DRV8880_15 Datasheet, PDF (30/48 Pages) Texas Instruments – DRV8880 2-A Stepper Motor Driver With AutoTune™

DRV8880
SLVSD18A – JUNE 2015 – REVISED JULY 2015
www.ti.com
In retry mode, the driver will be re-enabled after the OCP retry period (t_RETRY) has passed. nFAULT becomes
high again after the retry time. If the fault condition is still present, the cycle repeats. If the fault is no longer
present, normal operation resumes and nFAULT remains deasserted.
A microcontroller can retain control of the ENABLE pin while in retry mode if it is operated like an open-drain
output. Many microcontrollers support this. When the DRV8880 is operating normally, configure the MCU GPIO
as an input. In this state, the MCU can detect whenever nFAULT is pulled low. In order to disable the DRV8880
output, configure the GPIO output state as low, and then configure the GPIO as an output.
Alternatively, a logic-level FET may be used to create an open drain external to the MCU. In this case, an
additional MCU GPIO may be required in order to monitor the nFAULT pin.
MCU
V3P3
5.1 kŸ
ENABLE
DRV8880
MCU
V3P3
5.1 kŸ
ENABLE
DRV8880
FAULTn
Device
Logic
FAULTn
Device
Logic
FAULT
VM undervoltage
(UVLO2)
Logic undervoltage
(UVLO1)
VCP undervoltage
(CPUV)
Thermal Shutdown
(TSD)
Overcurrent
(OCP)
Figure 27. Methods For Operating in Retry Mode
CONDITION
VM < V_UVLO2
(max 6.4 V)
VM < V_UVLO2
(max 4.9 V)
VCP < V_CPUV
(typ VM + 1.8 V)
T_J > T_TSD
(min 150°C)
I_OUT > I_OCP
(min 2.5 A)
V_xISEN > V_OCP
(min 0.9 V)
Table 9. Fault Condition Summary
ERROR
REPORT
H-BRIDGE
CHARGE
PUMP
INDEXER
nFAULT
Disabled
Disabled Operating
None
Disabled Disabled Disabled
nFAULT
Disabled Operating Operating
nFAULT
Disabled Operating Operating
nFAULT
Disabled Operating Operating
V3P3
Operating
Operating
Operating
Operating
Operating
RECOVERY
VM > V_UVLO2
(max 6.5 V)
VM > V_UVLO2
(max 4.8 V)
VCP > V_CPUV
(typ VM + 1.9 V)
T_J < T_TSD - T_HYS
(T_HYS typ 35°C)
ENABLE
-or-
t_RETRY
30
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