Operating power amplifier integrated circuit LM4780 from National Semiconductor .
What is special? Well, first of all – it is very low harmonic distortion. Typically, manufacturers indicate the maximum power of its regular genius crafts at THD 10%. At the same chip, the CG at the maximum specified power is only 0.5%!
IC Features :
| Supply voltage | : 20 … 84V |
| Supply current absence of a signal | : 110mA |
| Output Power (CG = 0.5% = 35V Upit) |
: 60W |
| Harmonic (Pout = 30W, RL = 8Ohm) | : 0.03% |
| S / N ratio (weighted) | : 114% |
In the chip implements two identical channels of amplification and specifications are for the stereo mode of the amplifier. Chip can also operate in mono – in bridged mode. In this case, the output power at CG = 0.5% at 120 watts. The other characteristics remain practically unchanged.
Below is a schematic of the LM4780 Mono channel mode :
Parts list :
|
Notation on the chart |
Nominal |
|
C1 |
15 |
|
C2 |
15 |
|
C3 |
1uF |
|
C4 |
1uF |
|
C5 |
68uF/50V |
|
C6 |
68uF/50V |
|
C7 |
0.1 |
|
C8 |
10uF/50V |
|
C9 |
0.1 |
|
C10 |
1000uF/50V |
|
C11 |
10uF/50V |
|
C12 |
1000uF/50V |
|
C13 |
0.1 |
|
C14 |
0.1 |
|
R1 |
10K |
|
R2 |
1K |
|
R3 |
1K |
|
R4 |
15kOm |
|
R5 |
1K |
|
R6 |
15kOm |
|
R7 |
1K |
|
R8 |
20kOm |
|
R9 |
2.7 Ohm |
|
R10 |
2.7 Ohm |
|
R11 |
20kOm |
|
DA1 |
LM4780 |
