Patent ID: 11862202
Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 13:
14. A method for preventing reverse current flow through an isolation field effect transistor (ISOFET) of a data storage device comprising:
setting a first command current for a host voltage and a drive voltage of the data storage device;
measuring a first host analog-to-digital (ADC) voltage, a first drive ADC voltage and a first ADC current at the first command current;
setting a second command current for the host voltage and the drive voltage of the data storage device;
measuring a second host ADC voltage, a second drive ADC voltage and a second ADC current at the second command current;
calculating a Rdson of the ISOFET as, Rdson
  ⁢
  
   
    =
    
     
      
       Δ
       ⁢
       V
       ⁢
       2
      
      -
      
       Δ
       ⁢
       V
       ⁢
       1
      
     
     
      
       I
       ⁢
       2
      
      -
      
       I
       ⁢
       1
      
     
    
   
   ,, wherein ΔV2 is the difference between the second host ADC voltage and the second drive ADC voltage, ΔV1 is the difference between the first host ADC voltage and the first drive ADC voltage, I2 is the second ADC current and I1 is the first ADC current; and
calculating a voltage turnoff threshold Vthreshold as an ITurnoffCurrent multiplied by the calculated Rdson.