Speech Recorder

[summersnow]

Hi all,

I have a problem here. I'm using ISD2548P as a speech IC to record the messages that i need to use for my project.I follow the PUSH BUTTON circuit that provided in the data sheet to record the messages.I try to record and play the speech but nothing can be heard when i play it. :-\

From the Winbond/ISD chip corder FAQ list that i found,it stated that when the device are in Record,the MIC,MIc REF, AGC and ANA OUT pins are all setting at approximately 2.2V,and when they are in Playback,the speaker pins are biased up to an average of about 2.2V..

When i measured those pins for my circuit,the voltage that i get is 1.5++V..so is it because of the voltage not high enough that makes the speaker can't play the speech?

Is there any problems for this circuit?

The input voltage for this circuit is 5V and i'm using a 8ohm speaker.
Please help me on this..Thanks

 

[audioguru2]

The spec's say that the minimum speaker is 16 ohms. Your 8 ohm speaker draws twice as much current and maybe caused the output transistors to blow up in the IC.
Maybe your electret mic is a different type or maybe it is connected backwards.

 

[summersnow]

Hi.

I really don't know why..i read all of the application note and the spec for the chip and i still not able to find out the problem...

Audioguru,
i read the spec,it shows that 16 ohm is the minimum impedance..but it stated that 8 ohm is acceptable,just that will cause distortion and the sound is not tat big...so,is it that if i'm using 8ohm speaker,there should be some noise or sound? ???

i try to look for the data sheet for the electret microphone ..i try to fix the electret mic backwards but the result is still the same..no sound at all.. :'(

From the application information for chipcorder products,it stated that there should be 1.5V at the speaker pins when PD pins is low and the playback/record is high... 0V if the other way round..my circuit meets the specs..but it cant play at all..n i wonder it is able to record..

Any other suggestion on this?Really don't know how to continue...  :'(
Really thanks if you all can help..

 

[steven6]

The Speech Recorder is an invaluable tool, seamlessly capturing spoken words with precision. Its user-friendly interface and clear audio quality make it an essential asset for anyone looking to document or analyze speech.