BTS5590G Datasheet, PDF (27/46 Pages) Infineon Technologies AG – SPI Power Controller

SPOC - BTS5590G
Diagnosis
8.1
Diagnosis Word at SPI
The standard diagnosis at the SPI interface provides information about each channel. The error flags, an OR
combination of the over temperature flags and the over load monitoring signals are provided in the SPI standard
diagnosis bits ERRn.
The over load monitoring signals are latched in the error flags and cleared each time the standard diagnosis is
transmitted via SPI. In detail, they are cleared between the second and third raising edge of the SCLK signal.
The over temperature flags, which cause an overheated channel to stay switched off, are latched directly at the
gate control block. The latches are cleared by SPI command HWCR.CTL.
Please note:
The over temperature information is latched twice. When transmitting a clear thermal latch command (HWCR.CLT),
the error flag is cleared during command transmission of the next SPI frame and ready for latching after the third
raising edge of the SCLK signal. As a result, the first standard diagnosis information after a CTL command will
indicate a failure mode at the previously affected channels although the thermal latches have been cleared
already. In case of continuous over load, the error flags are set again immediately because of the over load
monitoring signal.
In case of high duty cyle (off state of output < t_{off-state_min}) the V_DS might not be equal to V_DD during the off state of
the power Mosfet. The over load monitoring signals might be set and latched in the error flags. See Application
Note “Software Strategy for Diagnosis during PWM-Operation“ for more details.
8.2
Load Current Sense Diagnosis
There is a current sense signal available at pin IS which provides a current proportional to the load current of one
selected channel. The selection is done by a multiplexer which is configured via SPI.
The current sense signal (ratio k_ILIS = I_L / I_S) is provided as long as no failure mode occurs. The ratio k_ILIS can be
adjusted to the load type (LED or bulb) via SPI register WDLR for channels 0 to 2. Usually a resistor R_IS is
connected from the current sense pin to GND. It is recommended to use resistors 2.5 kΩ <R_IS < 7 kΩ. A typical
value is 3.3 kΩ.
6000
5000
4000
dummy
bduulmb:mTy_j = 150°C
bduulmb:mTy_j = -40°C
ldeudm: Tm_{j y=} 150°C
led: T_j = -40°C
3000
2000
1000
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
I_L0,1 /A
Figure 14 Current Sense Ratio k_ILIS Channel 0,1 ¹⁾
1) The curves show the behavior based on characterization data. The marked points are guaranteed in this Data Sheet in
Section 8.4 (Position 8.4.1).
Data Sheet
27
Rev. 1.3, 2007-10-30