LT1158ISW#TR Linear Technology, LT1158ISW#TR Datasheet - Page 13

• Manufacturer Part Number: LT1158ISW#TR
• Description: IC DRIVER PWR MOSFET N-CH 16SOIC
• Manufacturer: Linear Technology

Specifications of LT1158ISW#TR

• Configuration: Half Bridge
• Input Type: PWM
• Current - Peak: 500mA
• Number Of Configurations: 1
• Number Of Outputs: 2
• High Side Voltage - Max (bootstrap): 56V
• Voltage - Supply: 5 V ~ 30 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Delay Time: -

APPLICATIONS INFORMATION
Low Current Shutdown
The LT1158 may be shutdown to a current level of 2mA by
pulling the enable pin 4 low. In this state both the top and
bottom MOSFETs are actively held off against any transients
which might occur on the output during shutdown. This
is important in applications such as 3-phase DC motor
control when one of the phases is disabled while the other
two are switching.
If zero standby current is required and the load returns to
ground, then a switch can be inserted into the supply path
of the LT1158 as shown in Figure 5. Resistor R
that the top MOSFET gate discharges, while the voltage
across the bottom MOSFET goes to zero. The voltage drop
across the P-channel supply switch must be less than
300mV, and R
This technique is not recommended for applications which
require the LT1158 V
Short-Circuit Protection in Bridge Applications
The LT1158 protects the top power MOSFET from output
shorts to ground, or in a full bridge application, shorts
across the load. Both standard 3-lead MOSFETs and cur-
rent-sensing 5-lead MOSFETs can be protected. The bottom
MOSFET is not protected from shorts to supply.
Current is sensed by measuring the voltage across a cur-
rent shunt in the source lead of a standard 3-lead MOSFET
ON/OFF
CMOS
100k
2N2222
100k
TO OTHER
CONTROL
CIRCUITS
Figure 5. Adding Zero Current Shutdown
VP0300
GS
+
must be 330k or greater for DC operation.
V
V
GND
+
+
DS
sensing function.
LT1158
B GATE DR
T GATE DR
T SOURCE
B GATE FB
T GATE FB
R
GS
V
+
GS
ensures
+
LOAD
1158 F05
(Figure 6). For the current-sensing MOSFET shown in
Figure 7, the sense resistor is inserted between the sense
and Kelvin leads.
The SENSE
at minimum spacing to prevent stray pickup, and a Kelvin
connection must be used at the current shunt for the 3-lead
MOSFET. Using a twisted pair is the safest approach and
is recommended for sense runs of several inches.
When the voltage across R
LT1158 FAULT pin begins to conduct, signaling a fault
condition. The current in a short circuit ramps very rapidly,
limited only by the series inductance and ultimately the
MOSFET and shunt resistance. Due to the response time
Figure 7. Short-Circuit Protection with Current-Sensing MOSFET
Figure 6. Short-Circuit Protection with Standard MOSFET
10k
10k
5V
5V
+
and SENSE
FAULT
FAULT
LT1158
LT1158
–
T GATE DR
T GATE DR
T SOURCE
T GATE FB
T GATE FB
T SOURCE
PC traces must be routed together
SENSE
SENSE
SENSE
SENSE
+
–
+
–
SENSE
R
SENSE
SENSE
exceeds 110mV, the
V
V
+
+
R
SENSE
LT1158
+
OUTPUT
+
KELVIN
1158 F07
1158 F06
13
1158fb