SLVSE65C July 2018 – December 2023 DRV8847
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
If a resistive load (RL) is connected between OUT1 and VM, then current flowing from supply (VM) is as:
Now, if the voltage drop at negative terminal of OL1_LS comparator is lower than 1.2-V (VOL_LS), the comparator sets output to "1" showing open load. Hence, the voltage required to trip OL1_LS comparator is calculated as:
By putting Equation 16 to Equation 17,
By solving Equation 18, the load resistance (RL) is expressed as,
By putting the values of VVM and VOL_HS in Equation 19, the load resistance (RL) is calculated as 135-kΩ for supply voltage (VVM) of 12-V. Hence, any resistive load connected between VM and OUTx above this value (at VVM = 12-V) is shown as an open-load.
In the open load detection for load connected to supply (VM) configuration, the resistive load threshold for an open load also depends on the supply voltage (VVM).