DRV8824-Q1_15 Datasheet, PDF (18/30 Pages) Texas Instruments – DRV8824-Q1 Automotive Motor Controller IC

DRV8824-Q1
SLVSCH0 – APRIL 2014
www.ti.com
Device Functional Modes (continued)
Mixed decay mode begins as fast decay, but at a fixed period of time (75% of the PWM cycle) switches to slow
decay mode for the remainder of the fixed PWM period. This occurs only if the current through the winding is
decreasing (per the indexer step table); if the current is increasing, then slow decay is used.
9 Application and Implementation
9.1 Application Information
The DRV8824-Q1 is used in bipolar stepper control. The following design procedure can be used to configure the
DRV8824-Q1.
9.2 Typical Application
VM
0.01 µF
Step
Motor
+-
0.01 µF
1 MΩ 0.1 µF
400 mΩ
400 mΩ
VM
+
0.01 µF
DRV8824-Q1
1
28
CP1
GND
2
27
CP2
nHOME
3
26
VCP
MODE2
4
25
VMA
MODE1
5
24
AOUT1
MODE0
6
23
ISENA
NC
7
22
AOUT2
STEP
8
21
BOUT2
nENBL
9
20
ISENB
DIR
10
19
BOUT1
DECAY
11
18
VMB
nFAULT
12
17
AVREF
nSLEEP
13
16
BVREF
nRESET
14
15
GND
V3P3OUT
10 kΩ
30 kΩ
10 kΩ
V3P3
10 kΩ
0.47 µF
Figure 8. Typical Application Schematic
9.2.1 Design Requirements
Table 3 gives design input parameters for system design.
DESIGN PARAMETER
Supply voltage
Motor winding resistance
Motor winding inductance
Motor full step angle
Target microstepping level
Target motor speed
Target full-scale current
Table 3. Design Parameters
REFERENCE
VM
R_L
L_L
θ_step
n_m
v
I_FS
EXAMPLE VALUE
24 V
1.0 Ω/phase
3.5 mH/phase
1.8°/step
8 microsteps per step
120 rpm
1.25 A
18
Submit Documentation Feedback
Copyright © 2014, Texas Instruments Incorporated