LM4868MT National Semiconductor, LM4868MT Datasheet
LM4868MT
Available stocks
Related parts for LM4868MT
LM4868MT Summary of contents
Page 1
... 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 ...
Page 2
Connection Diagrams See NS Package Number LQA24A for Exposed-DAP LLP Typical Application * 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 ...
Page 3
... 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˚C/W (Note 9) 42˚ ...
Page 4
... 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’ ...
Page 5
... 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 ...
Page 6
... 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 ...
Page 7
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 ...
Page 8
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 ...
Page 9
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 ...
Page 10
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 ...
Page 11
Typical Performance Characteristics Power Supply Rejection Ratio Supply Current vs Supply Voltage ( Refer to Figure 1. ) Components 1. R This is the inverting input resistance that sets the closed-loop gain in conjunction with R i forms a high ...
Page 12
Application Information headphones. The headphones operate in a manner very similar to a bridge-tied-load (BTL). The same DC voltage is applied to both headphone speaker terminals. This results in no net DC current flow through the speaker. AC current flows ...
Page 13
Application Information FIGURE 4. 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.) FIGURE 5. Input MUX Example STEREO-INPUT MULTIPLEXER (STEREO MUX) The ...
Page 14
... LM4868MTE can take advantage of forced air cooling. With an air flow rate of 450 linear-feet per minute and a 2.5in exposed copper or 5.0in the LM4868MTE can continuously drive a 3Ω load to full or GND and power. The LM4868LQ achieves the same output power DD level without forced-air cooling. In all circumstances and under all conditions, the junction temperature must be held below 150˚ ...
Page 15
Application Information tical in magnitude, but 180˚ out of phase. Taking advantage of this phase difference, a load is placed between -OUTA and +OUTA and driven differentially (’commonly referred to as bridge mode’). This results in a differential gain of ...
Page 16
Application Information pop performance. The selection of bypass capacitor values, especially C , depends on desired PSRR requirements, B click and pop performance (as explained in the section, Proper Selection of External Components), system cost, and size constraints. MICRO−POWER SHUTDOWN ...
Page 17
Application Information FIGURE 7. The PCDN042 provides additional ESD protection beyond the 8000V shown in the Absolute Maximum Ratings for the AMP2A output Single-Ended Output Power Performance and Measurement Considerations The LM4868 delivers clean, low distortion SE output power into ...
Page 18
Application Information V ), the smaller the turn-on pop. Choosing C DD 1.0µF along with a small value 0.39µF), produces a click-less and pop-less shutdown func- tion. As discussed above, choosing C sary for the desired bandwidth ...
Page 19
Application Information f = 100Hz/5 = 20Hz L and 20kHz 100kHz H As mentioned in the Selecting Proper External Compo- nents section, R and C create a highpass filter that sets the i i ...
Page 20
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 ...
Page 21
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 ...
Page 22
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 ...
Page 23
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 ...
Page 24
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 ...
Page 25
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 ...
Page 26
... 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 ...
Page 27
... 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 ...
Page 28
... 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 ...