LM1972 www.ti.com SNAS094D - APRIL 1995 - REVISED MARCH 2013 LM1972 Pot 2-Channel 78dB Audio Attenuator with Mute Check for Samples: LM1972 FEATURES DESCRIPTION * * * * The LM1972 is a digitally controlled 2-channel 78dB audio attenuator fabricated on a CMOS process. Each channel has attenuation steps of 0.5dB from 0dB-47.5dB, 1.0dB steps from 48dB-78dB, with a mute function attenuating 104dB. Its logarithmic attenuation curve can be customized through software to fit the desired application. 1 2 3-Wire Serial Interface Daisy-Chain Capability 104dB Mute Attenuation Pop and Click Free Attenuation Changes APPLICATIONS * * * * * Automated Studio Mixing Consoles Music Reproduction Systems Sound Reinforcement Systems Electronic Music (MIDI) Personal Computer Audio Control KEY SPECIFICATIONS * * * * * * Total Harmonic Distortion + Noise: 0.003 % (max) Frequency response: 100 kHz (-3dB) (min) Attenuation range (excluding mute): 78 dB (typ) Differential attenuation: 0.25 dB (max) Signal-to-noise ratio (ref. 4 Vrms): 110 dB (min) Channel separation: 100 dB (min) The performance of a Pot is demonstrated through its excellent Signal-to-Noise Ratio, extremely low (THD+N), and high channel separation. Each Pot contains a mute function that disconnects the input signal from the output, providing a minimum attenuation of 96dB. Transitions between any attenuation settings are pop free. The LM1972's 3-wire serial digital interface is TTL and CMOS compatible; receiving data that selects a channel and the desired attenuation level. The DataOut pin of the LM1972 allows multiple Pots to be daisy-chained together, reducing the number of enable and data lines to be routed for a given application. Typical Application Connection Diagram Figure 1. Typical Audio Attenuator Application Circuit Figure 2. 20-Lead SOIC - Top View See DW Package 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 (c) 1995-2013, Texas Instruments Incorporated LM1972 SNAS094D - APRIL 1995 - REVISED MARCH 2013 www.ti.com 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) (3) Supply Voltage (VDD-VSS) 15V VSS - 0.2V to VDD + 0.2V Voltage at Any Pin Power Dissipation (4) ESD SusceptabiIity 150 mW (5) 2000V Junction Temperature 150C Soldering Information DW Package (10 sec.) +260C -65C to +150C Storage Temperature (1) (2) (3) (4) (5) All voltages are measured with respect to GND pins (1, 3, 5, 6, 14, 16, 19), 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. Electrical Characteristics state DC and AC electrical specifications under particular test conditions. This assumes that the device is within the Operating Ratings. 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, JA, and the ambient temperature TA. The maximum allowable power dissipation is PD = (TJMAX - TA)/JA or the number given in the Absolute Maximum Ratings, whichever is lower. For the LM1972, TJMAX = +150C, and the typical junction-to-ambient thermal resistance, when board mounted, is 65C/W. Human body model, 100 pF discharged through a 1.5 k resistor. Operating Ratings (1) (2) Temperature Range TMIN TA TMAX Supply Voltage (VDD - VSS) (1) (2) 2 TMIN TA TMAX 0C TA +70C 4.5V to 12V All voltages are measured with respect to GND pins (1, 3, 5, 6, 14, 16, 19), 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. Electrical Characteristics state DC and AC electrical specifications under particular test conditions. This assumes that the device is within the Operating Ratings. The typical value is a good indication of device performance. Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 LM1972 www.ti.com SNAS094D - APRIL 1995 - REVISED MARCH 2013 Electrical Characteristics (1) (2) The following specifications apply for all channels with VDD = +6V, VSS = -6V, VIN = 5.5 Vpk, and f = 1 kHz, unless otherwise specified. Limits apply for TA = 25C. Digital inputs are TTL and CMOS compatible. Symbol Parameter Conditions LM1972 Typical (3) IS Supply Current Inputs are AC Grounded THD+N Total Harmonic Distortion plus Noise VIN = 0.5 Vpk @ 0dB Attenuation XTalk Crosstalk (Channel Separation) 0dB Attenuation for VIN Limit (4) Units (Limits) 2 4 0.0008 0.003 mA (max) % (max) 110 100 dB (min) 120 110 dB (min) VCH measured @ -78dB SNR Signal-to-Noise Ratio Inputs are AC Grounded @ -12dB Attenuation A-Weighted AM Mute Attenuation Attenuation Step Size Error Absolute Attenuation Error 96 dB (min) 0dB to -47.5dB 104 0.05 dB (max) -48dB to -78dB 0.25 dB (max) Attenuation @ 0dB 0.03 0.5 dB (min) Attenuation @ -20dB 19.8 19.0 dB (min) Attenuation @ -40dB 39.5 38.5 dB (min) Attenuation @ -60dB 59.3 57.5 dB (min) Attenuation @ -78dB 76.3 74.5 dB (min) Channel-to-Channel Attenuation Attenuation @ 0dB, -20dB, -40dB, -60dB 0.5 dB (max) Tracking Error Attenuation @ -78dB 0.75 dB (max) ILEAK Analog Input Leakage Current Inputs are AC Grounded 10.0 100 nA (max) RIN AC Input Impedance Pins 4, 20, VIN = 1.0 Vpk, f = 1 kHz 40 20 k (min) 60 k (max) IIN Input Current fCLK Clock Frequency VIH High-Level Input Voltage @ Pins 9, 10, 11 2.0 V (min) VIL Low-Level Input Voltage @ Pins 9, 10, 11 0.8 V (max) Data-Out Levels (Pin 12) VDD=6V, VSS=0V 0.1 V (max) 5.9 V (min) (1) (2) (3) (4) @ Pins 9, 10, 11 @ 0V < VIN < 5V 1.0 100 nA (max) 3 2 MHz (max) All voltages are measured with respect to GND pins (1, 3, 5, 6, 14, 16, 19), 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. Electrical Characteristics state DC and AC electrical specifications under particular test conditions. This assumes that the device is within the Operating Ratings. The typical value is a good indication of device performance. Typicals are measured at 25C and represent the parametric norm. Limits are specified to Texas Instrument's AOQL (Average Output Quality Level). Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 3 LM1972 SNAS094D - APRIL 1995 - REVISED MARCH 2013 www.ti.com Timing Diagram Figure 3. Timing Diagram PIN DESCRIPTIONS Signal Ground (3, 19): Each input has its own independent ground, GND1 and GND2. Signal Input (4, 20): There are 2 independent signal inputs, IN1 and IN2. Signal Output (2, 17): There are 2 independent signal outputs, OUT1 and OUT2. Voltage Supply (13, 15): Positive voltage supply pins, VDD1 and VDD2. Voltage Supply (7, 18): Negative voltage supply pins, VSS1 and VSS2. To be tied to ground in a single supply configuration. AC Ground (1, 5, 6, 14, 16): These five pins are not physically connected to the die in any way (i.e., No bondwires). These pins must be AC grounded to prevent signal coupling between any of the pins nearby. Pin 14 should be connected to pins 13 and 15 for ease of wiring and the best isolation, as an example. Logic Ground (8): Digital signal ground for the interface lines; CLOCK, LOAD/SHIFT, DATA-IN and DATA-OUT. Clock (9): The clock input accepts a TTL or CMOS level signal. The clock input is used to load data into the internal shift register on the rising edge of the input clock waveform. Load/Shift (10): The load/shift input accepts a TTL or CMOS level signal. This is the enable pin of the device, allowing data to be clocked in while this input is low (0V). Data-In (11): The data-in input accepts a TTL or CMOS level signal. This pin is used to accept serial data from a microcontroller that will be latched and decoded to change a channel's attenuation level. Data-Out (12): This pin is used in daisy-chain mode where more than one Pot is controlled via the same data line. As the data is clocked into the chain from the C, the preceding data in the shift register is shifted out the DATA-OUT pin to the next Pot in the chain or to ground if it is the last Pot in the chain. The LOAD/SHIFT line goes high once all of the new data has been shifted into each of its respective registers. 4 Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 LM1972 www.ti.com SNAS094D - APRIL 1995 - REVISED MARCH 2013 Connection Diagram Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 5 LM1972 SNAS094D - APRIL 1995 - REVISED MARCH 2013 www.ti.com Typical Performance Characteristics 6 Supply Current vs Supply Voltage Supply Current vs Temperature Figure 4. Figure 5. Noise Floor Spectrum by FFT Amplitude vs Frequency THD vs Freq by FFT VDD - VSS = 12V Figure 6. Figure 7. THD vs VOUT at 1 KHz by FFT VDD - VSS = 12V Crosstalk Test Figure 8. Figure 9. Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 LM1972 www.ti.com SNAS094D - APRIL 1995 - REVISED MARCH 2013 Typical Performance Characteristics (continued) THD + N vs Frequency and Amplitude FFT of 1 kHz THD Figure 10. Figure 11. FFT of 20 kHz THD THD + N vs Amplitude Figure 12. Figure 13. THD + N vs Amplitude THD + N vs Amplitude Figure 14. Figure 15. Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 7 LM1972 SNAS094D - APRIL 1995 - REVISED MARCH 2013 www.ti.com APPLICATION INFORMATION ATTENUATION STEP SCHEME The fundamental attenuation step scheme for the LM1972 Pot is shown in Figure 16. This attenuation step scheme, however, can be changed through programming techniques to fit different application requirements. One such example would be a constant logarithmic attenuation scheme of 1dB steps for a panning function as shown in Figure 17. The only restriction to the customization of attenuation schemes are the given attenuation levels and their corresponding data bits shown in Table 1. The device will change attenuation levels only when a channel address is recognized. When recognized, the attenuation level will be changed corresponding to the data bits shown in Table 1. As shown in Figure 19, an LM1972 can be configured as a panning control which separates the mono signal into left and right channels. This circuit may utilize the fundamental attenuation scheme of the LM1972 or be programmed to provide a constant 1dB logarithmic attenuation scheme as shown in Figure 17. LM1972 Channel Attenuation vs Digital Step Value Figure 16. LM1972 Attenuation Step Scheme LM1972 Channel Attenuation vs Digital Step Value (Programmed 1.0dB Steps) Figure 17. LM1972 1.0dB Attenuation Step Scheme 8 Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 LM1972 www.ti.com SNAS094D - APRIL 1995 - REVISED MARCH 2013 LM1972 Channel Attenuation vs Digital Step Value (Programmed 2.0dB Steps) Figure 18. LM1972 2.0dB Attenuation Step Scheme Figure 19. Mono Panning Circuit INPUT IMPEDANCE The input impedance of a Pot is constant at a nominal 40 k. To eliminate any unwanted DC components from propagating through the device it is common to use 1 F input coupling caps. This is not necessary, however, if the dc offset from the previous stage is negligible. For higher performance systems, input coupling caps are preferred. OUTPUT IMPEDANCE The output of a Pot varies typically between 25 k and 35 k and changes nonlinearly with step changes. Since a Pot is made up of a resistor ladder network with a logarithmic attenuation, the output impedance is nonlinear. Due to this configuration, a Pot cannot be considered as a linear potentiometer, but can be considered only as a logarithmic attenuator. It should be noted that the linearity of a Pot cannot be measured directly without a buffer because the input impedance of most measurement systems is not high enough to provide the required accuracy. Due to the low impedance of the measurement system, the output of the Pot would be loaded down and an incorrect reading will result. To prevent loading from occurring, a JFET input op amp should be used as the buffer/amplifier. The performance of a Pot is limited only by the performance of the external buffer/amplifier. MUTE FUNCTION One major feature of a Pot is its ability to mute the input signal to an attenuation level of 104dB as shown in Figure 16. This is accomplished internally by physically isolating the output from the input while also grounding the output pin through approximately 2 k. Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 9 LM1972 SNAS094D - APRIL 1995 - REVISED MARCH 2013 www.ti.com The mute function is obtained during power-up of the device or by sending any binary data of 01111111 and above (to 11111111) serially to the device. The device may be placed into mute from a previous attenuation setting by sending any of the above data. This allows the designer to place a mute button onto his system which could cause a microcontroller to send the appropriate data to a Pot and thus mute any or all channels. Since this function is achieved through software, the designer has a great amount of flexibility in configuring the system. DC INPUTS Although the Pot was designed to be used as an attenuator for signals within the audio spectrum, the device is capable of tracking an input DC voltage. The device will track DC voltages to a diode drop above each supply rail. One point to remember about DC tracking is that with a buffer at the output of the Pot, the resolution of DC tracking will depend upon the gain configuration of that output buffer and its supply voltage. It should also be remembered that the output buffer's supply voltage does not have to be the same as the Pot's supply voltage. This could allow for more resolution when DC tracking. SERIAL DATA FORMAT The LM1972 uses a 3-wire serial communication format that is easily controlled by a microcontroller. The timing for the 3-wire set, comprised of DATA-IN, CLOCK, and LOAD/SHIFT is shown in Figure 3. Figure 22 exhibits in block diagram form how the digital interface controls the tap switches which select the appropriate attenuation level. As depicted in Figure 3, the LOAD/SHIFT line is to go low at least 150 ns before the rising edge of the first clock pulse and is to remain low throughout the transmission of each set of 16 data bits. The serial data is comprised of 8 bits for channel selection and 8 bits for attenuation setting. For both address data and attenuation setting data, the MSB is sent first and the 8 bits of address data are to be sent before the 8 bits of attenuation data. Please refer to Figure 20 to confirm the serial data format transfer process. Table 1. LM1972 Micropot Attenuator Register Set Description MSB: LSB Address Register (Byte 0) 0000 0000 Channel 1 0000 0001 Channel 2 0000 0010 Channel 3 Data Register (Byte 1) 10 Contents Attenuation Level dB 0000 0000 0.0 0000 0001 0.5 0000 0010 1.0 0000 0011 1.5 ::::: :: 0001 1110 15.0 0001 1111 15.5 0010 0000 16.0 0010 0001 16.5 0010 0010 17.0 ::::: :: 0101 1110 47.0 0101 1111 47.5 0110 0000 48.0 0110 0001 49.0 0110 0010 50.0 ::::: :: Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 LM1972 www.ti.com SNAS094D - APRIL 1995 - REVISED MARCH 2013 Table 1. LM1972 Micropot Attenuator Register Set Description (continued) MSB: LSB 0111 1100 76.0 0111 1101 77.0 0111 1110 78.0 0111 1111 100.0 (Mute) 1000 0000 100.0 (Mute) ::::: :: 1111 1110 100.0 (Mute) 1111 1111 100.0 (Mute) Figure 20. Serial Data Format Transfer Process Pot SYSTEM ARCHITECTURE The Pot's digital interface is essentially a shift register, where serial data is shifted in, latched, and then decoded. As new data is shifted into the DATA-IN pin, the previously latched data is shifted out the DATA-OUT pin. Once the data is shifted in, the LOAD/SHIFT line goes high, latching in the new data. The data is then decoded and the appropriate switch is activated to set the desired attenuation level for the selected channel. This process is continued each and every time an attenuation change is made. Each channel is updated, only, when that channel is selected for an attenuator change or the system is powered down and then back up again. When the Pot is powered up, each channel is placed into the muted mode. Pot LADDER ARCHITECTURE Each channel of a Pot has its own independent resistor ladder network. As shown in Figure 21, the ladder consists of multiple R1/R2 elements which make up the attenuation scheme. Within each element there are tap switches that select the appropriate attenuation level corresponding to the data bits in Table 1. It can be seen in Figure 21 that the input impedance for the channel is a constant value regardless of which tap switch is selected, while the output impedance varies according to the tap switch selected. Figure 21. Pot Ladder Architecture DIGITAL LINE COMPATIBILITY The Pot's digital interface section is compatible with either TTL or CMOS logic due to the shift register inputs acting upon a threshold voltage of 2 diode drops or approximately 1.4V. Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 11 LM1972 SNAS094D - APRIL 1995 - REVISED MARCH 2013 www.ti.com DIGITAL DATA-OUT PIN The DATA-OUT pin is available for daisy-chain system configurations where multiple Pots will be used. The use of the daisy-chain configuration allows the system designer to use only one DATA and one LOAD/SHIFT line per chain, thus simplifying PCB trace layouts. In order to provide the highest level of channel separation and isolate any of the signal lines from digital noise, the DATA-OUT pin should be terminated through a 2 k resistor if not used. The pin may be left floating, however, any signal noise on that line may couple to adjacent lines creating higher noise specs. Figure 22. Pot System Architecture DAISY-CHAIN CAPABILITY Since the Pot's digital interface is essentially a shift register, multiple Pots can be programmed utilizing the same data and load/shift lines. As shown in Figure 24, for an n-Pot daisy-chain, there are 16n bits to be shifted and loaded for the chain. The data loading sequence is the same for n-Pots as it is for one Pot. First the LOAD/SHIFT line goes low, then the data is clocked in sequentially while the preceding data in each Pot is shifted out the DATA-OUT pin to the next Pot in the chain or to ground if it is the last Pot in the chain. Then the LOAD/SHIFT line goes high; latching the data into each of their corresponding Pots. The data is then decoded according to the address (channel selection) and the appropriate tap switch controlling the attenuation level is selected. CROSSTALK MEASUREMENTS The crosstalk of a Pot as shown in the Typical Performance Characteristics was obtained by placing a signal on one channel and measuring the level at the output of another channel of the same frequency. It is important to be sure that the signal level being measured is of the same frequency such that a true indication of crosstalk may be obtained. Also, to ensure an accurate measurement, the measured channel's input should be AC grounded through a 1 F capacitor. 12 Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 LM1972 www.ti.com SNAS094D - APRIL 1995 - REVISED MARCH 2013 CLICKS AND POPS So, why is that output buffer needed anyway? There are three answers to this question, all of which are important from a system point of view. The first reason to utilize a buffer/amplifier at the output of a Pot is to ensure that there are no audible clicks or pops due to attenuation step changes in the device. If an on-board bipolar op amp had been used for the output stage, its requirement of a finite amount of DC bias current for operation would cause a DC voltage "pop" when the output impedance of the Pot changes. Again, this phenomenon is due to the fact that the output impedance of the Pot is changing with step changes and a bipolar amplifier requires a finite amount of DC bias current for its operation. As the impedance changes, so does the DC bias current and thus there is a DC voltage "pop". Secondly, the Pot has no drive capability, so any desired gain needs to be accomplished through a buffer/noninverting amplifer. Third, the output of a Pot needs to see a high impedance to prevent loading and subsequent linearity errors from ocurring. A JFET input buffer provides a high input impedance to the output of the Pot so that this does not occur. Clicks and pops can be avoided by using a JFET input buffer/amplifier such as an LF412ACN. The LF412 has a high input impedance and exhibits both a low noise floor and low THD+N throughout the audio spectrum which maintains signal integrity and linearity for the system. The performance of the system solution is entirely dependent upon the quality and performance of the JFET input buffer/amplifier. LOGARITHMIC GAIN AMPUFIER The Pot is capable of being used in the feedback loop of an amplifier, however, as stated previously, the output of the Pot needs to see a high impedance in order to maintain its high performance and linearity. Again, loading the output will change the values of attenuation for the device. As shown in Figure 23, a Pot used in the feedback loop creates a logarithmic gain amplifier. In this configuration the attenuation levels from Table 1, now become gain levels with the largest possible gain value being 78dB. For most applications 78dB of gain will cause signal clipping to occur, however, because of the Pot's versatility the gain can be controlled through programming such that the clipping level of the system is never obtained. An important point to remember is that when in mute mode the input is disconnected from the output. In this configuration this will place the amplifier in its open loop gain state, thus resulting in severe comparator action. Care should be taken with the programming and design of this type of circuit. To provide the best performance, a JFET input amplifier should be used. Figure 23. Digitally-Controlled Logarithmic Gain Amplifier Circuit Figure 24. n-Pot Daisy-Chained Circuit Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 13 LM1972 SNAS094D - APRIL 1995 - REVISED MARCH 2013 www.ti.com REVISION HISTORY Changes from Revision C (March 2013) to Revision D * 14 Page Changed layout of National Data Sheet to TI format .......................................................................................................... 13 Submit Documentation Feedback Copyright (c) 1995-2013, Texas Instruments Incorporated Product Folder Links: LM1972 PACKAGE OPTION ADDENDUM www.ti.com 21-Nov-2017 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (C) Device Marking (4/5) LM1972M LIFEBUY SOIC DW 20 36 TBD Call TI Call TI 0 to 70 LM1972M LM1972M/NOPB ACTIVE SOIC DW 20 36 Green (RoHS & no Sb/Br) CU SN Level-3-260C-168 HR 0 to 70 LM1972M LM1972MX/NOPB ACTIVE SOIC DW 20 1000 Green (RoHS & no Sb/Br) CU SN Level-3-260C-168 HR 0 to 70 LM1972M (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 <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. 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Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 21-Nov-2017 Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device LM1972MX/NOPB Package Package Pins Type Drawing SOIC DW 20 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 1000 330.0 24.4 Pack Materials-Page 1 10.9 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 13.3 3.25 12.0 24.0 Q1 PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM1972MX/NOPB SOIC DW 20 1000 367.0 367.0 45.0 Pack Materials-Page 2 PACKAGE OUTLINE DW0020A SOIC - 2.65 mm max height SCALE 1.200 SOIC C 10.63 TYP 9.97 SEATING PLANE PIN 1 ID AREA A 0.1 C 20 1 13.0 12.6 NOTE 3 18X 1.27 2X 11.43 10 11 B 7.6 7.4 NOTE 4 20X 0.51 0.31 0.25 C A B 2.65 MAX 0.33 TYP 0.10 SEE DETAIL A 0.25 GAGE PLANE 0 -8 0.3 0.1 1.27 0.40 DETAIL A TYPICAL 4220724/A 05/2016 NOTES: 1. All linear dimensions are in millimeters. Dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.15 mm per side. 4. This dimension does not include interlead flash. Interlead flash shall not exceed 0.43 mm per side. 5. Reference JEDEC registration MS-013. www.ti.com EXAMPLE BOARD LAYOUT DW0020A SOIC - 2.65 mm max height SOIC 20X (2) SYMM 1 20 20X (0.6) 18X (1.27) SYMM (R0.05) TYP 10 11 (9.3) LAND PATTERN EXAMPLE SCALE:6X SOLDER MASK OPENING METAL SOLDER MASK OPENING METAL UNDER SOLDER MASK 0.07 MAX ALL AROUND 0.07 MIN ALL AROUND SOLDER MASK DEFINED NON SOLDER MASK DEFINED SOLDER MASK DETAILS 4220724/A 05/2016 NOTES: (continued) 6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site. www.ti.com EXAMPLE STENCIL DESIGN DW0020A SOIC - 2.65 mm max height SOIC 20X (2) SYMM 1 20 20X (0.6) 18X (1.27) SYMM 11 10 (9.3) SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL SCALE:6X 4220724/A 05/2016 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design. www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated (TI) reserves the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. 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Unless TI has explicitly designated an individual product as meeting the requirements of a particular industry standard (e.g., ISO/TS 16949 and ISO 26262), TI is not responsible for any failure to meet such industry standard requirements. Where TI specifically promotes products as facilitating functional safety or as compliant with industry functional safety standards, such products are intended to help enable customers to design and create their own applications that meet applicable functional safety standards and requirements. Using products in an application does not by itself establish any safety features in the application. Designers must ensure compliance with safety-related requirements and standards applicable to their applications. Designer may not use any TI products in life-critical medical equipment unless authorized officers of the parties have executed a special contract specifically governing such use. Life-critical medical equipment is medical equipment where failure of such equipment would cause serious bodily injury or death (e.g., life support, pacemakers, defibrillators, heart pumps, neurostimulators, and implantables). Such equipment includes, without limitation, all medical devices identified by the U.S. Food and Drug Administration as Class III devices and equivalent classifications outside the U.S. TI may expressly designate certain products as completing a particular qualification (e.g., Q100, Military Grade, or Enhanced Product). Designers agree that it has the necessary expertise to select the product with the appropriate qualification designation for their applications and that proper product selection is at Designers' own risk. Designers are solely responsible for compliance with all legal and regulatory requirements in connection with such selection. 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