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