1 Features
• 3.2-V to 65-V input range (3.9-V start-up)
• –65-V input reverse voltage rating
• Integrated charge pump to drive
– External back-to-back N-Channel MOSFETs
– External high side switch MOSFET
– External reverse polarity protection MOSFET
• Gate drive variants
– LM74502: 60-μA peak gate drive source
capacity
– LM74502H: 11-mA peak gate drive source
capacity
• 2.3-A peak gate sink current capacity
• Enable pin feature
• 45-μA typical operating quiescent current (EN/
UVLO = High)
• 1-μA shutdown current (EN/UVLO = Low)
• Adjustable overvoltage and undervoltage
protection
• –40°C to +125°C ambient operating temperature
range
• Available in 8-pin SOT-23 package 2.90 mm ×
1.60 mm
2 Applications
• Factory automation and control – PLC digital
output modules
• Industrial motor drives
• Industrial transport
• Power supply reverse polarity protection
3 Description
The LM74502, LM74502H is a controller which
operates in conjunction with an external back-to-back
connected N-channel MOSFETs to realize a low
loss reverse polarity protection and load disconnect
solution. The device can also be configured to drive
high side MOSFET as a load switch with overvoltage
protection . The wide supply input range of 3.2 V
to 65 V allows control of many popular DC bus
voltages such as 12-V, 24-V and 48-V input systems.
The device can withstand and protect the loads
from negative supply voltages down to –65 V. The
LM74502, LM74502H does not have reverse current
blocking and is suitable for input reverse polarity
protection only.
The LM74502 controller provides a charge pump
gate drive for an external N-channel MOSFET. with
the enable pin low, the controller is off and draws
approximately 1 μA of current, thus offering low
system current when put into sleep mode. LM74502
and LM74502H offers programmable overvoltage and
undervoltage protection which cuts off the load from
the input source in case of these fault events. The
devices are available in a 2.9 mm × 1.6 mm 8-pin
DDF package and are specified over a –40°C to
+125°C temperature range.