TDA9115 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'TDA9115' PDF : 45 Pages View PDF
TDA9115
Figure 13. EWOut output waveforms
V(EWOut)
VEW-Key
VEW-PCC
Keystone
alone
PCC
alone
V(VCap)
0
TVR 0
TVR
VEW(max)
VEW-DC HSIZE (I2C)
minimum
medium
maximum
VEW(min)
Breathing
compensation
VHEHT(mi n)
Vertical sawtooth
tVR
VRefO V(HEHT)
9.6 DYNAMIC CORRECTION OUTPUT
SECTION
9.6.1 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. It tracks with real verti-
cal amplitude and position (including breathing
compensation). It is also affected by C- and S-cor-
rections.
The use of this correction waveform is up to the
application (e.g. dynamic focus).
9.7 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). The polarity
of the output can be controlled by BOutPol I2C bus
bit. A NPN transistor open-collector is routed out to
the BOut pin.
During the operation, a sawtooth is to be found on
pin BISense, generated externally by the applica-
tion. According to BOutPh I2C bus bit, the R-S flip-
flop is set either at H-drive signal edge (rising or
falling, depending on BOHEdge I2C bus bit), or a
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