
LA2805, 2805M
No.3248–7/10
Proper Cares in Using IC
1. Printed Circuit Board
When designing the printed circuit board, make the ground line at pin 2 thicker and shorter. Especially, it should
be noted that if a common impedance exists in the ground, the distortion may worsen.
2. Power Amplifier
For the oscillation preventing capacitor connected across output pin 15 ground, it is recommended to use a
polyester film capacitor which is excellent in temperature characteristic and frequency characteristic. The use of
an aluminum electrolytic capacitor or ceramic capacitor may cause oscillation to occur at low temperature.
3. Shock Noise
The shock noise which occurs from the preamplifier at the time of input selection can be masked by applying
MUTE signal to pin 19. It is recommended that 3ms or greater of MUTE signal pulse width.
4. Control Input Circuit
Input circuit of control pins (22, 23, 24) is shown above.
Tri-state input pins (23, 24) selection level VCONT1, 2 :
VCONT1=VREF ×
[V],
VCONT2=VREF ×
[V]
5. Maximum Rating
If the IC is used in the vicinity of the maximum rating, even a slight variation in conditions may cause the
maximum rating to be exceeded, thereby leading to a breakdown. Allow an ample marging of variation for
supply voltage, etc. and use the IC in the range where the maximum rating is not exceed.
6. Short between Pins
If the supply voltage is applied when the space between pins is shorted, a breakdown or deterioration may occur.
When installing the IC on the board or applying the supply voltage, make sure that the space between pins is not
shorted with solder, etc.
7. Load Short
If the IC is used with the load shorted for a long time, a breakdown or deterioration may occur. Be sure not to
short the load.
6
7
3
7