NTE7047 Просмотр технического описания (PDF) - NTE Electronics

Номер в каталоге

Компоненты Описание

производитель

NTE7047

Integrated Circuit TV Color Small Signal Sub System

NTE Electronics 

Electrical Characteristics (Cont’d): (TA = +25°C, VP = V7–6 = 12V, carrier 38.9MHz, negative

modulation unless otherwise specified)

Parameter

Symbol

Test Conditions

Min Typ Max Unit

Vertical Circuit (Cont’d) (Vertical Guard, Note 24, Note 25)

Active Switching Level at a Deviation

with Respect to the DC Feedback

Level: Guard Level HIGH

∆V4 V27 = 2.5V

– 2.0 –

V

Notes:

Note 2. On set AGC.

Note 3. The input impedance has been chosen such that a SAW–filter can be applied.

Note 4. Measured with 0dB = 450µV.

Note 5. Measured at 10mV (RMS value) top sync input signal.

Note 6. So–called projected zero point; i.e. with switched demodulator.

Note 7. White 10% of the top sync amplitude.

Note 8. The differential gain is expressed as a percentage of the difference in peak amplitude be-

tween the largest and smallest value relative to the subcarrier amplitude at blanking level.

The differential phase is defined as the difference in degrees between the largest and small-

est phase angle. The differential gain and phase are measured with a DSB signal.

Note 9. This figure is valid for the complete video signal amplitude (peak white–to–black). The non–

linearity is expressed as a percentage of the maximum deviation of a luminance step from

the mean step, with respect to the mean step.

Note10. The figures are measured at an input signal of 10mV (RMS value).

Note 11. Measured with a source impedance of 75Ω.

Signal–to–noise ratio = 20 log

Vout black–to–white

Vn(rms) at B = 5MHz

Note12. The AFC control voltage is obtained by multiplying the IF output signal (which is also used

to drive the synchronous demodulator) with a reference carrier. This reference carrier is ob-

tained from the demodulator tuned circuit via a 90 degree phase shift network. The IF output

signal has an asymmetrical frequency spectrum with respect to the carrier frequency. To

avoid problems due to this asymmeterical signal the AFC circuit is followed by a sample–

and–hold circuit which samples during the sync level. As a result the AFC output voltage con-

tains no video information. The specified control steepness is without using an external load

resistor. The control steepness decreases when the AFC output is loaded with two resistors

between the voltage supply and GND.

Note13. At very weak input signals the drive signal for the AFC circuit will have a high noise content.

This noise input has an asymmetrical frequency spectrum which will cause an offset of the

AFC output voltage. To avoid problems due to this effect a notch filter can be built in to the

demodulator tuned circuit. The characteristics given for waek input signals are measured

without a notch circuit, with a SAW filter connected in front of the IC (input signal such that

the input signal of the IC is 150µV (RMS value).

Note14. The sound circuit is measured (unless otherwise specified) with an input signal of V15 of

50mV (RMS value), a carrier frequency of 5.5MHz at a ∆f of 27.5kHz and AF frequency of

1kHz. The QL of the demodulator tuned circuit is 16 and the volume control is connected to

the supply. The reference circuit must be tuned in such a way that the output is symmetrical

clipping at maximum volume.

Note15. The output signal is measured at a ∆f = 7.5kHz and maximum volume control.

Note16. The demodulator tuned circuit must be tuned at minimum distortion.

Note17. Weighted noise, measured according to: CCIR 468.

Note18. See also Note 1. The volume can be controlled by using a potentiometer connected to GND

(value 10kΩ) or by means of a variable direct voltage. In the latter case the relatively low input

impedance (Pin11) must be taken into account.

Share Link: