lm4870 National Semiconductor Corporation, lm4870 Datasheet
lm4870
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lm4870 Summary of contents
Page 1
... LM4870 1.1W Audio Power Amplifier with Shutdown Mode General Description The LM4870 is a bridge-connected audio power amplifier ca- pable of delivering 1.1W of continuous average power load with less than 0.5% THD+N over the audio spectrum from a 5V power supply. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal number of external components ...
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... HP-SENSE = HP-SENSE = 500 µ −500 µ JMAX )/ or the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4870 resistor. 2 220˚C (typ) 35˚C/W JC (typ) 100˚C/W JA −20˚C T +85˚C MAX A 2 ...
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... Supply Voltage DS100094-16 ( Figure 1 ) Functional Description = 1/( 1/( THD+N vs Frequency DS100094-10 THD+N vs Output Power DS100094-13 Power Derating Curve DS100094- This resistor also THD+N vs Frequency DS100094-11 THD+N vs Output Power DS100094-14 LM4870 Noise Floor vs Frequency DS100094-18 www.national.com ...
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... Rejection Ratio DS100094-24 Application Information BRIDGE CONFIGURATION EXPLANATION As shown in Figure 1 , the LM4870 has two operational am- plifiers internally, allowing for a few different amplifier con- figurations. The first amplifier’s gain is externally config- urable, while the second amplifier is internally fixed in a unity-gain, inverting configuration. The closed-loop gain of the first amplifier is set by selecting the ratio of R the second amplifier’ ...
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... HP-IN1 pin to be approximately 50 mV when there are no headphones plugged into the system. This logic-low volt- age at the HP-IN1 pin enables the LM4870 to amplify AC sig- nals. Resistor R3 limits the amount of current flowing out of the HP-IN1 pin when the voltage at that pin goes below ground resulting from the music coming from the headphone amplifier ...
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... A designer must first determine the needed supply rail to ob- tain the specified output power. The Output Power vs Supply Voltage graphs in the Typical Performance Characteris- tics section show how much power the LM4870 will output given different supply voltage. According to the graph, 4.6V 6 ...
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... GBWP = . With 150 kHz which is much smaller than the LM4870 GBWP of 4 MHz. This figure displays that if a designer has a need to design an amplifier with a higher differential gain, the = vd LM4870 can still be used without running into bandwidth problems ...
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... 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 specifications. Small Outline Package (M) Order Number LM4870M NS Package Number M16A 2. A critical component is any component of a life ...