ROHM BA7184

Video ICs
4-channel PRE / REC amplifier with
auto-tracking interface
BA7184S
The BA7184S is a PRE / REC amplifier developed for use in video cassette recorders. It is compatible with four-head
decks and features built-in FB damping, four preamplifiers, a chroma output amplifier, an FM output amplifier (with
AGC), an envelope detector and envelope comparator, a constant-current BTL-drive REC amplifier (with AGC) and
channel switching, EP / SP switching, and mode switching integrated onto a single monolithic IC.
Applications
•VCRs
•1)Features
The playback amplifier has a total gain of 56dB
(Typ.), and has a low-noise preamplifier. Designed
for VHS band operation with low external parts
count. The IC has 4 circuits for 4-head VCR applications.
2) Two playback output systems (through output and
AGC output). The AGC output level is 315mV P-P
(Typ.); suitable for FM brightness signal output.
3) Auto-tracking interface for automated tracking
adjustment. Linear detector characteristic with sensitivity that can be set using external components.
4) The recording amplifier uses constant-current BLT
drive that handles load variations (i.e. headimpedance) well, and gives stable recording characteristics. 2 circuits are provided for 4-head VCR use.
5) Built-in recording level AGC means adjustment of
FM recording current is not necessary.
6) Head switches for 4-channel PRE / REC system
provided.
7) Operates off a single 5V power supply, with low
power dissipation.
•Absolute maximum ratings (Ta = 25°C)
Parameter
Applied voltage
Power dissipation
Symbol
Limits
Unit
VCC
7.0
V
1050∗1
Pd
mW
Operating temperature
Topr
– 20 ~ + 65
°C
Storage temperature
Tstg
– 55 ~ + 125
°C
∗1 Reduced by 10.5mW for each increase in Ta of 1°C over 25°C (free air).
•Recommended operating conditions (Ta = 25°C)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Conditions
Playback / recording
VCC
4.5
5.0
5.5
V
13pin
䊊 Not designed for radiation resistance.
1
Video ICs
BA7184S
•Block diagram
24
23
22
21
RF
20
19
18
AT ENVE OUT
17
H SYNC IN
DET
AGC
AT ENVE PEAKING
DET
PRE
ENVE
PEAK
ENVE
PRE
LOGIC
PRE
15
14
13
EP
16
REC
AGC
SP
REC IN
VCC
12
ENVE COMP OUT
MUTE
11
TP / PB / EE / REC CTRL
DFF IN
COMP
10
REC DCFB 2
ENVE
PRE IN 4
(REC - OUT 4)
PRE
REC + OUT 2
9
2
PB RF OUT
8
PRE IN 3
(REC - OUT 3)
PB AGC OUT
7
GND 1
PB AGC FILTER
(REC DCFB 1)
6
PRE IN 2
(REC - OUT 2)
5
REC + OUT 1
4
PRE IN 1
(REC - OUT 1)
REC LEVEL ADJ
3
REC AGC FILTER
GND 2
2
EP / SP CTRL
1
AT ENVE FB
VCC
Video ICs
BA7184S
•Electrical characteristics (unless otherwise noted, Ta = 25°C, V
CC
Parameter
= 5.0V and f = 4.0MHz)
Conditions
Measurement
circuit
Symbol
Min.
Typ.
Max.
Unit
Iq (P)
—
27
45
mA
No signal
Fig. 1
Fig. 1
〈Playback system〉 (Pin 12: H)
Supply current
Voltage gain ch-1
GVP1
52
56
60
dB
Pin 4 input = 0.3mVP-P, pin 2: L, pin 16: L,
pin 20 output measurement
Voltage gain ch-2
GVP2
52
56
60
dB
Pin 6 input = 0.3mVP-P, pin 2: L, pin 16: H,
pin 20 output measurement
Fig. 1
Voltage gain ch-3
GVP3
52
56
60
dB
Pin 8 input = 0.3mVP-P, pin 2: H, pin 16: L,
pin 20 output measurement
Fig. 1
Voltage gain ch-4
GVP4
52
56
60
dB
Pin 10 input = 0.3mVP-P, pin 2: H, pin 16: H,
pin 20 output measurement
Fig. 1
Voltage gain differential
∆GVP
– 1.5
—
+ 1.5
dB
∆GVP = GVP1 – GVP2, GVP3 – GVP4
Fig. 1
dB
Pin 20 output level difference for f = 8.0 / 1.0MHz,
VIN = 0.3mVP-P.
Fig. 1
∆GVf
–8
– 1.7
—
2nd harmonic distortion
2HDP
—
– 42
– 35
dBc
VIN = 0.3mVP-P, 8.0MHz spurious
Fig. 1
3rd harmonic distortion
3HDP
—
– 50
– 35
dBc
VIN = 0.3mVP-P, 12.0MHz spurious∗2
Fig. 1
Maximum output level
VOMP
0.8
1.2
—
VP-P
When pin 20 output 2nd harmonic distortion is – 30dBc
Fig. 1
Crosstalk
CTP
—
– 45
– 30
dBc
Pin 20 output level difference for pin 2: H / L, pin 16: H / L.
Fig. 1
∆VODC
—
—
200
mVP-P
Pin 20 output DC offset for pin 2: H / L, pin 16: H / L.
Fig. 1
Input conversion noise
VNIN
—
0.25
1.0
µVrms Rg = 10Ω, input conversion of pin 20 output noise∗2
Fig. 1
AGC output level
VAGC
265
315
365
mVP-P
VIN = 0.3mVP-P, pin 21 output measurement
Fig. 1
∆VAGC
—
0.3
2.0
dB
Pin 21 output level differential for VIN = 0.15 to 0.6mVP-P.
Fig. 1
Fig. 1
Frequency characteristic
Output DC offset
AGC control sensitivity
AGC frequency characteristic
∆GVAF
–8
–3
—
dB
f = 8.0 / 1.0MHz, VIN = 0.3mVP-P∗2
PB switch ON resistance
RON5, 9
—
5
10
Ω
Pin 5 and pin 9 impedance∗2
Fig. 1
ENVE residual voltage
VENV1
—
0.7
1.0
V
Pin 18 output measurement when no signal
Fig. 1
ENVE output level
VENV2
2.4
2.9
3.4
V
Pin 18 output measurement when pin 20
output = 400mVP-P
Fig. 1
ENVE saturation voltage
VENV3
4.0
4.5
—
V
Pin 18 output measurement for large signal
Fig. 1
PRE ch 2 and 4 holding voltage
VTH16H
3.5
—
VCC
V
Pin 16 DC voltage for ch 2 and 4 operation
Fig. 1
PRE ch 1 and 3 holding voltage
VTH16L
0
—
1.2
V
Pin 16 DC voltage for ch 1 and 3 operation
Fig. 1
EP mode holding voltage
VTH2H
3.5
—
VCC
V
Pin 2 DC voltage for EP mode
Fig. 1
SP mode holding voltage
VTH2L
0
—
1.2
V
Pin 2 DC voltage for SP mode
Fig. 1
TP mode holding voltage
VTH12T
4.1
—
VCC
V
Pin 12 DC voltage for TRICK PLAY mode
Fig. 1
PB mode holdihg voltage
VTH12H
3.0
—
3.7
V
Pin 12 DC voltage for PB mode
Fig. 1
EE mode holding voltage
VTH12M
1.1
—
2.6
V
Pin 12 DC voltage for REC MUTE mode
Fig. 1
REC mode holding voltage
VTH12L
0
—
0.7
V
Pin 12 DC voltage for REC mode
Fig. 1
∗
2 Guaranteed design values.
Note: dBc: dB below carrier (used to express relative level from carrier reference for convenience sake)
3
Video ICs
Parameter
BA7184S
Symbol
Min.
Typ.
Max.
Unit
Iq (R)
—
67
100
mA
Conditions
Measurement
circuit
〈Recording system〉 (Pin 12: L)
Quiescent current
No signal
Fig. 2
Fig. 2
Recording AGC level 1
IOAR1
27
30
33
mAP-P
Pin 14 input = 125mVP-P, pin 2: L, pin 5
output measurement
Recording AGC level 2
IOAR2
24
27
30
mAP-P
Pin 14 input = 125mVP-P, pin 2: H, pin 9
output measurement
Fig. 2
AGC control sensitivity
∆IOAR
—
0.3
2.0
dB
Pin 14 input = 62.5mVP-P, to 250mVP-P, pin 5
output level differential
Fig. 2
AGC frequency characteristic
∆IOAF
–8
–3
—
dB
f = 8.0 / 1.0MHz, pin 14 input = 125mVP-P,∗2
Fig. 2
2nd harmonic distortion
2HDR
—
– 45
– 35
dBc
Pin 14 input = 125mVP-P, 8MHz spurious
Fig. 2
3rd harmonic distortion
3HDR
—
– 50
– 35
dBc
Pin 14 input = 125mVP-P, 12.0MHz spurious∗2
Fig. 2
Cross modulation distortion
CMDR
—
– 50
– 35
dBc
4.0MHz ± 630kHz spurious∗2
Fig. 2
When pin 5 output 2nd harmonic distortion is – 30dB
Fig. 2
Fig. 2
Maximum output level
IOMR
40
50
—
mAP-P
Recording current load characteristic
∆IORL
– 2.0
– 0.3
—
dB
Pin 5 output level difference when load
L: 8.2 and 12µH∗2
Mute attenuation ratio
MUR
—
– 45
– 35
dBc
Pin 5 output level difference for pin 12: M / L
Fig. 2
AGC mode holding voltage
VTH17H
2.8
—
VCC
V
Pin 17 DC voltage to maintain recording
AGC operation.
Fig. 2
AGC mode holding voltage
VTH17L
0
—
1.2
V
Pin 17 DC voltage to maintain recording AGC stopped.
Fig. 2
∗2 Guaranteed design values.
Note: dBc: dB below carrier (used to express relative level from carrier reference for convenience sake)
4
8
9
COMP MUTE
SP
10
11
REC MUTE ‘‘L’’
7
14
TRICK PLAY ‘‘H’’
PB: OPEN
PRE
0.1µ
ENVE
15
REC START ‘‘L’’
LOGIC
0.1µ
PRE
16
1k
6
17
PRE IN 4
18
10
5
0.1µ
4
10
PRE
PRE IN 3
RF
0.1µ
3
AGC
19
1k
PEAK ENVE
20
1k
DET
21
PRE IN 2
22
10
0.1µ
10
2
PRE IN 1
1
0.1µ
23
1k
10k
24
EP / SP CTRL
33k
0.01µ
390k
68p
22µ
3.9k
0.1µ
33k
REC IN
ENVE COMP OUT
DFF IN
H SYNC IN
AT ENVE OUT
AT ENVE
PEAKING
PB RF OUT
PB AGC OUT
Video ICs
BA7184S
Measurement circuits
•(Playback
system)
+
VCC 5V
13
REC
VCC
ENVE
AGC
EP
DET
PRE
12
Units: R [Ω]
C [F]
L [H]
Fig. 1
5
6
Fig. 2
PRE
7
16
ENVE
PRE
8
COMP MUTE
15
9
14
RF
SP
10
11
Units: R [Ω]
C [F]
L [H]
REC MUTE ‘‘L’’
LOGIC
TRICK PLAY ‘‘H’’
PB: OPEN
6
17
0.1µ
5
18
REC START ‘‘L’’
4
19
8.2µ
PEAK ENVE
0.1µ
PRE
REC OUT 2
AGC
0.1µ
3
20
10
21
8.2µ
DET
8.2µ
22
0.1µ
2
0.1µ
23
10
0.1µ
1
8.2µ
10k
24
REC OUT 1
EP / SP CTRL
33k
0.01µ
390k
68p
22µ
3.9k
0.1µ
33k
REC IN
ENVE COMP OUT
DFF IN
H SYNC IN
AT ENVE OUT
PB RF OUT
PB AGC OUT
REC LEVEL ADJ
Video ICs
BA7184S
(Recording system)
+
VCC 5V
VCC
13
REC
ENVE
AGC
EP
DET
PRE
12
Video ICs
BA7184S
system logic table
•(1)Control
DFF IN (pin 16)
• Playback input selection (head switching)
Function
Control pin
DFF IN
EP / SP
L
H
H
L
L
H
Selected playback input
Control voltage
VCTRL16 [V]
Ch3 (PRE IN3 8pin)
3.5 ~ VCC
Ch4 (PRE IN4 10pin)
0.0 ~ 1.2
Ch1 (PRE IN1 4pin)
—
Ch2 (PRE IN2 6pin)
—
(2) EP / SP control (pin 2)
• Recording output selection
• Playback input selection (see (1))
Control pin
EP / SP
Function
Control voltage
VCTRL2 [V]
Selected recording output
H
EP (REC OUT 8, 9, 10pin)
3.5 ~ VCC
L
SP (REC OUT 4, 5, 6pin)
0.0 ~ 1.2
(3) TP / PB / EE / REC CTRL (pin 12)
• Special playback / playback / recording mute / recording mode switching
Control pin
Function
Mode
PRE AMP AT ENVE ENV COMP REC MUTE REC AMP
PB / EE / REC
OT
ON
TRICK PLAY
ON
Control voltage
VCTRL12 [V]
ON
OFF
OFF
4.1 ~ VCC
H
PB
ON
ON
OFF
OFF
OFF
3.0 ~ 3.7
M
REC MUTE
OFF
OFF
OFF
ON
ON
1.1 ~ 2.6
L
REC
OFF
OFF
OFF
OFF
ON
0.0 ~ 0.7
• Pin 12 is biased internally in the IC. When open, PB mode is selected.
(4) H SYNC IN (pin 17)
• Special playback envelope comparator (ENVE COMP) output latch control.
• AGC operation control for recording.
Control pin
Function
Control voltage
VCTRL17 [V]
H SYNC
ENVE COMP
H
Set at falling edge
ON
2.8 ~ VCC
L
—
OFF
0.0 ~ 1.2
AGC detector
(5) ENVE COMP OUT (pin 15)
• Outputs playback envelope comparator data for special playback.
Control pin
Function
ENVE COMP
Playback input level
H
Ch1 or Ch2 > Ch3 or Ch4
L
Ch1 or Ch2 < Ch3 or Ch4
7
Video ICs
BA7184S
24
23
22
21
20
AGC
RF
DFF IN
ENVE COMP OUT
REC Y IN
REC C IN
19
18
PEAK
ENVE
+
0.01µ
390k
VCC 5V
68p
22µ
DET
H SYNC IN
AT ENVE OUT
AT ENVE
PEAKING
PB RF OUT
3.9k
33k
0.1µ
REC LEVEL ADJ
PB AGC OUT
•Application example
17
16
LOGIC
15
14
13
COMP
MUTE
VCC
REC
AGC
ENVE
ENVE
EP
SP
PRE
PRE
PRE
PRE
DET
6
7
•
22.9 ± 0.3
24
13
1
12
6.5 ± 0.3
0.51Min.
3.4 ± 0.2 3.95 ± 0.3
10
11
7.62
0.3 ± 0.1
0.5 ± 0.1
SDIP24
0°
12
~ 15°
Units: R [Ω]
C [F]
L [H]
PB: OPEN
0.1µ
TRICK PLAY ‘‘H’’
A
B
EP HEAD
Fig. 3
8
9
0.1µ
0.1µ
A
B
SP HEAD
External dimensions (Units: mm)
1.778
8
0.1µ
5
0.1µ
EP / SP CTRL
33k
10k
AT ENVE
GAIN
EP ‘‘H’’
4
0.1µ
3
REC MUTE ‘‘L’’
2
REC START ‘‘L’’
1
33k