1998 July 30
Philips Semiconductors Objective Specification, Revision 2.2
Pre-Amplifier for Hard Disk Drive with
MR-Read / Inductive Write Heads TDA5360
14
The following are valid READ fault conditions which set FLT=LOW
Rext pin open or shorted to GND or Vcc
Thermal Asperity detected
Read Head open
Power supplies too low (VCC and/or VEE)
Write current present in read mode
Illegal head address ( i.e. head 12, 13, 14 or 15)
In this case, besides asserting the fault flag, the MR bias current is diverted to the dummy head.
The following are valid WRITE fault conditions which set FLT=HIGH. An action can eventually be taken :
FAULT ACTION
No write current in write mode Disable write current
Rext pin open or shorted to GND or Vcc Disable write current
Open write head or shorted to GND Do not disable write current
Write data frequency too low Do not disable write current
Power supplies too low Disable write current
lllegal head address (i.e. HD 12, 13, 14, 15) Disable write current
If the write current is disabled, the writer is powered down. The only way to restart a write sequence is to switch R/W
high and then to switch R/W low again.
Trying to go in Write mode from a sleep or standby mode condition will disable the write current.
If two fault conditions occurs nearly at the same time, the first to occur will be loaded in Reg. 07.