lm4868 National Semiconductor Corporation, lm4868 Datasheet
lm4868
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lm4868 Summary of contents
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... LM4868MT will deliver 1.1W into 8Ω. See the Application Information sections for further information concern- ing the LM4868LQ and the LM4868MT. Note 2: An LM4868LQ or LM4868MTE that has been properly mounted to a circuit board and forced-air cooled will deliver 2.4W into 3Ω. Connection Diagrams ...
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... Refer to the Application Information section titled PROPER SELECTION OF EXTERNAL COMPONENTS for details concerning the value of C FIGURE 1. Typical Audio Amplifier Application Circuit (Pin out shown for the 24-pin Exposed-DAP LLP package. Numbers are for the 20-pin MTE and MT packages.) www.national.com (Continued) Top View Order Number LM4868LQ 2 20026738 20026731 . B ...
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... L LM4868LQ 3Ω L LM4868MTE 4Ω L LM4868LQ 4Ω L LM4868 8Ω L THD 1kHz (Note 16) LM4868MTE 3Ω L LM4868LQ 3Ω L LM4868MTE 4Ω L LM4868LQ 4Ω L LM4868 8Ω L THD kHz 32Ω 41˚C/W (Note 7) 51˚C/W (Note 8) 90˚ ...
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... Note 14: The quiescent power supply current depends on the offset voltage when a practical load is connected to the amplifier. Note 15: Output power is measured at the device terminals. Note 16: When driving 3Ω or 4Ω loads and operating supply, the LM4868LQ and LM4868MTE must be mounted to a circuit board that has a minimum of 2 2.5in of exposed, uniterrupted copper area connected to the LLP or TSSOP package’ ...
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... Typical Performance Characteristics MTE- and LQ- Specific Characteristics LM4868MTE THD+N vs Output Power LM4868LQ THD+N vs Output Power LM4868MTE THD+N vs Output Power 20026733 20026753 20026736 5 LM4868MTE THD+N vs Frequency 20026734 LM4868LQ THD+N vs Frequency 20026754 LM4868LQ THD+N vs Output Power 20026755 www.national.com ...
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... Power Derating Curve Note 18: This curve shows the LM4868MTE’s thermal dissipation ability at different ambient temperatures given these conditions: 500LFPM + JEDEC board: The part is soldered to a 1S2P 20-lead exposed-DAP TSSOP test board with 500 linear feet per minute of forced-air flow across it ...
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Typical Performance Characteristics THD+N vs Frequency THD+N vs Frequency THD+N vs Output Power 20026703 THD+N vs Output Power 20026705 THD+N vs Output Power 20026707 7 THD+N vs Frequency 20026704 20026706 20026708 www.national.com ...
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Typical Performance Characteristics THD+N vs Output Power THD+N vs Output Power Output Power vs Load Resistance www.national.com (Continued) 20026765 20026766 20026762 8 THD+N vs Frequency 20026763 THD+N vs Frequency 20026764 Power Dissipation vs Supply Voltage 20026760 ...
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Typical Performance Characteristics Output Power vs Supply Voltage Output Power vs Supply Voltage Output Power vs Load Resistance (Continued) 20026709 20026711 20026713 9 Output Power vs Supply Voltage 20026710 Output Power vs Load Resistance 20026712 Power Dissipation vs Output Power ...
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Typical Performance Characteristics Dropout Voltage vs Supply Voltage Power Dissipation vs Output Power Channel Separation www.national.com (Continued) 20026715 20026717 20026719 10 Power Derating Curve 20026716 Noise Floor 20026718 Channel Separation 20026720 ...
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... The signal return to circuit ground is through the headphone jack’s sleeve. speakers and The LM4868 eliminates these coupling capacitors. Amp2A is internally configured to apply V jack’s sleeve. This voltage matches the quiescent voltage present on the Amp1A and Amp1B outputs that drive the 11 ...
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... A). The inverting output (Trace C) and the non-inverting output (Trace D) are applied across an 8Ω BTL load. Figure 2 shows the LM4868’s lack of transients in the differ- ential signal (Trace B) across a BTL 8Ω load. The LM4868’s active-high SHUTDOWN pin is driven by the logic signal www ...
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... Exposed-DAP LLP package. Numbers are for the 20-pin MTE and MT packages.) FIGURE 5. Input MUX Example STEREO-INPUT MULTIPLEXER (STEREO MUX) The LM4868 has two stereo inputs. The MUX CTRL Pin controls which stereo input is active. As shown in the Truth Table for Logic Inputs, applying 0V to the MUX CTRL input activates stereo input 1, whereas applying V CTRL inputs activates stereo input 2 ...
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... NC) that implement the LM4868’s extra functionality, the LM4868MT/MTE and LM4863MT/MTE pin outs match. (Note 19) Note 19: If the LM4868 replaces an LM4863 and the input MUX circuitry is not being used, the LM4868 MUX CTRL pin must be tied to V the unused MUX inputs must be connected to GND. ...
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... LM4868’s supply pins and ground. Do not substitute a ce- ramic capacitor for the tantalum. Doing so may cause oscil- lation. Keep the length of leads and traces that connect capacitors between the LM4868’ ...
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... HP−IN pin to V speakers are muted and Amp1A and Amp2A drive a pair of headphones. When a switch shorts the HP−IN pin to GND, the LM4868 operates in bridge mode. If headphone drive is not needed, short the HP−IN pin to the −OUTB pin. Figure 7 shows an optional resistor connected between the amplifier output that drives the headphone jack sleeve and ground ...
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... I that is found using Equation (7 example when using a speaker with a low frequency limit of 150Hz shown in Figure 4 allows the LM4868 to drive high effi- i ciency, full range speaker whose response extends below 30Hz. Bypass Capacitor Value Selection Besides minimizing the input capacitor size, careful consid- eration should be paid to value of C nected to the BYPASS pin ...
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... Equation (10). 3ms 30ms 63ms Thus, a minimum gain of 2.83 allows the LM4868’s to reach full output swing and maintain low noise and THD+N perfor- mance. For this example, let A The amplifier’s overall gain is set using the input (R ...
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... With A (Continued) 100kHz, the closed-loop gain bandwidth product (GBWP) is (12) 300kHz. This is less than the LM4868’s 3.5MHz GBWP. With this margin, the amplifier can be used in designs that require more differential gain while avoiding performance,restricting bandwidth limitations. ...
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Application Information www.national.com (Continued) FIGURE 10. Recommended LQ PC Board Layout: Component-Side Layout FIGURE 11. Recommended LQ PC Board Layout: Upper Inner-Layer Layout 20 20026741 20026742 ...
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Application Information FIGURE 12. Recommended LQ PC Board Layout: FIGURE 13. Recommended LQ PC Board Layout: (Continued) Lower Inner-Layer Layout Bottom-Side Layout 21 20026743 20026744 www.national.com ...
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Application Information www.national.com (Continued) FIGURE 14. Recommended MTE PC Board Layout: Component-Side Silkscreen FIGURE 15. Recommended MTE PC Board Layout: Component-Side Layout 22 20026770 20026771 ...
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Application Information FIGURE 16. Recommended MTE PC Board Layout: FIGURE 17. Recommended MTE PC Board Layout: (Continued) Upper Inner-Layer Layout Lower Inner-Layer Layout 23 20026772 20026773 www.national.com ...
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Application Information www.national.com (Continued) FIGURE 18. Recommended MTE PC Board Layout: Bottom-Side Layout FIGURE 19. Recommended MT PC Board Layout: Component-Side Silkscreen 24 20026774 20026775 ...
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Application Information FIGURE 20. Recommended MT PC Board Layout: FIGURE 21. Recommended MT PC Board Layout: (Continued) Component-Side Layout Bottom-Side Layout 25 20026776 20026777 www.national.com ...
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... Physical Dimensions 24-Lead MOLDED PKG, Leadless Leadframe Package LLP 20-Lead MOLDED PKG, TSSOP, JEDEC, 4.4mm BODY WIDTH www.national.com inches (millimeters) unless otherwise noted Order Number LM4868LQ NS Package Number LQA24A Order Number LM4868MT NS Package Number MTC20 26 ...
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... Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 20-Lead MOLDED TSSOP, EXPOSED PAD, 6.5x4.4x0.9mm Order Number LM4868MTE NS Package Number MXA20A 27 www.national.com ...
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... 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 ...