LB11870 Datasheet, PDF (7/14 Pages) Sanyo Semicon Device – Three-Phase Brushless Motor Driver for Polygonal Mirror Motors

Pin Functions
Pin No.
3
1
46
44
Symbol
OUT1
OUT2
OUT3
GND3
Pin Description
Motor drive output
Output block ground
LB11870
VCC1
37
VM1
Output block power supply and current
38
VM2
detection.
Insert the resistor Rf between this pin and
VCC1.
The output current will be limited to the current
value
IOUT = VRF/Rf.
39
VCC2
Upper diode cathode connection. Short this pin
to VCC1.
11
IN1+
Hall element inputs.
12
IN1-
The high state is when IN+ is greater than IN-,
9
IN2+
and the low state is the reverse.
10
IN2-
An amplitude of at least 100mVp-p (differential)
6
IN3+
is desirable for the Hall element signal inputs. If
8
IN3-
noise on the Hall signals is a problem, insert
capacitors between the IN+ and IN- inputs.
6 9 11
Equivalent Circuit
39
300Ω
38
37
1 3 46
VREG
300Ω
44
300Ω
8 10 12
13
FGIN+ FG input.
14
FGIN-
If noise on the FG signal input is a problem,
connect a filter consisting of either a capacitor
or a capacitor and a resistor.
VREG
300Ω
13
15
GND1 Control circuit block ground
16
GND2 SUBGND pin
17
PWM
Sets the PWM oscillator frequency.
Insert a capacitor between this pin and ground.
The PWM oscillator frequency is set to about
34kHz when a 680pF capacitor is used.
VREG
300Ω
14
200Ω
17
Continued on next page.
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