LA7642N View Datasheet(PDF) - SANYO -> Panasonic

Part Name

Description

Manufacturer

LA7642N

SECAM Format Color TV Chrominance Circuit

SANYO -> Panasonic 

Continued from preceding page.

Parameter

R-Y linearity

ALC pulse height

Blanking period B-Y DC voltage

Blanking period R-Y DC voltage

SECAM output impedance: B-Y

SECAM output impedance: R-Y

Output impedance

Non-SECAM: B-Y

Output impedance

Non-SECAM: R-Y

Black level error B-Y

Black level error R-Y

[De-Emphasis Characteristics]

De-emphasis 63k B-Y

LA7642N

Symbol

Conditions

LINRY

Input a color bar signal (0 dB) to pin 14. In the

pin 6 (R-Y) output waveform measure the

amplitude of the blue green (+280 kHz) and

red (–280 kHz) components (A) and measure

the amplitude of the blue (+45 kHz) and

yellow (–45 kHz) components (B). Calculate

the value of LINRY from the following formula.

LINRY = (A/B) × (90/560) × 100 (%)

VALC

Measure the peak value of the pin 7 ALC

pulse signal.

Referenced to the blanking period DC level.

VALC The pin 7 blanking period DC level.

VRYBLK The pin 6 blanking period DC level.

ZBYS

The pin 7 output impedance. For reference

only.

Input a color bar signal (0 dB) to pin 14 and

measure the pin 7 B-Y amplitude Vb (V p-p).

Next, connect a 2-kΩ resistor between pin 7

and ground and measure the pin 7 B-Y

amplitude Vwrb (V p-p). Derive ZBYS from

the following formula.

ZBYS = (Vb – Vwrb)/Vwrb × 2k (Ω).

ZRYS

The pin 6 output impedance. For reference

only.

Input a color bar signal (0 dB) to pin 14 and

measure the pin 6 R-Y amplitude Vr (V p-p).

Next, connect a 2-kΩ resistor between pin 6

and ground and measure the pin 6 R-Y

amplitude Vwrr (V p-p). Derive ZRYS from

the following formula.

ZRYS = (Vr – Vwrr)/Vwrr × 2k (Ω).

The pin 7 output impedance. For reference

only.

ZBY Apply a 4-V signal to pin 7 (B-Y), measure

the influx current Ib, and derive ZBY from the

following formula. ZBY = 4/Ib (MΩ)

ZRY

The pin 6 output impedance. For reference

only.

Apply a 4-V signal to pin 6 (R-Y), measure

the influx current Ir, and derive ZRY from the

following formula. ZRY = 4/Ir (MΩ)

BBBY

The DC difference between the pin 7 no

signal period DC level and the signal period

DC level for a black-and-white signal.

Measure DBY (V) and calculate BBBY from

the following formula.

BBBY = DBY × 460/VBY kHz

BBRY

The DC difference between the pin 6 no

signal period DC level and the signal period

DC level for a black-and-white signal.

Measure DRY (V) and calculate BBRY from

the following formula.

BBRY = DRY × 460/VRY kHz

min

85

180

3.8

3.8

10

10

–5

–5

Ratings

typ

100

200

4.1

4.1

150

150

0

0

Unit

max

115

%

220 mVp-p

4.4

V

4.4

V

Ω

Ω

MΩ

MΩ

+5 kHz

+5 kHz

Input a signal to which a 63-kHz modulation

has been applied to pin 14 and measure the

pin 7 B-Y amplitude Vbon (V p-p) when

preemphasis is on. Next, turn off pre-

DE63B emphasis, measure the pin 7 B-Y amplitude

–1.0

–2.6

–4.0

dB

Vboff (V p-p), and calculate DE63B from the

following formula.

DE63B = 20 × log (Vboff/Vbon) (dB)

Continued on next page.

No. 5693-3/6

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