4-HEAD PLAYBACK AND RECORD AMPLIFIER FOR VCR
. ONE 5V POWER SUPPLY
. PLAYBACK/RECORD MODE SELECTION
THROUGH A LOGIC INPUT
. PINNING COMPATIBLE WITH STV5727 AND
. SO20 PACKAGE
. LOW NOISE AND WIDE BAND AMPLIFIERS
FOR 4 HEADS
. AUTOMATIC OFFSET CANCELLATION
BETWEEN THE 2 SELECTED HEADS
. ONE PLAYBACK OUTPUT WITH AGC
. ONE PLAYBACK OUTPUT (CONSTANT GAIN)
. ONE OUTPUT FOR AUTOMATIC VIDEO
. SP/LP ENVELOPE COMPARATOR OUTPUT
function of the selected input signal amplitude is
present on Pin TRIV.
The current input applied on RECIN Pin is amplified
through a transconductanceamplifier. Special care
has been taken to speed up commutation from
Playback to Record and from Record to Playback,
avoiding spikes through the loads (the rotary trans-
formers). The recording current level in LP mode is
0.9 time the value of SP one.
STV5725 is intended for 4 heads VCR applications.
It includes all the electrical functions necessary to
achieve play-back and record processing for VHS
Record or Playback Mode can be selected through
SWR Pin. SWH allows to select the video head
input (H1SP or H2SP, H1LP or H2LP), while SWM
will select the mode SP or LP.
Signals applied on H1SP, H2SP, H1LP and H2LP
input pins will be amplified by 60dB voltage gain.
IOUTSP and IOUTLP Pins are AC short-circuited to
ground. The input signal can be selected through
SWH and SWM inputs and the corresponding out-
put signal will be available on Pin CPB. The offset
voltage between the two selected heads is auto-
matically cancelled after 32 switching head cycles.
A constant output signal will be available on Pin
YPB thanks to an AGC function (Automatic Gain
Control). The time constant of the AGC is deter-
mined by the capacitor value connected to CAGC
Pin. For Automatic Tracking, a signal which is a
ORDER CODE : STV5725
This is advance information on a new product now in development or undergoing evaluation. Details are subject to change without no tice.