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Philips Semiconductors
Video output amplifier
SYMBOL
O
cathode output voltage overshoot
v
SVRRH
high supply voltage rejection ratio
SVRRL
low supply voltage rejection ratio
Notes
1. If the difference between V
2. SVRR: The ratio of the change in supply voltage to the change in input voltage when there is no change in output
voltage.
Cathode output
The cathode output is protected against peak currents
(caused by positive voltage peaks during high-resistance
flash) of 5 A maximum with a charge content of 100 C.
The cathode is also protected against peak currents
(caused by positive voltage peaks during low-resistance
flash) of 10 A maximum with a charge content of 100 nC.
Flashover protection
The TDA6111Q incorporates protection diodes against
CRT flashover discharges that clamp the cathode output
pin to the V
pin. The DC supply voltage at the V
DDH
has to be within the operating range of 180 to 210 V to
ensure that the Absolute Maximum Rating for V
250 V will not be exceeded during flashover. To limit the
diode current, an external 680
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 5 ns
and a decrease in the overshoot of approximately 4%.
1995 Feb 07
PARAMETER
and V
is less than 7 V, overshoot cannot be specified.
DDL
ip
DDH
carbon high-voltage
CONDITIONS
V
= 100 V (p-p);
ocAC
V
= 100 V square
ocDC
wave; f < 1 MHz;
t
= t
= 22 ns;
r
f
see Figs 4 and 5; note 1
f < 50 kHz; note 2
f < 50 kHz; note 2
V
to GND must be decoupled:
DDH
1. With a capacitor >20 nF with good HF behaviour
(e.g. foil). This capacitance must be placed as close
as possible to pins 6 and 4, but definitely within 5 mm.
2. With a capacitor >10 F on the picture tube base print
(common for three output stages).
V
to GND must be decoupled:
DDL
1. With a capacitor >20 nF with good HF behaviour
(e.g. ceramic). This capacitance must be placed as
close as possible to pins 2 and 4, but definitely within
10 mm.
pin
DDH
Switch-off behaviour
of
The switch-off behaviour of the TDA6111Q is defined:
when the bias current becomes zero, at V
than approximately 5 V, all the output pins
(pins 7, 8 and 9) will be high.
7
Preliminary specification
TDA6111Q
MIN.
TYP.
MAX.
9
85
70
(pin 2) lower
DDL
UNIT
%
dB
dB
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