TDA4866 4, Elektronika, elementy
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INTEGRATED CIRCUITS
DATA SHEET
TDA4866
Full bridge current driven vertical
deflection booster
Product specification
Supersedes data of 1996 Oct 10
File under Integrated Circuits, IC02
1999 Jun 14
Philips Semiconductors
Product specification
Full bridge current driven vertical deflection
booster
TDA4866
FEATURES
GENERAL DESCRIPTION
·
Fully integrated, few external components
The TDA4866 is a power amplifier for use in 90 degree
colour vertical deflection systems for frame frequencies of
50 to 160 Hz. The circuit provides a high CMRR current
driven differential input. Due to the bridge configuration of
the two output stages DC-coupling of the deflection coil is
achieved. In conjunction with TDA485x, TDA4841PS the
ICs offer an extremely advanced system solution.
·
No additional components in combination with the
deflection controller TDA485x, TDA4841PS
·
Pre-amplifier with differential high CMRR current mode
inputs
·
Low offsets
·
High linear sawtooth signal amplification
·
High efficient DC-coupled vertical output bridge circuit
·
Powerless vertical shift
·
High deflection frequency up to 160 Hz
·
Power supply and flyback supply voltage independent
adjustable to optimize power consumption and flyback
time
·
Excellent transition behaviour during flyback
·
Guard circuit for screen protection.
QUICK REFERENCE DATA
SYMBOL
PARAMETER
CONDITIONS MIN.
TYP.
MAX.
UNIT
DC supply;
note 1
V
P
supply voltage (pin 3)
8.2
-
25
V
V
FB
flyback supply voltage (pin 7)
note 2
-
-
60
V
I
q
quiescent current (pin 7)
-
7
10
mA
Vertical circuit
I
defl
deflection current
(peak-to-peak value; pins 4 and 6)
0.6
-
2
A
I
id
differential input current (peak-to-peak value)
note 3
-
±
500
±
600
m
A
Flyback generator
I
FB
maximum current during flyback
(peak-to-peak value; pin 7)
-
-
2
A
Guard circuit;
note 1
V
8
guard voltage
guard on
7.5
8.5
10
V
I
8
guard current
guard on
5
-
-
mA
Notes
1. Voltages refer to pin 5 (GND).
2. Up to 60 V
³
V
FB
³
40 V a decoupling capacitor C
FB
=22
m
F (between pin 7 and pin 5) and a resistor R
FB
= 100
W
(between pin 7 and V
FB
) are required (see Fig.4).
3. Differential input current I
id
=I
1
-
I
2
.
1999 Jun 14
2
Philips Semiconductors
Product specification
Full bridge current driven vertical deflection
booster
TDA4866
ORDERING INFORMATION
TYPE
NUMBER
PACKAGE
NAME
DESCRIPTION
VERSION
TDA4866
SIL9P
plastic single in-line power package; 9 leads
SOT131-2
BLOCK DIAGRAM
handbook, full pagewidth
GUARD
output
V
P
GND
V
FB
8
3
5
7
TDA4866
GUARD
CIRCUIT
FLYBACK
GENERATOR
6 OUTA
I
de
f
l
AMPLIFIER A
INA 1
C
SP
vertical
deflection
coil
R
SP
R
p
INPUT STAGE
PROTECTION
9
FEEDB
INB 2
R
ref
R
m
4 OUTB
AMPLIFIER B
from e.g.
TDA485x,
TDA4841PS
MED750
Fig.1 Block diagram.
PINNING
SYMBOL
PIN
DESCRIPTION
handbook, halfpage
INA
1
INA
1
input A
INB
2
INB
2
input B
V
P
3
V
P
3
supply voltage
OUTB
4
OUTB
4
output B
GND
5
ground
GND
5
TDA4866
OUTA
6
output A
OUTA
V
FB
6
V
FB
7
flyback supply voltage
7
GUARD
8
guard output
GUARD
8
FEEDB
9
feedback input
FEEDB
9
MED751
Fig.2 Pin configuration.
1999 Jun 14
3
Philips Semiconductors
Product specification
Full bridge current driven vertical deflection
booster
TDA4866
FUNCTIONAL DESCRIPTION
with R
bo
»
70 m
W
and
æ
1
–
1
V
Uloop
ö
»
0.98
è
ø
The TDA4866 consists of a differential input stage, two
output stages, a flyback generator, a protection circuit for
the output stages and a guard circuit.
for I
defl
= 0.7 A.
Differential input stage
The differential input stage has a high CMRR differential
current mode input (pins 1 and 2) that results in a high
electro-magnetic immunity and is especially suitable for
driver units with differential (e.g. TDA485x, TDA4841PS)
and single ended current signals. Driver units with voltage
outputs are simply applicable as well (e.g. two additional
resistors are required).
The deflection current can be adjusted up to
±
1 A by
varying R
ref
when R
m
is fixed to 1
W
.
High bandwidth and excellent transition behaviour is
achieved due to the transimpedance principle this circuit
works with.
Flyback generator
During flyback the flyback generator supplies the output
stage A with the flyback voltage. This makes it possible to
optimize power consumption (supply voltage V
P
) and
flyback time (flyback voltage V
FB
). Due to the absence of a
decoupling capacitor the flyback voltage is fully available.
In parallel with the deflection yoke and the damping
resistor (R
p
) an additional RC combination (R
SP
; C
SP
) is
necessary to achieve an optimized flyback behaviour.
The differential input stage delivers the driver signals for
the output stages.
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 TDA4866 requires no
external coupling capacitor (e.g. 2200
F) and operates
with one supply voltage V
P
and a separate adjustable
flyback supply voltage V
FB
only. The deflection current
through the coil (I
defl
) is measured with the resistor R
m
which produces a voltage drop (U
rm
) of: U
rm
»
m
Protection
The output stages are protected against:
·
Thermal overshoot
I
defl
.
At the feedback input (pin 9) a part of I
defl
is fed back to the
input stage. The feedback input has a current input
characteristic which holds the differential voltage between
pin 9 and the output pin 4 on zero. Therefore the feedback
current (I
9
) through R
ref
is:
R
m
´
·
Short-circuit of the coil (pins 4 and 6).
Guard circuit
The internal guard circuit provides a blanking signal for the
CRT. The guard signal is active HIGH:
·
At thermal overshoot
R
m
R
ref
I
9
»
---------- I
defl
´
·
When feedback loop is out of range
·
During flyback.
The input stage directly compares the driver currents into
pins 1 and 2 with the feedback current I
9
. Any difference of
this comparison leads to a more or less driver current for
the output stages. The relation between the deflection
current and the differential input current (I
id
) is:
The internal guard circuit will not be activated, if the input
signals on pins 1 and 2 delivered from the driver circuit are
out of range or at short-circuit of the coil (pins 4 and 6).
For this reason an external guard circuit can be applied to
detect failures of the deflection (see Fig.6). This circuit will
be activated when flyback pulses are missing, which is the
indication of any abnormal operation.
I
id
=
I
9
»
---------- I
defl
´
Due to the feedback loop gain (V
U loop
) and internal
bondwire resistance (R
bo
) correction factors are required
to determine the accurate value of I
defl
:
I
defl
=
I
id
´
R
ref
R
m
+
R
bo
´
æ
1
–
1
V
Uloop
ö
1999 Jun 14
4
-----------------
R
m
R
ref
------------------------
-----------------
è
ø
Philips Semiconductors
Product specification
Full bridge current driven vertical deflection
booster
TDA4866
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134); voltages referenced to pin 5 (GND); unless
otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN.
MAX.
UNIT
V
P
supply voltage (pin 3)
0
30
V
V
FB
flyback supply voltage (pin 7)
0
60
V
I
FB
flyback supply current
0
±
1.8
A
V
1
,V
2
input voltage
0
V
P
V
I
1
,I
2
input current
0
±
5
mA
V
4
,V
6
output voltage
0
V
P
V
I
4
,I
6
output current
note 1
0
±
1.8
A
V
9
feedback voltage
0
V
P
V
I
9
feedback current
0
±
5
mA
V
8
guard voltage
note 2
0
V
P
+ 0.4 V
I
8
guard current
0
±
5
mA
T
stg
storage temperature
-
20
+150
°
C
T
amb
operating ambient temperature
-
20
+75
°
C
T
j
junction temperature
note 3
-
20
+150
°
C
V
es
electrostatic handling for all pins
note 4
-
500
+500
V
Notes
1. Maximum output currents I
4
and I
6
are limited by current protection.
2. For V
P
> 13 V the guard voltage V
8
is limited to 13 V.
3. Internally limited by thermal protection; switching point
³
150
°
C.
4. Equivalent to discharging a 200 pF capacitor through a 0
W
series resistor.
THERMAL CHARACTERISTICS
SYMBOL
PARAMETER
VALUE
UNIT
R
th(j-mb)
thermal resistance from junction to mounting base
4
K/W
1999 Jun 14
5
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