ZHCSR87 December 2022 DRV8316C
PRODUCTION DATA
Driver propagation delay (tPD) and dead time (tdead) is specified with a typical and maximum value, but not with a minimum value. This is due to the direction of current at the OUTx pin when synchronous inputs are switching. Driver propagation delay and dead time can be shorter than typical values due to slower internal turn-ons of the high-side or low-side internal MOSFETs to avoid internal dV/dt coupling.
For more information and examples of how propagation delay and dead time differs for input PWM and output configurations, please visit the Delay and Dead Time in Integrated MOSFET Drivers application note.
The dead time from the microcontroller’s PWM outputs can be used as an extra precaution in addition to the DRV8316C internal shoot-through protection. This creates a condition where internal logic prioritizes the MCU dead time or driver dead time based on their durations.
If the MCU dead time is less than the driver dead time, the driver will compensate and make the true output dead time the value specified by the DRV8316C. If the MCU inserted dead time is larger than the driver dead time, then the DRV8316C will adjust accordingly to the MCU dead time as shown in the table below.
A summary of the device delay times with respect to synchronous inputs INHx and INLx, OUTx current direction, and inserted MCU dead time are shown in Table 9-2.
OUTx current direction | INHx | INLx | Propagation Delay (tPD) | Dead Time (tdead) | Inserted MCU dead time (tdead(MCU)) | |
tdead(MCU) < tdead | tdead(MCU) > tdead | |||||
Out of OUTx | Rising | Falling | Typical | Typical | Output dead time = tdead | Output dead time = tdead(MCU) |
Falling | Rising | Smaller than typical | Smaller than typical | Output dead time < tdead | Output dead time < tdead(MCU) | |
Into OUTx | Rising | Falling | Smaller than typical | Smaller than typical | Output dead time < tdead | Output dead time < tdead(MCU) |
Falling | Rising | Typical | Typical | Output dead time = tdead | Output dead time = tdead(MCU) | |