mouser.com/vishay / 23
X1 X3
TR1
SQC60002E
TR2
SQC60002E
R1
50uR
R2
10R/10W
GATE_PRELOAD
NTC2+
NTC2-
NTC2
NTC 10k
GATE_MAIN2
SOURCE_MAIN2
V-IN+ V-OUT+
SENSE-
SENSE+
SOURCE_PRELOAD
GATE_MAIN1
SOURCE_MAIN1
NTC1+
NTC1-
NTC1
NTC 10k
TR3
SQSA80ENW
X1 X3
TR1
SQC60002E
TR2
SQC60002E
R1
50uR
R2
10R/10W
GATE_PRELOAD
NTC2+
NTC2-
NTC2
NTC 10k
GATE_MAIN2
SOURCE_MAIN2
V-IN+ V-OUT+
SENSE-
SENSE+
SOURCE_PRELOAD
GATE_MAIN1
SOURCE_MAIN1
NTC1+
NTC1-
NTC1
NTC 10k
TR3
SQSA80ENW
Learn More
Learn More
NTCS SMD NTC
Thermistors
SQSA80ENW
TrenchFET
®
power
MOSFETs
Figure 3: Simplified schematic of the
ICSS power stage (Source: Vishay)
(10ms), and the output voltage X3 (in Figure 3) is monitored. If the output voltage has not reached
~90 percent of the input voltage after that time, the process is terminated, with the assumption a
short circuit has occurred in the load or wiring. If the output has reached the appropriate
level, then TR3 is switched off, and TR1/TR2 is switched on to energize the load.
With regard to protection features, a Vishay NTCC300E4 wire bondable thermistor
(NTC1 in Figure 3) is used to monitor the MOSFET die temperatures. Using
wirebondable NTCs ensures very close proximity to the MOSFET junction
temperature, the crucial measurement point. In the case of an over-temperature
condition, the load is disconnected from the battery. The control circuitry is monitored
for temperature overloads and a Vishay NTCS surface-mount thermistor (NTC2 in
Figure 3). The load current is continuously monitored for battery health and overcurrent
conditions using a customized version of a Vishay WSB8518-34 current shunt (R1 in Figure
3), which has a very low TCR (down to +-10 ppm/°C) and inductance which maximizes the
accuracy of the output signal.
A new high-current measurement and safety
switch has been presented that can be used in
any 12V or 48V battery management system as
well as to control any high current load in the
vehicle. ▼
Figure 2: ICSS
power stage
(Source: Vishay)
