三合微科股份有限公司
SAMHOP Microelectronics Corp.
SM7181
ECHO
Echo Mode & Surround Mode
SM7181 digitize the audio signal through A/D converter and store the value in a First-in- First-out 8Kbits
SRAM. After 3.2RCms of delay time the value store in the SRAM will be read out and reconstruct by
D/A converter then add with the present sound to become an echo signal output. The echo delay is
control by the RC of Pin 2, Pin 3.
Audio In
Add
Low Pass
Filter
AD Converter
Low Pass
Filter
DA Converter
Echo Mode
ABSOLUTE MAXIMUM RATINGS
( Ta = 25 oC, unless otherwise noted )
Symbol
Vcc
Icc
Pd
Topr
Tstg
Description
Supply voltage
Supply current
Power dissipation
Operation temperature
Storage temperature
Limits
6.5
100
1.7
-20 75
-25 125
SRAM
Unit
V
mA
W
oC
oC
Audio
out
Page 4