Datasheet
Application Note 12 2015-02-11
Revision 1.0
ISO2H823V2.5 Evaluation Board
Board Manual
Functional Description
Figure 11 SPI Mode 3, MS0 = 1, MS1 = 1
2.3 Process Side
2.3.1 Output Stage
Each channel contains a high-side power FET that is protected by embedded protection functions. The continuous
current for each channel is 600 mA nominal, which depends on the cooling conditions and the total power
dissipation.
2.3.1.1 Output Stage Control
Each output is independently controlled by an output latch and a common reset line via the pin ODIS that disables
all eight outputs and resets the latches.
2.3.1.2 Protection Functionality
Power Transistor Overvoltage Protection
Each of the eight output stages has it’s own zener clamp that causes a voltage limitation at the power transistor
when solenoid loads are switched off. V
ONCL
is then clamped to 52 V (typ.).
Power Transistor Overload Protection
The outputs are provided with a linear current limitation, which regulates the output current to the current limit value
in case of overload. The electrical operation point does not lead to a shutdown.
The excess power dissipation in the power transistor during current limitation will lead to a rapid increase of the
junction temperature. When the junction temperature exceeds 150°C (typ.) the output will switch off and will switch
on again when the junction temperature has cooled down by a temperature hysteresis of 15K (typ.). Therefore
during overload a thermal on-off toggling may occur.
SCLK
SDI
CS
SDO
uc_spi_mode 3.vsd
MS B LSB
UV MV CF
C3 C2 C1 C00 C400
Checksum
Checksum / Diagnosis
A6 A5 A4 A3 A2 A1 A0 0 0 0 0 0 0 0 0
Register -Address (R/W)
D7 D6 D5 D4 D3 D2 D1 D0
R
Read=0
Value „Zero“ for CRC
Value (Read )
C3 C2 C1 C0C4
MS B LS BMS B LS B
Collective Diagnosis
CD7 CD6 CD5 CD4 CD3 CD2 CD1 CD0
B it23 B it16 Bit15 B it8 B it7 B it0
MS B LS B
UV MV CF
C3 C2 C1 C00 C400
Checksum
Checksum / Diagnosis
A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
Register -Address (R/W)
d.c.
W
Write=1
Value (Write)
C3 C2 C1 C0C4
MS B LS BMS B LS B
Collective Diagnosis
CD7 CD6 CD5 CD4 CD3 CD2 CD1 CD0
B it23 B it16 Bit15 B it8 B it7 B it0
SDI
SDO
READ
WRITE
d.c. d.c. d.c. d.c. d.c. d.c. d.c.