TRS3238E - the ability for RS-232 to drive relays

Dice-K

Other Parts Discussed in Thread: TRS3238E, ULN2003LV

Hello,
I have a question about TRS3238E.

What mA is the ability for drive on the RS-232C output level side?
(The max power electric current level which I can use safely)

When I let load drive in a control signal line, I want to know how much output load I can drive.

Regards,
Dice-K

over 9 years ago

0 Ron Michallick over 9 years ago

TI__Guru**** 173126 points

Dice,

Do you mean the DOUT lines? They are designed to drive a load as low as 3k ohms.

The current limit is around 35mA per data sheet.

What type of load do you want to use?

0 Dice-K over 9 years ago in reply to Ron Michallick

Mastermind 7941 points

Hello Ronald,
Thank you for your reply.

The type of load is a relay.
I want to know whether it can drive load of 20mA to let a relay drive.

When it is load of 3kΩ, by the 5.4V output, it is 1.8mA.
Can this drive 20mA?

Best regards,
Dice-K

0 Ron Michallick over 9 years ago in reply to Dice-K

TI__Guru**** 173126 points

Dice,

I don't recommend this usage. Can I help you find an alternate solution.
Are you trying to run multiple 5V relays from a 3.3V power source?

0 Dice-K over 9 years ago in reply to Ron Michallick

Mastermind 7941 points

Hello Ronald,
Thank you for your reply.

I want to drive this relay.

en-g5v_1.pdf
As for this relay, 30mA is necessary for 5V.

Do you have a good solution?

Best regards,
Dice-K

0 Ron Michallick over 9 years ago in reply to Dice-K

TI__Guru**** 173126 points

Dice,

I suggest a 3.3V to 5V boost converter.

Webench applications

Then add ULN2003LV, which is a 7 channel relay driver.

Interface

Interface forum

TRS3238E - the ability for RS-232 to drive relays