Replacement for SN55115

Robert Curtis

Other Parts Discussed in Thread: SN55115, AM26C32, AM26LV32E, AM26LS33A

Hello,

I have a new design that I am interfacing to an old system. The old interface card used a SN55115 receiver. This device is going obsolete (at least in “W” packaging).

http://www.ti.com/pdfs/hirel/mltry/obsolete.pdf

Is there a more modern part that can be used as a replacement? I have not been able to find a +/- 15v common mode equivalent part.

Thanks,

Rob Curtis

over 11 years ago

0 Ron Michallick over 11 years ago

TI__Guru**** 164976 points

Robert,

Do you need the -55C to 125C temperature range?

0 Robert Curtis over 11 years ago in reply to Ron Michallick

Intellectual 430 points

No, I would be able to use an industrial range (-40 to 85).

0 Ron Michallick over 11 years ago in reply to Robert Curtis

TI__Guru**** 164976 points

Robert,

In RS422 there are quad receivers. I suggest using AM26C32 for VCC=5V or AM26LV32E for VCC=3.3V. These devices have a recommended VIC of +/-7V, but it can be exended to +/-15V with two external resistors.

The minimum added resistance to get +/-15V is 114% of the internal resistor. The maximum added resistance to get 500mV sensitivity is 150% of the internal resistor. The internal resistor for the AM26C32 is 17k nominal and the internal resistor on the AM26LV32E is 12k nominal. Picking the middle is 130%. Place the resistors close to the IC pins for best performance.

In RS485 there are -20V to +25V common mode range devices, but they are single channel.

0 Robert Curtis over 11 years ago in reply to Ron Michallick

Intellectual 430 points

Thank you for your help. This answers my question.

Regards,

Rob Curtis

0 Ron Michallick over 11 years ago in reply to Robert Curtis

TI__Guru**** 164976 points

Robert.

One more option; AM26LS33A is +/-15V common mode capable quad receiver.

Interface

Interface forum

Replacement for SN55115