I'm developing the PCB of my L297-L298 stepper motor driver, but I have a doubt about the SENSE pins of the L297 I.C. I understand that the pin 13 and 14 of the L297 are used for controlling the voltage on the two resistors(0,5 ohm), but since the current that flows on the resistors can reach 2A, does not this current flows on the pin of the L297, burning out the I.C.?

The schematic: Sense pins

Datasheet: datasheet

  • \$\begingroup\$ wrong specs, absolute max will indicate max input voltage. this is only 1V, bias current indicates load. \$\endgroup\$ Feb 12 '17 at 20:24

The 2 Amps don't flow through the pins. The pins just measure the voltage that is developed on the shunt resistors.

In the same way, a multimeter measuring voltage typically does not have significant current running through it.

  • \$\begingroup\$ Oh , so I guess that the L297 has an internal high resistance...or not? \$\endgroup\$ Feb 12 '17 at 20:29
  • \$\begingroup\$ The sensing pins yes. Probably in the upper tens~hundreds of kOhms. \$\endgroup\$
    – Wesley Lee
    Feb 12 '17 at 20:42

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