VISHAY SI9979

Si9979
Vishay Siliconix
Si9979
3-Phase Brushless DC Motor Controller
FEATURES
• Hall-Effect Commutation
é 60° or 120° Sensor Spacing
é Integral High-Side Drive for all
N-Channel MOSFET Bridges
é PWM Input
é
é
é
é
é
Quadrature Selection
Tachometer Output
Reversible
Braking
Output Enable Control
é
é
é
é
Cross Conduction Protection
Current Limiting
Undervoltage Lockout
Internal Pull-Up Resistors
DESCRIPTION
The Si9979 is a monolithic brushless dc motor controller with
integral high-side drive circuitry. The Si9979 is configured to
allow either 60° or 120° commutation sensor spacing. The
internal low-voltage regulator allows operation over a wide
input voltage range, 20- to 40-V dc.
quadrature select, and braking inputs are included for control
along with a tachometer output. Protection features include
cross conduction protection, current limiting, and undervoltage
lockout. The FAULT output indicates when undervoltage, over
current, disable, or invalid sensor shutdown has occurred.
The Si9979 provides commutation from Hall-effect sensors.
The integral high-side drive, which utilizes combination
bootstrap/charge pump supplies, allows implementation of an
all n-channel MOSFET 3-phase bridge. PWM, direction,
The Si9979 is specified to operate over the commercial
temperature range of 0 to 70°C (C suffix), and the industrial
temperature range of -40 to 85°C (D suffix).
FUNCTIONAL BLOCK DIAGRAM
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Si9979
Vishay Siliconix
ABSOLUTE MAXIMUM RATINGS
Voltage on Pin 42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 V
Operating Temperature
C Suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 70°C
D Suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40 to 85°C
Voltage on Pins 1-4, 10, 11 . . . . . . . . . . . . . . . .-0.3 V to VDD + 0.3 V
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65 to 150°C
Voltage on Pins 5-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to 5.5 V
Junction Temperature (TJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C
Voltage on Pins 26, 28, 30, 32, 34, 36 . . . . . . . . . . . . . . . . . . . . . 60 V
Power Dissipation (PD)
C Suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.70 W
D Suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.55 W
Voltage on Pins 27, 31, 35 . . . . . . . . . . . . . . . . . . . . . . . . . . -2 to 50 V
RECOMMENDED OPERATING RANGE
V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +20 to 40 VDC
RT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 kΩ Min
SPECIFICATIONS
Limits
Test Conditions
Unless Otherwise Specified
Parameter
Symbol
V+ = 20 to 40 V, IDD = 0 mA
-40°C to 85°C
Mina
Typb
Maxa
Units
Power
Supply Voltage Range
Logic Voltage
Supply Current
Logic Current
Internal Referencec
V+
VDD
20
-20 mA ≤ IDD ≤ 0 mA
14.5
I+
40
16
17.5
4.5
mA
-20
IDD
VREF
V
4.2
V
Commutation Inputs (INA, INB, INC, 60/120)
High-State
VIH
4.0
Low-State
VIL
High-State Input Current
IIH
VIH = VDD
Low-State Input Current
IIL
VIL = 0 V
1.0
10
-50
V
µA
Logic Inputs (F/R, EN, QS, PWM, BRK)
High-State
VIH
2.0
Low-State
VIL
High-State Input Current
IIH
VIH = 5.5 V
Low-State Input Current
IIL
VIL = 0 V
0.8
10
-125
V
µA
Outputs
Low-Side Gate Drive, High State
VGBH
Low-Side Gate Drive, Low State
VGBL
High-Side Gate Drive, High State
VGTH
High-Side Gate Drive, Low State
VGTL
Capacitor Voltaged
VCAP
Low-Side Switching, Rise Time
trL
Low-Side Switching, Fall Time
tfL
High-Side Switching, Rise Time
trH
High-Side Switching, Fall Time
tfH
Break-Before-Make Time
TACH Output/FAULT Output
TACH Output Pulsewidth
S-60752-Rev. D, 05-Apr-99
2
14
16
0.1
TA = 0 to 70°C
C Suffix
16
18
TA = -40 to 85°C
D Suffix
16
20
55
Risetime = 1 to 10 V
Falltime = 10 to 1 V
CL = 600 pF
25
70
100
ns
40
100
tBHL
300
tT
V
0.1
V+ = 40 V
tBLH
VOL
17.5
IOL = 1.0 mA
0.15
300
600
0.4
V
ns
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Si9979
Vishay Siliconix
SPECIFICATIONS
Limits
Test Conditions
Unless Otherwise Specified
Parameter
Symbol
-40°C to 85°C
Mina
V+ = 20 to 40 V, IDD = 0 mA
Typb
Maxa
Units
Protection
Low-Side Undervoltage Lockout
Low-Side Hysteresis
High-Side Undervoltage Lockout
UVLL
12.2
VH
0.8
SA, B, C = 0 V
UVLH
V
VDD - 3.3
Current Limit
Comparator Input Bias Current
IIB
Comparator Threshold Voltage
VTH
Common Mode Voltage
VCM
One Shot Pulse Width
µA
-5
TA = 0 to 70°C
C Suffix
90
100
110
TA = -40 to 85°C
D Suffix
85
100
125
0
tp
1
RT = 10 k, CT = 0.001 µF
8
10
12
RT = 10 k, CT = 0.01 µF
80
100
120
mV
V
µs
Notes
a. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum.
b. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing.
c. The reference voltage is not available for external use.
d. VCAP = (V+) + (VDD)
COMMUTATION TRUTH TABLE
Inputs
Sensors
(60°Spacing)
Outputs
Sensors
(60°Spacing)
Top Drive
Bottom Drive
INA
INB
INC
INA
INB
INC
EN
F/R
BRK
IS+
GTA
GTB
GTC
GBA
GBB
GBC
FAULT
0
0
0
1
0
1
1
1
0
0
1
0
0
0
1
0
1
1
0
0
1
0
0
1
1
0
0
1
0
0
0
0
1
1
1
1
0
1
1
0
1
1
0
0
0
1
0
0
0
1
1
1
1
1
0
1
0
1
1
0
0
0
1
0
1
0
0
1
0
1
1
0
1
1
1
1
0
0
0
0
1
1
0
0
1
0
0
1
0
0
1
1
1
0
0
0
0
1
0
1
0
1
0
0
0
1
0
1
1
0
0
0
0
1
0
1
0
0
1
1
0
0
1
0
0
1
0
0
0
0
0
1
1
0
0
1
1
1
0
1
1
0
1
0
0
0
0
0
1
0
1
0
1
1
1
1
0
1
0
1
0
0
0
1
0
0
0
1
0
1
0
1
1
0
1
1
1
0
0
0
1
0
0
0
0
1
1
0
0
1
0
0
1
1
0
0
0
0
1
0
0
0
1
1
X
X
X
X
X
X
0
X
0
X
0
0
0
0
0
0
0
Disable
X
X
X
X
X
X
0
X
1
X
0
0
0
1
1
1
0
Power Down
L
L
L
L
L
L
1
X
1
0
0
0
0
1
1
1
1
Brake
L
L
L
L
L
L
1
X
1
1
0
0
0
1
1
1
0
Over I in BRK
L
L
L
L
L
L
1
X
0
1
0
0
0
0
0
0
0
Over I
1
0
1
1
1
1
1
X
0
X
0
0
0
0
0
0
0
1
0
1
1
1
1
1
X
1
X
0
0
0
1
1
1
0
0
1
0
0
0
0
1
X
0
X
0
0
0
0
0
0
0
0
1
0
0
0
0
1
X
1
X
0
0
0
1
1
1
0
Notes:
L. Any valid sensor combination
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Conditions
X. Don’t care
S-60752-Rev. D, 05-Apr-99
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Si9979
Vishay Siliconix
PIN CONFIGURATION
PIN DESCRIPTION
Pins 1-3: INA, INB, INC
Pin 7: QS (Quadrature Select)
INA, INB, and INC are the commutation sensor inputs, and are
intended to be driven by open collector Hall effect switches.
These inputs have internal pull up resistors tied to VDD, which
eliminates the need for external pull up resistors.
This input determines whether the bottom MOSFETs or both
bottom and top MOSFETs switch in response to the PWM
signal. A logic “1” on this input enables only the bottom
MOSFETs. This is the default condition as this pin is pulled up
internally. When this pin is pulled to ground, both the bottom
and top MOSFETs are enabled.
Pin 4: 60/120
The 60/120 input allows the use of the Si9979 with either a 60°
or 120° commutation sensor spacing. An internal pull up
resistor, which is tied to VDD, sets the default condition to 60°
spacing. 120° spacing is selected by pulling this input to
ground.
Pin 5: EN (Enable)
A logic “1” on this input allows commutation of the motor. This
is the default condition as this pin is pulled up internally. When
this pin is pulled to ground, all gate drive outputs are turned off.
Pin 6: F/R (Forward/Reverse)
A logic “1” on this input selects commutation for motor rotation
in the “forward” direction. This is the default condition as this
pin is pulled up internally. When this pin is pulled to ground, the
commutation sensor logic levels are inverted internally,
causing reverse rotation.
S-60752-Rev. D, 05-Apr-99
4
Pin 8: PWM
An open collector (drain) or TTL compatible signal is applied to
this input to control the motor speed. The QS input determines
which MOSFETs are switched in response to the PWM signal.
If no PWM signal is being used, this input is left open. It is
pulled up internally, which allows the MOSFETs to follow the
commutation sequence.
Pin 9: BRK
With this input at logic “1”, the top MOSFETs are turned off and
the bottom MOSFETs are turned on, shorting the motor
windings together. This provides a braking torque which is
dependent on the motor speed. This is the default condition as
this pin is pulled up internally. When this pin is pulled to
ground, the MOSFETs are allowed to follow the commutation
sequence.
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Pin 10: TACH
Pin 27: SC
This output provides a minimum 300-nanosecond output pulse
for every commutation sensor transition, yielding a 6 pulse per
electrical revolution tachometer signal. This output is open
drain.
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 C output.
Pin 11: FAULT
Pin 28: CAPC
The FAULT output switches low to indicate that at least one of
the following conditions exists, controller disable (EN),
undervoltage lockout, invalid commutation sensor code
shutdown, or overcurrent shutdown. This output is open drain.
This pin is the positive supply of the high-side circuitry. The
bootstrap capacitor for Phase C is connected between this pin
and SC.
Pin 17: RT/CT
The junction of the current limit one shot timing resistor and
capacitor is connected to this pin. This one-shot is triggered by
the current limit comparator when an overcurrent condition
exists. This action turns off all the gate drives for the period
defined by RT and CT , thus stopping the flow of current.
Pin 29: GBB
This is the gate drive output for the bottom MOSFET in
Phase B.
Pin 30: GTB
This is the gate drive output for the top MOSFET in Phase B.
Pin 18: RT
Pin 31: SB
One side of the current limit one shot timing resistor is
connected to this pin.
This pin is negative supply of the high-side drive circuitry. As
such, it is the connection for the negative side of the bootstrap
Pin 19: IS+
Pin 34: GTA
This is the sensing input of the current limit comparator and
should be connected to the positive side of the current sense
resistor. When the voltage across the current sense resistor
exceeds 100 mV, the comparator switches and triggers the
current limit one-shot. The one-shot turns off all the gate drives
for the period defined by RT and CT, thus stopping the flow of
current. If the overcurrent condition remains after the
shutdown period, the gate drives will be held off until the
overcurrent condition no longer exists.
This is the gate drive output for the top MOSFET in Phase A.
Pin 35: SA
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: CAPA
Pin 20: ISThis pin is the ground reference for the current limit
comparator. It should be connected directly to the ground side
of the current sense resistor to enhance noise immunity.
This pin is the positive supply of the high-side circuitry. The
bootstrap capacitor for Phase A is connected between this pin
and SA.
Pin 42: V+
Pins 12-16, 21-24, 37-41, 44-48: GND
These pins are the return path for both the logic and gate drive
circuits. Also, they serve to conduct heat out of the package,
into the circuit board.
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: VDD
Pin 25: GBC
This is the gate drive output for the bottom MOSFET in
Phase C.
VDD is the internal logic and gate drive voltage. It is necessary
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.
Pin 26: GTC
This is the gate drive output for the top MOSFET in Phase C.
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Si9979
Vishay Siliconix
APPLICATIONS
FIGURE 1. Three-Phase Brushless DC Motor Controller
FIGURE 2. Single H-Bridge Controller
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FIGURE 3. Three-Phase AC Motor Controller
FIGURE 4. External VDD Regulator
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