I am using a Bipolar stepper motor( 4lead, 1.2A/phase) 10R/ phase resistance) with the L297/L298 combination controller and driver.

When the motor is in a static position, a holding torque applied, the motor
is starting to overheat, hot to touch. Also, when the motor is moving at 120 rpm L298 gets hot upto 100 degrees within 5 min.
I am using 22k/33pf as RC for oscillator.
The circuit is similar to www.kevinro.com/chpdrv.pdf

Also The L297 uses a comparator to determine applied
winding current, based on sense resistors and a reference voltage. If, in a bid to reduce the static position phase current and the demands on the power
supply, I attempt to decrease the reference voltage to lower than the sensed voltage (sensed phase current), then the Vref and current sense inputs
become 'noisy' , indeed the circuitry as a whole is 'noisy', the motor although it maintains its static position, is vibrating (unstable) and the phases appear to be being turned on and off.


How to prevent this overheating?