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can I get the digital buffer to do this

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aliyesami

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I have to convert 3.2 volts to about 4.5 volts.
so if i use a buffer chip say 74LS07 , i can connect its VCC to 4.5v supply n then supply the input of buffer with a 3.2v signal.
will i get the output as 4.5 v?

thanks
Sami
 

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The old 74LS series are 5 V devices with 10% voltage variation. So 4.5V is the minimum guaranteed operating voltage. Therefore if you run it on a 4.5V you have no margin, and if the voltage droops for any reason you will be running the part outside it's recommended operating conditions.

The part has a Vih of 2V so 3.2V will be recognized as a logic high.
 

aliyesami

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The old 74LS series are 5 V devices with 10% voltage variation. So 4.5V is the minimum guaranteed operating voltage. Therefore if you run it on a 4.5V you have no margin, and if the voltage droops for any reason you will be running the part outside it's recommended operating conditions.

The part has a Vih of 2V so 3.2V will be recognized as a logic high.
so basically my theory is correct just have to increase the VCC on buffer or use a newer buffer?
 

aliyesami

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i really need an answer to this can anyone help?
basically i want to drive the 5v SIM module with my 3.3v micro so i need to translate signals between 3v and 5v .

thanks

- - - Updated - - -

i really need an answer to this can anyone help?
basically i want to drive the 5v SIM module with my 3.3v micro so i need to translate signals between 3v and 5v .

thanks
 

KlausST

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Hi,

only very old SIM cards use 5V. Are you sure you need 5V?

You talk about supply voltage. But good old (5V supply) TTL levels are low: <0.7V and High >2.0V. So a modern (3.3V supplied) microcontroller usually is well within specification.

check datasheet: SN74AHCT1G125.

Klaus
 

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