710

Motor driver ICs

BA6809F / BA6819AF

FOperation notes

(1)

Thermal shutdown circuit

The IC has a built-in thermal shutdown circuit. The is a

temperature difference of 20

_C (typical) between the

temperatures at which the circuit is activated and deacti-

vated.

The circuit is activated at the temperature of about 175

_C

(typical), so that all outputs are turned OFF. Normal op-

eration resumes when the circuit is deactivated.

(2)

Power dissipation

Power consumed in the IC can be calculated from the fol-

lowing equation :

where

Make sure that your application does not exceed the al-

lowable power dissipation of the IC.

(3)

Hall amplifier input voltage

The R1 and R2 resistances must be set so as to maintain

the Hall amplifier input bias voltage within the range of 0V

*2V) including the signal amplitude.

The Hall device may be affected by power supply noise

due to the PCB conductor pattern. If you have this prob-

lem, insert a capacitor C1 as shown in Fig. 5.

If the conductor lines from the Hall device output termi-

nals to the Hall inputs of the IC are particularly long, noise

can be picked up and fed into the inputs. If you have this

problem, insert a capacitor C2 as shown in Fig. 5. Note

that the Hall inputs have no hysteresis in this IC.

where RH is the Hall device impedance.

R1

)R2)RH

Hall current is given by=