TDA4867J Philips Semiconductors, TDA4867J Datasheet - Page 4

• Manufacturer Part Number: TDA4867J
• Description: Full bridge current driven vertical deflection booster
• Manufacturer: Philips Semiconductors

Philips Semiconductors
PINNING
FUNCTIONAL DESCRIPTION
The TDA4867J consists of a differential input stage, two
output stages, a flyback generator, a protection circuit for
the output stages and a guard circuit.
Differential input stage
The differential input stage has a high CMRR differential
current mode input (pin INP and pin INN) that results in a
high electromagnetic immunity and is especially suitable
for driver units with differential (e.g. TDA485x or SAA4856)
and single-ended current signals.
The differential input stage delivers the driver signals for
the output stages.
2003 Feb 05
handbook, halfpage
INP
INN
V
OUTB
GND
OUTA
V
GUARD
FEEDB
SYMBOL
P
FB
Full bridge current driven vertical
deflection booster
GUARD
FEEDB
OUTB
OUTA
GND
Fig.2 Pin configuration.
V FB
PIN
INP
INN
V P
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
TDA4867J
non-inverted input
inverted input
supply voltage
output B
ground
output A
flyback supply voltage
guard output or power save
mode input
feedback input
MGU989
DESCRIPTION
4
In combination with the SAA4856 the power save mode
can be achieved via the input pins without additional
components.
Output stages
The two output stages are current driven in opposite phase
and operate in combination with the deflection coil in a full
bridge configuration. Therefore, the TDA4867J requires no
external coupling capacitor and operates with one supply
voltage (V
voltage (V
(I
voltage drop: U
is fed back to the input stage. The feedback input has a
current input characteristic which holds the differential
voltage between pin FEEDB and pin OUTB on zero.
Therefore the feedback current (I
The input stage directly compares the driver currents into
pins INP and INN with the half of the feedback current
(I
or less driver current for the output stages. The relation
between the deflection current and the differential input
current (I
The deflection current can be adjusted up to 1.25 A by
varying R
Flyback generator
The flyback generator supplies the output stage A during
flyback. This makes it possible to optimize power
consumption (supply voltage V
voltage V
decoupling capacitor the flyback voltage is fully available.
In parallel with the deflection yoke and the damping
resistor (R
resistor (R
optimized depending on the value of C
I
I
I
FEEDB
i dif
defl
defl
FEEDB
) is measured with the resistor R
=
I
). Any difference of this comparison leads to a more
i dif
2 I
i(dif)
FB
--------- -
R
ref
R
P
FB
p
SP
) and a separate adjustable flyback supply
ref
) an additional capacitor (C
) separately. Due to the absence of a
m
when R
) only. The deflection current through the coil
FEEDB
) have to be used. The flyback time can be
= I
-----------------
2 R
R
rm
INP
I
defl
ref
m
R
m
I
m
--------- -
R
INN
R
is fixed to 1 .
ref
m
) is:
I
defl
I
defl
. At pin FEEDB a part of I
P
) and flyback time (flyback
FEEDB
Preliminary specification
2
or:
m
SP
which produces a
) through R
SP
TDA4867J
) and a series
.
ref
is:
defl