LM9073T National Semiconductor, LM9073T Datasheet - Page 9

• Manufacturer Part Number: LM9073T
• Description: Dual High Current Low-Dropout System Regulator
• Manufacturer: National Semiconductor

ON/OFF Input Keep-Alive Input Main Output Voltage External Supply Output
Falling Edge
Rising Edge
Control Logic Truth Table
Application Information
Pin Description and Functionality
The LM9073 is a precision dual voltage regulator optimized
for use in powertrain module applications but will also find
Input Voltage (pin 4)
The LM9073 has been designed to connect directly to the ig-
nition or battery supply in automotive applications. For this
type of supply the regulator been designed to withstand up to
+60V and −45V supply transients such as load dump. An ov-
ervoltage shut down protection circuit turns OFF both of the
regulator outputs should supply transients exceed typically
+33V to fully protect all load circuitry. This higher threshold
allows normal operation with 24V
the event when two batteries are used to start a vehicle. Pro-
tection of the system is also provided for inadvertent reverse
polarity battery connections.
H
H
L
L
Rising Edge
X
X
H
L
L
DC
applied to the input as in
<
<
<
4.5V or
5.35V
4V or
0V
5V
5V
5V
5V
Figure 1. Circuit Block Diagram
9
Voltage
0V
5V
5V
5V
5V
use in a wide variety of automotive and industrial applica-
tions were precision supply regulation is required in harsh
operating environments. The following will describe the func-
tionality of each of the package pins.
The current drain on the supply line is directly proportional to
the load currents on the two voltage regulators. With no load
current on either output the regulator requires 15mA maxi-
mum quiescent current for biasing internal circuitry. During
dropout conditions (V
can rise to 50% of the total load current. With less than 3V
applied to the input, internal biasing circuitry shuts OFF.
When switched OFF the regulator can remain connected to
the battery supply with a current drain of less than 100µA.
Main Output (pin 10)
The Main Output regulator provides a well controlled (2% tol-
erance maximum) 5V supply line with a total load current
X
Rising after delay
Rising after delay
Reset Output
IN
0V
5V
0V
5V
<
5.5V) the additional input current
OFF, Input curent
Keep-Alive, Continued normal
Threshold depends on Reset
Outputs turn ON, Power ON
Main output pulled out of
DS101296-16
Outputs turned ON by
Operating Condition
Reset flag generated.
Adjust seting (pin 11)
Normal ON condition
Keep-Alive Input
delayed reset
regulation,
operation
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<
100µA