Sanyo LA7668N Specifications

Ordering number : EN5097

Monolithic Linear IC

LA7668N

Video Signal Auto-White Processing IC

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

[LA7668N]

SANYO: DIP24S

Specifications

Maximum Ratings at Ta = 25°C

Parameter	Symbol	Conditions	Ratings	Unit
Maximum supply voltage	VCC 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

Operating Conditions at Ta = 25°C

Parameter	Symbol	Conditions	Ratings	Unit
Recommended supply voltage	VCC		5.0	V
Operating supply voltage range	VCC op		4.5 to 5.5	V

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

Parameter	Symbol	Conditions	min	typ	max	Unit
Current drain (off)	IOFF	Pin 17 = 5 V, no input	16.0	20.0	25.0	mA
Current drain (on)	ION	Pin 17 = 0 V, no input	18.0	22.0	28.0	mA
BGZ output 1	VBGZ1	IOUT = 3 mA	3.7	4.0	4.3	V
BGZ output 2	VBGZ2	IOUT = 3 mA, VCC = 4.5 V	3.65	4.0	4.3	V
BGZ maximum output current	IOMAX	VCC = 4.5 V	5.0	8.0		mA

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

LA7668N

Continued from preceding page.

Parameter	Symbol	Conditions	min	typ	max	Unit
[Luminance Signal System]
Voltage gain	VGY	VIN = 1.0 Vp-p	6.0	6.5	7.0	dB
Frequency characteristics	fY	When 3 dB down from the 1 MHz output level	7.0	8.5		MHz
Signal input level	VIY			1.0	1.2	Vp-p
Output DC level	VOYDC	Pedestal level	0.7	0.9	1.1	V
Pin 18 output	V18		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	VGC	VIN = 0.66 Vp-p	6.3	6.8	7.2	dB
Maximum gain	VGMAX	When f = 3.58 MHz, APL = 0%	7.3	7.8	8.3	dB
Minimum gain	VGMIN	When f = 3.58 MHz, APL = 100%	5.7	6.2	6.7	dB
Frequency characteristics	fC	When 3 dB down from the 1 MHz output level	4.0	5.0		MHz
Signal input level	VIC			0.66	0.8	Vp-p
Output DC level	VOCDC		1.1	1.4	1.7	V
[Control System]
Mute on voltage	VON		1.0		VCC	V
Mute off voltage	VOFF		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 Functions

Pin No.	Symbol	Function
1	LPFD	Correction signal frequency control
2	HU	Correction reference voltage (3.2 V)
3	YIN	Luminance signal input
4	HD	Correction reference voltage (3.1 V)
5	SYNC	Sync separator input
6	VCC	Power supply
7	BGP	BGP delay time constant
8	APLDET	APL level detection filter
9	HPFIN	High-frequency detection filter (input)
10	HPFOUT	High-frequency detection filter (output)
11	HEDET	High-frequency detection circuit control voltage
12	CIN	Chrominance signal input
13	COUT	Chrominance signal output
14	APLH	APL discrimination reference voltage (high)
15	APLL1	APL discrimination reference voltage (low)
16	APLL2	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	BGZOUT	4.0 V BGZ voltage output
21	LD	Correction reference voltage (2.9 V)
22	YOUT	Luminance signal output
23	LU	Correction reference voltage (2.3 V)
24	LPFU	Correction signal frequency control

No. 5097-2/11

LA7668N

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.

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