639

Optical disc ICs

BA5937AFP

(2)

Voltage setting for loading motor driver (ex: forward mode)

∗When setting the output voltage from the loading driver,

even if an output voltage is set that exceeds the maxi-

mum output voltage with respect to the power supply

voltage, the output will not exceed the maximum output

voltage.

If a voltage is set that is under the maximum output volt-

age, the example above is applicable. Also, by having the

loading input (pin 19) open, the maximum output voltage

with respect to the power supply voltage is output.

(3)

The BA5937AFP contains a thermal shutdown cir-

cuit.

When the chip temperature reaches 175

_C (Typ.), the

output current is muted. If the chip temperature then

drops below 150

_C (Typ.), then the mute is released.

(4)

If the voltage of the bias pin (pin 23) drops below

1.0V (Typ.), outputs are muted.

For normal conditions, have the voltage above 1.4V and

below 6.5V.

(5)

By having the mute pin (pin 7) voltage pulled up to

2.0V or greater, you can mute the output current for chan-

nels 1 and 4. For normal conditions, have pin 7 open or

at 0.5V or below.

(6)

If the voltage of the thermal shutdown, mute ON, or

bias pin drops, the mute is activated; however, in these

situations, only the drivers are muted. Also, the output pin

voltage becomes the internal bias voltage (approx.

*VF)/2).

(7)

Connect a bypass capacitor (approx. 0.1

µF) be-

tween the bases of the power supply pins of this IC.

(8)

Even though the radiation fins are connected to

ground within the package, be sure to also connect them

to a ground externally as well.