a8904 Allegro MicroSystems, Inc., a8904 Datasheet - Page 6

• Manufacturer Part Number: a8904
• Description: 3-phase Brushless Dc Motor Controller/driver With Back Emf Sensing
• Manufacturer: Allegro MicroSystems, Inc.

A8904
ELECTRICAL CHARACTERISTICS (continued) at T
Negative current is defi ned as coming out of (sourcing) the specifi ed device terminal.
* Operation at an oscillator frequency greater than the specifi ed minimum value is possible but not waranteed.
Characteristic
C
C
Max. FLL Oscillator Frequency
Oscillator High Duration
Oscillator Low Duration
Maximum Output Current
Transconductance Gain
Centertap Resistors
Back-EMF Threshold with respect
to V
WD
WD
CTAP
Threshold Voltage
Current
at FCOM transition
I
OUT
Symbol
I
f
V
R
V
CWD
ton
toff
OSC
(MAX)
g
—
TH
TL
CT
m
3-Phase Brushless DC Motor Controller/Driver
Charging, D26 = 0, D27 = 0
Charging, D26 = 0, D27 =1
Charging, D26 = 1 D27 = 0
Charging, D26 = 1, D27 =1
D3 = 0, D4 = 0, D28 = 0
D3 = 0, D4 = 1, D28 = 0
D3 = 1, D4 = 0, D28 = 0
D3 = 1, D4 = 1, D28 = 0
D3 = 0, D4 = 0, D28 = 1
D3 = 0, D4 = 1, D28 = 1
D3 = 1, D4 = 0, D28 = 1
D3 = 1, D4 = 1, D28 = 1
D28 = 1
D28 = 0
Test Conditions
A
= +25°C, V
with Back EMF Sensing
DD
= 5.0 V
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
Min.
0.22
2.25
-9.0
-5.0
500
500
415
210
420
20*
-18
-27
-36
1.0
0.9
5.0
5.0
20
20
—
—
—
Typ.
0.25
600
250
600
500
300
125
250
500
-10
-20
-30
-40
2.5
1.2
1.0
-20
10
20
—
—
—
Limits
Max.
0.28
2.75
700
700
585
290
580
-22
-33
-44
-37
-11
1.4
1.1
13
37
—
—
—
—
—
—
Units
mA/V
mA/V
MHz
mV
mV
mA
mA
mA
mA
mA
mA
kΩ
μA
μA
μA
μA
ns
ns
V
V
A
A
6