TI DRV8711DCPR Stepper motor controller ic Datasheet

Product
Folder
Sample &
Buy
Technical
Documents
Support &
Community
Tools &
Software
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
STEPPER MOTOR CONTROLLER IC
FEATURES
1
•
Pulse Width Modulation (PWM) Microstepping
Motor Driver
– Built-In 1/256-Step Microstepping Indexer
– Drives External N-Channel MOSFETs
– Optional STEP/DIR Pins
– Optional PWM Control Interface for DC
Motors
Flexible Decay Modes, Including Automatic
Mixed Decay Mode
Stall Detection With Optional BEMF Output
Highly cConfigurable Va SPI Serial Interface
Internal Reference and Torque DAC
8-V to 52-V Operating Supply Voltage Range
Scalable Output Current
Thermally Enhanced Surface Mount Package
5-V Regulator Capable of 10-mA Load
2
•
•
•
•
•
•
•
•
•
Protection and Diagnostic Features
– Overcurrent Protection (OCP)
– Overtemperature Shutdown (OTS)
– Undervoltage Lockout (UVLO)
– Individual Fault Condition Indication Bits
– Fault Condition Indication Pin
APPLICATIONS
•
•
•
•
Office Automation Machines
Factory Automation
Textile Machines
Robotics
DESCRIPTION
The DRV8711 is a stepper motor controller that uses external N-channel MOSFETs to drive a bipolar stepper
motor or two brushed DC motors. A microstepping indexer is integrated, which is capable of step modes from full
step to 1/256-step.
An ultra-smooth motion profile can be achieved using adaptive blanking time and various current decay modes,
including an auto-mixed decay mode. Motor stall is reported with an optional back-EMF output.
A simple step/direction or PWM interface allows easy interfacing to controller circuits. A SPI serial interface is
used to program the device operation. Output current (torque), step mode, decay mode, and stall detection
functions are all programmable via a SPI serial interface.
Internal shutdown functions are provided for over current protection, short circuit protection, under voltage
lockout and overtemperature. Fault conditions are indicated via a FAULTn pin, and each fault condition is
reported via a dedicated bit through SPI.
The DRV8811 is packaged in a PowerPAD™ 38-pin HTSSOP package with thermal pad (Eco-friendly: RoHS
and no Sb/Br).
ORDERING INFORMATION (1)
TA
–40°C to 85°C
(1)
(2)
PACKAGE
(2)
PowerPAD™ (HTSSOP) – PWP
ORDERABLE PART NUMBER
Reel of 2000
Tube of 40
DRV8711DCPR
DRV8711DCP
TOP-SIDE MARKING
DRV8711
For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.
1
2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2013, Texas Instruments Incorporated
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
FUNCTIONAL BLOCK DIAGRAM
VM
0.1µF
+
1µF
0.01µF
100µF
CP2
CP1
VM
VCP
VM
5V OUT
VM
Charge
Pump
V5
Gate
Drive
&
OCP
Regs
VINT
A1LS
PWM
logic
1µ F
RESET
UVLO
PUC
VM
DCM
Step
Motor
AOUT2
A2LS
+
Comp
+
-
DIR/AIN2
AISENP
ISEN
amp
-
STEP/AIN1
A2HS
Gate
Drive
&
OCP
OverTemp
SLEEPn
VM
AOUT1
+
0.1µF
A1HS
HS Gate Drive
AISENN
+
Comp
-
BIN1
SIN
DAC
BIN2
VM
X
B1HS
Gate
Drive
&
OCP
Torque
DAC
SCS
BOUT1
B1LS
Logic
PWM
logic
SCLK
SDATI
B2HS
Gate
Drive
&
OCP
Reference
SDATO
VM
DCM
BOUT2
B2LS
+
Comp
+
BISENP
ISEN
amp
-
+
-
-
FAULTn
BISENN
+
Comp
SIN
DAC
STALLn / BEMFVn
X
Torque
DAC
Stall detect
BEMF
1nF
GND
2
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
TERMINAL FUNCTIONS
NO.
I/O (1)
5, 29,
38,
PPAD
-
Device ground
All pins must be connected to ground
VM
4
-
Bridge A power supply
Connect to motor supply voltage. Bypass to GND with a 0.01-μF
ceramic capacitor plus a 100-μF electrolytic capacitor.
VINT
7
-
Internal logic supply voltage
Logic supply voltage. Bypass to GND with a 1-μF 6.3-V X7R ceramic
capacitor.
V5
6
O
5-V regulator output
5-V linear regulator output. Bypass to GND with a 0.1-μF 10-V X7R
ceramic capacitor.
CP1
1
IO
Charge pump flying capacitor
CP2
2
IO
Charge pump flying capacitor
Connect a 0.1-μF X7R capacitor between CP1 and CP2. Voltage
rating must be greater than applied VM voltage.
VCP
3
IO
High-side gate drive voltage
NAME
DESCRIPTION
EXTERNAL COMPONENTS OR CONNECTIONS
POWER AND GROUND
GND
Connect a 1-μF 16-V X7R ceramic capacitor to VM
CONTROL
SLEEPn
8
I
Sleep mode input
Logic high to enable device, logic low to enter low-power sleep mode
STEP/AIN1
10
I
Step input/Bridge A IN1
Indexer mode: Rising edge causes the indexer to move one step.
External PWM mode: controls bridge A OUT1 Internal pulldown.
DIR/AIN2
11
I
Direction input/Bridge A IN2
Indexer mode: Level sets the direction of stepping.
External PWM mode: controls bridge A OUT2 Internal pulldown.
BIN1
12
I
Bridge B IN1
Indexer mode: No function
External PWM mode: controls bridge B OUT1 Internal pulldown.
BIN2
13
I
Bridge B IN2
Indexer mode: No function
External PWM mode: controls bridge B OUT2 Internal pulldown.
RESET
9
I
Reset input
Active-high reset input initializes all internal logic and disables the Hbridge outputs. Internal pulldown.
SCS
16
I
Serial chip select input
Active high to enable serial data transfer. Internal pulldown.
SCLK
14
I
Serial clock input
Rising edge clocks data into part for write operations. Falling edge
clocks data out of part for read operations. Internal pulldown.
SDATI
15
I
Serial data input
Serial data input from controller. Internal pulldown.
SDATO
17
O
Serial data output
Serial data output to controller. Open-drain output requires external
pull-up.
STALLn/
BEMFVn
19
OD
Stall/Back EMF valid
Internal stall detect mode: logic low when motor stall detected.
External stall detect mode: Active low when valid back EMF
measurement is ready.
Open-drain output requires external pullup.
FAULTn
18
OD
Fault
Logic low when in fault condition. Open-drain output requires external
pullup.
Faults: OCP, PDF, OTS, UVLO
BEMF
20
O
Back EMF
Analog output voltage represents motor back EMF. Place a 1-nF lowleakage capacitor to ground on this pin.
SERIAL INTERFACE
STATUS
OUTPUTS
A1HS
36
O
Bridge A out 1 HS gate
Connect to gate of HS FET for bridge A out 1
AOUT1
37
I
Bridge A output 1
Connect to output node of external FETs of bridge A out 1
A1LS
35
O
Bridge A out 1 LS gate
Connect to gate of LS FET for bridge A out 1
A2HS
31
O
Bridge A out 2 HS gate
Connect to gate of HS FET for bridge A out 2
AOUT2
30
I
Bridge A output 2
Connect to output node of external FETs of bridge A out 2
A2LS
32
O
Bridge A out 2 LS gate
Connect to gate of LS FET for bridge A out 2
AISENP
34
I
Bridge A Isense + in
Connect to current sense resistor for bridge A
AISENN
33
I
Bridge A Isense - in
Connect to ground at current sense resistor for bridge A
B1HS
27
O
Bridge B out 1 HS gate
Connect to gate of HS FET for bridge B out 1
(1)
Directions: I = input, O = output, OZ = 3-state output, OD = open-drain output, IO = input/output
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
3
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
TERMINAL FUNCTIONS (continued)
NAME
NO.
I/O
(1)
DESCRIPTION
EXTERNAL COMPONENTS OR CONNECTIONS
BOUT1
28
I
Bridge B output 1
Connect to output node of external FETs of bridge B out 1
B1LS
26
O
Bridge B out 1 LS gate
Connect to gate of LS FET for bridge B out 1
B2HS
22
O
Bridge B out 2 HS gate
Connect to gate of HS FET for bridge B out 2
BOUT2
21
I
Bridge B output 2
Connect to output node of external FETs of bridge B out 2
B2LS
23
O
Bridge B out 2 LS gate
Connect to gate of LS FET for bridge B out 2
BISENP
25
I
Bridge B Isense + in
Connect to current sense resistor for bridge B
BISENN
24
I
Bridge B Isense - in
Connect to ground at current sense resistor for bridge B
CRITICAL COMPONENTS
PIN
NAME
COMPONENT
4
VM
100-µF electrolytic rated for VM voltage to GND 0.01-µF ceramic rated for VM voltage to GND
1-µF ceramic X7R rated 16 V to VCP
3
VCP
1, 2
CP1, CP2
6
V5
7
VINT
1-µF ceramic X7R rated 6.3 V to GND
17
SDATO
Requires external pullup to logic supply
18
FAULTn
Requires external pullup to logic supply
19
STALLn/BEMFVn
Requires external pullup to logic supply
20
BEMF
0.1-µF rated for VM + 12 V between these pins
0.1-µF ceramic X7R rated 6.3 V to GND
1-nF low-leakage capacitor to GND
DCP (HTSSOP) PACKAGE
CP1
CP2
VCP
VM
GND
V5
VINT
SLEEPn
RESET
STEP / AIN1
DIR / AIN2
BIN1
BIN2
SCLK
SDATI
SCS
SDATO
FAULTn
STALLn / BEMFVn
4
1
2
3
38
37
36
4
5
35
34
6
7
33
32
31
8
9
10
11
GND
(PPAD)
30
29
28
12
27
13
26
14
25
15
24
16
23
17
22
18
21
19
20
Submit Documentation Feedback
GND
AOUT1
A1HS
A1LS
AISENP
AISENN
A2LS
A2HS
AOUT2
GND
BOUT1
B1HS
B1LS
BISENP
BISENN
B2LS
B2HS
BOUT2
BEMF
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
ABSOLUTE MAXIMUM RATINGS (1)
(2) (3)
over operating free-air temperature range (unless otherwise noted)
Power supply voltage range
DRV8711
UNIT
-0.6 to 60
V
-0.6 to VM + 12
V
5V regulator voltage (V5)
-0.6 to 5.5
V
Internal regulator voltage (VINT)
-0.6 to 2.0
V
Digital pin voltage range (SLEEPn, RESET, STEP/AIN1, DIR/AIN2, BIN1, BIN2, SCS, SCLK, SDATI,
SDATO, FAULTn, STALLn/BEMFVn)
-0.6 to 5.5
V
-0.6 to VM + 12
V
Low-side gate drive pin voltage range (A1LS, A2LS, B1LS, B2LS)
-0.6 to 12
V
Phase node pin voltage range (AOUT1, AOUT2, BOUT1, BOUT2)
-0.6 to VM
V
ISENSEx pin voltage (AISENP, AISENN, BISENP, BISENN)
-0.7 to +0.7
V
BEMF pin voltage range (BEMF)
-0.6 to VM
V
Operating virtual junction temperature range, TJ
-40 to 150
°C
Storage temperature range, Tstg
-60 to 150
°C
Charge pump voltage range (CP1, CP2, VCP)
High-side gate drive pin voltage range (A1HS, A2HS, B1HS, B2HS)
(1)
(2)
(3)
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute–maximum–rated conditions for extended periods may affect device reliability.
All voltage values are with respect to network ground terminal.
Power dissipation and thermal limits must be observed.
THERMAL INFORMATION
DRV8711
THERMAL METRIC
(1)
DCP
UNITS
38 PINS
θJA
Junction-to-ambient thermal resistance (2)
32.7
θJCtop
Junction-to-case (top) thermal resistance (3)
17.2
(4)
θJB
Junction-to-board thermal resistance
ψJT
Junction-to-top characterization parameter (5)
ψJB
Junction-to-board characterization parameter (6)
θJCbot
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Junction-to-case (bottom) thermal resistance
14.3
°C/W
0.5
14.1
(7)
0.9
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, high-K board, as
specified in JESD51-7, in an environment described in JESD51-2a.
The junction-to-case (top) thermal resistance is obtained by simulating a cold plate test on the package top. No specific JEDECstandard test exists, but a close description can be found in the ANSI SEMI standard G30-88.
The junction-to-board thermal resistance is obtained by simulating in an environment with a ring cold plate fixture to control the PCB
temperature, as described in JESD51-8.
The junction-to-top characterization parameter, ψJT, estimates the junction temperature of a device in a real system and is extracted
from the simulation data for obtaining θJA, using a procedure described in JESD51-2a (sections 6 and 7).
The junction-to-board characterization parameter, ψJB, estimates the junction temperature of a device in a real system and is extracted
from the simulation data for obtaining θJA , using a procedure described in JESD51-2a (sections 6 and 7).
The junction-to-case (bottom) thermal resistance is obtained by simulating a cold plate test on the exposed (power) pad. No specific
JEDEC standard test exists, but a close description can be found in the ANSI SEMI standard G30-88.
Spacer
RECOMMENDED OPERATING CONDITIONS
over operating free-air temperature range (unless otherwise noted)
MIN
NOM
MAX
UNIT
VM
Motor power supply voltage range
8
52
V
IVS
V5 external load current
0
10
mA
TA
Operating ambient temperature range
-40
85
°C
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
5
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
ELECTRICAL CHARACTERISTICS
over operating free-air temperature range (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Power Supplies
IVM
VM operating supply current
VM = 24 V
17
20
mA
IVMQ
VM sleep mode supply current
VM = 24 V, SLEEPn = 0
65
98
μA
VM rising
7.1
8
VM falling
6.3
VUVLO
VM undervoltage lockout voltage
V
Internal Linear Regulators
V5
V5 output voltage
VM ≥ 12 V, IOUT = 1 mA - 10 mA
4.8
5
5.2
V
VINT
VINT voltage
No external load – reference only
1.7
1.8
1.9
V
0.8
V
Logic-Level Inputs
VIL
Input low voltage
VIH
Input high voltage
VHYS
Input hysteresis voltage
IIL
Input low current
VIN = 0 V
-5
IIH
Input high current
VIN = 5 V
30
1.5
V
300
50
mV
5
μA
70
μA
SDATAO, STALLn, FAULTn OUTPUTS (Open-Drain Outputs)
VOL
Output low voltage
IO = 5 mA
IOH
Output high leakage current
VO = 3.3 V
0.5
V
1
µA
MOSFET Drivers
VOUTH
High-side gate drive output voltage
VM = 24 V, IO = 100 μA
VM+10
V
VOUTL
Low-side gate drive output voltage
VM = 24 V, IO = 100 μA
10
V
tDEAD
Output dead time digital delay (dead
time is enforced in analog circuits)
IOUTH
IOUTl
tDRIVE
tDRIVE
Peak output current gate drive
(source)
Peak output current gate drive (sink)
Peak current drive time (source)
Peak current drive time (sink)
DTIME = 00
400
DTIME = 01
450
DTIME = 10
650
DTIME = 11
850
IDRIVEP = 00
50
IDRIVEP = 01
100
IDRIVEP = 10
150
IDRIVEP = 11
200
IDRIVEN = 00
100
IDRIVEN = 01
150
IDRIVEN = 10
200
IDRIVEN = 11
400
TDRIVEP = 00
250
TDRIVEP = 01
500
TDRIVEP = 10
1000
TDRIVEP = 11
2000
TDRIVEN = 00
250
TDRIVEN = 01
500
TDRIVEN = 10
1000
TDRIVEN = 11
2000
ns
mA
mA
ns
ns
Motor Driver
tOFF
PWM off time adjustment range
Set by TOFF register
0.5
128
μs
tBLANK
Current sense blanking time
Set by TBLANK register
0.5
5.12
μs
6
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
ELECTRICAL CHARACTERISTICS (continued)
over operating free-air temperature range (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
OCPTH = 00
160
250
320
OCPTH = 01
380
500
580
OCPTH = 10
620
750
850
OCPTH = 11
840
1000
1200
Die temperature
150
160
180
UNIT
Protection Circuits
VOCP
Overcurrent protection trip level
(Voltage drop across external FET)
tTSD
Thermal shutdown temperature (1)
tHYS
Thermal shutdown hysteresis
20
mV
°C
°C
Current Sense Amplifiers
AV
Gain
ISGAIN = 00
5
ISGAIN = 01
10
ISGAIN = 10
20
ISGAIN = 11
tSET
Settling time (to ±1%)
VOFS
Offset voltage
VIN
Input differential voltage range
V/V
40
ISGAIN = 00, ΔVIN = 400 mV
150
ISGAIN = 01, ΔVIN = 200 mV
300
ISGAIN = 10, ΔVIN = 100 mV
600
ISGAIN = 11, ΔVIN = 50 mV
1.2
ISGAIN = 00, input shorted
-300
ns
µs
4
mV
300
mV
Current Control DACs
Resolution
Full-scale step response
VREF
(1)
256
10% to 90%
Full-scale (reference) voltage
2.50
2.75
steps
5
µs
3
V
Not tested in production - guaranteed by design.
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
7
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
SPI INTERFACE TIMING REQUIREMENTS
over operating free-air temperature range (unless otherwise noted)
No.
PARAMETER
CONDITIONS
MIN
MAX
UNIT
1
tCYC
Clock cycle time
250
ns
2
tCLKH
Clock high time
25
ns
3
tCLKL
Clock low time
25
ns
4
tSU(SDATI)
Setup time, SDATI to SCLK
5
ns
5
tH(SDATI)
Hold time, SDATI to SCLK
1
ns
6
tSU(SCS)
Setup time, SCS to SCLK
5
ns
7
tH(SCS)
Hold time, SCS to SCLK
1
ns
8
tL(SCS)
Inactive time, SCS (between writes)
9
tD(SDATO)
Delay time, SCLK to SDATO (during read)
tSLEEP
Wake time (SLEEPn inactive to high-side gate drive enabled)
tRESET
Delay from power-up or RESETn high until serial interface functional
7
6
100
ns
10
ns
1
ms
10
μs
8
SCS
1
SCLK
2
3
SDATI
X
X
4
5
9
SDATO
valid
SDATO
8
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
INDEXER TIMING REQUIREMENTS
over operating free-air temperature range (unless otherwise noted)
No.
PARAMETER
CONDITIONS
MIN
MAX
UNIT
250
kHz
1
fSTEP
Step frequency
2
tWH(STEP)
Pulse duration, STEP high
1.9
μs
3
tWL(STEP)
Pulse duration, STEP low
1.9
μs
4
tSU(STEP)
Setup time, command to STEP rising
200
ns
5
tH(STEP)
Hold time, command to STEP rising
200
ns
1
2
3
STEP
DIR, MODE
4
5
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
9
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
FUNCTIONAL DESCRIPTION
PWM Motor Drivers
The DRV8711 contains two H-bridge motor pre-drivers with current-control PWM circuitry.
More detailed descriptions of the sub-blocks are described in the following sections.
Direct PWM Input Mode
Direct PWM mode is selected by setting the PWMMODE bit in the OFF register. In direct PWM input mode, the
AIN1, AIN2, BIN1, and BIN2 directly control the state of the output drivers. This allows for driving up to two
brushed DC motors. The logic is shown below:
Table 1. Direct PWM Input Mode Logic
xIN1
xIN2
xOUT1
xOUT2
OPERATION
0
0
0
1
Z
Z
Asynchronous Fast Decay
L
H
1
Reverse Drive
0
H
L
Forward Drive
1
1
L
L
Slow Decay
Note that if mixed or auto mixed decay modes are used, they will apply to every cycle, since current change
information is not available.
In direct PWM mode, the current control circuitry is still active. The full-scale VREF is set to 2.75 V. The
TORQUE register may be used to scale this value, and the ISEN sense amp gain may still be set using the
ISGAIN bits of the CTRL register.
x1HS
Gate
Drive
&
OCP
xIN1
VM
xOUT1
x1LS
xIN2
PWM
logic
x2HS
Gate
Drive
&
OCP
VM
xOUT2
x2LS
+
RISENSE
Comp
xISENP
+
ISEN
amp
xISENN
-
+
-
+
Comp
VREF
X
ISGAIN
1V
TORQUE
Torque
DAC
Figure 1. Direct PWM Input Mode
10
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
The current through the motor windings is regulated by an adjustable fixed-off-time PWM current regulation
circuit. When an H-bridge is enabled, current rises through the winding at a rate dependent on the DC voltage
and inductance of the winding and the magnitude of the back EMF present. Once the current hits the current
chopping threshold, the bridge disables the current for a fixed period of time, which is programmable between
500 nS and 128 µS by writing to the TOFF bits in the OFF register. After the off time expires, the bridge is reenabled, starting another PWM cycle.
The chopping current is set by a comparator which compares the voltage across a current sense resistor
connected to the xISENx pins, multiplied by the gain of the current sense amplifier, with a reference voltage. The
current sense amplifier is programmable in the CTRL register.
When driving in PWM mode, the chopping current is calculated as follows:
2.75V · TORQUE
ICHOP =
256 · ISGAIN · RISENSE
(1)
Where TORQUE is the setting of the TORQUE bits, and ISGAIN is the programmed gain of the ISENSE
amplifiers (5, 10, 20, or 40).
Microstepping Indexer
Built-in indexer logic in the DRV8711 allows a number of different stepping configurations. The MODE bits in the
CTRL register are used to configure the stepping format as shown in the table below:
Table 2. Microstepping Indexer Logic
MODE3
MODE2
MODE1
MODE0
STEP MODE
0
0
0
0
Full step (2-phase excitation)
with 71% current
0
0
0
1
1/2 step
0
0
1
0
1/4 step
0
0
1
1
1/8 step
0
1
0
0
1/16 step
0
1
0
1
1/32 step
0
1
1
0
1/64 step
0
1
1
1
1/128 step
1
0
0
0
1/256 step
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
11
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
Table 3 shows the relative current and step directions for full-step through 1/8-step operation. Higher
microstepping resolutions follow the same pattern. The AOUT current is the sine of the electrical angle; BOUT
current is the cosine of the electrical angle.
The reset state is 45°. This state is entered at power-up or application of RESETn. This is shown in the table
below by cells shaded in yellow.
Table 3. Step Directions
FULL STEP
1/8 STEP
1
1
1
0
100
0
2
20
98
11.325
3
38
92
22.5
4
56
83
33.75
5
71
71
45 (home state)
6
83
56
56.25
7
92
38
67.5
8
98
20
78.75
9
100
0
90
10
98
-20
101.25
11
92
-38
112.5
12
83
-56
123.75
13
71
-71
135
14
56
-83
146.25
15
38
-92
157.5
16
20
-98
168.75
17
0
-100
180
18
-20
-98
191.25
19
-38
-92
202.5
20
-56
-83
213.75
21
-71
-71
225
22
-83
-56
236.25
23
-92
-38
247.5
24
-98
-20
258.75
25
-100
0
270
26
-98
20
281.25
27
-92
38
292.5
28
-83
56
303.75
29
-71
71
315
30
-56
83
326.25
31
-38
92
337.5
32
-20
98
348.75
2
3
4
3
5
6
2
4
7
8
5
9
10
3
6
11
12
7
13
14
4
ELECTRICAL
ANGLE
(DEGREES)
1/4 STEP
2
1
AOUT CURRENT BOUT CURRENT
(% FULL-SCALE) (% FULL-SCALE)
1/2 STEP
8
15
16
At each rising edge of the STEP input, or each time a '1' is written to the RSTEP bit in the CTRL register, the
indexer travels to the next state in the table. The direction is shown with the DIR pin high and the RDIR bit in the
CTRL register set to '0', or the DIR pin low and the RDIR bit set to '1'. If the DIR pin is low with the RDIR bit '0',
or the DIR pin is high with the RDIR bit '1', the sequence is reversed. Positive current is defined as xOUT1 =
positive with respect to xOUT2.
Note that if the step mode is changed while stepping, the indexer will advance to the next valid state for the new
MODE setting at the rising edge of STEP.
12
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
Current Regulation
The current through the motor windings is regulated by an adjustable fixed-off-time PWM current regulation
circuit. When an H-bridge is enabled, current rises through the winding at a rate dependent on the DC voltage
and inductance of the winding and the magnitude of the back EMF present. Once the current hits the current
chopping threshold, the bridge disables the current for a fixed period of time, which is programmable between
500 nS and 128 µS by writing to the TOFF bits in the OFF register. After the off time expires, the bridge is reenabled, starting another PWM cycle.
In stepping motors, current regulation is used to vary the current in the two windings in a sinusoidal fashion to
provide smooth motion.
The PWM chopping current is set by a comparator which compares the voltage across a current sense resistor
connected to the xISENx pins, multiplied by the gain of the current sense amplifier, with a reference voltage. The
current sense amplifier is programmable in the CTRL register.
VM
x1HS
Gate
Drive
&
OCP
Registers
xOUT1
x1LS
PWM
logic
VM
x2HS
Gate
Drive
&
OCP
xOUT2
x2LS
+
Comp
xISENP
RISENSE
+
ISEN
amp
xISENN
-
+
-
+
Comp
2.75 V
SIN
DAC
Indexer
X
ISGAIN
1V
TORQUE
Torque
DAC
Figure 2. PWM Chopping Current
To generate the reference voltage for the current chopping comparator, the output of a sine lookup table is
multiplied by the value of the bits in the TORQUE register. This result is applied to a sine-weighted DAC, whose
full-scale output voltage is 2.75 V.
Therefore, the full-scale (100%) chopping current is calculated as follows:
2.75V · TORQUE
IFS =
256 · ISGAIN · RISENSE
(2)
Where TORQUE is the setting of the TORQUE bits, and ISGAIN is the programmed gain of the ISENSE
amplifiers (5, 10, 20, or 40).
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
13
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
Example:
If a 0.1-Ω sense resistor is used, ISGAIN is set to 0 (gain of 5), and TORQUE is set to 255, the full-scale (100%)
chopping current will be (2.75V * 255) / (256 * 5 * 0.1Ω) = 5.5A.
Decay Modes
During PWM current chopping, the H-bridge is enabled to drive through the motor winding until the PWM current
chopping threshold is reached. This is shown in Figure 3, Item 1. The current flow direction shown indicates
positive current flow in the step table below.
Once the chopping current threshold is reached, the H-bridge can operate in two different states, fast decay or
slow decay.
In fast decay mode, once the PWM chopping current level has been reached, the H-bridge reverses state to
allow winding current to flow in a reverse direction. If synchronous rectification is enabled (SRn pin logic low), the
opposite FETs are turned on; as the winding current approaches zero, the bridge is disabled to prevent any
reverse current flow. If SRn is high, current is recirculated through the body diodes, or through external Schottky
diodes. Fast-decay mode is shown in Figure 3, Item 2.
In slow-decay mode, winding current is re-circulated by enabling both of the low-side FETs in the bridge. This is
shown in Figure 3, Item 3.
VM
PWM
ON
PWM OFF
Slow Decay
1 Drive Current
1
xOUT2
xOUT1
3
2 Fast decay (reverse)
Fast Decay
3 Slow decay (brake)
2
Mixed Decay
TDECAY
TBLANK
TOFF
Itrip
Figure 3. Decay Modes
The DRV8711 supports fast decay and slow decay modes in both indexer and direct PWM modes. In addition, in
indexer mode only, it supports fixed mixed decay and auto mixed decay modes. Decay mode is selected by the
DECMOD bits in the DECAY register.
Mixed decay mode begins as fast decay, but after a programmable period of time (set by the TDECAY bits in the
DECAY register) switches to slow decay mode for the remainder of the fixed off time. Even if mixed decay is
selected, if the current is increasing or remaining the same (per the step table), then slow decay is used.
Auto mixed decay mode samples the current level at the end of the blanking time, and if the current is above the
Itrip threshold, immediately changes the H-bridge to fast decay. During fast decay, the (negative) current is
monitored, and when it falls below the Itrip threshold (and another blanking time has passed), the bridge is
switched to slow decay. Once the fixed off time expires, a new cycle is started.
If the bridge is turned on and at the end of TBLANK the current is below the Itrip threshold, the bridge remains on
until the current reaches Itrip. Then slow decay is entered for the fixed off time, and a new cycle begins.
Refer to Figure 4 and Figure 5.
14
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
The upper waveform shows the behavior if I < Itrip at the end of tBLANK. Note that (at slow motor speeds, where
back EMF is not significant), the current increase during the ON phase is the same magnitude as the current
decrease in fast decay, since both times are controlled by tBLANK, and the rate of change is the same (full VM is
applied to the load inductance in both cases, but in opposite directions). In this case, the current will gradually be
driven down until the peak current is just hitting Itrip at the end of the blanking time, after which some cycles will
be slow decay, and some will be mixed decay.
tON
tON
tOFF
tBLANK
I below Itrip
after tBLANK
tOFF
tBLANK
Itrip
At Itrip and after
tBLANK, slow decay
I < Itrip
tON
tON
tOFF
I above Itrip
after tBLANK
tOFF
On
tBLANK tBLANK
tBLANK tBLANK
Fast
Decay
Itrip
Slow
Decay
I > Itrip, start
fast decay
When I < Itrip in fast decay
and tBLANK expires, change
to slow decay
Figure 4. I < Itrip at the End of tBLANK
If the Itrip level changes during a PWM cycle (in response to a step command to the indexer), the current cycle is
immediately terminated, and a new cycle is begun. Refer to the drawing below.
If the Itrip level has increased, the H-bridge will immediately turn on; if the Itrip level has decreased, fast decay
mode is begun immediately. The top waveform shows what happens when the Itrip threshold decreases during a
PWM cycle. The lower Itrip level results in the current being above the Itrip threshold at the end of tBLANK on
the following cycle. Fast decay is entered until the current is driven below the Itrip threshold.
Itrip decrease
tON
tBLANK
tOFF
tON
tBLANK
tOFF
Itrip
Decrease in Itrip terminates
cycle, fast decay begins
Itrip increase
tON
tBLANK
When I < Itrip in fast decay
change to slow decay
tON
On
tOFF
tBLANK
Fast
Decay
Slow
Decay
Itrip
Increase in Itrip terminates
cycle, bridge turns on
Figure 5. Itrip Level Changing During a PWM Cycle
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
15
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
Blanking Time
After the current is enabled in an H-bridge, the voltage on the ISEN pin is ignored for a period of time before
enabling the current sense circuitry. This blanking time is adjustable from 1 µS to 5.12 µs, in 20 ns increments,
by setting the TBLANK bits in the BLANK register. Note that the blanking time also sets the minimum on time of
the PWM.
The same blanking time is applied to the fast decay period in auto decay mode. The PWM will ignore any
transitions on Itrip after entering fast decay mode, until the blanking time has expired.
To provide better current control at very low current steps, an adaptive blanking time mode can be enabled by
setting the ABT bit in the BLANK register. If ABT is set, at current levels below 30% of full scale current (as
determined by the step table), the blanking time (so also the minimum on time) is cut in half, to 50% of the value
programmed by the TBLANK bits.
For higher degrees of micro-stepping it is recommended to enable ABT bit for better current regulation.
Pre-Drivers
An internal charge pump circuit and pre-drivers inside the DRV8711 directly drive N-channel MOSFETs, which
drive the motor current.
The peak drive current of the pre-drivers is adjustable by setting the bits in the DRIVE register. Peak source
currents may be set to 50 mA, 100 mA, 150 mA, or 200 mA. The peak sink current is approximately 2x the peak
source current. Adjusting the peak current will change the output slew rate, which also depends on the FET input
capacitance and gate charge.
When changing the state of the output, the peak current is applied for a short period of time (tDRIVE), to charge
the gate capacitance. After this time, a weak current source is used to keep the gate at the desired state. When
selecting the gate drive strength for a given external FET, the selected current must be high enough to fully
charge and discharge the gate during the time when driven at full current, or excessive power will be dissipated
in the FET.
During high-side turn-on, the low-side gate is pulled low. This prevents the gate-source capacitance of the lowside FET from inducing turn-on.
The pre-driver circuits include enforcement of a dead time in analog circuitry, which prevents the high-side and
low-side FETs from conducting at the same time. Additional dead time is added with digital delays. This delay
can be selected by setting the DTIME bits in the CTRL register.
16
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
tDRIVE
High Z
HS drive
(mA)
High Z
High Z
Low Z
Low
Z
xHS
(V)
tDRIVE
High Z
Low Z
High Z
High Z
LS drive
(mA)
Low
Z
xLS
(V)
tDEAD
tDEAD
Figure 6. Pre-Drivers
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
17
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
Gate Pre-drive Source Capability
I (mA) source
I (mA) source
TDRIVEP = 00
TDRIVEP = 01
200 mA
200 mA
IDRIVEP = 11
IDRIVEP = 11
150 mA
150 mA
IDRIVEP = 10
IDRIVEP = 10
100 mA
100 mA
IDRIVEP = 01
IDRIVEP = 01
50 mA
50 mA
IDRIVEP = 00
IDRIVEP = 00
Holding Current
Holding Current
t (ns)
250 ns 500 ns
1 µs
t (ns)
2 µs
250 ns 500 ns
I (mA) source
1 µs
2 µs
I (mA) source
TDRIVEP = 10
TDRIVEP = 11
200 mA
200 mA
IDRIVEP = 11
IDRIVEP = 11
150 mA
150 mA
IDRIVEP = 10
IDRIVEP = 10
100 mA
100 mA
IDRIVEP = 01
IDRIVEP = 01
50 mA
50 mA
IDRIVEP = 00
IDRIVEP = 00
Holding Current
Holding Current
t (ns)
250 ns 500 ns
1 µs
t (ns)
2 µs
250 ns 500 ns
1 µs
2 µs
Gate Pre-drive Sink Capability
TDRIVEN = 00
250 ns 500 ns
1 µs
TDRIVEN = 01
2 µs
250 ns 500 ns
1 µs
2 µs
t (ns)
Holding Current
t (ns)
Holding Current
IDRIVEN = 00
IDRIVEN = 00
100 mA
100 mA
IDRIVEN = 01
IDRIVEN = 01
200 mA
200 mA
IDRIVEN = 10
IDRIVEN = 10
300 mA
300 mA
IDRIVEN = 11
IDRIVEN = 11
400 mA
400 mA
I (mA) sink
250 ns 500 ns
I (mA) sink
TDRIVEN = 10
1 µs
2 µs
250 ns 500 ns
TDRIVEN = 11
1 µs
2 µs
t (ns)
t (ns)
Holding Current
Holding Current
IDRIVEN = 00
100 mA
IDRIVEN = 00
100 mA
IDRIVEN = 01
200 mA
IDRIVEN = 01
200 mA
IDRIVEN = 10
300 mA
IDRIVEN = 10
300 mA
IDRIVEN = 11
400 mA
IDRIVEN = 11
400 mA
I (mA) sink
I (mA) sink
Figure 7. Gate Pre-Drive Source/Sink Capability
Configuring Pre-drivers
IDRIVE and TDRIVE are selected based on the size of external FETs used. These registers need to be
configured so that the FET gates are charged completely during TDRIVE. If IDRIVE and TDRIVE are chosen to
be too low for a given FET, then the FET may not turn on completely. It is suggested to adjust these values insystem with the required external FETs and stepper motor in order to determine the best possible setting for any
application.
Note that TDRIVE will not increase the PWM time or change the PWM chopping frequency.
18
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
In a system with capacitor charge Q and desired rise time RT, IDRIVE and TDRIVE can be initially selected
based on:
IDRIVE > Q / RT
TDRIVE > 2 x RT
For best results, select the smallest IDRIVE and TDRIVE that meet the above conditions.
Example:
If the gate charge is 15 nC and the desired rise time is 400 ns, then select:
IDRIVEP = 50 mA, IDRIVEN = 100 mA
TDRIVEP = TDRIVEN = 1 µs
External FET Selection
In a typical setup, the DRV8711 can support external FETs over 50 nC each. However, this capacity can be
lower or higher based on the device operation. For an accurate calculation of FET driving capacity, use the
following equation.
20mA · (2 · DTIME + TBLANK + TOFF)
Q<
(3)
4
Example:
If a DTIME is set to 0 (400 ns), TBLANK is set to 0 (1 µs), and TOFF is set to 0 (500 ns), then the DRV8711 will
support Q < 11.5 nC FETs (please note that this is an absolute worst-case scenario with a PWM frequency
~ 430 kHz).
If a DTIME is set to 0 (400 ns), TBLANK is set to 0 (1 µs), and TOFF is set to 0x14 (10 µs), then the DRV8711
will support Q < 59 nC FETs (PWM frequency ~ 85 kHz).
If a DTIME is set to 0 (400 ns), TBLANK is set to 0 (1 µs), and TOFF is set to 0x60 (48 µs), then the DRV8711
will support Q < 249 nC FETs (PWM frequency ~ 20 kHz).
Stall Detection
The DRV8711 implements a back EMF monitoring scheme that is capable of detecting a stall during stepper
motor motion. This stall detection is intended to be used to get an indication when a motor is run into a
mechanical stop, or when an increased torque load on the motor causes it to stall.
To determine that a stall has occurred, a drop in motor back EMF is detected. The DRV8711 supports two
methods of this detection: an automatic internal stall detection circuit, or the ability to use an external
microcontroller to monitor back EMF.
During a zero-current step, one side of the H-bridge is placed in a high impedance state, and the opposite lowside FET is turned on for a brief duration defined by TORQUE register SMPLTH bit [10:8]. This allows the current
to decay quickly through the low-side FET and the opposite body diode. Which side of the bridge is tri-state and
which one is driven low depends on the current direction on the previous step. The bridge with the high side that
has been actively PWMed (at the beginning of the PWM cycle during blank time) prior to entering the zerocurrent step will be held low and the opposite side will be tri-stated.
Back EMF is sampled on the tri-stated output pin at the end of SMPLTH time (TORQUE register bit [10:8]). The
back EMF from the selected pin is divided by 4, 8, 16, or 32, depending on the setting of the VDIV bits in the
STALL register. The voltage is buffered and held on an external capacitor placed on the BEMF pin. The signal on
the BEMF output pin can be further processed by a microcontroller to implement more advanced control and stall
detection algorithms.
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
19
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
VM
AOUT1
BEMF
buffer
2
VDIV
VM
Step
Motor
AOUT2
2
control
logic
To
STATUS
register
STALLn/
BEMFVn
VDIV
VM
SDCNT
2
BOUT1
+
counter
comp
2
reference
1.80 V
VM
VDIV
BOUT2
8
SDTHR
DAC
SDTHR
DAC
2
VDIV
Figure 8. Stall Detection
Internal Stall Detection
To use internal stall detection, the EXSTALL bit in the CTRL register is set to ‘0’. In this mode, the
STALLn/BEMFVn output pin is used to signal a valid stall condition.
Step time, or rate at which step input is applied to DRV8711, has to be greater than SMPLTH time for back EMF
sampling.
Using internal stall detection, a stall is detected when the sampled back EMF drops below the value set by the
SDTHR bits in the STALL register. A programmable counter circuit allows the assertion of the STALLn output to
be delayed until the back EMF has been sampled below the SDTHR value for more than one zero-current step.
The counter is programmed by the SDCNT bits in the STALL register, and provides selections of 1, 2, 4, or 8
steps.
When the stall is detected (at the end of a SMPLTH interval), the STALLn/BEMFVn pin is driven active low, and
the STD bit and the STDLAT bit in the STATUS register are set. The STALLn/BEMFVn pin will deassert and the
STD bit will automatically clear at the next zero-current step if a stall condition is not detected, while the STDLAT
bit will remain set until a '0' is written to it. The STDLAT is reset when the STD bit clears after the first zero-cross
step that does not detect a stall condition.
This stall detection scheme is only effective when the motor is stalled while running at or above some minimum
speed. Since it relies on detecting a drop in motor back EMF, the motor must be rotating with sufficient speed to
generate a detectable back EMF. During motor start-up, and at very slow step rates, the stall detection is not
reliable.
Since back EMF can only be sampled during a zero-current state, stall detection is not possible in full step mode.
During full-step operation, the stall detect circuit is gated off to prevent false signaling of a stall.
The correct setting of the SDTHR bits needs to be determined experimentally. It is dependent on many factors,
including the electrical and mechanical characteristics of the load, the peak current setting, and the supply
voltage.
20
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
External Stall Detection
To use an external microcontroller to manage stall detection, the EXSTALL bit in the CTRL register is set to ‘1’.
In this mode, the STALLn / BEMFVn output pin is used to signal a valid back EMF measurement is ready. In
addition, the SDT and SDTLAT bits are also set at this time.
BEMFVn and BEMF are still valid outputs in this mode even if the step time is smaller than SMPLTH time.
When the BEMFVn pin goes active low, it is an indication that a valid back EMF voltage measurement is
available. This signal could be used, for example, to trigger an interrupt on a microcontroller. The microcontroller
can then sample the voltage present (using an A/D converter) on the BEMF pin.
After sampling the back EMF voltage, the microcontroller writes a ‘0’ to the SDTLAT bit to clear the SDT bit and
BEMFVn pin, in preparation for the next back EMF sample. If the SDTLAT bit is not cleared by the
microcontroller, it will automatically be cleared in the next zero-current step.
For either internal or external stall detection, at very high motor speeds when the PWM duty cycle approaches
100%, the inductance of the motor and the short duration of each step may cause the time required for current
recirculation to exceed the step time. In this case, back EMF will not be correctly sampled, and stall detection
cannot function. This condition occurs most at high degrees of micro-stepping, since the zero current step lasts
for a shorter duration. It is advisable to run the motor at lower degrees of micro-stepping at higher speeds to
allow time for current recirculation if stall detection is needed in this condition.
RESET and SLEEPn Operation
An internal power-up reset circuit monitors the voltage applied to the VM pin. If VM falls below the VM
undervoltage lockout voltage, the part is reset, as described below for the case of asserting the RESET pin.
If the RESET pin is asserted, all internal logic including the indexer is reset. All registers are returned to their
initial default conditions. The power stage will be disabled, and all inputs, including STEP and the serial interface,
are ignored when RESET is active.
On exiting reset state, some time (approximately 1 mS) needs to pass before the part is fully functional.
Applying an active low input to the SLEEPn input pin will place the device into a low power state. In sleep mode,
the motor driver circuitry is disabled, the gate drive regulator and charge pump are disabled, and all analog
circuitry is placed into a low power state. The digital circuitry in the device still operates, so the device registers
can still be accessed via the serial interface.
When SLEEPn is active, the RESET pin does not function. SLEEPn must be exited before RESET will take
effect.
When exiting from sleep mode, some time (approximately 1 mS) needs to pass before applying a STEP input, to
allow the internal circuitry to stabilize.
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
21
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
Microstepping Drive Current
The following plots are examples of stepper motor current in one of the windings. Since these waveforms are
dependent on DRV8711 register settings as well as the external FETs, sense resistor, and stepper motor, they
should only be used as a reference.
1/4 stepping
1/8 stepping
Current
Current
STEP
STEP
1/16 stepping
1/128 stepping
Current
STEP
Current
STEP
Figure 9. Microstepping Drive Current
22
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
Protection Circuits
The DRV8711 is fully protected against undervoltage, overcurrent and overtemperature events.
Overcurrent Protection (OCP)
Overcurrent is sensed by monitoring the voltage drop across the external FETs. If the voltage across a driven
FET exceeds the value programmed by the OCPTH bits in the DRIVE register for more than the time period
specified by the OCPDEG bits in the DRIVE register, an OCP event is recognized. When operating in direct
PWM mode, during an OCP event, the H-bridge experiencing the OCP event is disabled; if operating in indexer
mode, both H-bridges will be disabled. In addition, the corresponding xOCP bit in the STATUS register is set,
and the FAULTn pin is driven low. The H-bridge(s) will remain off, and the xOCP bit will remain set, until it is
written to 0, or the device is reset.
Pre-Driver Fault
If excessive current is detected on the gate drive outputs (which would be indicative of a failed/shorted output
FET or PCB fault), the H-bridge experiencing the fault is disabled, the xPDF bit in the STATUS register is set,
and the FAULTn pin is driven low. The H-bridge will remain off, and the xPDF bit will remain set until it is written
to 0, or the device is reset.
Thermal Shutdown (TSD)
If the die temperature exceeds safe limits, all FETs in the H-bridge will be disabled, the OTS bit in the STATUS
register will be set, and the FAULTn pin will be driven low. Once the die temperature has fallen to a safe level
operation will automatically resume and the OTS bit will reset. The FAULTn pin will be released after operation
has resumed.
Undervoltage Lockout (UVLO)
If at any time the voltage on the VM pin falls below the undervoltage lockout threshold voltage, all FETs in the Hbridge will be disabled, the UVLO bit in the STATUS register will be set, and the FAULTn pin will be driven low.
Operation will resume and the UVLO bit will reset when VM rises above the UVLO threshold. The FAULTn pin
will be released after operat ion has resumed.
During any of these fault conditions, the STEP input pin will be ignored.
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
23
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
Serial Data Format
The serial data consists of a 16-bit serial write, with a read/write bit, 3 address bits and 12 data bits. The three
address bits identify one of the registers defined in the register section above.
To write to a register, data is shifted in after the address as shown in the timing diagram below:
SCS
SCLK
1
SDATI
WRT
A.
2
3
A2
4
A1
A0
5
6
D11
D10
7
Note 1
8
D9
D8
X
9
10
11
12
13
14
15
16
D7
D6
D5
D4
D3
D2
D1
D0
Any amount of time may pass between bits, as long as SCS stays active high. This allows two 8-bit writes to be used.
Figure 10. Write Operation
Data may be read from the registers through the SDATO pin. During a read operation, only the address is used
form the SDATI pin; the data bits following are ignored. Reading is enabled by setting the READ bit at the
beginning of the access:
SCS
SCLK
1
SDATI
READ
2
A2
3
A1
4
6
D11
D10
7
8
Note 1
9
10
11
12
13
14
6
15
D6
D5
D4
D3
D2
D1
16
A0
SDATO
(1)
5
D9
D8
D7
D0
Any amount of time may pass between bits, as long as SCS stays active high. This allows two 8-bit writes to be used.
Figure 11. Read Operation
24
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
CONTROL REGISTERS
The DRV8711 uses internal registers to control the operation of the motor. The registers are programmed via a
serial SPI communications interface. At power-up or reset, the registers will be pre-loaded with default values as
shown below.
Following is a map of the DRV8711 registers:
DRV8711 REGISTER MAP
Name
11
CTRL
TORQUE
10
9
DTIME
8
7
6
5
4
EXSTALL
ISGAIN
2
1
0
RSTEP
RDIR
ENBL
Address
Hex
RW
00
TORQUE
RW
01
MODE
SMPLTH
Reserved
3
OFF
Reserved
PWMMODE
TOFF
RW
02
BLANK
Reserved
ABT
TBLANK
RW
03
TDECAY
RW
04
SDTHR
RW
05
RW
06
DECAY
DECMOD
Reserved
STALL
VDIV
SDCNT
DRIVE
IDRIVEP
IDRIVEN
STATUS
Name
TDRIVEP
STDLAT
Reserved
11
10
9
8
7
TDRIVEN
STD
6
UVLO
5
OCPDEG
BPDF
4
APDF
3
OCPTH
BOCP
2
AOCP
1
OTS
0
RW
07
Address
Hex
Figure 12. DRV8711 Register Map
Individual register contents are defined below.
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
25
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
CTRL Register
Address = 0x00h
BIT
NAME
SIZE
R/W
DEFAULT
DESCRIPTION
0
ENBL
1
R/W
0
0: Disable motor
1: Enable motor
1
RDIR
1
R/W
0
0: Direction set by DIR pin
1: Direction set by inverse of DIR pin
2
RSTEP
1
W
0
0: No action
1: Indexer will advance one step; automatically cleared after write
0000: Full-step, 71% current
0001: Half step
0010: 1/4 step
0011: 1/8 step
0100: 1/16 step
0101: 1/32 step
0110: 1/64 step
0111: 1/128 step
1000: 1/256 step
1001 – 1111: Reserved
6-3
MODE
4
R/W
110
7
EXSTALL
1
R/W
0
0: Internal stall detect
1: External stall detect
0
ISENSE amplifier gain set
00: Gain of 5
01: Gain of 10
10: Gain of 20
11: Gain of 40
Dead time set
00: 400 ns dead time
01: 450 ns dead time
10: 650 ns dead time
11: 850 ns dead time
9-8
11-10
ISGAIN
DTIME
2
R/W
2
R/W
11
TORQUE Register
Address = 0x01h
BIT
NAME
SIZE
R/W
DEFAULT
7-0
TORQUE
8
R/W
0xFFh
DESCRIPTION
Sets full-scale output current for both H-bridges
10-8
SIMPLTH
3
R/W
1
Back EMF sample threshold
000: 50 µs
001: 100 µs
010: 200 µs
011: 300 µs
100: 400 µs
101: 600 µs
110: 800 µs
111: 1000 µs
11
Reserved
1
-
-
Reserved
OFF Register
Address = 0x02h
BIT
NAME
SIZE
R/W
DEFAULT
7-0
TOFF
8
R/W
0x30h
8
PWMMODE
1
R/W
0
0: Use internal indexer
1: Bypass indexer, use xINx inputs to control outputs
11-9
Reserved
3
-
-
Reserved
26
DESCRIPTION
Sets fixed off time, in increments of 500 ns
0x00h: 500 ns
0xFFh: 128 µs
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
BLANK Register
Address = 0x03h
BIT
NAME
SIZE
R/W
DEFAULT
DESCRIPTION
Sets current trip blanking time, in increments of 20 ns
0x00h: 1.00 µs
…
0x32h: 1.00 µs
0x33h: 1.02 µs
…
0xFEh: 5.10 µs
0xFFh: 5.12 µs
Also sets minimum on-time of PWM
7-0
TBLANK
8
R/W
0x80h
8
ABT
1
R/W
0
0: Disable adaptive blanking time
1: Enable adaptive blanking time
11-9
Reserved
3
-
-
Reserved
DECAY Register
Address = 0x04h
BIT
NAME
SIZE
R/W
DEFAULT
7-0
TDECAY
8
R/W
0x10h
DESCRIPTION
Sets mixed decay transition time, in increments of 500 ns
10-8
DECMOD
3
R/W
1
000: Force slow decay at all times
001: Slow decay for increasing current, mixed decay for
decreasing current (indexer mode only)
010: Force fast decay at all times
011: Use mixed decay at all times
100: Slow decay for increasing current, auto mixed decay for
decreasing current (indexer mode only)
101: Use auto mixed decay at all times 110 – 111: Reserved
11
Reserved
1
-
-
Reserved
STALL Register
Address = 0x05h
BIT
NAME
SIZE
R/W
DEFAULT
7-0
SDTHR
8
R/W
0x40h
10-8
11
SDCNT
VDIV
2
2
R/W
R/W
DESCRIPTION
Sets stall detect threshold
The correct setting needs to be determined experimentally
0
00: STALLn asserted on first step with back EMF below SDTHR
01: STALLn asserted after 2 steps
10: STALLn asserted after 4 steps
11: STALLn asserted after 8 steps
0
00: Back EMF is divided by 32
01: Back EMF is divided by 16
10: Back EMF is divided by 8
11: Back EMF is divided by 4
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
27
DRV8711
SLVSC40 – JUNE 2013
www.ti.com
DRIVE Register
Address = 0x06h
BIT
1-0
3-2
5-4
7-6
9-8
11-10
28
NAME
OCPTH
OCPDEG
TDRIVEN
TDRIVEP
IDRIVEN
IDRIVEP
SIZE
2
2
2
2
2
2
R/W
R/W
R/W
R/W
R/W
R/W
R/W
DEFAULT
DESCRIPTION
0
OCP threshold
00: 250 mV
01: 500 mV
10: 750 mV
11: 1000 mV
10
OCP deglitch time
00: 1 µs
01: 2 µs
10: 4 µs
11: 8 µs
1
Low-side gate drive time
00: 250 ns
01: 500 ns
10: 1 µs
11: 2 µs
1
High-side gate drive time
00: 250 ns
01: 500 ns
10: 1 µs
11: 2 µs
0
Low-side gate drive peak current
00: 100 mA peak (sink)
01: 200 mA peak (sink)
10: 300 mA peak (sink)
11: 40 0mA peak (sink)
0
High-side gate drive peak current
00: 50 mA peak (source)
01: 100 mA peak (source)
10: 150 mA peak (source)
11: 200 mA peak (source)
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
DRV8711
www.ti.com
SLVSC40 – JUNE 2013
STATUS Register
Address = 0x07h
BIT
NAME
SIZE
R/W
DEFAULT
DESCRIPTION
0
OTS
1
R
0
0: Normal operation
1: Device has entered overtemperature shutdown
OTS bit will clear once temperature has fallen to safe levels
1
AOCP
1
R/W
0
0: Normal operation
1: Channel A overcurrent shutdown
Write a ‘0’ to this bit to clear the fault and resume operation
2
BOCP
1
R/W
0
0: Normal operation
1: Channel B overcurrent shutdown
Write a ‘0’ to this bit to clear the fault and resume operation
3
UVLO
1
R
0
0: Normal operation
1: Undervoltage lockout
UVLO bit will clear after VM has increased over VUVLO
4
APDF
1
R/W
0
0: Normal operation
1: Channel A predriver fault
Write a ‘0’ to this bit to clear the fault and resume operation
5
BPDF
1
R/W
0
0: Normal operation
1: Channel B predriver fault
Write a ‘0’ to this bit to clear the fault and resume operation
6
STD
1
R
0
0: Normal operation
1: Stall detected
7
STDLAT
1
R/W
0
0: Normal operation
1: Latched stall detect
Write a ‘0’ to this bit to clear the fault and resume operation
11-8
Reserved
4
-
-
Reserved
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: DRV8711
29
PACKAGE OPTION ADDENDUM
www.ti.com
28-Jun-2013
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
(2)
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
DRV8711DCP
ACTIVE
HTSSOP
DCP
38
50
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
DRV8711
DRV8711DCPR
ACTIVE
HTSSOP
DCP
38
2000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
DRV8711
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
Samples
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other
changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest
issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and
complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale
supplied at the time of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms
and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary
to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily
performed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and
applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information
published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or
endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the
third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration
and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered
documentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service
voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.
TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements
concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support
that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause
harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use
of any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to
help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and
requirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties
have executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in
military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components
which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and
regulatory requirements in connection with such use.
TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of
non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
Products
Applications
Audio
www.ti.com/audio
Automotive and Transportation
www.ti.com/automotive
Amplifiers
amplifier.ti.com
Communications and Telecom
www.ti.com/communications
Data Converters
dataconverter.ti.com
Computers and Peripherals
www.ti.com/computers
DLP® Products
www.dlp.com
Consumer Electronics
www.ti.com/consumer-apps
DSP
dsp.ti.com
Energy and Lighting
www.ti.com/energy
Clocks and Timers
www.ti.com/clocks
Industrial
www.ti.com/industrial
Interface
interface.ti.com
Medical
www.ti.com/medical
Logic
logic.ti.com
Security
www.ti.com/security
Power Mgmt
power.ti.com
Space, Avionics and Defense
www.ti.com/space-avionics-defense
Microcontrollers
microcontroller.ti.com
Video and Imaging
www.ti.com/video
RFID
www.ti-rfid.com
OMAP Applications Processors
www.ti.com/omap
TI E2E Community
e2e.ti.com
Wireless Connectivity
www.ti.com/wirelessconnectivity
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2013, Texas Instruments Incorporated
Similar pages