TDA6108 Philips Semiconductors, TDA6108 Datasheet - Page 10

• Manufacturer Part Number: TDA6108
• Description: Triple video output amplifier
• Manufacturer: Philips Semiconductors

Philips Semiconductors
External flashover protection
For sufficient flashover protection it is necessary to apply
an external diode and 100
See application note “Application and Product description
of TDA6107Q/N1” (report number AN96072).
To limit the diode current an external 1 k carbon
high-voltage resistor in series with the external diode and
a 2 kV spark gap are needed (for this resistor value, the
CRT has to be connected to the main PCB).
V
1. With a capacitor >20 nF with good HF behaviour
2. With a capacitor >3.3 F on the picture tube base
Switch-off behaviour
The switch-off behaviour of the TDA6108JF is controllable.
This is due to the fact that the output pins of the
TDA6108JF are still under control of the input pins for low
power supply voltages (approximately 30 V and higher).
Bandwidth
The addition of the flash resistor produces a decreased
bandwidth and increases rise and fall times. For further
information, see Application note of the TDA6108JF.
1999 Oct 29
DD
Triple video output amplifier
(e.g. foil); this capacitor must be placed as close as
possible to pins 6 and 4, but definitely within 5 mm.
print.
must be decoupled to GND:
resistor for each channel.
10
Dissipation
Regarding dissipation, distinction must first be made
between static dissipation (independent of frequency) and
dynamic dissipation (proportional to frequency).
The static dissipation of the TDA6108JF is due to voltage
supply currents and load currents in the feedback network
and CRT.
The static dissipation P
Where:
The dynamic dissipation P
Where:
The IC must be mounted on the picture tube base print to
minimize the load capacitance C
P
P
stat
V
I
V
I
dyn
C
C
f
V
DD
O(c)
i
DD
O(c)
o(c)(p-p)
L
int
= input frequency
= non-blanking duty cycle.
= load capacitance
=
= supply current
=
= internal load capacitance ( 4 pF)
= supply voltage
= DC value of cathode current.
= DC value of cathode voltage
V
3 V
DD
= output voltage (peak-to-peak value)
DD
I
DD
+
C
3 V
L
+
stat
C
O(c)
int
dyn
equals:
equals:
I
f
O(c)
i
L
.
V
Product specification
o(c)(p-p)
TDA6108JF