Harman Kardon AVR 325, Руководство по обслуживанию

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MITSUMI
Video Switch · 75
Ω
driver · Y/C mix MM1501
·Measurement Procedures (MM1501 ~ MM1504)
Consumption current
I
CC
Connect a DC ammeter to V
CC
pin and measure. Hereafter, short
the ammeter to use.
Input a 2.0V
P-P
(1.0V
P-P
for MM1502 and MM1504), 100kHz sine
wave to SG1. If TP1 voltage is V1 and TP3 voltage is V2, find Gv
using the following formula:
G
V
= 20LOG (V2/V1) dB
Frequency characteristic
fc
In the above Gv measurement, if TP3 voltage at 10MHz is V3, find
fc as follows:
fc = 20LOG (V3/V2) dB
Differential gain
DG
Input a 2.0V
P-P
(1.0V
P-P
for MM1502 and MM1504) staircase to SG1
and measure differential gain at TP3.
APL = 10 ~ 90%
Differential phase
DP The same as for DG, but measure differential phase.
Total harmonic distortion ratio
THD
Input a 2.5V
P-P
(1.25V
P-P
for MM1502, MM1504), 1kHz sine wave to
SG1, connect a distortion factor meter to TP3 and measure.
Output dynamic range
V
D
Input a 100kHz sine wave to SG1. Change the amplitude of the sine
wave, and measure V
D
, the maximum amplitude under THD 1%, at
TP3.
Output offset voltage
V
OFF
Measure the DC voltage difference of each switch status at TP2.
VC1 = 2.1V and VC2 = 0.7V. Input a 2.0V
P-P
, 4.43MHz sine wave to
SG1, and operate SW3. If TP3 voltage when there is an output
signal on the OUT pin is V4, and when there is no signal TP3
voltage is V5, then find C
T
by the following formula:
C
T
= 20LOG (V5/V4) dB
Impress an optional DC voltage on TP5 and TP6. Gradually
increase from VC1 = 0V. When TP6 voltage is output on TP2, TP4
voltage is V
IH
. Gradually lower from VC1 = V
CC
, and when TP5
voltage is output on TP2, TP4 voltage is V
IL
.
SW input voltage
V
I
Cross talk
C
T
Voltage gain
G
V
AVR325 harman/kardon
113