LM4780 / 3886 / 3875 / 1875 Comparison

• Comparison of typical electrical characteristics
• Equivalent Schematics
• Distortion versus Power Output
• Distortion versus Frequency

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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)	LM4780	LM3886	LM3875	LM1875
Nominal Power Output	Po (W)	60 + 60	68	56	20
Year Started Production		2004	2002	Not known	Not known
Overture(tm) Amplifier?		Yes	Yes	Yes	No
SPiKe protection?		Yes	Yes	Yes	No
Mute?		Yes	Yes	No	No
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 Dissipation	Pdiss (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-C	ThetaJC (degC/W)	0.8	1	1	3
Thermal Resistance J-A	ThetaJA (degC/W)	30	43	43	73
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 specified	Not specified	Not 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 specified	30 [ at |V+|=|V-|=30V ] ; 20 [ at |V+|=|V-|=25V ]
Instantaneous Peak Output Power	Peak Po (W)	Not specified	135	100	Not 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 specified	Not specified	Not 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 specified	0.022 to 0.07 (0.6 Max) [ at Pout=20W, F=20Hz to 20KHz ]
Channel Separation [ Po=10W, F=1KHz ]	Xtalk (dB)	70	N/A	N/A	N/A
Channel Separation [ Po=10W, F=10KHz ]	Xtalk (dB)	72	N/A	N/A	N/A
Slew Rate	SR (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 specified	0.01 (0.2 Max)	0.01 (0.2 Max)	0.0 (0.5 Max)
Output Current Limit	Io (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+ Rail	PSRR+ (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- Rail	PSRR- (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 Gain	Avo (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 Product	GBWP (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)	97	92.5	98	Not 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 specified	Not specified	122 [ at Ppeak=100W ]	Not specified
Intermodulation Distortion [ F=60Hz,7KHz, 4:1 (SMPTE) ]	IMD (%)	0.004	0.004	0.004	Not specified
Intermodulation Distortion [ F=60Hz,7KHz, 1:1 (SMPTE) ]	IMD (%)	0.009	0.009	0.006	Not specified
Minimum Stable Gain	Gmin	10	10	10	10

Equivalent Schematics

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

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© 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

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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

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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

© 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