STV9118 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STV9118' PDF : 46 Pages View PDF
STV9118
Figure 13. EWOut output waveforms
V(EWOut)
VEW-Key
VEW-PCC
VEW-DC
VEW-TCor
VEW-BCor
VEW(max)
HSIZE (I2C)
maximum
medium
Keystone
alone
V(VCap)
0
TVR 0
PCC
alone
Top
Bottom
Corners
alone
minimum
VEW(min)
Breathing
compensation
VHEHT(min)
VRefO V(HEHT)
TVR 0
TVR tVR
Vertical sawtooth
10.6 - DYNAMIC CORRECTION OUTPUT SECTION
10.6.1 - Vertical dynamic correction output
VDyCor
A parabola at vertical deflection frequency is avail-
able on pin VDyCor. Its amplitude is adjustable via
VDC-AMP I2C bus control and polarity controlled
via VDyCorPol I2C bus bit. It tracks with real verti-
cal amplitude and position (including breathing
compensation). It is also affected by C- and S-cor-
rections.
The signal is buffered by an NPN emitter follower,
the emitter of which is routed to VDyCor output,
with an internal resistor to ground
The use of the correction waveform is up to the ap-
plication (e.g. dynamic focus).
10.7 - DC/DC CONTROLLER SECTION
The section is designed to control a switch-mode
DC/DC converter. A switch-mode DC/DC conver-
tor generates a DC voltage from a DC voltage of
different value (higher or lower) with little power
losses. The DC/DC controller is synchronized to
horizontal deflection frequency to minimize poten-
tial interference into the picture.
Its operation is similar to that of standard UC3842.
The schematic diagram of the DC/DC controller is
in Figure 14. The BOut output controls an external
switching circuit (a MOS transistor) delivering
pulses synchronized on horizontal deflection fre-
quency, the phase of which depends on I2C bus
configuration, see the table at the end of this chap-
ter. Their duration depends on feedback provided
to the circuit, generally a copy of DC/DC converter
output voltage and a copy of current passing
through the DC/DC converter circuitry (e.g. current
through external power component). A NPN tran-
sistor open-collector is routed out to the BOut pin.
34/46
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