LA76814
Audio Block Input Signals and Test Conditions
Unless otherwise specified, the following conditions apply when each measurement is made.
1. Bus control condition:
AUDIO.MUTE = "0", AUDIO.SW = "1", VOL.FIL = "0", IF.AGC. = "1"
2. Input 4.5MHz, 90dBµ and CW at pin 54.
3. Enter an input signal from pin 51.
Parameter
Maximum gain
Variable range
Frequency
characteristics
Mute
Distortion
Symbol
AGMAX
ARANGE
AF
AMUTE
ATHD
Test point
1
1
1
1
1
Input signal
1kHz, CW
400mVrms
1kHz, CW
400mVrms
20kHz, CW
400mVrms
1kHz, CW
400mVrms
1kHz, CW
400mVrms
Test method
Measure the 1kHz component at the pin 1.
···· V1[mVrms]
AGMAX = 20Log (V1/400) [dB]
Measure the 1kHz component at the pin 1.
···· V2[mVrms]
ARANGE = 20Log (V1/V2) [dB]
Measure the 20kHz component at the pin 1.
···· V3[mVrms]
AF = 20Log (V3/V1) [dB]
Measure the 20kHz component at the pin 1.
···· V4[mVrms]
AMUTE = 20Log (V1/V4) [dB]
Measure the distortion of the 1kHz component at
the pin 1.
Bus conditions
VOLUME = "1111111"
VOLUME = "0000000"
VOLUME = "1111111"
VOLUME = "1111111"
AUDIO.MUTE = ”1”
VOLUME = "1111111"
S/N
Crosstalk
ASN
ACT
No signal
Measure the noise level (DIN AUDIO) at the pin 1. VOLUME = "1111111"
1
···· V5[mVrms]
ASN = 20Log (V1/V5) [dB]
1kHz, CW
Measure the 1kHz component at the pin 1.
1
400mVrms ···· V6[mVrms]
VOLUME = "1111111"
AUDIO.SW = "0"
ACT = 20Log (V1/V6) [dB]
No.A0253-11/35