LM9071S National Semiconductor, LM9071S Datasheet - Page 5

• Manufacturer Part Number: LM9071S
• Description: Low-Dropout System Voltage Regulator with Delayed Reset
• Manufacturer: National Semiconductor

Reset Operation and Protection Features
Block Diagram
Application Hints
The LM9071 voltage regulator has been optimized for use in
microprocessor based automotive systems. Several unique
design features have been incorporated to address many
FMEA (Failure Mode Effects Analysis) concerns for fail-safe
system performance.
FAULT TOLERANT FEATURES
While not specifically guaranteed due to production testing
limitations, the LM9071 has been tested and shown to con-
tinue to provide a regulated output and, not generate an
erroneous system reset signal while subjected to high levels
of RF electric field energy (up to 300 V/m signal strength
over a 2 MHz to 400 MHz frequency range). This is very
important in vehicle safety related applications where the
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system must continue to operate normally. To maintain this
immunity to RFI the output bypass capacitor is important
(47 µF is recommended).
An output bypass capacitor of at least 10 µF is required for
stability (47 µF is recommended). The ESR of this capacitor
should be less than 3Ω. An input capacitor of 1 µF or larger
is recommended to improve line transient and noise perfor-
mance.
Conventional load dump protection is built in to withstand up
to +60V and −50V transients. Protection against reverse
polarity battery connections is also built in. With a reversed
battery connection the output of the LM9071 will not go more
negative than one diode drop below ground. This will prevent
damage to any of the 5V load circuits.
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