A4984 Datasheet, PDF (2/21 Pages) Allegro MicroSystems – DMOS Microstepping Driver with Translator and Overcurrent Protection

A4984
DMOS Microstepping Driver with Translator
and Overcurrent Protection
Description (continued)
In Mixed decay mode, the device is set initially to a fast decay for
a proportion of the fixed off-time, then to a slow decay for the
remainder of the off-time. Mixed decay current control results in
reduced audible motor noise, increased step accuracy, and reduced
power dissipation.
Internal synchronous rectification control circuitry is provided
to improve power dissipation during PWM operation. Internal
circuit protection includes: thermal shutdown with hysteresis,
undervoltage lockout (UVLO), and crossover-current protection.
Special power-on sequencing is not required.
The A4984 is supplied in three surface mount packages: two QFN
packages, the 4 mm × 4 mm, 0.75 mm nominal overall height ES
package, and the 5 mm × 5 mm × 0.90 mm ET package. The LP
package is a 24-pin TSSOP. All three packages have exposed pads
for enhanced thermal dissipation, and are lead (Pb) free (suffix –T),
with 100% matte tin plated leadframes.
Selection Guide
Part Number
Package
A4984SESTR-T
24-pin QFN with exposed thermal pad
A4984SETTR-T
32-pin QFN with exposed thermal pad
A4984SLPTR-T
24-pin TSSOP with exposed thermal pad
Packing
1500 pieces per 7-in. reel
1500 pieces per 7-in. reel
4000 pieces per 13-in. reel
Absolute Maximum Ratings
Characteristic
Load Supply Voltage
Output Current
Logic Input Voltage
Logic Supply Voltage
VBBx to OUTx
Sense Voltage
Reference Voltage
Operating Ambient Temperature
Maximum Junction
Storage Temperature
Symbol
V_BB
I_OUT
V_IN
V_DD
V_SENSE
V_REF
T_A
T_J(max)
T_stg
Range S
Notes
Rating
35
±2
–0.3 to 5.5
–0.3 to 5.5
35
0.5
5.5
–20 to 85
150
–55 to 150
Units
V
A
V
V
V
V
V
ºC
ºC
ºC
Allegro MicroSystems, Inc.
2
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com