BA6800 ROHM [Rohm], BA6800 Datasheet - Page 6

• Manufacturer Part Number: BA6800
• Description: Fluorescent display tube level meter driver, 16-point x 2 channel, VU scale, bar display
• Manufacturer: ROHM [Rohm]

FTiming chart
FAttached components (refer to “Circuit operation”)
C
VR
justment (3k recommended).
C
respect to the AC input signal. In the example given, the
attack time is about 4mS and the release time is about
1sec.
R
R
Set so that I
R
Conditions for base bias current (I
V
the base current is given by the following formula.
Set resistors R
Q
tors for which V
R8 to R
grid when the fluorescent tube is not lit.
The application example given is for general cases. Se-
lect the resistors to suit the characteristics of the fluores-
cent tube used.
C
Capacitor C
ture characteristics.
Audio ICs
F
1
3
3
6
4
5
1
, R
: Pullup resistor for the input switching terminal (pin 7).
and C
and R
and R
= 0.6V :
and Q
and R
1
I
I
and VR
B
B
R
R
1
(mA)
, C
>
4
6
25
4
2
7
5
2
26
: Resistors that reverse bias the segments and
<
and R
: grid output inverting transistors. Use transis-
: input coupling capacitors.
: resistor for the grid leak current path (I
: base bias resistors for Q
Fluorescent tube grid current
: set the oscillator frequency.
2
5
Gleak
: AC sensitivity adjustment and balance ad-
should be a component with good tempera-
5*0.6
0.6
4
CEO
2
and R
5*0.6
: set the response characteristics with
R
R
> V
4
6
(k )
= 7.3
(R
6
CC
(R
h
7
*
) V
) < 0.6V.
FE
5
and R
R
EE
6
0.6
(k )
.
B
7
) flow are V
) so that
1
and Q
2
CC
.
= 5V and
Gleak
).
FOperation notes
(1)
to pins 1 and 3) to adjust the 0dB input level and the dis-
persion of ch1 and ch2.
(2)
for the 16th LED is shown in Fig. 6.
(3)
tor (pin 28) should be in the range of 20k and 100k .
If it is outside this range, oscillation may stop due to the
influence of temperature (see Fig. 7).
Adjust the potentiometers VR
The temperature characteristic for the lighting limit
The external resistor R26 connected to the oscilla-
1
and VR
BA6800AF
2
(connected
809