FAN8732CG Datasheet, PDF (15/20 Pages) Fairchild Semiconductor – Spindle motor and 5-CH actuator driver [Spindle(PWM), Sled 2-CH(PWM) 3-CH(Linear)]

FAN8732G/FAN8732BG/FAN8732CG
4. Power Save & Channel Selection
MUTE/SB logic tables are as below.
Logic Input
Mute(pin41) SB(pin38)
L
L
L
H
H
L
H
H
CH1
off
off
on
CH2
off
off
Drive Change
CH3 CH4
off
off
on
off
CH5
off
off
spindle
off
off
on
off
on
on
on
5. SB(Short Brake Mode Selection)
When SB pin enabled(low), the brake mechanism of 3-phase spindle driver is changed to short brake.
SHORT BRAKE OPERATING SCHEME
Vcc
OFF
38
ON
1KΩ
20KΩ
OFF
12
ON
13
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MOTOR
When short brake is enabled all lower output transistors are turned on and all upper output transistors are turned off, so the cur-
rent due to the motor back EMF(electro motive force) is freewheeled through lower transistors and lower freewheeling diodes.
It is general that the short brake is safer than the reverse brake in high speed applications. But it is not true in all cases because
the current in the short brake is depend on the amount of the motor back EMF. So in high speed applications we suggest an
optimal brake which is our patent. Please contact sales persons or offices if you need more information about the optimal
brake.
6. TSD(Thermal Shut Down)
When the chip temperature rises up to about 160^oC(degree), all output drivers are shut down. When the chip temperature falls
off to about 130^oC, then the drivers recover normal operation. TSD has the temperature hysteresis of about 30^oC.
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