u4460bg ETC-unknow, u4460bg Datasheet - Page 3

• Manufacturer Part Number: u4460bg
• Description: Video Amplifier With Fpll Demodulation
• Manufacturer: ETC-unknow

Rev. A1: 15.08.1995
FPLL, VCO and AFC
The FPLL circuit (frequency phase locked loop) consists
of a frequency and phase detector to generate control
voltage for the VCO tuning. In the locked mode the VCO
is controlled by the phase detector and in unlocked mode
the frequency detector is superimposed. The VCO
operates with an external resonance circuit (L and C par-
allel) and is controlled by internal varicaps. The VCO
control voltage is also converted to a current and
represents the AFC output signal at Pin 23.
A practicable VCO alignment of the external coil is the
adjustment to zero AFC output current at Pin 23. At centre
frequency the AFC output current is equal to zero. The
optional potentiometer at Pin 27 allows an offset
compensation of the VCO phase for improved sound
quality (fine adjustment). Without a potentiometer (open
circuit at Pin 27) this offset compensation is not active.
The oscillator signal passes a phase shifter and supplies
the in–phase signal (0) and the quadrature signal (90) of
the generated picture carrier.
Absolute maximum values
Reference point pin 3 (8, 17), unless otherwise specified
*) Equivalent to discharging a 200 pF capacitor through a 0 resistor
Operating range
TELEFUNKEN Semiconductors
Supply voltage
Supply current
Power dissipation, V
Output currents
External voltages
Junction temperature
Storage temperature
Electrostatic handling *)
Supply voltage range
Ambient temperature
s
= + 9 V
Parameters
Parameters
Pin 24
Pin 24
Pin 13
Pin 5, 6, 7, 11, 13, 18,
19, 27
Pin 20,21
Pin 12
Pin 20,23
all pins
Pin25
Preliminary Information
Video demodulation and amplifier
The video IF signal, which is applied from the gain
controlled IF amplifier, is multiplied with the inphase
component of the VCO signal. The video demodulator is
designed for low distortion and large bandwidth. The
demodulator output signal passes an integrated low pass
filter for attenuation of the residual vision carrier and is
fed to the video amplifier. The video amplifier is realized
by an operational amplifier with internal feedback and 8
MHz bandwidth (–3dB). The video signal is fed to VIF–
AGC and to the video output buffer. This amplifier with
6dB gain offers easy adaption of the sound trap. For
nominal video IF modulation the video output signal at
Pin 13 is 2 V (peak to peak value).
Internal voltage stabilizer
The internal bandgap reference ensures constant
performance independant of supply voltage and
temperature.
Symbol
Symbol
V
T
T
T
V
I
V
V
junc
ESD
amb
I
out
stor
P
ext
s
s
s
–25 to +125
4.5 to 9.0
0 to +85
+ 13.5
Value
Value
+ 4.5
+ 3.5
+125
t.b.f.
765
9.0
V
85
5
s
U4460BG
Unit
mW
Unit
mA
mA
V
V
V
V
V
V
V
C
C
C
3 (9)