BA6820F ROHM Electronics, BA6820F Datasheet - Page 9

• Manufacturer Part Number: BA6820F
• Description: Led Level Meter Driver, 12-point X 2 Channel, vu Scale, Bar Display
• Manufacturer: ROHM Electronics

(8)
Pin 11 is the GND for the pin 12 to pin 21 driver circuits,
and pin 10 is the GND for the other signal circuits (see
Fig. 8).
Pins 10 and 11 are not connected internally, so both must
be connected to GND.
The large LED current that flows from pin 11 has a large
high-frequency component, so care must be taken with
regard to the PCB layout to avoid faulty operation of the
IC, and incorrect lighting of the LEDs due to noise.
FOperation notes
(1)
pins 1 and 3 to set the 0dB levels and adjust the channel
1 and channel 2 balance.
(2)
(pin 9). The external component values for C
0.01 F and 41k (or 39k ). If you wish to use other val-
ues, they should be in the ranges 0.001 F to 0.1 F and
10k to 100k . (see Fig. 9).
(3)
BA6822S / F comparators are large, and the compara-
tors will operate even with low-level signals.
For this reason, noise may cause the LEDs to light when
they should not, and to prevent this, GND line noise
should be kept sufficiently low.
(4)
age applied to them that is higher than V
GND (e.g. supply the LED current from a source other
than V
(5)
on and off in the range GND to V
with a large high-frequency component is generated.
Therefore, if the input and output lines are close, the out-
670
Audio ICs
GND terminal (pins 10 and 11)
Use the potentiometers VR1 and VR2 connected to
The recommended oscillator frequency is 4kHz
The dynamic ranges for the BA6820F and
Take care to ensure the none of the pins have a volt-
In general, the level meter output block is switched
CC
).
CC
, and a large voltage
CC
or lower than
5
and R
3
are
put may be fed back to the input and cause oscillation,
incorrect LED lighting, or faulty operation of the IC. De-
sign the PCB artwork so that there is no coupling be-
tween the input and output lines or with other units, in the
same way as for linear amplifier PCB design. If they must
be physically close, insert a capacitor between the input
and GND to reduce the AC input impedance, and prevent
noise from entering the input.
BA6820F / BA6822S / BA6822F