A3986
Dual Full-Bridge MOSFET Driver
with Microstepping Translator
THERMAL CHARACTERISTICS
Characteristic
Package Thermal Resistance
Symbol
R
θJA
Test Conditions*
4-layer PCB, based on JEDEC standard
1-layer PCB with copper limited to solder pads
Value Units
47
114
ºC/W
ºC/W
*Additional thermal information available on Allegro Web site.
RESET
t
STEPH
t
WAKE
STEP
t
STEPL
t
SU
MSx, DIR
t
H
Figure 1. Logic Interface Timing Diagram
Table 1. Microstep Resolution Truth Table
MS2
0
0
1
1
MS1
0
1
0
1
Microstep Resolution
Full Step
Half Step
Quarter Step
Sixteenth Step
Table 2. Mixed Decay Selection Truth Table
PFD2
0
0
1
1
PFD1
0
1
0
1
Percentage of Fast decay
0% (
≡
Slow Decay)
8% (7 cycles)
26% (23 cycles)
100% (
≡
Fast Decay)
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
6
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
