LM4982 Ground-Referenced, Ultra Low Noise, 80mW Stereo Headphone Amplifier with IntelliSense and I2C Volume Control General Description Key Specifications The LM4982 is a ground referenced, variable gain audio power amplifier capable of delivering 80mW of continuous average power into a 16Ω single-ended load with less than 1% THD+N from a 3V power supply. The I2C volume control allows +18 to -76 dB gain settings. The LM4982 utilizes advanced charge pump technology to generate the LM4982’s negative supply voltage. This eliminates the need for output-coupling capacitors typically used with single-ended loads. IntelliSense is a new circuit technology that allows the LM4982 to detect whether a mono or stereo headphone plug has been inserted into the output jack. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. The LM4982 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 LM4982 incorporates selectable low-power consumption shutdown and channel select modes. The LM4982 contains advanced pop & click circuitry that eliminates noises which would otherwise occur during turn-on and turn-off transitions. j Improved PSRR at 217Hz 66dB j Stereo Output Power at VDD = 3V, RL = 32Ω, THD+N = 1% j Shutdown current 51mW (typ) 0.1µA (typ) Features Ground referenced outputs I2C Volume and mode controls Available in space-saving micro SMD package Ultra low current shutdown mode Advanced pop & click circuitry eliminates noises during turn-on and turn-off transitions n 1.6 – 4.0V operation n No output coupling capacitors, snubber networks, bootstrap capacitors or gain-setting resistors required n Mono/Stereo headphone detect n n n n n Applications n n n n n n Notebook PCs Desktop PCs Mobile Phones PDAs Portable electronic devices MP3 Players Boomer ® is a registered trademark of National Semiconductor Corporation. © 2006 National Semiconductor Corporation DS201614 www.national.com LM4982 Ground-Referenced, Ultra Low Noise, 80mW Stereo Headphone Amplifier with IntelliSense and I2C Volume Control February 2006 LM4982 Typical Application 20161466 FIGURE 1. Typical Audio Amplifier Application Circuit www.national.com 2 LM4982 Connection Diagrams micro SMD Package micro SMD Marking 20161401 20161459 Top View XY - Date Code TT - Lot Traceability GG3 – LM4982 See NS Package Number LM4982TL Top View Order Number LM4982TL Pin Descriptions Pin Designator Pin Name Pin Function A1 SGND Amplifier ground A2 HPE Headphone sende input A3 PVDD Charge pump / digital power supply A4 CCP+ Charge pump fly capacitor positive side B1 OUT_L Left channel output B2 IN_L Left channel input B3 I2C_VDD I2C power supply B4 PGND Charge pump / digital ground C1 SVSS Amplifier negative supply C2 IN_R Right channel input C3 SCL I2C SCL line C4 CCP- Charge pump fly capacitor negative side D1 OUT_R Right channel output D2 SVDD Amplifier positive supply D3 SDA I2C SDA line D4 CPOUT Charge pump power output 3 www.national.com LM4982 Absolute Maximum Ratings (Note 2) Junction Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Thermal Resistance Supply Voltage θJA (typ) - (TLA16XXX) 4.5V Storage Temperature Power Dissipation (Note 3) Temperature Range TMIN ≤ TA ≤ TMAX Internally Limited ESD Susceptibility (Note 4) 2000V ESD Susceptibility (Note 5) 200V 105˚C/W (Note X) Operating Ratings −65˚C to +150˚C −0.3V to VDD +0.3V Input Voltage 150˚C −40˚C ≤ TA ≤ +85˚C 1.6V ≤ VDD ≤ 4.0V Supply Voltage Audio Amplifier Electrical Characteristics VDD = 3V (Notes 1, 2) The following specifications apply for VDD = 3V, RL = 16Ω, AV = 0dB, unless otherwise specified. Limits apply for TA = 25˚C. Symbol IDD Parameter Quiescent Power Supply Current Full Power Mode Conditions LM4982 Units (Limits) Typical (Note 6) Limits (Notes 7, 8) VIN = 0V, inputs terminated, both channels enabled 8.1 11.5 mA (max) VIN = 0V, inputs terminated, one channel enabled 5.1 7.3 mA VIN = 0V, inputs terminated, No headphone inserted 2.15 mA ISD Shutdown Current With SD enabled 0.1 1.5 µA (max) VOS Output Offset Voltage RL = 32Ω 0.7 4.5 mV (max) AV Gain Max and Min settings [B0:B4] = 00000 –70 dB [B0:B4] = 11111 +18 dB RIN Input Resistance gain setting 18dB 22 gain setting –76dB 200 THD+N = 1% (max); f = 1kHz, RL = 16Ω, per channel 47 THD+N = 1% (max); f = 1kHz, RL = 32Ω, per channel 51 POUT Stereo Output Power THD+N Total Harmonic Distortion + Noise PSRR Power Supply Rejection Ratio Full Power Mode PO = 50mW, f = 1kHz RL = 16Ω, single channel 0.05 PO = 50mW, f = 1kHz RL = 32Ω, single channel 0.025 15 29 kΩ (min) kΩ (max) 40 mW (min) kΩ mW % VRIPPLE = 200mVP-P, input referred f = 217Hz 66 f = 1kHz 55 f = 20kHz 40 56 dB SNR Signal-to-Noise-Ratio RL = 32Ω, POUT = 20mW, f = 1kHz, BW = 20Hz to 22kHz 100 dB TWU Wake Up Time From Shutdown Charge Pump Wake-Up Time 300 µs TWU Wake Up Time Headphone Sense Debounce Time 200 ms XTALK Crosstalk RL = 16Ω, POUT = 1.6mW, f = 1kHz, A-weighted filter 70 dB ZOUT Output Impedance In Shutdown Mode 180 kΩ ± 0.1 IL Input Leakage Vih HPS in threshold 0.9 x VDD [min] V Vil HPS in threshold 0.7 x VDD [max] V www.national.com 4 nA (Notes 1, 2) (Continued) The following specifications apply for VDD = 3V, RL = 16Ω, AV = 0dB, unless otherwise specified. Limits apply for TA = 25˚C. Symbol RINT Parameter Conditions Intellisense Threshold Resistance LM4982 Typical (Note 6) Limits (Notes 7, 8) 6 3 9 Units (Limits) Ω (min) Ω (max) Control Interface Electrical Characteristics (Notes 1, 2) The following specifications apply for 1.6V < VDD < 4.0V, unless otherwise specified. Limits apply for TA = 25˚C. Symbol Parameter Conditions LM4982 Typical (Note 6) Limits (Notes 7, 8) Units (Limits) t1 SCL period 2.5 t2 SDA Setup Time 100 ns (min) t3 SDA Stable Time 0 ns (min) t4 Start Condition Time 100 ns (min) t5 Stop Condition Time 100 ns (min) VIH 0.7 x I2CVDD V (min) VIL 2 V (max) 0.3 x I CVDD µs (min) Note 1: All voltages are measured with respect to the GND 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 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 LM4982, see power derating currents for more information. Note 4: Human body model, 100pF discharged through a 1.5kΩ resistor. Note 5: Machine Model, 220pF - 240pF discharged through all pins. Note 6: Typicals are measured at +25˚C and represent the parametric norm. Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level). Note 8: Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis. 5 www.national.com LM4982 Audio Amplifier Electrical Characteristics VDD = 3V LM4982 Typical Performance Characteristics THD+N vs Frequency VDD = 1.8V, RL = 16Ω, PO = 2mW, Stereo THD+N vs Frequency VDD = 1.8V, RL = 16Ω, PO = 7mW, Mono 20161475 20161474 THD+N vs Frequency VDD = 1.8V, RL = 32Ω, PO = 2mW, Stereo THD+N vs Frequency VDD = 1.8V, RL = 32Ω, PO = 7mW, Mono 20161477 20161476 THD+N vs Frequency VDD = 3V, RL = 16Ω, PO = 25mW, Stereo THD+N vs Frequency VDD = 3V, RL = 16Ω, PO = 50mW, Mono 20161482 www.national.com 20161483 6 LM4982 Typical Performance Characteristics (Continued) THD+N vs Frequency VDD = 3V, RL = 32Ω, PO = 25mW, Stereo THD+N vs Frequency VDD = 3V, RL = 32Ω, PO = 50mW, Mono 20161484 20161485 THD+N vs Frequency VDD = 3.6V, RL = 16Ω, PO = 60mW, Stereo THD+N vs Frequency VDD = 3.6V, RL = 16Ω, PO = 100mW, Mono 20161478 20161479 THD+N vs Frequency VDD = 3.6V, RL = 32Ω, PO = 60mW, Stereo THD+N vs Frequency VDD = 3.6V, RL = 32Ω, PO = 100mW, Mono, 20161480 20161481 7 www.national.com LM4982 Typical Performance Characteristics (Continued) THD+N vs Output Power VDD = 1.8V, RL = 16Ω, f = 1kHz, Mono THD+N vs Output Power VDD = 1.8V, RL = 16Ω, f = 1kHz, Stereo 20161486 20161487 THD+N vs Output Power VDD = 1.8V, RL = 32Ω, f = 1kHz, Stereo THD+N vs Output Power VDD = 1.8V, RL = 32Ω, f = 1kHz, Mono 20161488 20161489 THD+N vs Output Power VDD = 3V, RL = 16Ω, f = 1kHz, Stereo THD+N vs Output Power VDD = 3V, RL = 16Ω, f = 1kHz, Mono 201614B2 20161494 www.national.com 8 LM4982 Typical Performance Characteristics (Continued) THD+N vs Output Power VDD = 3V, RL = 32Ω, f = 1kHz, Mono THD+N vs Output Power VDD = 3V, RL = 32Ω, f = 1kHz, Stereo 20161495 20161496 THD+N vs Output Power VDD = 3.6V, RL = 16Ω, f = 1kHz, Stereo THD+N vs Output Power VDD = 3.6V, RL = 16Ω, f = 1kHz, Mono 20161490 20161491 THD+N vs Output Power VDD = 3.6V, RL = 32Ω, f = 1kHz, Stereo THD+N vs Output Power VDD = 3.6V, RL = 32Ω, f = 1kHz, Mono 20161492 20161493 9 www.national.com LM4982 Typical Performance Characteristics (Continued) Power Dissipation vs Output Power VDD = 1.8V, RL = 16Ω, f = 1kHz Power Dissipation vs Output Power VDD = 1.8V, RL = 32Ω, f = 1kHz 20161497 20161498 Power Dissipation vs Output Power VDD = 3V, RL = 32Ω, f = 1kHz Power Dissipation vs Output Power VDD = 3V, RL = 16Ω, f = 1kHz 201614A4 201614A5 Power Dissipation vs Output Power VDD = 3.6V, RL = 32Ω, f = 1kHz Power Dissipation vs Output Power VDD = 3.6V, RL = 16Ω, f = 1kHz 201614A2 www.national.com 201614A3 10 (Continued) Output Power vs Power Supply Voltage RL = 16Ω, f = 1kHz, Mono Output Power vs Power Supply Voltage RL = 16Ω, f = 1kHz, Stereo 201614B5 201614B6 Output Power vs Power Supply Voltage RL = 32Ω, f = 1kHz, Stereo Output Power vs Power Supply Voltage RL = 32Ω, f = 1kHz, Mono 201614B7 201614B8 Power Supply Current vs Power Supply Voltage VIN = 0V, Stereo Power Supply Current vs Power Supply Voltage VIN = 0V, Mono 201614A6 201614A7 11 www.national.com LM4982 Typical Performance Characteristics LM4982 Typical Performance Characteristics (Continued) PSRR vs Frequency VDD = 1.8V, Vripple = 200mVp-p PSRR vs Frequency VDD = 3V, Vripple = 200mVp-p 201614B1 201614A8 Crosstalk VDD = 3V, RL = 16Ω, PO= 50mW PSRR vs Frequency VDD = 3.6V, Vripple = 200mVp-p 201614B3 201614B0 Crosstalk VDD = 3V, RL = 32Ω, PO= 50mW 201614B4 www.national.com 12 LM4982 Application Information 20161468 FIGURE 2. I2C Bus Format 20161467 FIGURE 3. I2C Timing Diagram TABLE 1. Chip Address Chip Address D7 D6 D5 D4 D3 D2 D1 D0 1 1 1 0 1 1 0 0 TABLE 2. Control Registers D7 D6 D5 D4 D3 D2 D1 D0 Mode Control 0 0 0 0 CD3 CD2 CD1 CD0 Volume Control 1 0 0 VD4 VD3 VD2 VD1 VD0 TABLE 3. Mode Control CD3 CD2 CD1 CD0 1 Intellisense Enabled 0 Intellisense Disabled 1 Mute Enabled 0 Mute Disabled 1 Stereo 0 Mono * 1 Normal Operation 0 Shutdown Enabled * Mono mode mixes (Left + Right) / 2, into Left output I2C VOLUME CONTROL The LM4982 can be configured in 32 different gain steps by forcing I2C volume control bits to a desired gain according to the table below: 13 www.national.com LM4982 Application Information (Continued) TABLE 4. Volume Control VD4 VD3 VD2 VD1 VD0 Gain (dB) 0 0 0 0 0 –70 0 0 0 0 1 –60 0 0 0 1 0 –52 0 0 0 1 1 –44 0 0 1 0 0 –38 0 0 1 0 1 –34 0 0 1 1 0 –30 0 0 1 1 1 –27 0 1 0 0 0 –24 0 1 0 0 1 –21 0 1 0 1 0 –18 0 1 0 1 1 –16 0 1 1 0 0 –14 0 1 1 0 1 –12 0 1 1 1 0 –10 0 1 1 1 1 –8 1 0 0 0 0 –6 1 0 0 0 1 –4 1 0 0 1 0 –2 1 0 0 1 1 0 1 0 1 0 0 2 1 0 1 0 1 4 1 0 1 1 0 6 1 0 1 1 1 8 1 1 0 0 0 10 1 1 0 0 1 12 1 1 0 1 0 13 1 1 0 1 1 14 1 1 1 0 0 15 1 1 1 0 1 16 1 1 1 1 0 17 1 1 1 1 1 18 www.national.com 14 LM4982 Application Information (Continued) HP SENSE FUNCTION Connecting headphones to the headphone jack disconnects the headphone jack contact pin from OUT_L and allows Rpu to pull the HP Sense pin up to VDD. This enables the device. A microprocessor or a switch can replace the headphone jack contact pin. Shutdown (Bit CD0) HPS pin Operational Mode Logic High Logic Low Standby Mode Logic High Logic High Full Power Mode Logic Low Logic Low Micro-Power Shutdown Logic Low Logic High Micro-Power Shutdown 20161460 FIGURE 5. MONO/STEREO OPERATION When Intellisense is disabled the value of the CD1 bit of the mode control determines if the LM4982 is in mono or stereo mode. When the LM4982 is in mono mode the left and right input signals are mixed to the left channel amplifier and attenuated by -6dB. The right channel amplifier is put in shutdown to save power. The mixing function allows full reproduction of a stereo input signal in a mono headphone and optimum headroom is kept by attenuating by a factor of two. I2C COMPATIBLE INTERFACE The LM4982 uses a serial bus, which conforms to the I2C protocol, to control the chip’s functions with two wires: clock (SCL) and data (SDA). The clock line is uni-directional. The data line is bi-directional (open-collector). The maximum clock frequency specified by the I2C standard is 400kHz. In this discussion, the master is the controlling microcontroller and the slave is the LM4982. The bus format for the I2C interface is shown in Figure 2. The bus format diagram is broken up into six major sections: The "start" signal is generated by lowering the data signal while the clock signal is high. The start signal will alert all devices attached to the I2C bus to check the incoming address against their own address. The 8-bit chip address is sent next, most significant bit first. The data is latched in on the rising edge of the clock. Each address bit must be stable while the clock level is high. After the last bit of the address bit is sent, the master releases the data line high (through a pull-up resistor). Then the master sends an acknowledge clock pulse. If the LM4982 has received the address correctly, then it holds the data line low during the clock pulse. If the data line is not held low during the acknowledge clock pulse, then the master should abort the rest of the data transfer to the LM4982. The 8 bits of data are sent next, most significant bit first. Each data bit should be valid while the clock level is stable high. After the data byte is sent, the master must check for another acknowledge to see if the LM4982 received the data. If the master has more data bytes to send to the LM4982, then the master can repeat the previous two steps until all data bytes have been sent. The "stop" signal ends the transfer. To signal "stop", the data signal goes high while the clock signal is high. The data line should be held high when not in use. 201614A1 FIGURE 4. INTELLISENSE National’s Intellisense technology allows the LM4982 to detect whether a mono or stereo headphone has been insterted in to the headphone jack. If a mono headphone is inserted into a device that is designed for a stereo headphone, one of the amplifiers will be shorted to ground. Without Intellisense, this may damage the device or, best case, the device will draw excessive current, shortening battery life. Intellisense works by first waiting for one of the following events: • When the device powers up, if a headphone is already inserted • When a headphone is inserted, if the device is already powered up • After the thermal shutdown circuitry is activated. The occurrence of one of these events triggers the Intellisense circuitry to apply a small voltage on both left and right outputs and sense the resulting current through the load. If the load connected to the amplifier is greater than 9Ω, the amplifier driving it will be in full power mode. If the load is less than 3Ω, the LM4982 will assume a short to ground and shutdown the driving amplifier. Intellisense puts the LM4982 in mono mode when the right channel is shorted. For extra protection both amplifiers will be shutdown when the left channel is shorted to ground. The Intellisense feature can be enabled and disabled through an I2C command. This Intellisense feature is designed for headphones with a nominal impedance of 16Ω or greater, using lower impedance loads may cause this feature to operate incorrectly. 15 www.national.com LM4982 Application Information Since the LM4982 has two operational amplifiers in one package, the maximum internal power dissipation point is twice that of the number which results from Equation 1. Even with large internal power dissipation, the LM4982 does not require heat sinking over a large range of ambient temperatures. The maximum power dissipation point obtained must not be greater than the power dissipation that results from Equation 2: (Continued) I2C INTERFACE POWER SUPPLY PIN (I2CVDD) The LM4982’s I2C interface is powered up through the I2CVDD pin. The LM4982’s I2C interface operates at a voltage level set by the I2CVDD pin which can be set independent to that of the main power supply pin VDD. This is ideal whenever logic levels for the I2C interface are dictated by a microcontroller or microprocessor that is operating at a lower supply voltage than the main battery of a portable system. PDMAX = (TJMAX - TA) / (θJA) POWER SUPPLY BYPASSING As with any power amplifier, proper supply bypassing is critical for low noise performance and high power supply rejection. Applications that employ a 5V regulator typically use a 10µF in parallel with a 0.1µF filter capacitors to stabilize the regulator’s output, reduce noise on the supply line, and improve the supply’s transient response. However, their presence does not eliminate the need for a local 1.0µF tantalum bypass capacitance connected between the LM4982’s supply pins and ground. Keep the length of leads and traces that connect capacitors between the LM4982’s power supply pins and ground as short as possible. For the micro SMD package, θJA = 105˚C/W. TJMAX = 150˚C for the LM4982. Depending on the ambient temperature, TA, of the system surroundings, Equation 2 can be used to find the maximum internal power dissipation supported by the IC packaging. If the result of Equation 1 is greater than that of Equation 2, then either the supply voltage must be decreased, the load impedance increased or TA reduced. Power dissipation is a function of output power and thus, if typical operation is not around the maximum power dissipation point, the ambient temperature may be increased accordingly. SELECTING PROPER EXTERNAL COMPONENTS Optimizing the LM4982’s performance requires properly selecting external components. Though the LM4982 operates well when using external components with wide tolerances, best performance is achieved by optimizing component values. ELIMINATING THE OUTPUT COUPLING CAPACITOR The LM4982 features a low noise inverting charge pump that generates an internal negative supply voltage. This allows the outputs of the LM4982 to be biased about GND instead of a nominal DC voltage, like traditional headphone amplifiers. Because there is no DC component, the large DC blocking capacitors (typically 220µF) are not necessary. The coupling capacitors are replaced by two, small ceramic charge pump capacitors, saving board space and cost. Eliminating the output coupling capacitors also improves low frequency response. In traditional headphone amplifiers, the headphone impedance and the output capacitor form a high pass filter that not only blocks the DC component of the output, but also attenuates low frequencies, impacting the bass response. Because the LM4982 does not require the output coupling capacitors, the low frequency response of the device is not degraded by external components. Charge Pump Capacitor Selection Use low ESR (equivalent series resistance) ( < 100mΩ) ceramic capacitors with an X7R dielectric for best performance. Low ESR capacitors keep the charge pump output impedance to a minimum, extending the headroom on the negative supply. Higher ESR capacitors result in reduced output power from the audio amplifiers. Charge pump load regulation and output impedance are affected by the value of the flying capacitor (C1). A larger valued C1 (up to 3.3uF) improves load regulation and minimizes charge pump output resistance. Beyond 3.3uF, the switch-on resistance dominates the output impedance for capacitor values above 2.2uF. The output ripple is affected by the value and ESR of the output capacitor (C2). Larger capacitors reduce output ripple on the negative power supply. Lower ESR capacitors minimize the output ripple and reduce the output impedance of the charge pump. The LM4982 charge pump design is optimized for 2.2uF, low ESR, ceramic, flying, and output capacitors. In addition to eliminating the output coupling capacitors, the ground referenced output nearly doubles the available dynamic range of the LM4982 when compared to a traditional headphone amplifier operating from the same supply voltage. OUTPUT TRANSIENT (’CLICK AND POPS’) ELIMINATED The LM4982 contains advanced circuitry that virtually eliminates output transients (’clicks and pops’). This circuitry prevents all traces of transients when the supply voltage is first applied or when the part resumes operation after coming out of shutdown mode. Input Capacitor Value Selection Amplifying the lowest audio frequencies requires high value input coupling capacitors (Ci in Figure 1). A high value capacitor can be expensive and may compromise space efficiency in portable designs. In many cases, however, the speakers used in portable systems, whether internal or external, have little ability to reproduce signals below 150Hz. Applications using speakers with this limited frequency response reap little improvement by using high value input and output capacitors. Besides affecting system cost and size, Ci has an effect on the LM4982’s click and pop performance. The magnitude of the pop is directly proportional to the input capacitor’s size. POWER DISSIPATION Power dissipation is a major concern when using any power amplifier and must be thoroughly understood to ensure a successful design. Equation 1 states the maximum power dissipation point for a single-ended amplifier operating at a given supply voltage and driving a specified output load. PDMAX = (2VDD) www.national.com 2 / (2π2RL) (2) (1) 16 (Continued) fi-3dB = 1 / 2πRiCi Thus, pops can be minimized by selecting an input capacitor value that is no higher than necessary to meet the desired −3dB frequency. As shown in Figure 1, the internal input resistor, Ri and the input capacitor, Ci, produce a -3dB high pass filter cutoff frequency that is found using Equation (3). Conventional headphone amplifiers require output capacitors; Equation (3) can be used, along with the value of RL, to determine towards the value of output capacitor needed to produce a –3dB high pass filter cutoff frequency. (3) Also, careful consideration must be taken in selecting a certain type of capacitor to be used in the system. Different types of capacitors (tantalum, electrolytic, ceramic) have unique performance characteristics and may affect overall system performance. (See the section entitled Charge Pump Capacitor Selection.) 17 www.national.com LM4982 Application Information LM4982 Demo Board Artwork 201614A0 Top Layer 20161470 Mid Layer 1 www.national.com 18 LM4982 Demo Board Artwork (Continued) 20161471 Mid Layer 2 20161469 Bottom Layer 19 www.national.com LM4982 Revision History www.national.com Rev Date 1.0 7/19/05 Description First PDF. 1.1 7/26/05 Edited 20161401 (markings) and 20161459 (micro SMD pkg drawing) 1.2 10/26/05 Text edits input. Also replaced 201614 61 with 66. 1.3 10/28/05 Texts edit. 1.4 11/01/05 Deleted PSRR (Stndby Mode) in the 3V EC table (per Nisha). 1.5 11/03/05 Added the boards and few text edits 1.6 11/07/05 Few text edits. 1.7 01/23/06 Added the Typ Perf curves, boards, and text edits. 1.8 01/27/06 Fixed typos, edited 66, 01, and more of the curves. 1.9 2/09/06 Input few text edits. First WEB released. 20 inches (millimeters) unless otherwise noted 16-Bump micro SMD Order Number LM4982TL NS Package Number TLA16CZA X1 = 2.543 ± 0.03 X2 = 2.949 ± 0.03 X3 = 0.6 ± 0.075 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 herein: 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. 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. BANNED SUBSTANCE COMPLIANCE National Semiconductor manufactures products and uses packing materials that meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. Leadfree products are RoHS compliant. National Semiconductor Americas Customer Support Center Email: [email protected] Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Support Center Email: [email protected] National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: [email protected] Tel: 81-3-5639-7560 LM4982 Ground-Referenced, Ultra Low Noise, 80mW Stereo Headphone Amplifier with IntelliSense and I2C Volume Control Physical Dimensions