752161473GP CTS Resistor Products, 752161473GP Datasheet
752161473GP
Specifications of 752161473GP
752161473GPB
Related parts for 752161473GP
752161473GP Summary of contents
Page 1
LM4805 Low Voltage High Power Audio Power Amplifier General Description The LM4805 is a boosted audio power amplifier designed for driving 8ohm speakers in portable applications. It delivers at least 1W continuous power to an 8Ω load from any input ...
Page 2
Typical Application * Cf2 is optional. FIGURE 1. Typical Audio Amplifier Application Circuit www.national.com 20126210 2 ...
Page 3
Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage ( Supply Voltage ( Storage Temperature Input Voltage Power Dissipation (Note 3) ESD ...
Page 4
Electrical Characteristics V The following specifications apply for V wise specified. Limits apply for T = 25˚C. A Symbol Parameter V Feedback Pin Reference Voltage FB Note 1: All voltages are measured with respect to the GND pin, unless otherwise ...
Page 5
Typical Performance Characteristics THD+N vs Frequency 6dB THD+N vs Frequency 26dB THD+N vs Frequency V = 4.2V 6dB ...
Page 6
Typical Performance Characteristics THD+N vs Frequency V = 4.2V 26dB THD+N vs Output Power 6dB THD+N vs Output Power 26dB ...
Page 7
Typical Performance Characteristics THD+N vs Output Power V = 4.2V 6dB THD+N vs Output Power V = 4.2V 26dB Supply Current vs Supply Voltage (Continued) = 8Ω L 20126223 = ...
Page 8
Typical Performance Characteristics Power Dissipation vs Output Power 16Ω 1kHz DD L Power Dissipation vs Output Power V = 4.2V 16Ω 1kHz DD L Output Power vs Load Resistance ...
Page 9
Typical Performance Characteristics Output Power vs Supply Voltage R = 16Ω 1kHz L PSRR vs FREQUENCY 26dB 200mV ripple P-P PSRR vs FREQUENCY V = 4.2V 26dB ...
Page 10
Typical Performance Characteristics Amplifier Frequency Response vs Input Capacitor Size Switch Current Limit vs Duty Cycle - ”X” Feedback Voltage vs Temperature www.national.com (Continued) 20126242 20126243 20126246 10 Amplifier Open Loop vs Frequency Respose 20126241 Oscillator Frequency vs Temperature - ...
Page 11
... The closed-loop gain of the first amplifier is set by selecting the ratio while the second amplifier’s gain is fixed by the two internal 20kΩ resistors. Figure 1 shows that the output of amplifier one serves as the input to amplifier two. This results in both amplifiers producing sig- nals identical in magnitude, but out of phase by 180˚ ...
Page 12
Application Information nal power dissipation is 4 times that of a single-ended am- plifier. The maximum power dissipation for a given BTL application can be derived from Equation 4(V ) DMAX(AMP) DD BOOST CONVERTER POWER DISSIPATION ...
Page 13
... SETTING THE OUTPUT VOLTAGE (V (Continued) CONVERTER The output voltage is set using the external resistors R1 and R2 (see Figure 1). A value of approximately 15k is recom- mended for R2 to establish a divider current of approxi- mately 92µ calculated using the formula: FEED-FORWARD COMPENSATION FOR BOOST CONVERTER Although the LM4805’ ...
Page 14
Application Information put ripple. Continuous operation is defined as not allowing the inductor current to drop to zero during the cycle. It should be noted that all boost converters shift over to discontinuous operation as the output load is reduced ...
Page 15
Application Information GENERAL MIXED-SIGNAL LAYOUT RECOMMENDATION This section provides practical guidelines for mixed signal PCB layout that involves various digital/analog power and ground traces. Designers should note that these are only "rule-of-thumb" recommendations and the actual results will depend heavily ...
Page 16
Demonstration Board Layout www.national.com Composite Layer 20126251 Top Layer 20126253 16 ...
Page 17
Demonstration Board Layout (Continued) Silkscreen 20126252 Bottom Layer 20126254 17 www.national.com ...
Page 18
Revision History Rev 1.0 www.national.com Date Description 8/11/05 Changed the project title from 3V, 1W Boosted Amplifier into Low Voltage High Power Audio Power Amplifier (per Nisha P.), then re-released D/S to the WEB. 18 ...
Page 19
Physical Dimensions inches (millimeters) unless otherwise noted 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 ...