1997 Mar 03
7
Philips Semiconductors
Product specification
Video output amplifier
TDA6106Q
Fig.4 Output voltage (pin 8 falling edge) as a function of AC input signal.
150
140
100
60
50
51
49
s
t
overshoot (in %)
t
t
0
x
x
t f
pd
t
Voc
Vi
MGA975
Flashover protection
The TDA6106Q incorporates a protection diode against
CRT flashover discharges that clamp the cathode output
voltage to a maximum of V
DD
+ V
diode
. To limit the diode
current, an external 1.5 k
Ω
carbon high-voltage resistor in
series with the cathode output and a 2 kV spark gap are
needed (for this resistor-value, the CRT has to be
connected to the main PCB). This addition produces an
increase in the rise and fall times of approximately 7.5 ns
and a decrease in the overshoot of approximately 1.3%.
V
DD
to GND must be decoupled:
1. With a capacitor larger than 20 nF with good HF
behaviour (e.g. foil). This capacitor must be placed as
close as possible to pins 6 and 4, but definitely within
5 mm.
2. With a capacitor larger than10
µ
F on the picture tube
base print (shared by three output stages).
Switch-off behaviour
The output pins of the TDA6106Q are still under the control
of the input pin for a supply voltage down to approximately
30 V.
