FAN73892 Fairchild Semiconductor, FAN73892 Datasheet - Page 14

• Manufacturer Part Number: FAN73892
• Description: The FAN73892M is a monolithic three-phase half-bridge gate-drive IC designed for high-voltage, high-speed, driving MOSFETs and IGBTs operating up to +600V
• Manufacturer: Fairchild Semiconductor

© 2011 Fairchild Semiconductor Corporation
FAN73892 • Rev.1.0.1
2.4 Fault-Out (
FAN73892 provides an integrated fault output (
an adjustable fault-clear timer (t
situations that cause the gate driver to report a fault via
the
low-side gate driver supply voltage (V
second is when the current-sense pin (CS) recognizes a
fault. If a fault condition occurs, the
pulled to COM, the fault-clear timer is activated, and all
outputs (HO1, 2, 3 and LO1, 2, 3) of the gate driver are
turned off. The fault output stays LOW until the fault
condition has been removed and the fault-clear timer
expires. Once the fault-clear timer expires, the voltage
on the
The fault-clear time (t
current source (I
RCIN pin, as shown as:
The R
discharge curve with respect to the external capacitor
C
capacitor C
The output of current-sense comparator (CS_COMP)
passes a noise filter, which inhibits an over-current
shutdown caused by parasitic voltage spikes of V
This corresponds to a voltage level at the comparator of
V
V
comparator (CS_COMP), as shown in Figure 41.
Figure 42 shows the waveform definitions of RCIN,
and the low-side driver; which uses a soft turn-off
method when an under-voltage condition of the low-side
gate driver supply voltage (V
(CS) recognizes a fault. If a fault condition occurs, the
(HO1,2,3 and LO1,2,3) of the gate driver are turned off.
Low-side outputs decline linearly by the internal sink
current source (I
in Figure 42.
FO
t
CSTH+
CSHYS
RCIN
FLTCLR
FO
Pin is internally pulled to COM and all outputs
. The time constant is defined by the external
=60mV
FO
ON,RCIN
pin. The first is an under-voltage condition of
- V
=
Figure 41. Over-Current Protection
pin returns to pull-up voltage.
RCIN
C
CSHYS
RCIN
FO
and the R
of the MOSFET is a characteristic
is
RCIN
SOFT
= 500mV - 60mV =440mV, where
I
RCIN
×
) and Over-Current Protection
V
=5μA) and an external C
the
=40mA) for soft turn-off, as shown
FLTCLR
RCIN
ON,RCIN
,
TH
hysteresis
) is determined by an internal
DD
[
s
) or the current-sense pin
]
of the MOSFET.
FLTCLR
FO
). There are two
of
pin is internally
DD
the
) and the
RCIN
FO
CS
current
at the
) and
.
FO
(1)
,
3. Noise Filter
3.1 Input Noise Filter
Figure 43 shows the input noise filter method, which has
symmetry duration between the input signal (t
the output signal (t
spikes and short pulses. This input filter is applied to the
waveforms (Example A in Figure 43) shows an input
signal duration (t
(t
the input signal time (t
(t
shows an input signal time (t
input filter time (t
duration between input signal time (t
output signal time (t
HINx
Figure 42. R
14
FLTIN
OUTPUT
): it is approximately the same duration between
,
). The lower pair of waveforms (Example B)
Figure 43. Input Noise Filter Definition
LINx
CIN
, and EN inputs. The upper pair of
and Fault-Clear Waveform Definition
INPUT
FLTIN
OUTPUT
OUTPUT
) much longer than input filter time
); it is approximately the same
INPUT
).
) and helps to reject noise
) and the output signal time
INPUT
) slightly longer than
INPUT
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) and the
INPUT
) and