ROHM BA7149F Datasheet

1

Video ICs

Electronic viewfinder driver

BA7149F

The BA7149F is an electronic viewfinder driver for video cameras. It separates the synchronous signal from the input
video signal, and outputs the vertical deflection drive output and horizontal deflection signals. HD and VD output sig­nals with guaranteed phase difference are also provided for on-screen displays (OSD). The differences between the
BA7149F and the BA7148F are the horizontal blanking, horizontal AFC output, HD output phase and pulse width.

•

Applications

Video cameras

•

Features

1) Operates off a 5V power supply.

2) Built-in vertical deflection circuit.

3) Built-in wide-bandwidth amplifier.

4) Built-in HD and VD output terminals.

5) Few attached components required.

6) SOP 16pin package.

7) Compatible with 10µ sec flyback pulses.

•

Absolute maximum ratings (Ta = 25°C)

Parameter

Symbol Limits Unit

8.0 V

500

∗

mW

°C
°C

V

CC Max.

– 20 ~ + 75
– 55 ~ + 125

Pd
Topr
Tstg

Applied voltage
Power dissipation
Operating temperature
Storage temperature

∗

Reduced by 5mW for each increase in Ta of 1°C over 25°C.

•

Recommended operating conditions (Ta = 25°C)

Parameter

Symbol Min. Typ. Max. Unit

V

CC

4.5 5.0 5.5 V

Power supply voltage

2

Video ICs BA7149F

•

Pin descriptions

FunctionFunction
19
210
311
412
513
614
715
816

Pin No. Pin No.

Vertical control input
Power supply 1
Vertical deflection drive (POS)
GND 1
Vertical deflection drive (NEG)
Vertical oscillator external resistor
Vertical oscillator external capacitor
VD output

HD output
GND 2
Video input
Power supply 2
Video output
Phase comparator output
Horizontal oscillator external resistor
Horizontal AFC output

•

Block diagram

16 15 14 13 12 11 10 9

12345678

H.OSC

PHASE

COMP

6dB

AMP

V.SEPA

V.OSCV.DRIVE

V.BLK

H.BLK

SYNC
SEPA

3

Video ICs BA7149F

•

Electrical characteristics (unless otherwise noted, Ta = 25°C and Vcc = 5.0V)

Parameter

Symbol Min. Typ. Max. Unit

I

CC

31.0 42.0 55.0 mA

G

V

5.3 6.0 6.7 dB

D

RV

3.20 3.50 —

f

C

– 2.0 0.0 + 2.0 dB

— 45 120

T

H · BL

9.6 10.7 11.4 µs

T

V · BL

870 970 1070 µs

f

H · O

13.9 15.7 17.5

∆f

CAP

± 2.1 ± 3.0 —

T

HP

10.2 11.1 12.0 µs

T

HPH

– 1.9 – 1.2 – 0.5 µs

V

HPL

0.5 1.1 1.7 V

f

V · O

51.3 54.8 58.2 Hz

2.10 2.70 —

2.10 2.70 —

T

HVD

17.3 21.3 25.3 µs

T

HD

8.7 9.9 11.1 µs

T

VD

860 960 1060 µs

V

HV · L

— 0.1 0.3 V

V

HV · H

4.7 4.9 — V

V

P-P

mV

P-P

V

P-P

V

P-P

kHz
kHz

V

syn · Min.

V

VP · Max.

V

VN · Max.

䊊Not designed for radiation resistance.

Operating current dissipation

Voltage gain
D range
Frequency characteristic
Minimum sync separation voltage
Horizontal blanking width
Vertical blanking width

Free-running frequency
Capture range
AFC output pulse width
AFC lock-in phase
Pulse voltage low

Free-running frequency
Pin 3 maximum output amplitude
Pin 5 maximum output amplitude

Phase difference
H

D pulse width

V pulse width
Pulse voltage low
Pulse voltage high

〈VIDEO AMP〉

〈

HD · VD〉

〈

Horizontal〉

〈

Vertical〉

4

Video ICs BA7149F

1pin

V

12pin

1pin

1.9k

10k

500

500

+

2.33V

Fig.1

•

Input / output circuits

2pin

3pin
5pin

4pin

300

300

2, 3, 4, 5pin

Fig.2

6pin

12pin

2k

2k

12k

6pin

1.5V

V

+

Fig.3

8pin

2pin

8pin

10k

20k

20k

Fig.5

9pin

2pin

9pin

25k

10k

20k

Fig.6

7pin

12pin

7pin

12pin

20k 20k

5k 5k 5k

8µA

Fig.4

11pin

11pin

12pin

1k

1.25k

100

100

50

+

1.87V
36µA

V

Fig.8

14pin

12pin

3k

14pin

3k 3k 3k

3k

3k 3k 3k

Fig.9

13pin

12pin

13pin

100

3k

100

1mA

Fig.7

5

Video ICs BA7149F

16pin

2pin

16pin

500

20k

12pin

20k

Fig.11

15pin

12pin

10k

15pin

2k2k

2.8V

10k

10k

12k

V

+

Fig.10

•

Circuit operation

Input signals

63.556µ

H Pulse only

0.29V at 11pin

adj.at 11pin

4.7µ

262.5H

16.683m

V Pulse only

H Pulse only

Pulse IH

Pulse IS

Pulse IV

IH

Fig.12

The video signal input to pin 11 is detected by the charg­ing and discharging of an external capacitor. Sync sepa­ration is done in the SYNC SEPA block. The H. SYNC
signal is sent to the H. OSC, and the V. SYNC signal is
sync-separated in the vertical sync pulse interval and sup­plied to the V. OSC block.
The H. OSC block consists of a PLL that oscillates in sync
with the sync-separated H. SYNC signal, and outputs the
HD pulse and horizontal deflection pulse.
In the V. OSC block, a direct-control method is used with
the sync signal. To synchronize the vertical oscillator cir-

cuit, the inherent oscillation period of the oscillation circuit
is made slightly larger than the vertical sync signal period,
so that the sync signal always enters slightly early.
The oscillator output alone is not enough to ensure stable
operation for the vertical deflection output circuit, so it is
amplified by the V. DRIVE block.
The horizontal and vertical blanking signals generated in
the H. OSC and V. OSC blocks are used to erase the hor­izontal retrace line from the video signal input to pin 11.
The signal is inverted and amplified by a 6dB inverting
amplifier and output as a negative-polarity video signal.

6

Video ICs BA7149F

•

Application example

FBT

+

16

1

15 14 13 12 11 10 9

8765432

H.OSC

PHASE

COMP

6dB

AMP

SYNC
SEPA

V.SEPA

V.OSCV.DRIVE

V.BLK

H.BLK

+

100k

390k

VIDEO OUT

VIDEO IN

470

+

470

+

0.22

µ

10k

HD

VD

15k

VR1

100

+

3.9

15k

VCC

1µ

1µ

100µ

0.1µ

5mH + 36Ω

0.022µ

47µ

47µ

0.022µ

510k

VCC

1500pF

V

CC

∗

1 The resistors connected to pins 6 and 15 should have a tolerance of ± 2%, and a temperature

coefficient of ± 100ppm or lower.

∗

2 The capacitor connected to pin7 should have a tolerance of ± 5%, and a temperature coefficient of

± 250ppm or lower.

Fig.13

7

Video ICs BA7149F

•

Operation notes
(1) H.OSC free-run frequency and capture range
The free-run frequency is determined by the 115kΩ
resistor connected between pin 15 and GND. The cap­ture range is varied by the resistors and capacitor con­nected to pins 14 and 15.
The free-run frequency and capture range for this IC
are guaranteed for these circuit constant values, and
we recommend that you use them. The resistor 115kΩ
connected between pin15 and GND should have a tol­erance of ± 2%, and a temperature coefficient of ±
100ppm or lower.
(2) V.OSC free-run frequency
The V.OSC free-run frequency is determined by the
15kΩ resistor connected between pin 6 and GND, and
the 0.1µF capacitor connected between pin 7 and
GND.
The free-run frequency and capture range for this IC
are guaranteed for these circuit constant values, and
we recommend that you use them. The resistor 15kΩ
connected between pin 6 and GND should have a tol­erance of ± 2%, and a temperature coefficient of ±
100ppm or lower, and the capacitor connected
between pin 7 and GND should have a tolerance of ±
5%, and a temperature coefficient of ± 250ppm or
lower.

(3) Use with PAL systems
In PAL systems, change the value of the resistor con­nected between pin 6 and GND to 18kΩ.
(4) PCB pattern
The large-signal systems and small-signal systems in
the IC have been kept separate, and the external wring
must also be done in such a way to prevent interfer­ence from occurring. In particular, to prevent the FBT
return current from interfering with the V. OSC circuit
on pins 6 and 7, do not directly connect the pin 4 GND
and pin 6 and 7 GND.

1

16
2
3
4
5
6
7
8

9

10

11

12

13

14

15

G

FBT

V

CC

∗

Do not connect pin 4 GND

to pin 6 and 7 GND.

Fig.14

•

External dimensions (Units: mm)

SOP16

0.4 ± 0.11.27

0.15

0.15 ± 0.1

0.3Min.

4.4 ± 0.2

6.2 ± 0.3

0.11

1.5 ± 0.1

1

16

10.0 ± 0.2

8

9