a8904 Allegro MicroSystems, Inc., a8904 Datasheet - Page 17

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

28X
A8904
24X
0.10
0.10
0.41 ±0.10
0.25
C
+0.05
–0.06
C
28
1
24
1
A
2
For reference only
(reference JEDEC MO-153 AET)
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
A
2
B
9.70 ±0.10
For reference only
Pins 6 and 7, and 18 and 19 internally fused
Dimensions in millimeters
(Reference JEDEC MS-013 AD)
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
15.40±0.20
5.00
1.27
0.65
3-Phase Brushless DC Motor Controller/Driver
LB package, 24-pin SOICW
LP package, 28-pin TSSOP
with exposed thermal pad
3.00
7.50±0.10
0.20 ±0.10
0.10 MAX
4.40 ±0.10
SEATING
PLANE
2.65 MAX
1.20 MAX
SEATING
PLANE
10.30±0.33
6.40 ±0.20
C
C
A Terminal #1 mark area
B
C
Reference land pattern layout (reference IPC7351 SOP65P640X120-29CM);
All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances; when
mounting on a multilayer PCB, thermal vias at the exposed thermal pad land
can improve thermal dissipation (reference EIA/JEDEC Standard JESD51-5)
Exposed thermal pad (bottom surface)
A Terminal #1 mark area
B
Reference pad layout (reference IPC SOIC127P1030X265-24M)
All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances
GAUGE PLANE
GAUGE PLANE
4° ±4
0.25
0.84
SEATING PLANE
0.25
0.27
4° ±4
SEATING PLANE
0.60 ±0.15
0.15
+0.44
–0.43
(1.00)
+0.07
–0.06
+0.05
–0.06
with Back EMF Sensing
1.65
2.20
28
1
24
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
1
2
0.45
2
B
C
PCB Layout Reference View
PCB Layout Reference View
5.00
0.65
0.65
3.00
1.27
9.60
6.10
17