refer to PROPER SELECTION OF EXTERNAL COMPONENTS for information concerning proper placement and selection of CB. 6 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 Typical Performance Characteristics THD+N vs Frequency THD+N vs Frequency Figure 5. Figure 6. THD+N vs Frequency THD+N vs Frequency Figure 7. Figure 8. THD+N vs Frequency THD+N vs Frequency Figure 9. Figure 10. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 7 LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 8 THD+N vs Output Power THD+N vs Output Power Figure 11. Figure 12. THD+N vs Output Power THD+N vs Output Power Figure 13. Figure 14. THD+N vs Output Power THD+N vs Output Power Figure 15. Figure 16. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 Typical Performance Characteristics (continued) Output Power vs Supply Voltage Output Power vs Supply Voltage Figure 17. Figure 18. Output Power vs Supply Voltage Output Power vs Load Resistance Figure 19. Figure 20. Power Dissipation vs Output Power Power Derating Curve Figure 21. Figure 22. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 9 LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 10 Dropout Voltage vs Supply Voltage Noise Floor Figure 23. Figure 24. Frequency Response vs Input Capacitor Size Power Supply Rejection Ratio Figure 25. Figure 26. Open Loop Frequency Response Supply Current vs Supply Voltage Figure 27. Figure 28. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 Typical Performance Characteristics for the LM4864LD (1) (1) THD+N vs Frequency THD+N vs Frequency Figure 29. Figure 30. THD+N vs Power Out THD+N vs Power Out Figure 31. Figure 32. Output Power vs Supply Voltage Power Dissipation vs Output Power Figure 33. Figure 34. The NGY0010A package has its exposed-DAP soldered to an exposed 1.2in2 area of 1oz printed circuit board copper. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 11 LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com APPLICATION INFORMATION BRIDGE CONFIGURATION EXPLANATION As shown in Figure 1, the LM4864 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 Ri while the second amplifier's gain is fixed by the two internal 10kΩ 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 180°. Consequently, the differential gain for the IC is AVD = 2*(RF/Ri) (1) 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 its 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 AUDIO POWER AMPLIFIER DESIGN section. A bridge configuration, such as the one used in LM4864, 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. If an output coupling capacitor is not used in a single-ended configuration, the halfsupply bias across the load would result in both increased internal lC power dissipation as well as permanent loudspeaker damage. POWER DISSIPATION Power dissipation is a major concern when designing a successful amplifier, whether the amplifier is bridged or single-ended. Equation 2 states the maximum power dissipation point for a bridge amplifier operating at a given supply voltage and driving a specified output load. PDMAX = (VDD)2/(2π2RL) Single-Ended (1) (2) However, a direct consequence of the increased power delivered to the load by a bridge amplifier is an increase in internal power dissipation point for a bridge amplifier operating at the same conditions. PDMAX = 4(VDD)2/(2π2RL) Bridge Mode (2) (3) Since the LM4864 has two operational amplifiers in one package, the maximum internal power dissipation is 4 times that of a single-ended amplifier. Even with this substantial increase in power dissipation, the LM4864 does not require heatsinking. From Equation 2, assuming a 5V power supply and an 8Ω load, the maximum power dissipation point is 633 mW. The maximum power dissipation point obtained from Equation 3 must not be greater than the power dissipation that results from Equation 4: PDMAX = (TJMAX − TA)/θJA (3) (4) For package DGK0008A, θJA = 210°C/W, for package D00008A, θJA = 170°C/W, for package P0008E, θJA = 107°C/W, and for package NGY0010A, θJA = 63°C/W. TJMAX = 150°C for the LM4864. Depending on the ambient temperature, TA, of the system surroundings, Equation 4 can be used to find the maximum internal power dissipation supported by the IC packaging. If the result of Equation 3 is greater than that of Equation 4, then either the supply voltage must be decreased, the load impedance increased, the ambient temperature reduced, or the θJA reduced with heatsinking. In many cases larger traces near the output, VDD, and GND pins can be used to lower the θJA. The larger areas of copper provide a form of heatsinking allowing a higher power dissipation. For the typical application of a 5V power supply, with an 8Ω load, the maximum ambient temperature possible without violating the maximum junction temperature is approximately 44°C provided that device operation is around the maximum power dissipation point and assuming surface mount packaging. Internal power dissipation is a function of output power. If typical operation is not around the maximum power dissipation point, the ambient temperature can be increased. Refer to Typical Performance Characteristics for power dissipation information for lower output powers. 12 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 EXPOSED-DAP PACKAGE PCB MOUNTING CONSIDERATION The LM4864's exposed-dap (die attach paddle) package (NGY) provides a low thermal resistance between the die and the PCB to which the part is mounted and soldered. This allows rapid heat transfer from the die to the surrounding PCB copper traces, ground plane, and surrounding air. The NGY package should have its DAP soldered to a copper pad on the PCB. The DAP's PCB copper pad may be connected to a large plane of continuous unbroken copper. This plane forms a thermal mass, heat sink, and radiation area. Further detailed and specific information concerning PCB layout, fabrication, and mounting an NGY (WSON) package is available from Texas Instruments's Package Engineering Group under application note AN1187. POWER SUPPLY BYPASSING As with any power 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. The effect of a larger half supply bypass capacitor is improved PSRR due to increased half-supply stability. Typical applications employ a 5V regulator with 10 μF and a 0.1 μF bypass capacitors which aid in supply stability, but do not eliminate the need for bypassing the supply nodes of the LM4864. The selection of bypass capacitors, especially CB, is thus dependent upon desired PSRR requirements, click and pop performance as explained in PROPER SELECTION OF EXTERNAL COMPONENTS, system cost, and size constraints. SHUTDOWN FUNCTION In order to reduce power consumption while not in use, the LM4864 contains a shutdown pin to externally turn off the amplifier's bias circuitry. This shutdown feature turns the amplifier off when a logic high is placed on the shutdown pin. The trigger point between a logic low and logic high level is typically half supply. It is best to switch between ground and supply to provide maximum device performance. By switching the shutdown pin to VDD, the LM4864 supply current draw will be minimized in idle mode. While the device will be disabled with shutdown pin voltages less than VDD, the idle current may be greater than the typical value of 0.7 μA. In either case, the shutdown pin should be tied to a definite voltage to avoid unwanted state changes. In many applications, a microcontroller or microprocessor output is used to control the shutdown circuitry which provides 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 enables the amplifier. If the switch is open, then the external pull-up resistor will disable the LM4864. This scheme ensures that the shutdown pin will not float, thus preventing unwanted state changes. 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 LM4864 is tolerant to a variety of external component combinations, consideration to component values must be used to maximize overall system quality. The LM4864 is unity-gain stable, giving a designer maximum system flexibility. The LM4864 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 1 Vrms are available from sources such as audio codecs. Please refer toAUDIO 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 1. The input coupling capacitor, Ci, 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 150 Hz. In this case using a large input capacitor may not increase system performance. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 13 LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com In addition to system cost and size, click and pop performance is effected by the size of the input coupling capacitor, Ci. A larger input coupling capacitor requires more charge to reach its quiescent DC voltage (nominally ½ 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, CB, is the most critical component to minimize turn-on pops since it determines how fast the LM4864 turns on. The slower the LM4864's outputs ramp to their quiescent DC voltage (nominally ½ VDD), the smaller the turn-on pop. Choosing CB equal to 1.0 μF along with a small value of Ci (in the range of 0.1 μF to 0.39 μF), should produce a clickless and popless shutdown function. While the device will function properly, (no oscillations or motorboating), with CB equal to 0.1 μF, the device will be much more susceptible to turn-on clicks and pops. Thus, a value of CB equal to 1.0 μF or larger is recommended in all but the most cost sensitive designs. AUDIO POWER AMPLIFIER DESIGN Design a 300 mW/8Ω Audio Amplifier Given: Power Output 300 mWrms 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 fromFigure 18 and Figure 19 in Typical Performance Characteristics, the supply rail can be easily found. A second way to determine the minimum supply rail is to calculate the required Vopeak using Equation 5 and add the dropout voltage. Using this method, the minimum supply voltage would be (Vopeak + (2*VOD)), where VOD is extrapolated from Figure 23 in Typical Performance Characteristics. (5) Using Figure 17 for an 8Ω load, the minimum supply rail is 3.5V. But since 5V is a standard supply voltage in most applications, it is chosen for the supply rail. Extra supply voltage creates headroom that allows the LM4864 to reproduce peaks in excess of 500 mW 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 POWER DISSIPATION. Once the power dissipation equations have been addressed, the required differential gain can be determined from Equation 6. (6) (7) RF/Ri = AVD/2 From Equation 6, the minimum AVD is 1.55; use AVD = 2. Since the desired input impedance was 20 kΩ, and with a AVD of 2, a ratio of 1:1 of RF to Ri results in an allocation of Ri = RF = 20 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 pole gives 0.17 dB down from passband response which is better than the required ±0.25 dB specified. fL = 100 Hz/5 = 20 Hz fH = 20 kHz × 5 = 100 kHz (8) (9) As stated in External Components Description , Ri in conjunction with Ci create a highpass filter. Ci ≥ 1/(2π*20 kΩ*20 Hz) = 0.397 μF; use 0.39 μF 14 Submit Documentation Feedback (10) (11) Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 The high frequency pole is determined by the product of the desired high frequency pole, fH, and the differential gain, AVD. With a AVD = 2 and fH = 100 kHz, the resulting GBWP = 100 kHz which is much smaller than the LM4864 GBWP of 18 MHz. This figure displays that if a designer has a need to design an amplifier with a higher differential gain, the LM4864 can still be used without running into bandwidth problems. LM4864LD DEMO BOARD ARTWORK Figure 35. Silk Screen View of LM4864LD Figure 36. Top Layer of LM4864LD Figure 37. Bottom Layer of LM4864LD Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 15 LM4864 SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 www.ti.com LM4864 MDC MWC 725MW Audio Power Amplifier With Shutdown Mode Figure 38. Die Layout (B - Step) Table 1. DIE/WAFER CHARACTERISTICS Fabrication Attributes General Die Information Physical Die Identification LM4862B Bond Pad Opening Size (min) 86µm x 86µm Die Step B Bond Pad Metalization ALUMINUM Passivation NITRIDE Physical Attributes Wafer Diameter 150mm Back Side Metal Bare Back Dise Size (Drawn) 1283µm x 952µm 51mils x 37mils Back Side Connection GND Thickness 406µm Nominal Min Pitch 117µm Nominal Special Assembly Requirements: Note: Actual die size is rounded to the nearest micron. Die Bond Pad Coordinate Locations (B - Step) (Referenced to die center, coordinates in µm) NC = No Connection SIGNAL NAME PAD# NUMBER X/Y COORDINATES PAD SIZE X Y X Y BYPASS 1 -322 523 86 x 86 GND 2 -359 259 86 x 188 INPUT + 3 -359 5 86 x 86 GND 4 -359 -259 86 x 188 NC 5 -323 -523 86 x 86 INPUT - 6 -109 -523 86 x 86 VOUT 1 7 8 -523 86 x 86 VDD 8 358 -78 86 x 188 GND 9 358 141 86 x 188 NC 10 359 406 86 x 86 NC 11 323 523 86 x 86 VOUT 2 12 8 523 86 x 86 SHUTDOWN 13 -109 523 86 x 86 16 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 LM4864 www.ti.com SNAS109F – SEPTEMBER 1999 – REVISED MAY 2013 REVISION HISTORY Changes from Revision E (May 2013) to Revision F • Page Changed layout of National Data Sheet to TI format .......................................................................................................... 16 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LM4864 17 PACKAGE OPTION ADDENDUM www.ti.com 21-Aug-2022 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) Samples (4/5) (6) LM4864M/NOPB ACTIVE SOIC D 8 95 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 LM48 64M Samples LM4864MM ACTIVE VSSOP DGK 8 1000 Non-RoHS & Green Call TI Level-1-260C-UNLIM -40 to 85 Z64 Samples LM4864MM/NOPB ACTIVE VSSOP DGK 8 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 Z64 Samples LM4864MMX/NOPB ACTIVE VSSOP DGK 8 3500 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 Z64 Samples LM4864MX/NOPB ACTIVE SOIC D 8 2500 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 LM48 64M Samples (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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