IC-MFL Datasheet, PDF (10/13 Pages) IC-Haus GmbH – 8-/12-FOLD FAIL-SAFE LOGIC N-FET DRIVER

iC-MFL / iC-MFLT
8-/12-FOLD FAIL-SAFE LOGIC N-FET DRIVER
DETECTING SINGLE ERRORS
Rev C1, Page 10/13
If single errors are detected, safety-relevant applica-
I(OUTx)
[µA]
tions require externally connected switching transistors
to be specifically shut down. Single errors can occur
when a pin is open (due to a disconnected bonding
150
wire or a bad solder connection, for example) or when
two pins are short-circuited.
−30 kΩ
When two output of different logic levels are short-
circuited, the driving capability of the lowside driver will
predominate, keeping the connected N-channel FETs
in a safe shutdown state.
V(OUTx)
1
2
3
4
5 ^[V]
With open pins VCC, GND or GNDR iC-MFL switches
the output stages to a safe, predefined low state via
pull-down resistors or pull-down current sources at the
inputs, subsequently shutting down any externally con-
nected N-channel FETs.
I(OUTx)
[µA]
150
Figure 6: Output characteristic at OUTx with open
GND pin
Loss of GND potential
If ground potential is not longer applied to GND, the
output stages are shut down and the outputs tied to
GNDR via internal pull-down resistors with a typical
value of 30 kΩ.
I(OUTx)
[mA]
−30kΩ
3.6
V(OUTx)
1
2
3
4
5 ^[V]
Figure 5: Output characteristic at OUTx with discon-
nected VCC supply
V(OUTx)
1
2
3
4
5
[V]
Loss of VCC potential
If the supply voltage is disconnected from VCC pin, the
outputs are tied to GNDR via internal pull-down resis-
tors of typically 30 kΩ which form a passive path from
the gate of an external switching transistor to ground.
A further increase of output current may occur due to
self-supply effects via the output of the iC, as indicated
by the arrows in Figure 5.
Figure 7: Output characteristic at OUTx with open
GNDR pin
Loss of GNDR potential
If ground potential is no longer applied to the GNDR-
pin, the output stage highside drivers are shut down
and the outputs actively tied to GND via the lowside
drivers.