a8902 Allegro MicroSystems, Inc., a8902 Datasheet - Page 4

• Manufacturer Part Number: a8902
• Description: 3-phase Brushless Dc Motor Controller/driver With Back-emf Sensing
• Manufacturer: Allegro MicroSystems, Inc.

4
8902–A
3-PHASE BRUSHLESS DC
MOTOR CONTROLLER/DRIVER
Characteristic
C
C
Max. FLL Oscillator Frequency
I
BRAKE Threshold
BRAKE Hysteresis Current
Transconductance Gain
Centertap Resistors
Back-EMF Hysteresis
OUT
WD
WD
(MAX)
Current
Threshold Voltage
CHIP SELECT
Maximum CLOCK frequency .............................................................. 3.3 MHz
Minimum CHIP SELECT setup time before CLOCK rising edge .......... 100 ns
Minimum CHIP SELECT hold time after CLOCK rising edge ............... 150 ns
Minimum DATA setup time before CLOCK rising edge ........................ 150 ns
Minimum DATA hold time after CLOCK rising edge ............................. 150 ns
Minimum CLOCK low time before CHIP SELECT .................................. 50 ns
CLOCK
DATA
Symbol
V
I
I
f
V
BRKL
R
V
CWD
OSC
g
—
—
BRK
TL
TH
CT
m
E
C
Charging
V
D3 = 0, D4 = 0
D3 = 0, D4 = 1
D3 = 1, D4 = 0
D3 = 1, D4 = 1
V
V
FCOM Transition
A
DD
BRK
BEMF
= 5.0 V, T
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
= 750 mV
- V
D
CTAP
Test Conditions
A
at
= 25 C
C
B
D
Dwg. WP-019
Min.
0.22
2.25
0.42
-9.0
-5.0
1.0
0.9
0.5
1.5
5.0
5.0
12
—
—
Typ.
0.25
1.75
0.50
250
-10
-20
2.5
1.2
1.0
0.6
20
10
20
—
Limits
Max.
0.28
2.75
0.58
-11
-37
1.4
1.1
0.7
2.0
—
—
—
13
37
Units
MHz
A/V
mA
mV
mV
k
V
V
A
A
A
V
A
A