LM339: Maximum output current

Zach Kimble

Part Number: LM339

Hello,

The datasheet for LM339 does not seem to specify a maximum recommended IOL, just an absolute maximum output current. What is the maximum IOL per channel for this device? Can all 4 channels be tied together to multiply that maximum IOL by 4 for a single load?

Best regards,

Zach Kimble

2 months ago

0 Clemens Ladisch 2 months ago

Guru 321920 points

The electrical characteristics guarantee at least 4 mA with V_OL = 400 mV, or 16 mA with V_OL = 1.5 V. Figures 6-19…6-22 show that the output saturates near 20 mA.

The output is a BJT, so you should not simply tie multiple outputs together. In a low-voltage application, use a CMOS comparator like the LM339LV, or else add an external buffer, or use a different comparator.

0 Ron Michallick 2 months ago

TI__Guru**** 170776 points

Zach,

How many channels and how much current and maximum VOL do you need?

0 Zach Kimble 2 months ago in reply to Ron Michallick

TI__Intellectual 2170 points

Hi Clemens and Ron,

Thank you for your feedback. I need 4 channels but I don't have a specific current or VOL in mind, just wondering what the part can do.

If I end up needing higher current in the same footprint, what device would you recommend? LM339LV seems to have similar saturation current.

Best regards,

Zach Kimble

+1 HO SIU 2 months ago in reply to Zach Kimble

TI__Genius 13345 points

Hi Zach,

What supply voltage do you plan on operating the comparator at? The LM339LV has a pretty strong output stage; the short circuit current of the LM339LV saturates at ~100mA at V+ = 5V (vs. ~20mA at V+ = 5V for the LM339B):

LM339LV:

LM339B:

0 Zach Kimble 2 months ago in reply to HO SIU

TI__Intellectual 2170 points

Hi Philip,

I apologize, I was looking at the wrong graph (the 1.8V one). This should be plenty of current.

Thank you!

Best regards,

Zach Kimble

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LM339: Maximum output current