SLOS893D September 2014 – August 2025 DRV2624
PRODUCTION DATA
The DRV2624 has a diagnostic routine that can be selected by the MODE[1:0] parameter. The purpose of the routine is to determine if the actuator can be safely and correctly driven. If a problem is detected by the diagnostic routine, the DIAG_RESULT bit asserts (high). After running the diagnostic routine, the DIAG_RESULT is checked to assess the result of the diagnostic routine. If the diagnostic routine does not finish due to a critical condition, such as a UVLO, over temperature or over-current condition, the diagnostic routine is aborted and the DIAG_RESULT is set to 1.
The diagnostic routine is composed of 2 sub-routines: a resistance measurement routine and a functional routine.
The resistance measurement sub-routine reports the resistance of the actuator as seen from the differential output pins (OUT+ and OUT-) and placed on the DIAG_Z_RESULT parameter. The resistance measurement sub-routine is always executed during the diagnostics routine and the output is reported in the DIAG_Z_RESULT. The only exception is during an over-temperature or UVLO condition, in which case the diagnostic routine aborts immediately and the device goes into standby state.
An over-current condition never happens in this sub-routine, even in the presence of a short, because the resistance measurement injects a small current that is not detected by the over-current detection circuit. The resistance measurement sub-routine is the first to be executed. Also, this sub-routine does not cause the DIAG_RESULT bit to assert.
After the resistance measurement, the diagnostic routine plays a diagnostic waveform to determine whether the actuator can be successfully driven. A short or open condition, as well as failure to detect a valid BEMF causes the DIAG_RESULT bit to assert. Note that if a critical problem is experienced during the diagnostic routine, such as an over-current condition, the routine can be aborted, and the DIAG_RESULT asserts.