MITSUBISHI SOUND PROCESSOR ICs
M61508FP
THE ELECTRIC VOLUME of BUILD-IN NON FADER VOLUME with TONE CONTROL
ZERO-CROSSING DETECTION CIRCUIT
1. Meaning of Zero-Crossing Detection Circuit
In the conventional Serial Data Control Type Volume, Analog SW inside switches over
simultaneously with Latch Condition Detector. And the operation completes.
CLK
D32
D33
D34
DATA
Audio Signal
Signal GND(1/2Vcc)
Latch Conditions
Noise Factor when
Signal is present
In this case the changing noise occurs at the time of Latch Condition Detector, the
Analog SW switches over (Zero-cross Detector Strobe occurs) in the moment that the
Analog Signal cross Signal Ground (1/2VCC).
CLK
D32
D33
D34
DATA
Signal GND (1/2Vcc)
Latch Conditions
Zero-cross Detector Strobe
(Form signal from inside IC)
Analog SW changing
Other,In the case of Audio Signal isn't inputted (No signal),even if only Zero-cross
Detector Circuit detects Latch Condition, Analog SW doesn't switch over for the
Audio Signal never cuts Signal Ground (1/2VCC).
The Time Function switches the Analog SW after some time T.
The Timer Time can setting with the Serial Data of 5mS,10mS,15mS,20mS.
D-61508-98-C
MITSUBISHI
ELECTRIC
(16/22)