Sanyo LA7668N Specifications

Monolithic Linear IC

Ordering number : EN5097

61595HA (OT) No. 5097-1/11

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN

Video Signal Auto-White Processing IC

LA7668N

Overview

The LA7668N is a low-cost video signal auto-white
processing IC that provides brightness adapted
compression and expansion functions. Furthermore, the
LA7668N incorporates on-chip a Sanyo developed
vertical line saturation suppression function for image
quality enhancement.

Features and Functions

• APL; frequency adaptive Y/C correction

• Vertical line saturation suppression function

• Correction circuit on/off function

• Built-in synchronization/burst gate separation circuit

• 4.0 V band gap Zener output

• Variable correction curve (using an external resistor)

Package Dimensions

unit: mm

3067-DIP24S

Specifications

Maximum Ratings at Ta = 25°C

Operating Conditions at Ta = 25°C

Electrical Characteristics at Ta = 25°C, VCC= 5.0 V

Parameter Symbol Conditions Ratings Unit

Maximum supply voltage V

CC

max 7.0 V
Allowable power dissipation Pd max Ta ≤ 65°C 200 mW
Operating temperature Topr –10 to +65 °C
Storage temperature Tstg –55 to +125 °C

Parameter Symbol Conditions Ratings Unit

Recommended supply voltage V

CC

5.0 V

Operating supply voltage range V

CC

op 4.5 to 5.5 V

Parameter Symbol Conditions min typ max Unit

Current drain (off) I

OFF

Pin 17 = 5 V, no input 16.0 20.0 25.0 mA

Current drain (on) I

ON

Pin 17 = 0 V, no input 18.0 22.0 28.0 mA

BGZ output 1 V

BGZ1IOUT

= 3 mA 3.7 4.0 4.3 V
BGZ output 2 V

BGZ2IOUT

= 3 mA, VCC= 4.5 V 3.65 4.0 4.3 V
BGZ maximum output current I

OMAXVCC

= 4.5 V 5.0 8.0 mA

Continued on next page.

[LA7668N]

SANYO: DIP24S

Continued from preceding page.

Pin Functions

No. 5097-2/11

LA7668N

Parameter Symbol Conditions min typ max Unit
[Luminance Signal System]
Voltage gain VG

Y

VIN= 1.0 Vp-p 6.0 6.5 7.0 dB

Frequency characteristics f

Y

When 3 dB down from the 1 MHz output level 7.0 8.5 MHz

Signal input level V

IY

1.0 1.2 Vp-p

Output DC level V

OYDC

Pedestal level 0.7 0.9 1.1 V

Pin 18 output V

18

1.75 2.0 2.25 V

γ characteristics 90 ∆

γ90

APL = 90%, VIN= 100 IRE 101 105 109 IRE

γ characteristics 50 ∆

γ50

APL = 50%, VIN= 40 IRE 41 45 49 IRE

γ characteristics 10-1 ∆

γ10-1

APL = 10%, VIN= 80 IRE 81 85 89 IRE

γ characteristics 10-2 ∆

γ10-2

APL = 10%, VIN= 40 IRE 43 47 52 IRE
[Chrominance Signal System]
Voltage gain VG

C

VIN= 0.66 Vp-p 6.3 6.8 7.2 dB
Maximum gain VG

MAX

When f = 3.58 MHz, APL = 0% 7.3 7.8 8.3 dB
Minimum gain VG

MIN

When f = 3.58 MHz, APL = 100% 5.7 6.2 6.7 dB
Frequency characteristics f

C

When 3 dB down from the 1 MHz output level 4.0 5.0 MHz
Signal input level V

IC

0.66 0.8 Vp-p

Output DC level V

OCDC

1.1 1.4 1.7 V
[Control System]
Mute on voltage V

ON

1.0 V

CC

V

Mute off voltage V

OFF

0 0.5 V
Pin 2 voltage V2 2.81 3.2 3.61 V
Pin 4 voltage V3 2.72 3.1 3.50 V
Pin 11 voltage V11 2.19 2.5 2.82 V
Pin 14 voltage V14 2.29 2.6 2.94 V
Pin 15 voltage V15 2.11 2.4 2.71 V
Pin 16 voltage V16 2.02 2.3 2.60 V
Pin 21 voltage V21 2.54 2.9 3.27 V
Pin 23 voltage V23 2.02 2.3 2.60 V

Pin No. Symbol Function

1 LPF

D

Correction signal frequency control

2 H

U

Correction reference voltage (3.2 V)

3 Y

IN

Luminance signal input

4 H

D

Correction reference voltage (3.1 V)
5 SYNC Sync separator input
6 V

CC

Power supply
7 BGP BGP delay time constant
8 APL

DET

APL level detection filter
9 HPF

IN

High-frequency detection filter (input)

10 HPF

OUT

High-frequency detection filter (output)

11 HE

DET

High-frequency detection circuit control voltage

12 C

IN

Chrominance signal input

13 C

OUT

Chrominance signal output

14 APL

H

APL discrimination reference voltage (high)

15 APL

L1

APL discrimination reference voltage (low)

16 APL

L2

APL discrimination reference voltage (for the high-frequency detection circuit)

17 MUTE Correction circuit muting
18 2.0VBIAS Luminance signal system bias
19 GND Ground
20 BGZ

OUT

4.0 V BGZ voltage output

21 L

D

Correction reference voltage (2.9 V)

22 Y

OUT

Luminance signal output

23 L

U

Correction reference voltage (2.3 V)

24 LPF

U

Correction signal frequency control

Application Circuit Diagram

No. 5097-3/11

LA7668N

Pin Descriptions

• Pins 1 and 24

Pins 1 and 24 are frequency control pins for the correction signal. If the capacitors C1 and C2 were not connected to pins
1 and 24, when correction was applied to signals that include noise as shown in the figure below, the noise level would
increase. Accordingly, the capacitors C1 and C2 are used to reduce the high frequencies so that high-frequency noise
levels are not aggravated. (frequency-adaptive type circuit)

C1 is provided for when the gain is increased, and C2 for when the gain is decreased. About 2 MHz when C = 82 pF.

No. 5097-4/11

LA7668N

• Pins 2, 4, 21 and 23
These are gamma correction reference voltage pins. The gamma characteristics can be changed by changing the voltages
applied to these pins from external circuits.

Pins 2 and 4 are the reference voltages used when APL is high, and pins 21 and 23 are the reference voltages used when
APL is low.

The figures below shows the characteristics curves.

No. 5097-5/11

LA7668N

• Pin 3
Pin 3 is the luminance signal input pin.
The reference input level is 1.0 Vp-p.

• Pin 5
Pin 5 is the sync separator input pin.

• Pin 6
Pin 6 is the power supply pin. The recommended operating voltage range is 4.5 to 5.5 V. However, operation as low as

4.3 V is possible, although certain device characteristics will be degraded.

• Pin 7
Pin 7 is used to construct the filter that determines the BGP delay time.

No. 5097-6/11

LA7668N

• Pin8
Pin 8 is used to construct the APL level detection filter.

• Pins 9 and 10
Pins 9 and 10 are used for the high-frequency detection circuit high-pass filter capacitor.

The signal input to pin 3 (the Y input signal) is accepted by an emitter-follower circuit, which outputs a signal clamped
to 2.0 V from pin 9. This 2.0 V clamped high-frequency signal is detected by the high-pass filter formed by C1. (A 2 to
3 MHz signal is detected when C1 is 20 pF.)

• Pin 11
Pin 11 is the high-frequency detection circuit control voltage pin.

The pin 11 voltage sets the high-frequency detection level. (Pin 11 should normally be set to 2.5 V.) Thus an externally
applied voltage can be used to change this detection level.

No. 5097-7/11

LA7668N

The capacitor between pins 9 and 10 extracts the high-frequency component for vertical line saturation control. The pin
11 voltage determines the level at which saturation control is not applied. (Note that this circuit only operates when APL
is low. The operating level is determined by the pin 16 voltage.)

• Pin 12
Pin 12 is the chrominance signal input pin.

• Pin 13
Pin 13 is the chrominance signal output pin.

No. 5097-8/11

LA7668N

The chrominance signal input circuit is a
switching circuit, but could consist of a Y/C
separator. This circuit is designed to reduce the
noise due to the influence of the SYNC signal.

• Pins 14, 15 and 16
Pins 14, 15 and 16 are the APL level reference voltage pins.

When the APL filter pin (pin 8) voltage is higher than the pin 14 reference voltage (2.6 V), the APL level is judged to be
high. If that voltage is lower than the pin 15 reference voltage, the APL level is judged to be low. Pin 16 is a reference
voltage for the high-frequency detection circuit, and the vertical line saturation suppression circuit operates when the pin
8 voltage is lower than the pin 16 voltage. See the description of the APL filter voltage characteristics on page 10 for
details on the relationship between the APL level and the APL filter pin voltage.

• Pin 17
Pin 17 mutes the correction circuit.

• Pin 18
Pin 18 is the 2.0 V Y signal system reference voltage pin.

This reference voltage pin determines the Y signal system clamp and output voltages. C1 is used to exclude noise from
the reference voltage line.

No. 5097-9/11

LA7668N

• Pin 19
Pin 19 is the IC ground pin.

• Pin 20
Pin 20 is the BGZ output voltage pin. C1 is used to exclude noise and prevent oscillation. The pin 20 circuit can supply
an output current of up to 4 mA when VCCis 4.5 V. Note that if VCCis under 4.3 V, the pin 20 voltage will become
lower due to the influence of the transistor’s VCE. (The IC can be operated with VCCas low as 4.3 V if an output
current is not taken from this pin.) The figure below shows the output voltage vs. current characteristics, i.e., the BGZ
output voltage characteristics.

• Pin 22
Pin 22 is the Y output pin.

No. 5097-10/11

LA7668N

PS No. 5097-11/11

LA7668N

Characteristic Output Waveforms

This catalog provides information as of June, 1995. Specifications and information herein are subject to change
without notice.

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SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees
jointly or severally.

■ Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for
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regarding its use or any infringements of intellectual property rights or other rights of third parties.