TEA5101A
APPLICATION INFORMATION
PC BOARD LAYOUT
VOUT first value (100V) will be the reference.
The best performances of the high voltage video
amplifier will be obtained only with a carefully desi-
gned PC board. Output to input capacitances are
of particular importance.
The dynamic dissipation depends on the signal
spectrum and the load capacitance.
- Dynamicpower witha typical picture with150 Vpp
modulation is typically 1W.
- For a sine wave,dynamicdissipation peramplifier
is Pd = F x Cl x Vopp x Vdd x 0.8.
For a single amplifier, the input-output capaci-
tance, in parallel with the relatively high feedback
resis-tance, creates a polein the closed-loop trans-
fer function. A low parasitic capacitance (0.3pF)
feedbackresistor and HF isolated printed wires are
necessary. Further more, capacitive coupling from
the output of an amplifier toward the input of an-
other one may induce excessive crosstalk.
The load capacitance CL includes CRT and board
capacitance (10pF), and amplifier output capaci-
tance (8pF) : total CL value is about 20pF. For a
5MHZ, 50 Vpp sine wave and a 20pF load capaci-
tance, the maximum dynamic power is 2.5W.
- Generally, the maximum dynamic power is
reached with a white noise (tuner noise).
- Typical value is about 2W.
POWER DISSIPATION
Total dissipation is typically 3.6W (2.6W + 1W).
With a maximum static dissipation of 3.5W, total
dissipation is :
- 4.5W with a typical picture (UER pattern)
- 5.5W with white noise
The power dissipation consists of a static part and
a dynamic part. The static dissipation varies with
the output voltage. With VDD = 200V, Pstat = 2.6W
typ(3.5W max) at VOUT = 100V, 1.5W typ at 150V
and 3W typ at 50V (with R feedback= 39kΩ).
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STMICROELECTRONICS [ ST ]
