LM4938MH National Semiconductor, LM4938MH Datasheet
LM4938MH
Specifications of LM4938MH
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LM4938MH Summary of contents
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... Note 1: When properly mounted to the circuit board, LM4938MH will deliver 2W into 4Ω. See Application Information section Exposed-DAP package PCB Mounting Considerations for more information. Note 2: An LM4938MH that has been properly mounted to the circuit board and forced-air cooled will deliver 2.2W into 3Ω. Block Diagram Boomer ® ...
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... Connection Diagram See NS Package Number MXA28A for Exposed-DAP TSSOP www.national.com TSSOP Package 20095602 Top View Order Number LM4938MH 2 ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage Storage Temperature Input Voltage Power Dissipation (Note 11) ESD Susceptibility (Note 12) ESD Susceptibility (Note 13) Junction Temperature Soldering Information Small Outline Package Vapor Phase (60 sec ...
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Electrical Characteristics for Bridged Mode Operation The following specifications apply for V Symbol Parameter P Output Power O THD+N Total Harmonic Distortion + Noise PSRR Power Supply Rejection Ratio SNR Signal to Noise Ratio X Channel Separation talk Electrical Characteristics ...
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... Note 7: All voltages are measured with respect to the ground pins, unless otherwise specified. All specifications are tested using the typical application as shown in Figure 1. Note 8: When driving 3Ω loads from a 5V supply the LM4938MH must be mounted to the circuit board and forced-air cooled. Note 9: When driving 4Ω loads from a 5V supply the LM4938MH must be mounted to the circuit board. ...
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Typical Application Truth Table for Logic Inputs Gain Mode Headphone Sel Sense ...
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Typical Performance Characteristics THD+N vs Output Power 4Ω 1kHz DD L THD+N vs Output Power 32Ω, SE 1kHz DD L THD+N vs Output Power V = ...
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Typical Performance Characteristics THD+N vs Output Power 32Ω, SE 1kHz DD L THD+N vs Frequency 4Ω THD+N vs Frequency 32Ω, ...
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Typical Performance Characteristics THD+N vs Frequency 4Ω 600mW Frequency Response 4Ω Frequency Response 32Ω ...
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Typical Performance Characteristics Frequency Response 4Ω Frequency Response 32Ω PSRR vs Frequency 8Ω, Unterminated DD L www.national.com (Continued) ...
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Typical Performance Characteristics PSRR vs Frequency 32Ω, Unterminated DD L PSRR vs Frequency 8Ω, Unterminated DD L PSRR vs Frequency 32Ω, Unterminated ...
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Typical Performance Characteristics Crosstalk vs Frequency 32Ω Crosstalk vs Frequency 32Ω Power Derating Curve (Note 17) www.national.com (Continued) = 30mW, SE 20095610 ...
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Typical Performance Characteristics Power Dissipation vs Output Power Power Dissipation vs Output Power (Continued) Bass Boost Characteristics 20095665 Power Dissipation vs 20095651 13 External Gain/ 20095661 Output Power 20095652 www.national.com ...
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... Typical Performance Characteristics Note 17: These curves show the thermal dissipation ability of the LM4938MH at different ambient temperatures given these conditions: 2 500LFPM + 2in : The part is soldered to a 2in 2 2in on bottom: The part is soldered to a 2in 2 2 2in : The part is soldered to a 2in , 1oz. copper plane. ...
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... The last two area recommendations apply for 25˚C ambient temperature. Increase the area to compensate for ambient temperatures above 25˚C. In sys- tems using cooling fans, the LM4938MH can take advantage of forced air cooling. With an air flow rate of 450 linear-feet 2 per minute and a 2 ...
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... DMAX JMAX The LM4938’ 150˚C. In the MH package soldered JMAX to a DAP pad that expands to a copper area of 2in PCB, the LM4938MH’s θ is 41˚C/W. At any given ambient JA temperature T , use Equation (4) to find the maximum inter- A nal power dissipation supported by the IC packaging. Rear- ranging Equation (4) and substituting P sults in Equation (5) ...
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Application Information through the feedback resistor Thus, pops can be mini- f mized by selecting an input capacitor value that is no higher than necessary to meet the desired −6dB frequency. As shown in Figure 2, the input ...
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Application Information MICRO-POWER SHUTDOWN The voltage applied to the SHUTDOWN pin controls the LM4938’s shutdown function. Activate micro-power shut- down by applying V to the SHUTDOWN pin. When active, DD the LM4938’s micro-power shutdown feature turns off the amplifier’s bias ...
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Application Information GAIN SELECT FUNCTION (Bass Boost) The LM4938 features selectable gain, using either internal or external feedback resistors. Either set of feedback resistors set the gain of the output amplifiers. The voltage applied to the GAIN SELECT pin controls ...
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Application Information VOLUME CONTROL TABLE ( Table 2 ) Gain Voltage Range (% of Vdd) (dB) Low High Recommended 0 77.5% 100.00% 100.000% -1 75.0% 78.5% 76.875% -2 72.5% 76.25% 74.375% -3 70.0% 73.75% 71.875% -4 67.5% 71.25% 69.375% -5 ...
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... Recommended Printed Circuit Board Layout The following figures show the recommended PC board layouts for the LM4938MH. This circuit is designed for use with an external 5V supply and 4Ω speakers. This circuit board is easy to use. Apply 5V and ground to the board’s V (13) DD speakers between the board’ ...
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Recommended Printed Circuit Board Layout www.national.com (Continued) FIGURE 5. Top Layer Silkscreen FIGURE 6. Top Layer TSSOP 22 20095682 20095683 ...
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Recommended Printed Circuit Board Layout (Continued) FIGURE 7. Inner Layer (2) FIGURE 8. Inner Layer (3) 23 20095685 20095686 www.national.com ...
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Recommended Printed Circuit Board Layout www.national.com (Continued) FIGURE 9. Bottom Layer TSSOP 24 20095684 ...
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Item Part Number 1 551011373-001 10 482911373-001 20 151911368-001 25 152911368-001 26 152911368-002 27 152911368-003 28 152911368-004 29 152911368-005 30 472911368-001 31 472911368-002 32 472911368-003 33 472911368-004 40 131911368-001 41 131911368-002 42 131911368-003 43 131911368-004 44 131911368-005 45 131911368-006 Analog ...
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Revision History Rev 1.0 www.national.com Date Description 7/15/05 Added f = 1kHz to the titles on A2, A3, A4, A5, A6, A7, and A8. Re-released D the WEB. ...
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... Deutsch Tel: +49 (0) 69 9508 6208 English www.national.com Français Tel: +33 ( 8790 Exposed-DAP TSSOP Package Order Number LM4938MH 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 affect its safety or effectiveness. ...