L9825_03 STMICROELECTRONICS [STMicroelectronics], L9825_03 Datasheet - Page 8

• Manufacturer Part Number: L9825_03
• Description: Octal Low-side Driver For Resistive and Inductive Loads With Serial / Parallel Input Control, Output Protection and Diagnostic
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L9825
Fault condition 2) "open load" or "output short circuit to GND" : the output is switched off and the voltage at the
output drops below the diagnostics threshold, because the load current is lower than the output diagnostic cur-
rent source, the load is interrupted. The diagnostic bit is low.
For outputs 3 to 8 the output status signals, are fed directly to the SPI register.
Table 3. Diagnostic for outputs 1 to 8 in SPI controlled mode.
The fault condition 1) "output short circuit to Vbat" :
For outputs 3 to 6 is the same as of outputs 1 and 2.
For outputs 7 and 8 : the output was switched on and the voltage at the output exceeds the diagnostics thresh-
old. The output operates in current regulation mode or has been switched off due to thermal shutdown. The sta-
tus bit is low.
Fault condition 2) "open load" or "output short circuit to GND" is the same as of outputs 1 and 2.
At the falling edge of NCS the output status data are transferred to the shift register. When NSC is low, data bits
contained in the shift register are transferred to SDO output et every rising CLK edge.
Figure 3. The Pulse Diagram to Read the Outputs Status Register
Figure 4. The Structure of the Outputs Status Register
8/11
Output 1 ... 8
off
off
on
on
NCS
CLK
SDI
SDO
Diag2 Diag4 Diag6 Diag8 Diag1 Diag3 Diag5 Diag7
MSB
Output-voltage
> DG-threshold
< DG-threshold
< DG-threshold
> DG-threshold
MSB
MSB
6
6
5
5
4
4
LSB
3
Status-bit
3
high
high
low
low
2
2
Diagnostic-bit output 7
Diagnostic-bit output 5
Diagnostic-bit output 3
Diagnostic-bit output 1
Diagnostic-bit output 8
Diagnostic-bit output 6
Diagnostic-bit output 4
Diagnostic-bit output 2
1
1
LSB
LSB
correct operation
correct operation
fault condition 2)
fault condition 1)
Output-mode