tda9725 NXP Semiconductors, tda9725 Datasheet - Page 7

• Manufacturer Part Number: tda9725
• Description: Y/c Automatic Adjustment Processor Vhs Standard
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FUNCTIONAL DESCRIPTION
Record (REC)/electric to electric (EE) mode
L
From input pin 43 the CVBS signal is fed via the automatic
gain control (AGC) and subclamp (SCL) to the output
pin 41. Instead of the controlled and clamped CVBS signal
it is also possible to switch (dependent on the level at
pin 42) white, black or sync-level to this pin. To eliminate
chrominance parts the CVBS signal is fed to the luminance
low-pass filter (YLPF) and to the sync separator stage.
The sync signal is available at pin 45. The signal is also fed
via vertical emphasis non-linear emphasis (NLE),
deviation control stage, main emphasis and white-dark clip
to the FM modulator. The FM signal is available at pin 11.
C
The chrominance signal is selected out of CVBS (from
pin 43) in BPF 4.43 MHz (band-pass filter) and controlled
in automatic chrominance control (ACC).
The chrominance signal is mixed with 5.06 MHz to
627 kHz and via LPF 627 kHz to the output pin 30.
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
Note
1. Charge device model class B: discharging a 200 pF capacitor via a 0
THERMAL CHARACTERISTICS
1996 Oct 14
V
V
V
I
P
T
T
V
R
UMINANCE
I
HROMINANCE
stg
amb
CC
I
n
tot
es
Y/C automatic adjustment processor
(VHS standard)
th j-a
SYMBOL
SYMBOL
supply voltage
input voltage at pin 22
input voltage on all other pins
input current at pin 22
total power dissipation
storage temperature
operating ambient temperature
electrostatic handling for all pins
thermal resistance from junction to ambient in free air
PARAMETER
PARAMETER
note 1
7
Playback (PB)/video to video (VV) mode
L
The FM signal is fed via FM AGC and double limiter to the
controlled FM demodulator. After demodulation and
filtering in sub low-pass filter (SUBLPF) main
de-emphasis, YLPF and non-linear de-emphasis the
signal is fed to the vertical noise reduction (YNR) and in
parallel to the sync separator. The chrominance signal is
added in the Y/C mixer. The complete CVBS signal is
available at pin 41.
C
The 627 kHz chrominance signal coming from tape via
BPF 627 kHz and field ACC to the balanced mixer. Mixed
with 5.06 MHz the 4.43 MHz chrominance signal is fed via
comb driver stage to the external comb filter (pin 35) and
via internal conjugated complex (C*) stage and internal AC
coupling to the luminance part.
Record and playback
In both modes record (REC) and playback (PB) the
5.06 MHz mixer frequency is produced by the 20.24 MHz
voltage controlled oscillator (VCO) and a divide-by-four.
CONDITIONS
UMINANCE
HROMINANCE
series resistor.
0
0
0
25
20
300
MIN.
VALUE
43
TYP.
Product specification
6.0
1.6
V
10
1250
+150
+70
+300
MAX.
CC
TDA9725
UNIT
K/W
V
V
V
mA
mW
V
C
C
UNIT