SINGLE CHIP SPEAKERPHONE WITH 8 - OHM LOUDSPEAKER AMPLIFIER
sames
SAN2202 APPLICATION NOTE
SINGLE CHIP “SPEAKERPHONE” WITH 8 - OHM LOUDSPEAKER AMPLIFIER
1 Scope
This application ...
Description
sames
SAN2202 APPLICATION NOTE
SINGLE CHIP “SPEAKERPHONE” WITH 8 - OHM LOUDSPEAKER AMPLIFIER
1 Scope
This application note describes a low-cost add-on circuit for driving an 8Ω-Loudspeaker to get a simple loudhearing (“Speakerphone”) Telephone. To possible ways of supplying the amplifier are shown: SAN2202a: SAN2202b: Amplifier supply in shunt transistor path Amplifier supply by power extraction circuit (SAN3020)
It can be added to any SA253x application without interfering with PTT-relevant parameters, like AC-impedance, Sidetone cancellation or DC-mask.
2 Key Features Low cost additional circuit enables use of loudhearing function Full duplex “handsfree” operation via handset microphone and loudspeaker (at distances <2m between
telephone and user) Can be added to any SA253x- application Enables use of low cost 8Ω - Loudspeaker High output power with low distortion Entirely powered from the telephone line No influence of loudspeaker amplifier in AC-impedance, sidetone cancellation or DC-mask Loudspeaker volume adjustable by potentiometer Excellent sidetone cancellation of SAS253x circuits enables high loudspeaker volume without howling between handset microphone and loudspeaker
SAN2202
PDS038-SA2531/2-001
Rev. B
21-03-00
SAN2202
TABLE OF CONTENTS
1 SCOPE.......................................................................................................................................................................................................
Similar Datasheet