LB11852FV
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8
Description of Pre-driver Bock
*1 : Power-GND wiring
The SGND is connected to the control circuit power supply system.
*2 : Power stabilization capacitor
For the power stabilization capacitor on the signal side, use a capacitor of 0.1F or more. Connect the capacitor
between V
CC
and GND with a thick and along the shortest possible route.
*3 : Power-side power stabilization capacitor
For the power-side power stabilization capacitor, use a capacitor of 1F or more. Connect the capacitor between the
power-side power supply and GND with a thick and along the shortest possible route.
*4 : IN
+
, IN
-
pins
Hall signal input pins
Wiring should be short to prevent noise from being carried.
If noise is carried, insert a capacitor between the IN
+
and IN
-
pins.
The Hall input circuit functions as a comparator with hysteresis (15mV).
It also has a soft switch zone with 30mV (input signal difference voltage).
It is also recommended that the Hall input level should be a minimum of 100mV (p-p).
*5 : CPWM pin
Pin to connect the capacitor used to generate the PWM basic frequency
Use of CP = 200pF causes oscillation at f = 30kHz, which is the basic frequency of PWM.
As this is also used for the current limiter reset signal, a capacitor must be connected even if the speed is not going to
be controlled.
*6 : CT pin
Pin to connect the capacitor used for lock detection
The constant-current charging and constant-current discharging circuits incorporated cause locking when the pin
voltage reaches 3.0V, and releasing the lock protection when it drops to 1.0V.
Connect this pin to the GND when it is not to be used (locking not necessary).
*7 : SENSE pin
Current limiter detection pin
When the pin voltage exceeds 0.21V, the current limiter is activated, and operation enters lower regeneration mode.
Connect this pin to the GND when it is not to be used.
*8 : FG pin
Rotational speed detection pin
This is an open collector output that can detect the rotational speed using the FG output corresponding to the phase
changeover.
Keep this pin open when it is not to be used.
