AMIS-39100:
Octal High Side Driver with Protection
Data Sheet
8.6 Diagnostics
8.6.1. Short-Circuit Diagnostics
The diagnostic circuit in the AMIS-39100 monitors the actual output status at the pins of the device and stores the result in the
diagnostic register, which is then latched in the output register at the rising edge of the WR-pin. Each driver has its corresponding
diagnostic bit DIAG_x. By comparing the actual output status (DIAG_x) with the requested driver status (CMD_x) you can diagnose the
correct operation of the application according to Table 9.
8.6.2. Thermal Shutdown (TSD) Diagnostic
In case of TSD activation, all bits DIAG 1 to DIAG 8 in the SPI output register are set into the fault state and all drivers will be switched
off (see Table 9). The TSD error condition is active until it is reset by the next correct communication on SPI interface (i.e. number of
clock pulses during WR=0 is divisible by 8), provided that the device has cooled down under the TSD trip point.
Table 9: OUT Diagnostics
Requested driver
status
On
On
Off
Off
Note:
(1)
(2)
The correct diagnostic information is available after T_diagnostic_OFF time.
All 8 diagnostic bits DIAG_x must be in the fault condition to conclude a TSD diagnostic.
CMD_x
Actual output status
DIAG_x
Diagnosis
1
1
0
0
High
Low
High
Low
1
0
1
0
Normal state
(2)
Short to ground or TSD
(1)
(2)
Short to VB or missing load or TSD
(1)
Normal state
8.6.3. Ground Loss
Due to its design, the AMIS-39100 is protected for withstanding module ground loss and driver output shorted to ground at the same
time.
8.6.4. Power Loss
Table 10: Power Loss
VDDN
VB
0
0
0
1
1
1
0
1
Possible Case
System stopped
Start case or sleeping mode with missing VDDN
Action
Nothing
Eight switches in the off-state
Power down consumption on VB
Eight switches in the off-state
Normal consumption on VDDN
Nominal functionality
Missing VB supply
VDDN normally present
System functional
AMI Semiconductor
– Jan. 07, M-20557-002
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