SM1350ADJM
FUNCTIONAL DESCRIPTION
Chattering Prevention
STN, STOP chattering prevention function
(a) Oscillator stopping (Standby Mode)
The oscillator starts when STN goes from HIGH to LOW in standby mode. Input data is received and melody data
output starts 81.9ms after the oscillator start if STN is LOW. SM1350 dose not operate even if the signal is input to
STOP in standby mode.
61.0Hz
STN
OSC
Input Reception
Melody Output
(SP pin)
81.9ms
81.9ms
Figure 1. STN,STOP chattering prevention timing (oscillator stopping)
(b) Oscillator running
Input data is considered valid 81.9ms after STN and STOP have last changed state. Input data is considered invalid
for intervals less than 65.5ms.
61.0Hz
STN or
STOP
65.5ms
81.9ms
Input Reception
Figure 2. STN,STOP chattering prevention timing (oscillator running)
SEIKO NPC CORPORATION - 7