19-4168; Rev 0; 2/09
Signal-Line Overvoltage Protector
for Low-Voltage Devices
The MAX9940 signal-line overvoltage protector for low-
voltage digital communication ports provides protection
against high-voltage faults and ESD strikes. The
MAX9940 is especially useful for sensitive communica-
tion protocols such as Maxim 1-Wire® that cannot
afford standard means of fault protection, such as large
series resistors or large line capacitances.
The MAX9940 operates from a single supply voltage of
+2.2V to +5.5V and consumes only 13µA of quiescent
supply current. The EXT port is protected up to 28V.
The device features a reaction time of 60ns for fast
action during fault conditions and operates over the
-40°C to +125°C automotive temperature range.
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
♦ 28V Protection on EXT
♦ Extended ESD Protection
±4kV IEC 61000-4 Contact on EXT
♦ +2.2V to +5.5V Supply Voltage Range
♦ 13µA Quiescent Supply Current
♦ 60ns Fault Reaction Time
♦ Small, 5-Pin SC70
♦ -40°C to +125°C Temperature Range
MAX9940AXK+ -40°C to +125°C 5 SC70
+Denotes a lead(Pb)-free/RoHS-compliant package.
Block Diagram/Typical Application Circuit
VDD = 3.3V
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.