DataSheet.es    


PDF BA7746 Data sheet ( Hoja de datos )

Número de pieza BA7746
Descripción VCR Hi-Fi audio signal REC / PB amplifier
Fabricantes ROHM Semiconductor 
Logotipo ROHM Semiconductor Logotipo



Hay una vista previa y un enlace de descarga de BA7746 (archivo pdf) en la parte inferior de esta página.


Total 12 Páginas

No Preview Available ! BA7746 Hoja de datos, Descripción, Manual

Video ICs
VCR Hi-Fi audio signal REC / PB
amplifier
BA7746S / BA7746FS
The BA7746S and BA7746FS contains the recording and playback amplifiers required for Hi-Fi VCR signal process-
ing. The recording system uses a constant-current amplifier with AGC to eliminate the need to adjust the recording
current, and ensure stable operation as the head wears. The IC also features REC MUTE and OVER REC functions.
The playback system has a high-gain preamplifier, a low- offset head switch, VCA, and an EP-gain amplifier.
In addition, all functions operate off a single 5V supply, and a H / L control system eliminates the need for special
power supplies for the recording and playback systems. The IC has low power consumpution, and comes in a com-
pact 32-pin SSOP-A package that requires little area on the PCB. It will improve the reliability and performance of
your designs while reducing external component requirements.
Applications
VCRs
Features
1) The low-noise playback amplifier has a total gain of
79dB (Typ.). Designed for VHS-band operation with
low external parts count. It has two built-in circuits
for Hi-Fi VCR operation.
2) The circuit has been designed to suppress head-
switching noise.
3) Built-in EP / SP gain switching function that boosts
the playback gain by 5dB.
4) Built-in VCA for easy playback output adjustment.
5) High-output recording amplifier for audio FM record-
ing.
6) Constant-current drive povides stable recording
characteristics when the load (head impedance) is
fluctuating.
7) Built-in recording level AGC eliminates the need to
adjust recording current.
8) Built-in low-pass filter limits the input bandwidth of
the recording amplifier.
9) Built-in OVER REC recording current amplifier
function and REC MUTE function that stops record-
ing output.
10) Low power consumption. Operates off a single 5V
power supply.
11) Record / playback switching can be done directly
via the system controller, and consumes littele
power.
12) Possible to construct a high-performance audio
system by pairing this chip with a Hi-Fi-audio signal
processing IC.
Absolute maximum ratings (Ta = 25°C)
Parameter
Symbol
Limits
Unit
Power supply voltage
Power
dissipation
BA7746S
BA7746FS
VCC
Pd
7.0
10501
8002
V
mW
mW
Operating temperature
Topr
– 10 ~ + 70
°C
Storage temperature
Tstg – 55 ~ + 125 °C
1 When mounted on a 90mm × 50mm × 1.6mm glass epoxy board, reduced by 10.5mW for each increase in Ta of 1°C over 25°C.
2 When mounted on a 90mm × 50mm × 1.6mm glass epoxy board, reduced by 8mW for each increase in Ta of 1°C over 25°C.
1

1 page




BA7746 pdf
Video ICs
Pin No.
Pin name, function and remarks
Voltage
REC AGC FILTER
REC AGC filter.
13
The attack characteristics of the recording amplifier
can be adjusted using the CR circuit.
REC: 0V
PB: 0V
Reduce the CR circuit GND-side impedance to
improve the common-mode distortion.
BA7746S / BA7746FS
Circuit diagram
2k
2k
REC CURRENT SENSE
Terminal for monitoring the recording current.
14
Open emitter output.
The REC AGC output current can be adjusted with
REC: 0.58V
PB: 0V
the R value.
e.g. 12Ω...48.2mAP-P, 15Ω...38.6mAP-P
15
REC OUT
Recording amplifier output and head switch.
15
Open collector output.
The head switch turns on and off in accordance with
REC: 4.1V
PB: 0V
the REC / PB control signal
14
MAIN GND
16 Earth for circuits other than the preamplifier.
Reference potential for the IC
GND
PRE AC-FB ch1
AC feedback terminal for the playback amplifier
17 (ch1).
REC: 0V
PB: 0.8V
The high-frequency characteristics of the playback
amplifier can be adjusted with the R value
PRE IN ch1
Input terminal for the playback amplifier (ch1).
The low-frequency cutoff characteristics can be
adjusted with the value of the input coupling
18 capacitor.
REC: 0V
PB: 0.7V
The frequency characteristics can be adjusted so
that it is flat with the L value of the rotary
transformer, and the external capacitor C (100pF
etc.).
4k
17
13k
18
5

5 Page





BA7746 arduino
Video ICs
Operation notes
(1) preamplifier
The preamplifier in this IC is a high-gain amplifier for
FM audio. This amplifier has been carefully designed
for stability. However, the design of the PCB greatly
effects the stability of the preamplifier. A list of general
precautions are given below. Take note when design-
ing the PCB.
1)The oscillation margin is reduced when the input
and output patterns are physically close.
The input and output wiring should not come out of
the same side of tha IC.
Good example
Input
IC
Output
Bad example
Input
IC
Output
2)The GND pattern should be connected at one point
to the main IC GND (pin 16). In addition, the pream-
plifier input-side GND and output-side GND should
be as close as possible to the main IC GND.
Good example
Input
Output
BA7746S / BA7746FS
Bad example
Input
Output
RL
PRE
GND
IC MAIN
GND
Output
GND
3)A large GND pattern under the IC has a shielding
effect, and reduced the chance of picking up exter-
nal noise.
4)When the preamplifier is connected to a capacitive
load such as shilded wire, or when the output cur-
rent is large, the output may oscillate. In this case,
connect a resistor to the preamplifier output (approx.
390).
BA7746S / FS
REC
270mVP-P
BH780XK series
REC
LPF
REC
LPF
MOD
MOD
PRE
660mVP-P
390
FM DE
BPF MOD
HEAD AMP
Hi-Fi AUDIO
Connection example for BA7746S / BA7746FS and BH780XK series.
RL
PRE
GND
IC MAIN
GND
Output
GND
11

11 Page







PáginasTotal 12 Páginas
PDF Descargar[ Datasheet BA7746.PDF ]




Hoja de datos destacado

Número de piezaDescripciónFabricantes
BA7743FSVTR HiFi Audio Signal REC/PB AmplifiersROHM Semiconductor
ROHM Semiconductor
BA7745VCR Hi-Fi audio signal REC / PB amplifier with flying-erase oscillatorROHM Semiconductor
ROHM Semiconductor
BA7745FSVCR Hi-Fi audio signal REC / PB amplifier with flying-erase oscillatorROHM Semiconductor
ROHM Semiconductor
BA7746VCR Hi-Fi audio signal REC / PB amplifierROHM Semiconductor
ROHM Semiconductor

Número de piezaDescripciónFabricantes
SLA6805M

High Voltage 3 phase Motor Driver IC.

Sanken
Sanken
SDC1742

12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.

Analog Devices
Analog Devices


DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.


DataSheet.es    |   2020   |  Privacy Policy  |  Contacto  |  Buscar