STV9118 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STV9118' PDF : 46 Pages View PDF
STV9118
The frequency range in which the AGC loop can
regulate the amplitude also depends on this ca-
pacitor.
The C- and S-corrections of shape serve to com-
pensate for the vertical deflection system non-line-
arity. They are controlled via CCOR and SCOR
I2C bus controls.
Shape-corrected sawtooth with regulated ampli-
tude is lead to amplitude control stage. The dis-
charge exponential is replaced by VVOB level,
which, under control of the CONTROLLER, cre-
ates a rapid falling edge and a flat part before be-
ginning of new ramp. Mean value of the waveform
output on pin VOut is adjusted by means of VPOS
I2C bus control, its amplitude through VSIZE I2C
bus control. Vertical moiré is superimposed.
Figure 11. Vertical section block diagram
The biasing voltage for external DC-coupled verti-
cal power amplifier is to be derived from VRefO
voltage provided on pin RefOut, using a resistor di-
vider, this to ensure the same temperature drift of
mean (DC) levels on both differential inputs and to
compensate for spread of VRefO value (and so
mean output value) between particular devices.
10.4.2 - Vertical moiré
To blur the interaction of deflection lines with CRT
mask grid pitch that can generate moiré pattern,
the picture position is to be alternated at half-frame
frequency. For this purpose, a square waveform at
half-frame frequency is superimposed on the out-
put waveform’s DC value. Its amplitude is adjusta-
ble through VMOIRE I2C bus control,.
Charge current
Transconductance amplifier
VSyn2
Synchro
Polarity
OSC
Cap.
VCap
22
Discharge
Controller
Q1
REF
Sampling
sawtooth
discharge
20 VAGCCap
Sampling
Capacitance
S-correction
SCOR (I2C)
CCOR (I2C)
C-correction
18 VEHTIn
19
VOscF
VVOB VSIZE (I2C)
VMOIRE (I2C)
VPOS (I2C)
23 VOut
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