tda9610h NXP Semiconductors, tda9610h Datasheet - Page 38

• Manufacturer Part Number: tda9610h
• Description: Audio Fm Processor For Vhs Hi-fi Audio
• Manufacturer: NXP Semiconductors

Adjustment of VCO frequency
Set the TDA9610H in record mode (NTSC off), no audio
input signal.
Measure the frequency at FMOUT (pin 56) with a
frequency counter and use the VCO TEST modes
(see Section “Function byte”) to output only the channel of
interest.
Adjust the VCO frequencies to 1.4 MHz 10 kHz and
1.8 MHz 10 kHz by means of the potentiometers at
pin 64 (FADJL) and pin 53 (FADJR).
When NTSC is to be the main video standard, set
NTSC on and adjust to 1.3 MHz and 1.7 MHz for optimum
frequency accuracy.
Standard FM deviation and audio level
Reference levels of frequency deviation and audio output
level are set by the resistor value at pin 24 (RVAR);
simultaneous for left, right, playback and record. Typical
resistor values can be calculated with equation:
Where:
If adjustment for overall tolerance is needed, R has to be
made adjustable for the range 0.7R
Set the TDA9610H in playback. Use a HF test generator to
make a carrier of 1.4 MHz with the desired modulation and
input this signal at FMINL (pin 61) or before the band-pass
filter and measure the audio output level at LINEL (pin 27).
R
Philips Semiconductors
1995 Mar 21
typ
A = reference audio output level (1 kHz audio
frequency).
Audio FM processor for VHS hi-fi audio
f = reference FM deviation.
=
---------------------------------------------- 2.2 k
-------------------------------------- -
400 mV (RMS)
----------------- -
50 kHz
A
f
2
typ
to 1.4R
typ
.
38
Power-down mode
To lower the dissipation in a stand-by situation, the 12 V
supply voltage at pin 19 (V
switched off, with pins 19 and 20 ‘floating’. No low-ohmic
DC path to ground may be seen from pins 19 and 20,
because this will drain extra current from the 5 V supply via
these pins to ground.
Because of the fact that the I
outputs RAF, NTSC and XS are supplied via the 5 V
supply, no I
still be used.
For instance, XS can be used to drive external mute
transistors to mute the DC jump at the line outputs when
switching the 12 V supply.
RAF I/O
The status of the I
(RAF = HIGH; record). This output can be used to switch
the audio FM head amplifier to playback and record. If
accurate fast switching of the TDA9610H is needed, this
pin can also be used as input. Thereby overruling the I
RAF bit. To make this possible the RAF output is current
limited.
When using the RAF pin as output, no more than 35 A
(LOW) and 185 A (HIGH) current may be drawn from this
pin to assure the mode of the TDA9610H is not changed.
When using the RAF pin as input, the voltage source used
must be capable of delivering at least 345 A (forced
HIGH; 3.5 V) or sinking at least 65 A (forced
LOW; 1.5 V).
2
C settings will be lost and the output pins can
2
C RAF bit is output at pin 14
DDA1
2
C circuitry and the digital
) and pin 20 (V
Product specification
TDA9610H
DDH
) may be
2
C