SGS Thomson Microelectronics TDA4950 Datasheet
TV EAST/WEST CORRECTION CIRCUIT
.
LOW DISSIPATION
.
SQUARE GENERATOR FOR PARABOLIC
CURRENT
.
EXTERNA L KEYSTONE AD JUST MENT (sym metry of the parabola)
.
INPUT FOR DYNAMIC FIELD CORRECTION
(beam current change)
.
ST ATIC P ICTURE WI DTH A DJ USTM ENT
.
PULSE-WIDTH MODULATOR
.
FINAL STAGE D-C LASS WITH EN ERGY REDELIVERY
.
PARASITIC PARABOLA SUPPRESSION,
DURIN G FLYBACK TIME OF TH E VERTICAL
SAWTOOTH
POWERDIP8
(Plastic Package)
TDA4950
(Th = 0.4mm)
DESCRIPTION
The TDA4950 is a monolithic integrated circuit in a
8 pin minidip plastic package designed for use in
the east-west pin-cushion correction by driving a
diode modulator in TV and monitor applications.
PIN CONNECTIONS
KEYSTONE CORRECTION INPUT
FRAME SAWTOOTH CURRENT INPUT
CURRENT REFERENCE
GND
1
2
3
4
ORDER CODE :
8
NON-INVERTING INPUT 100
7
PARABOLA OUTPUT INVERTING INPUT
+V
6
5
S
OUTPUT
TDA4950
µ
A CURRENT SINK
October 1998
4950-01.EPS
1/5
TDA4950
BLOCK DIAGRAM
TDA4950
1
2
I
IN
VS - 3 V
Q7
CURRENT LIMITER
BE
OP1
VS - 6 V
BE
Q1
Q2
R5
Q5
Q6
Q8 Q9
Q4Q13
Q10
7
R9
8
COMPARATOR AND OUTPUT STAGE
V
OP2
Q11
R10 R11 R12 R13
+V
6
S
Q14
Q13
REF
R5
R6
Q12
R7
R2
Q21
D2
D3
Z1
Q15
Q16
Q20
Q22
D1
5
OUTPUT
I
REF
4
GND
Q18Q17
R3
R4
Q19
R8
OP3
FULL-WAVE RECTIFIER
PARABOLA NETWORK
CURRENT REFERENCE
3
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
I
S
P
tot
, TjStorage and Junction Temperature – 25, +150
T
stg
Supply Voltage 35 V
S
Supply Current 500 mA
Power Dissipation at T
= 70 °C 800 mW
amb
THERMAL DATA
Symbol Parameter Value Unit
R
th (j-a)
R
th (j-c)
ELECTRICAL CHARACTERISTICS
Thermal Resistance Junction-ambient Max. 100
Thermal Resistance Junction-pin (4) Max. 70
= 25oC, VS = 26 V, V
(T
amb
= 0, S1 and S2 in "a" position,
fr
refer to test circuit unless otherwise specified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
– I
V
V
V
I
S
V
ref
7(A)
7(B)
Supply Voltage 17 24 30 V
S
Supply Current 4.5 7 mA
Internal Reference Voltage 7.6 8.0 8.8 V
Internal Reference Current V
ref
/R3 0.73 mA
ref
Pin 7 Output Voltage Ifr = 0 µA, see Figure 2 15.3 16.0 16.7 V
Pin 7 Output Voltage Ifr = 30 µA, see Figure 2 15 V
°
°
C/W
°
C/W
4950-02.EPS
C
4950-01.TBL
4950-02.TBL
4950-03.TBL
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