Question: SN75189. About the voltage range of "Vc" in the datasheet.

Toshiya Hiramatsu

Other Parts Discussed in Thread: SN75189

Hi,

I have a question about SN75189.
Could you please see Figure 1 of the SN75189 data sheet?
http://focus.tij.co.jp/jp/lit/ds/symlink/sn75189.pdf

What is voltage range of "Vc"?

Could you please teach me?
Thanks in advance,

Toshiya

over 14 years ago

0 Ron Michallick over 14 years ago

TI__Guru**** 151276 points

Hello Toshiya-san,

Response control pin voltage is always less than +/-1V because of the input transistor's base emitter junction and a diode to ground. Therefore current, not voltage, controls the threshold voltage. This means that any voltage is allowed for "Vc” provided the series resistor limits the current to a safe level, less than +/-10mA.

Regards,
Ron M.

0 Toshiya Hiramatsu over 14 years ago in reply to Ron Michallick

Intellectual 630 points

Hello Ron-san,

Thanks for your explanation.

About "+/-10mA".
Is it an ability value?

Regards,

Toshiya.

0 Ron Michallick over 14 years ago in reply to Toshiya Hiramatsu

TI__Guru**** 151276 points

Toshiya-san,

1) 10mA of current is considered safe and non destructive on clamped input pins.
2) 10mA is a very large shift in receiver threshold offset; it is much more than normally required.

Regards,
Ron M.

0 Toshiya Hiramatsu over 14 years ago in reply to Ron Michallick

Intellectual 630 points

Ron-san,

Thanks.

Regards,

Toshiya.

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Question: SN75189. About the voltage range of "Vc" in the datasheet.