SI9979_04 VISHAY [Vishay Siliconix], SI9979_04 Datasheet - Page 6

• Manufacturer Part Number: SI9979_04
• Description: 3-Phase Brushless DC Motor Controller
• Manufacturer: VISHAY [Vishay Siliconix]

Si9979
Vishay Siliconix
PIN DESCRIPTION (CONT’D)
Pin 34: GT
This is the gate drive output for the top MOSFET in Phase A.
Pin 35: S
This pin is negative supply of the high-side drive circuitry. As
such, it is the connection for the negative side of the bootstrap
capacitor, the top MOSFET Source, the bottom MOSFET
Drain, and the Phase A output.
Pin 36: CAP
This pin is the positive supply of the high-side circuitry. The
bootstrap capacitor for Phase A is connected between this pin
and SA.
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6
APPLICATION CIRCUITS
Commutation
Sensors
To
A
A
PWM IN
FAULT
A
TACH
GND
V+
1 mF
R
T
C
T
42
43
10
18
17
11
1
2
3
5
6
9
4
7
8
FIGURE 1. Three-Phase Brushless DC Motor Controller
V+
V
IN
IN
IN
EN
F/R
BRK
60/120
TACH
QS
PWM
FAULT
R
R
GND
DD
T
T
A
B
C
/C
12−16, 21−24
37−41, 44−48
T
Si9979
CAP
CAP
CAP
GND
GB
GT
GT
GB
GB
GT
I
S
I
S
S
S
S
+
B
B
B
A
A
B
C
A
C
C
A
C
−
34
35
36
30
31
32
26
27
28
35
29
25
19
20
Pin 42: V+
The supply voltage for the Si9979 is connected between this
pin and ground. The internal logic and high-side supply
voltages are derived from V+.
Pin 43: V
V
to connect a capacitor between this pin and ground to insure
that the current surges seen at the turn on of the bottom
MOSFETs does not trip the undervoltage lockout circuitry.
DD
CB
CB
CB
C
R
is the internal logic and gate drive voltage. It is necessary
A
B
C
R
DD
S
Q1
Q4
LITTLE FOOT
Q2
Q5
S-41209—Rev. E, 21-Jun-04
Document Number: 70012
Q3
Q6
C
A
B
To
Motor
Windings