ROHM BA7180AS, BA7180AFS Datasheet
1
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.
1) The playback amplifier has a total gain of 57dB (Typ.),
and has a low-noise preamplifier. Designed for VHSband 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 300mV
P-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 impedance) well, and gives stable recording characteristics. 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
Power dissipation
Operating temperature
Storage temperature
V
CC
7.0 V
Pd
BA7180AS 1000
∗
1
mW
BA7180AFS 937.5
∗
2
Topr – 20 ~ + 65 °C
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.
•
Features
•
Applications
VCRs
•
Recommended operating conditions (Ta = 25°C)
Parameter Symbol Min. Typ. Max. Unit
Playback / recording V
CC
4.5 5.0 5.5 V
2
Video ICs BA7180AS / BA7180AFS
•
Block diagram
BA7180AS
BA7180AFS
AGC
23456
7
8910
20 19 18 17 16 15 14 13 12
PREPRE
AGC
DET
MUTE
REC
DET
HPF
LOGIC
DET
HPF
RF
GND 2
REC DCFB
GND 1
N.C.
N.C.
1
22
11
21
N.C.
N.C.
+
–
–
PRE / REC
–
(REC
OUTREC
VCC
VCC
(REC
12345678910
20 19 18 17 16 15 14 13 12 11
DET
AGC
PRE PRE
– +–
REC
MUTE
DET
HPF
RF
HPF
AGC
LOGIC
GND 2
N.C.
GND
N.C.
PRE / REC
DET
–
(REC
OUTREC
–
(REC
V
CC
VCC
OUT 1)
OUT 2)
OUT 1)
OUT 2)
DFF IN
DET FILTER
PRE IN 1
PRE IN 2
REC AGC FILTER
PB / EE / REC CTRL
DFF IN
DET FILTER
REC DCFB
PRE IN 1
PRE IN 2
+
REC AGC FILTER
PB / EE / REC CTRL
REC IN
AT ENVE OUT
PB RF OUT
H SYNC IN
PB AGC FILTER
PB AGC OUT
REC LEVEL ADJ
REC IN
AT ENVE OUT
PB RF OUT
H SYNC IN
PB AGC FILTER
PB AGC OUT
REC LEVEL ADJ
–
+
3
Video ICs BA7180AS / BA7180AFS
•
Electrical characteristics (unless otherwise noted, Ta = 25°C, VCC = 5.0V and f = 4.0MHz)
Difference in pin 16 output level for
f = 8.0 / 1.0MHz, V
IN
= 0.3mV
P-P
Parameter Symbol Min. Typ. Max. Unit Conditions (BA7180AS)
Measurement
circuit
〈
Playback system〉(Pin 11 in Fig.1 measurement circuit "H" )
Quiescent current Iq
(P)
—1845mANo signal
Fig.1
Voltage gain CH-1 G
VP1
54 57 60 dB
Pin 5 input = 0.3mV
P-P
, pin 1: L,
pin 16 output measurement
Fig.1
Voltage gain CH-2 G
VP2
54 57 60 dB
Pin 7 input = 0.3mV
P-P
, pin 1: L,
pin 16 output measurement
Fig.1
Voltage gain differential
∆G
VP
–1 0 + 1 dB ∆GVP = G
VP1
– G
VP2
Fig.1
Frequency characteristic
2nd harmonic distortion
∆G
Vf
– 7 – 3 0 dB
Fig.1
2HD
P
— – 45 – 38 dBc
V
IN
= 0.3mV
P-P
, 8.0MHz spurious
Fig.1
3rd harmonic distortion 3HD
P
— – 45 – 40 dBc
V
IN
= 0.3mV
P-P
, 1 2.0MHz spurious,
guaranteed design value.
Fig.1
Maximum output level V
OMP
1.0 1.5 — V
P-P
When pin 16 output 2nd harmonic distortion is -30dBc
Fig.1
Crosstalk
Output DC offset
Input conversion noise
AGC output level
AGC control sensitivity
CT
P
— – 38 – 32 dBc
Difference in pin 16 output level for pin 1: H / L.
Fig.1
∆V
ODC
– 150 0 + 150 mV
P-P
Pin 16 output DC offset for pin 1: H / L.
Fig.1
V
NIN
— 0.25 1.0 µVrms
RG = 10Ω
, input conversion of pin 14
output noise, guaranteed design value.
Fig.1
V
AGC
250 300 350
mV
P-P
VIN = 0.3mV
P-P
,
Pin 19 output measurement
Fig.1
∆V
AGC
— 0.3 2.0 dB
Pin 19 output level difference for
V
IN
= 0.15 ~ 0.6mV
P-P
Fig.1
AGC amp frequency
characteristic
∆G
VAF
– 3 0.5 + 3 dB
Difference in pin 19 output level for f = 8.0 / 1.0MHz
VIN = 0.3mVP-P, guaranteed design value.
Fig.1
PB switch ON resistance R
ON9
—410Ω
Pin 9 impedance, guaranteed design value.
Fig.1
PRE CH 2 threshold voltage
PRE CH 1 threshold voltage
V
TH1H
3.5 — V
CC
V Pin 1 DC voltage for CH 2 operation
Pin 1 DC voltage for CH 1 operation
Fig.1
V
TH1L
0—1.2V
Fig.1
ENVE output level
ENVE output level
ENVE saturation voltage
V
ENV2
1.9 2.4 2.9 V
Pin 15 output measurement when
pin 16 output = 100mV
P-P
Fig.1
V
ENV3
3.45 3.7 3.95 V
Pin 15 output measurement when
pin 16 output = 400mV
P-P
Fig.1
V
ENV4
4.0 4.5 — V
Pin 15 output measurement for large signal
Fig.1
PB mode holding voltage
EE mode holding voltage
REC mode threshold voltage
V
TH10H
3.8 — V
CC
V Pin 11 DC voltage for PB mode
Pin 11 DC voltage for REC MUTE mode
Pin 11 DC voltage for REC mode
Fig.1
V
TH10M
2.2 — 2.8 V Fig.1
V
TH10L
0 — 1.2 V Fig.1
4
Video ICs BA7180AS / BA7180AFS
Parameter Symbol UnitMin. Typ. Max.
〈
Recording system
〉
Quiescent current
Recording AGC level
AGC control sensitivity
REC amplifier frequency characteristic
2nd harmonic distortion
— 72 110 mA
I
OAR
27 30 33
∆I
OAR
— 0.3 1.5 dB
Pin 9 output level difference for pin 13
input = 62.5mV
P-P
~ 250mV
P-P
∆I
OAF
– 4 – 1.5 — dB
2HD
R
— – 45 – 38 dBc
3HD
R
— – 50 – 40 dBc
CMD
R
— – 50 – 40 dBc
4.0MHz
± 630kHz spurious, guaranteed design value.
Maximum output level 40 50 — mA
P-P
When pin 9 output 2nd harmonic distortion is -30dB
∆I
ORL
– 1.5
– 0.35
—dB
Pin 9 output level difference for load L: 8.2
~ 12
µH, guaranteed design value.
MU
R
— – 45 – 38 dBc
Pin 9 output level difference for pin 11: M / H.
AGC mode holding voltage
AGC mode holding voltage
V
TH15H
2.7 — VCCV
Pin 17 DC voltage to maintain recording AGC operation
Pin 17 DC voltage to maintain recording AGC stopped
V
TH15L
0 — 1.2 V
mA
P-P
I
OMR
No signal
Pin 13 input = 125mV
P-P
, pin 9
output measurement
Iq
(R)
3rd harmonic distortion
Cross modulation distortion
Recording current load
characteristic
Mute attenuation ratio
Conditions (BA7180AS)
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Fig.2
Pin 13 input = 125mV
P-P
12MHz spurious,
guaranteed design value.
Pin 9 output level difference for f = 8.0 / 1.0MHz,
pin 12 input = 125mV
P-P,
guaranteed design value.
Pin 13 input = 125mV
P-P
8MHz spurious
Note:
dBc: dB below carrier (used to express relative level from carrier reference for convenience sake)
Measurement
circuit
(Pin 11 in Fig. 2 mesurement circuit "L")
•
Reference values (unless otherwise noted, Ta = 25°C, VCC = 4.8V and f = 4.0MHz)
Parameter Symbol UnitTyp. Max.
ENVE output level
ENVE output level
V
ENV2' 1.8 2.3 2.8 V
Pin 15 output measurement when
pin 16 output = 100mV
P-P.
Pin 15 output measurement when
pin 16 output = 400mV
P-P.
VENV3' 3.35 3.6 3.85 V
Min. Conditions (BA7180AS)
Loading...