LM4780 / 3886 / 3875 / 1875 Comparison

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Comparison of typical electrical characteristics

Refer to the Design Log for an analysis of the similarity of the LM4780 and LM3886.

Parameter [ Conditions ]Symbol (Units) LM4780LM3886LM3875LM1875
Nominal Power OutputPo (W) 60 + 60685620
Year Started Production  20042002Not knownNot known
Overture(tm) Amplifier?  YesYesYesNo
SPiKe protection?  YesYesYesNo
Mute?  YesYesNoNo
Package  TO-220 27 pin (TA27A, Non-isolated, Tab at V-)TO-220 11 pin (TA11B, Non-isolated, Tab at V-) (TF11B isolated)TO-220 11 pin (TA11B, Non-isolated, Tab at V-) (TF11B isolated)TO-220 5 pin (T05A, Non-isolated, Tab at ??)
Package DissipationPdiss (W) 125 ; 68 [ at Po=30 W ]125 ; 50 [ with 1.3 degC/W heatsink ]125 ; 38 [ with 1.5 degC/W heatsink ]32 [ with 1degC/W heatsink ]
Thermal Resistance J-CThetaJC (degC/W) 0.8113
Thermal Resistance J-AThetaJA (degC/W) 30434373
Power Supply Voltage|V+| + |V-| (V) 20 (Min) to 84 (Max)20 (Min) to 84 (Max)20 (Min) to 84 (Max)60 (Max)
Conditions for following Electrical Characteristics (unless otherwise specified)  |V+|=|V-|=35V, Rl=8Ohm, Tamb=25DegC, Imute=-1mA|V+|=|V-|=28V, Rl=4Ohm, Tamb=25DegC, Imute=-0.5mA|V+|=|V-|=35V, Rl=8Ohm, Tamb=25DegC|V+|=|V-|=25V, Rl=8Ohm, Tamb=25DegC, Av=20 (26 dB), fo=1KHz
Output Power [ RL=8Ohm ] Po (W) 60 (50 Min) [ at THD + N = 0.5% max., f=1KHz, 20KHz ]38 (30 Min) [ at THD + N = 0.1%, f=1Khz to 20Khz ] ; 50 [ at |V+|=|V-|=35V ]56 [ at THD + N = 0.1%, f=1Khz to 20Khz ]20 [ at |V+|=|V-|=30V ]
Output Power [ RL=6Ohm ] Po (W) 55 (50 Min) [ at THD + N = 0.5%, f=1Khz, 20KHz, |V+|=|V-|=30V ]Not specifiedNot specifiedNot specified
Output Power [ RL=4Ohm ] Po (W) 55 (50 Min) [ at THD + N = 0.5%, f=1Khz, 20KHz, |V+|=|V-|=25V ]68 (60 Min) [ at THD + N = 0.1%, f=1Khz to 20Khz, |V+|=|V-|=28V ]Not specified30 [ at |V+|=|V-|=30V ] ; 20 [ at |V+|=|V-|=25V ]
Instantaneous Peak Output PowerPeak Po (W) Not specified135100Not specified
Total Harmonic Distortion Plus Noise [ RL=8Ohm ] THD + N (%) 0.03 [ at Pout=30W, F=20Hz to 20KHz, Av=26dB ]0.03 [ at Pout=40W, F=20Hz to 20KHz, Av=26dB ]0.06 [ at Pout=40W, F=20Hz to 20KHz, Av=26dB ]0.015 to 0.05 (0.4 Max) [ at Pout=20W, F=20Hz to 20KHz ]
Total Harmonic Distortion Plus Noise [ RL=6Ohm ] THD + N (%) 0.05 [ at Pout=30W, F=20Hz to 20KHz, Av=26dB ]Not specifiedNot specifiedNot specified
Total Harmonic Distortion Plus Noise [ RL=4Ohm ] THD + N (%) 0.07 [ at Pout=30W, F=20Hz to 20KHz, Av=26dB ]0.03 [ at Pout=40W, F=20Hz to 20KHz, Av=26dB ]Not specified0.022 to 0.07 (0.6 Max) [ at Pout=20W, F=20Hz to 20KHz ]
Channel Separation [ Po=10W, F=1KHz ] Xtalk (dB) 70N/AN/AN/A
Channel Separation [ Po=10W, F=10KHz ] Xtalk (dB) 72N/AN/AN/A
Slew RateSR (V/uS) 19 (8 Min] [ Vin=2Vp-p, Trise=2ns ]19 (8 Min) [ Vin=2Vp-p, Trise=2ns ]11 (5 Min, 16 Max) [ Vin=1.414 Vrms, f=10KHz, Square-wave, RL=2KOhm ]8 [ at Po=20W, RL=8Ohm, BW=70KHz ]
Total Quiescent Power Supply Current [ Vcm=0V, Vo=0V, Io=0mA ] I+ (mA) 110 (170 Max) [ both channels ]50 (85 Max)30 (70 Max)70 (100 Max)
Input Offset Voltage [ Vcm=0V, Io=0mA ] Vos (mV) 1 (10 Max)1 (10 Max)1 (10 Max)1 (15 Max)
Input Bias Current [ Vcm=0V, Io=0mA ] Ib (uA) 0.2 (1 Max)0.2 (1 Max)0.2 (1.0 Max)0.2 (2.0 Max)
Input Offset Current [ Vcm=0V, Io=0mA ] Ios (uA) Not specified0.01 (0.2 Max)0.01 (0.2 Max)0.0 (0.5 Max)
Output Current LimitIo (A) 11.5 (7 Min) [ at |V+|=|V-|=20V, ton=10ms ]11.5 (7 Min) [ at |V+|=|V-|=20V, ton=10ms, Vo=0V ]6 (4 Min) [ at |V+|=|V-|=10V, ton=10ms, Vo=0V ]4 (3 Min) [ at Vout=Vsupply-10V ]
Output Dropout Voltage [ Io=+100mA ] Vod (V) 1.6 (2.0 Max) [ at |V+-Vo-|, V+=28V ]1.6 (2.0 Max) [ at |V+-Vo-|, V+=28V ]1.6 (5.0 Max) [ at |V+-Vo-|, V+=20V ]Not specified
Output Dropout Voltage [ Io=-100mA ] Vod (V) 2.5 (3.0 Max) [ at |Vo-V-|, V-=-28V ]2.5 (3.0 Max) [ at |Vo-V-|, V-=-28V ]2.7 (5.0 Max) [ at |Vo-V-|, V-=-20V ]Not specified
Power Supply Rejection Ratio on V+ RailPSRR+ (dB) 120 (85 Min) [ at V+=40V to 20V, V-=40V, Vcm=0, Io=0 ]120 (85 Min) [ at V+=40V to 20V, V-=40V, Vcm=0, Io=0 ]120 (85 Min) [ at V+=40V to 20V, V-=40V, Vcm=0, Io=0 ]95 (52 Min) [ at Finject=1KHz, Vinject=1Vrms ]
Power Supply Rejection Ratio on V- RailPSRR- (dB) 105 (85 Min) [ at V+=40V, V-=-40 to -20V, Vcm=0, Io=0 ]105 (85 Min) [ at V+=40V, V-=-40 to -20V, Vcm=0, Io=0 ]120 (85 Min) [ at V+=40V, V-=-40 to -20V, Vcm=0, Io=0 ]83 (52 Min) [ at Finject=1KHz, Vinject=1Vrms ]
Common Mode Rejection Ratio [ V+=60 to 20V, V-=-20 to -60V, Vcm=20 to -20V, Io=0 ] CMRR 110 (85 Min)110 (85 Min)120 (80 Min)Not specified
Open Loop Voltage GainAvo (dB) 115 (90 Min) [ at Rl=2KOhm, DeltaVo=40V ]115 (90 Min) [ at |V+|=|V-|=28V, Rl=2KOhm, DeltaVo=40V ]120 (90 Min) [ at |V+|=|V-|=40V, Rl=2KOhm, DeltaVo=60V ]90
Gain Bandwidth ProductGBWP (MHz) 8 (2 Min) [ at Fin=100KHz, Vin=50mVRMS ]8 (2 Min) [ at |V+|=|V-|=30V, Fo=100KHz, Vin=50mVRMS ]8 (2 Min) [ at |V+|=|V-|=40V, Fo=100KHz, Vin=50mVRMS ]5.5 [ at Fo=20KHz ]
Input Noise [ Rin=600Ohm (Input Referred) ] eIN (uV) 2.0 (10.0 Max) [ IHF A Weighting Filter ]2.0 (10.0 Max) [ IHF A Weighting Filter ]2.0 (8.0 Max) [ IHF A Weighting Filter ]3.0 [ CCIR standard test ]
Signal-to-Noise Ratio [ Po=1W, A-Weighted, Meas at 1KHz, Rs=25Ohm ] SNR (dB) 9792.598Not specified
Signal-to-Noise Ratio [ A-Weighted, Meas at 1KHz, Rs=25Ohm ] SNR (dB) 114 [ at Po=50W ]110 [ at Po=60W ]114 [ at Po=40W ]Not specified
Signal-to-Noise Ratio [ A-Weighted, Meas at 1KHz, Rs=25Ohm ] SNR (dB) Not specifiedNot specified122 [ at Ppeak=100W ]Not specified
Intermodulation Distortion [ F=60Hz,7KHz, 4:1 (SMPTE) ] IMD (%) 0.0040.0040.004Not specified
Intermodulation Distortion [ F=60Hz,7KHz, 1:1 (SMPTE) ] IMD (%) 0.0090.0090.006Not specified
Minimum Stable GainGmin 10101010


Equivalent Schematics

LM1875


Click for a larger image (54K)

© National Semiconductor Corporation 2003. Reproduced for the purpose of fair research from the LM1875 PDF data sheet dated Jul 2003.

LM3875

Click for a larger image (17K)

© National Semiconductor Corporation 1999. Reproduced for the purpose of fair research from the LM3875 PDF data sheet dated June 1999. The schematic excludes the active protection circuitry.

LM3886

Click for a larger image (28K)

© National Semiconductor Corporation 2003. Reproduced for the purpose of fair research from the LM3886 PDF data sheet dated October 2003. The schematic excludes the active protection circuitry.

LM3886 Annotated Equivalent Schematic

Click for a larger image (38K)

Annotated for the purpose of fair research by Glenn Baddeley, 5 Sep 2004, from the LM3886 PDF data sheet dated October 2003. Refer to email correspondence with the Design Support Group at National Semiconductor for an explanation of the annotations. Original schematic © National Semiconductor Corporation 2003.

LM4780 Annotated Equivalent Schematic

Click for a larger image (81K)

Annotated for the purpose of fair research by Glenn Baddeley, 26 Sep 2004, from the LM3886 PDF data sheet dated October 2003 and the LM4780 PDF data sheet dated July 2003. There is no equivalent schematic published in the LM4780 PDF data sheet, but as it consists of two LM3886 die, a good equivalent schematic can be inferred. Refer to email correspondence with the Design Support Group at National Semiconductor for an explanation of the annotations.


Distortion versus Power Output

© National Semiconductor Corporation 2004. Reproduced for the purpose of fair research.

Maximum power supply voltages and an 8 Ohm load are shown.

LM1875

LM3875

  

LM3886

  

LM4780


Distortion versus Frequency

© National Semiconductor Corporation 2004. Reproduced for the purpose of fair research.

Maximum power supply voltages and an 8 Ohm load are shown.

LM1875

LM3875

LM3886

LM4780


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