2 x 8 Channel 0,6A Evaluation Board with ISO1H811G
www.Infineon.com Page 7 from 14 EVAL 2x8-ISO1H811G
V1.1
Output Stage
Each channel contains a high-side vertical power FET that is protected by embedded protection
functions. The continuous current for each channel is 625mA (all channels ON).
Each output is independently controlled by an output latch and a common reset line via the pin /DIS
that disables all eight outputs and reset the latches. A logic high input data bit turns the respective
output channel ON. A logic low data bit turns that output channel OFF.
Power Transistor Over-Voltage Protection
Each of the eight output stages has it own zener clamp that causes a voltage limitation at the power
transistor when inductive loads are switched off. V
ON
is then clamped to 47V (min.).
Inductive and over-voltage output clamp (each channel)
Energy is stored in the load inductance.
E
L
= 1 / 2 x L x I
L
²
Inductive load switch-off energy dissipation (each channel)
While demagnetizing the load inductance, the energy dissipation in the DMOS with an approximate
solution for R
L
> 0is:
Power Transistor Over-current Protection
The outputs are provided with a current limitation that enters a repetitive switched mode after an initial
peak current has been exceeded. The initial peak short circuit current limit I
L(SCp)
is set to a minimum of
0.7A at T
j
= 125°C. During the repetitive mode, short circuit current limit I
L(SCr)
is set to 1.1A (typ.). If
this operation leads to an over-temperature condition, a second protection level (T
j
> 135°C) will
change the output into a low Pulse-Width Modulated duty cycle (selective thermal shutdown with
restart) to prevent critical chip temperatures.
Common Diagnostic Output
The over-temperature detection information of the channels is OR-wired in the common diagnostic
output block. The information is send via the integrated coreless transformer to the input interface. The
output stage at pin DIAG has an open drain functionality combined with a current source. The red LED
D20 and D21 show the current state of the DIAG output.
LED ON: one of the Channels has over-temperature or the VBB Supply is below the operating
range
