BA7180AS Datasheet, PDF (1/12 Pages) Rohm – 2-channel PRE / REC amplifier with auto-tracking interface

Video ICs
2-channel PRE / REC amplifier with
auto-tracking interface
BA7180AS / BA7180AFS
The BA7180AS and BA7180AFS are PRE / REC amplifiers developed for use in video cassette recorders. They
have been designed for use in two-head decks and feature built-in FB damping, two preamplifiers, a chroma output
amplifier, an FM output amplifier (with AGC), an envelope detector, a constant-current BTL-drive REC amplifier (with
AGC) and built-in channel and REC / PB switches on a single monolithic IC.
•^Applications
VCRs
•^Features
1) The playback amplifier has a total gain of 57dB (Typ.),
and has a low-noise preamplifier. Designed for VHS-
band operation with low external parts count.The ICs
have 2 circuits for 2-head VCR applications.
2) Two playback output systems (through output and
AGC output). The AGC output level is 300mVP-P
(Typ.); suitable for FM brightness signal output.
3) Auto-tracking interface for automated tracking
adjustment. The detector characteristic is non-linear
to improve tracking accuracy during playback of low
signal levels.
4) The recording amplifier uses constant-current BLT
drive that handles load variations (i.e. head imped-
ance) well, and gives stable recording characteris-
tics. A single circuit is provided for 2-head VCR use.
5) Built-in recording level AGC means adjustment of
FM recording current is not necessary.
6) Head switches for 2-channel PRE / REC system
provided.
7) Operates off a sigle 5V power supply, with low
power dissipation.
•^{Absolute maximum ratings (Ta = 25°C)}
Parameter
Symbol
Limits
Unit
Power supply voltage
VCC
BA7180AS
Power dissipation
Pd
BA7180AFS
7.0
V
1000^∗1
mW
937.5^∗2
Operating temperature
Topr
– 20 ~ + 65
°C
Storage temperature
Tstg
– 55 ~ + 150
°C
∗1 Reduced by 10.0mW for each increase in Ta of 1°C over 25°C (free air).
∗2 When mounted on a 90mm × 90mm, t = 1.6mm glass epoxy board, reduced by 7.5mW for each
increase in Ta of 1°C over 25°C.
•^{Recommended operating conditions (Ta = 25°C)}
Parameter
Symbol Min. Typ. Max.
Unit
Playback / recording
VCC
4.5
5.0
5.5
V
1