8906, katalog

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8906
BIDIRECTIONAL 3-PHASE BRUSHLESS DC MOTOR
CONTROLLER/DRIVER WITH BACK-EMF SENSING
LOAD
SUPPLY
1
V
BB
COMMUTAT
ION
DELAY
24
C
D1
The A8906CLB is a bidirectional three-phase brushless dc motor
controller/driver. The three half-bridge outputs are low on-resistance n-
channel DMOS devices capable of driving up to 1 A. The A8906CLB
provides complete, reliable, self-contained back-EMF sensing motor
startup and running algorithms. A programmable digital frequency-
locked loop speed control circuit together with the linear current control
circuitry provides precise motor speed regulation.
C
D2
2
23
DATA IN
C
WD
3
22
CLOCK
C
ST
4
21
CHIP SELECT
OUT
A
5
20
RESET
A serial port allows the user to program various features and
modes of operation, such as the speed control parameters, rotational
direction, startup current limit, sleep mode, diagnostic modes, and
others.
GROUND
6
19
GROUND
GROUND
7
18
GROUND
OUT
B
8
MUX
17
DATA OUT
The A8906CLB is fabricated in Allegro’s BCD (Bipolar CMOS
DMOS) process, an advanced mixed-signal technology that combines
bipolar, analog and digital CMOS, and DMOS power devices. The
A8906CLB is provided in a 24-lead wide-body SOIC batwing package.
It provides for the smallest possible construction in surface-mount
applications.
OUT
C
9
FLL
16
OSCILLATOR
CENTERTAP
10
V
DD
15
LOGIC
SUPPLY
BOOST
CHARGE
PUMP
BRAKE
11
14
SECTOR
DATA
C
RES
12
13
FILTER
PRELIMINARY INFORMATION
(Subject to change without notice)
March 1, 1999
Dwg. PP-040B
FEATURES
DMOS Outputs
ABSOLUTE MAXIMUM RATINGS
at T
A
= +25
°
C
Low
r
DS(on)
Startup Commutation Circuitry
Load Supply Voltage, V
BB
. . . . . . . . . .
14 V
Output Current, I
OUT
. . . . . . . . . . . .
Back-EMF Commutation Circuitry
1.25 A
Logic Supply Voltage, V
DD
. . . . . . . . .
6.0 V
Logic Input Voltage Range,
V
IN
. . . . . . . . . . .
-0.3 V to V
DD
+ 0.3 V
Package Power Dissipation, P
D
See Graph
Operating Temperature Range,
T
A
. . . . . . . . . . . . . . . . . .
0
±
Direction Control
Serial Port Interface
Frequency-Locked Loop Speed Control
Sector Data Tachometer Signal Input
°
°
Programmable Start-Up Current
C to +70
C
Diagnostics Mode
Junction Temperature, T
J
. . . . . . .
+150
°
C†
Sleep Mode
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . .
-55
°
C to +150
°
C
Linear Current Control
† Fault conditions that produce excessive junction
temperature will activate device thermal shutdown
circuitry. These conditions can be tolerated, but
should be avoided.
Output current rating may be restricted to a value
determined by system concerns and factors.
These include: system duty cycle and timing,
ambient temperature, and use of any heatsinking
and/or forced cooling. For reliable operation, the
specified maximum junction temperature should
not be exceeded.
Internal Current Sensing
Dynamic Braking Through Serial Port
Power-Down Dynamic Braking
System Diagnostics Data Out
Data Out Ported in Real Time
Internal Thermal Shutdown Circuitry
Always order by complete part number, e.g.,
A8906CLB
.
9
8906
BIDIRECTIONAL
3-PHASE BRUSHLESS DC
MOTOR CONTROLLER/DRIVER
FUNCTIONAL BLOCK DIAGRAM
LOGIC
SUPPLY
C
D1
C
D2
C
ST
4
BRAKE
11
C
RES
12
15
V
24
2
DD
BRAKE
BOOST
CHARGE
PUMP
LOAD
SUPPLY
V
BB
1
OUT
A
FCOM
COMMUTATION
DELAY
5
OUT
A
OUT
B
ST
ART-UP
OSC.
8
OUT
B
OUT
C
BLANK
9
OUT
C
CENTERTAP
10
C
WD
3
WATCHDOG
TIMER
SECTOR
DATA
14
OSC
16
FREQUENCY-
LOCKED LOOP
CHARGE
PUMP
CURRENT
CONTROL
R
S
6-7
GROUND
DATA IN
23
SERIAL PORT
MUX
TSD
1
8-1
9
GROUND
21
22
20
17
13
FILTER
Dwg. FP-034
2.5
R = 6
θ
JT
C/W
2.0
1.5
1.0
R = 55
°
C/W
θ
JA
0.5
0
25
50
75
100
125
150
TEMPERATURE in
°
C
Dwg. GP-019B
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1999 Allegro MicroSystems, Inc.
°
8906
BIDIRECTIONAL
3-PHASE BRUSHLESS DC
MOTOR CONTROLLER/DRIVER
ELECTRICAL CHARACTERISTICS at T
A
= +25
°
C, V
DD
= 5.0 V
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max. Units
Logic Supply Voltage
V
DD
Operating
4.5
5.0
5.5
V
Logic Supply Current
I
DD
Operating
—
7.5
10
mA
Sleep Mode
—
250
500
µ
A
Load Supply Voltage
V
BB
Operating
4.0
—
14
V
Thermal Shutdown
T
J
—
165
—
°
C
Thermal Shutdown Hysteresis
∆
T
J
—
20
—
°
C
Output Drivers
Output Leakage Current
I
DSX
V
BB
= 14 V, V
OUT
= 14 V
—
1.0
300
µ
A
V
BB
= 14 V, V
OUT
= 0 V
—
-1.0
-300
µ
A
Total Output ON Resistance
r
DS(on)
I
OUT
= 600 mA
—
1.0
1.4
Ω
(Source + Sink + R
S
)
Output Sustaining Voltage
V
DS(sus)
V
BB
= 14 V, I
OUT
= I
OUT
(MAX), L = 3 mH
14
—— V
Clamp Diode Forward Voltage
V
F
I
F
= 1.0 A
—
1.25
1.5
V
Control Logic
Logic Input Voltage
V
IN(0)
SECTOR DATA, RESET, CLK,
-0.3
—
1.5
V
V
IN(1)
CHIP SELECT, OSC
3.5
—
5.3
V
Logic Input Current
I
IN(0)
V
IN
= 0 V
——-0.5
µ
A
I
IN(1)
V
IN
= 5.0 V
——1.0
µ
A
DATA Output Voltage
V
OUT(0)
I
OUT
= 500
µ
A
——1.5
V
V
OUT(1)
I
OUT
= -500
µ
A
3.5
—— V
C
ST
Current
I
CST
Charging
-9.0
-10
-11
µ
A
Discharging
—
500
—
µ
A
C
ST
Threshold
V
CSTH
2.25
2.5
2.75
V
V
CSTL
0.85
1.0
1.15
V
Filter Current
I
FILTER
Charging
-9.0
-10
-11
µ
A
Discharging
9.0
10
11
µ
A
Leakage, V
FILTER
= 2.5 V
——5.0
nA
Filter Threshold
V
FILTERTH
1.57
1.85
2.13
V
C
D
Current
I
CD
Charging
-18
-20
-22
µ
A
(C
D1
or C
D2
)
Discharging
32
40
48
µ
A
C
D
Current Matching
—
I
CD(DISCHRG)
/I
CD(CHRG)
1.8
2.0
2.2
—
C
D
Threshold
V
CDTH
2.25
2.5
2.75
V
Continued next page …
8906
BIDIRECTIONAL
3-PHASE BRUSHLESS DC
MOTOR CONTROLLER/DRIVER
ELECTRICAL CHARACTERISTICS continued
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max. Units
C
WD
Current
I
CWD
Charging
-9.0
-10
-11
µ
A
C
WD
Threshold Voltage
V
TL
0.22
0.25
0.28
V
V
TH
2.25
2.5
2.75
V
Max. FLL Oscillator Frequency
f
OSC
V
DD
= 5.0 V, T
A
= 25
°
C
12
——MHz
I
OUT
(MAX)
—
D3 = 0, D4 = 0
1.0
1.2
1.4
A
D3 = 0, D4 = 1
0.9
1.0
1.1
A
D3 = 1, D4 = 0
0.5
0.6
0.7
A
D3 = 1, D4 = 1
—
250
—
mA
BRAKE Threshold
V
BRK
1.5
1.75
2.0
V
BRAKE Hysteresis Current
I
BRKL
V
BRK
= 750 mV
—
20
—
µ
A
Transconductance Gain
g
m
0.42
0.50
0.58
A/V
Centertap Resistors
R
CT
5.0
10
13
k
Ω
Back-EMF Hysteresis
—
V
BEMF
- V
CTAP
at
5.0
20
37
mV
FCOM Transition
-5.0
-20
-37
mV
SERIAL PORT TIMING CONDITIONS
CHIP SELECT
E
A
B
CLOCK
C
D
C
D
DATA
Dwg. WP-019
A.
Minimum CHIP SELECT setup time before CLOCK rising edge ..........
100 ns
B.
Minimum CHIP SELECT hold time after CLOCK rising edge ...............
150 ns
C.
Minimum DATA setup time before CLOCK rising edge ........................
150 ns
D.
Minimum DATA hold time after CLOCK rising edge .............................
150 ns
E.
Minimum CLOCK low time before CHIP SELECT ..................................
50 ns
F.
Maximum CLOCK frequency ..............................................................
3.3 MHz
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8906
BIDIRECTIONAL
3-PHASE BRUSHLESS DC
MOTOR CONTROLLER/DRIVER
TERMINAL FUNCTIONS
Term.
Terminal Name
Function
1
LOAD SUPPLY
V
BB
; the 5 V or 12 V motor supply.
2
C
D2
One of two capacitors used to generate the ideal commutation points from the
back-EMF zero crossing points.
3
C
WD
Timing capacitor used by the watchdog circuit to disable the back-EMF compara-
tors during commutation transients, and to detect incorrect motor position.
4
C
ST
Startup oscillator timing capacitor.
5
OUT
A
Power amplifier A output to motor.
6-7
GROUND
Power and logic ground and thermal heat sink.
8
OUT
B
Power amplifier B output to motor.
9
OUT
C
Power amplifier C output to motor.
10
CENTERTAP
Motor centertap connection for back-EMF detection circuitry.
11
BRAKE
Active low turns ON all three sink drivers shorting the motor windings to ground.
External capacitor and resistor at B
RAKE
provide brake delay.
12
C
RES
External reservoir capacitor used to hold charge to drive the source drivers’
gates. Also provides power for brake circuit.
13
FILTER
Analog voltage input to control motor current. Also, compensation node for
internal speed control loop.
14
SECTOR DATA
External tachometer input. Can use sector or index pulses from disk to provide
precise motor speed feedback to internal frequency-locked loop.
15
LOGIC SUPPLY
V
DD
; the 5 V logic supply.
16
OSCILLATOR
Clock input for the speed reference counter. Typical max. frequency is 10 MHz.
17
DATA OUT
Thermal shutdown indicator, FCOM, TACH, or SYNC signals available in real
time, controlled by 2-bit multiplexer in serial port.
18-19
GROUND
Power and logic ground and thermal heat sink.
20
RESET
When pulled low forces the chip into sleep mode; clears all serial port bits.
21
CHIP SELECT
Strobe input (active low) for data word.
22
CLOCK
Clock input for serial port.
23
DATA IN
Sequential data input for the serial port.
24
C
D1
One of two capacitors used to generate the ideal commutation points from the
back-EMF zero crossing points.
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8906, katalog

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