Daewoo DDT-21H9ZDF(21"), Service Manual

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Service Manual CP-099/FS
4-6 TDA8357J Vertical Amplifier
4-6-1- Features
- Few external components required
- High efficiency fully DC coupled vertical bridge output circuit
- Vertical flyback switch with short rise and fall times
- Built-in guard circuit
- Thermal protection circuit
- Improved EMC performance due to differential inputs.
4-6-2- General description
The TDA8357 is a power circuit for use in 90
o
and 110
o
colour deflection systems for 25 for 200 Hz field
frequencies, and for 4:3 and 16:9 picture tubes. The IC contains a vertical deflection output circuit, operating
as a high efficiency class G system. The full bridge output circuit allows DC coupling of the deflection coil in
combination with single positive supply voltages.
The IC is constructed in a Low Voltage DMOS(LVDMOS) process that combines bipolar, CMOS and DMOS
devices. DMOS transistors are used in the output stage because of absence of second breakdown.
4-6-3- Quick reference data
SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT.
Supplies
V
P
supply voltage 7.5 12 18 V
V
FB
flyback supply voltage 2 xV
P
45 66 V
I
q(P)(av)
average quiescent supply current during scan - 10 15 mA
I
q(FB)(av)
average quiescent flyback supply current during scan - 10 15 mA
P
tot
total power dissipation - - 8 W
Inputs and outputs
V
i(P-P)
input voltage(peak-to-peak value) - 1000 4500 mV
I
o(P-P)
output current(peak-to-peak value) - - 2.0 A
Flyback switch
I
o(peak)
maximum (peak) output current t 1.5 ms - - 1.2 A
Thermal data; in accordance with IEC 60747-1
T
stg
storage temperature -55 - +150
oC
T
amb
ambient temperature -25 - +85
oC
T
j
junction temperature - - 150
oC