TECHNICAL DATA
5-V Low-Drop Voltage Regulator
ILE4267
ILE 4267 is a 5-V low-drop voltage regulator in a
TO220-7 package. It supplies an output current of > 400
mA. The IC is shortcircuit-proof and incorporates
temperature protection that disables the IC at
overtemperature.
Features
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Output voltage tolerance
≤
± 2 %
400 mA output current capability
Low-drop voltage
Very low standby current consumption
Input voltage up to 40 V
Overvoltage protection up to 60 V (≤ 400 ms)
Reset function down to 1 V output voltage
ESD protection up to 2000 V
Adjustable reset time
On/off logic
Overtemperature protection
Reverse polarity protection
Short-circuit proof
Wide temperature range
Suitable for use in automotive electronics
Application
The IC regulates an input voltage
V,
in the range 5.5 V < Vi
<
40 V to V
Qrated
= 5.0 V. A
reset signal is generated for an output voltage V
Q
of < 4.5 V. The reset delay can be set
with an external capacitor. The device has two logic inputs. It is turned-ON by a voltage of
> 4 V on E2 by the ignition for example. It remains active as a function of the voltage on
E6, even if the voltage on E2 goes Low. This makes it possible to implement a self-holding
circuit without external components. When the device is turned-OFF, the output voltage
drops to 0 V and current consumption tends towards 0
µ
A
.
Design Notes for External Components
The input capacitor Ci is necessary for compensation line influences. The resonant circuit
consisting of lead inductance and input capacitance can be damped by a resistor of
approx. 1
Ω
in series with Ci. The output capacitor is necessary for the stability of the
regulating circuit. Stability is guaranteed at values of
≥
22
µF
and an ESR of
≤
3
Ω
within
the operating temperature range.
1
ILE4267
Circuit Description
The control amplifier compares a reference voltage, which is kept highly accurate by
resistance adjustment, to a voltage that is proportional to the output voltage and drives the
base of the series transistor via a buffer. Saturation control as a function of the load
current prevents any over-saturating of the power element.
A comparator in the reset-generator block compares a reference that is independent of the
input voltage to the scaled-down output voltage. If this reaches a value of 4.5 V, the reset-
delay capacitor is discharged and then the reset output is set Low. As the output voltage
increases again, the reset-delay capacitor is charged with constant current from V
Q
=
4.5
V onwards. When the capacitor voltage reaches the upper switching threshold, reset goes
High again. The reset delay can be set within wide range by selection of the external
capacitor. With the integrated tum-ON/tum-OFF logic it is simple to implement delayed
tum-OFF without external components.
Truth Table for Turn-ON/Turn-OFF Logic
E2, Inhibit
L
H
H
X
L
L
Hold
X
X
L
L
L
H
V
Q
OFF
ON
ON
ON
ON
OFF
Remarks
Initial state. Inhibit internally pulled up
Regulator switched on via Inhibit, by ignition for example
Hold clamped active to ground by controller while Inhibit is still high
Previous state remains, even ignition is shut off: self-holding state
Ignition shut off while regulator is in self-holding state
Regulator shut down by releasing of Hold while Inhibit remains Low, final
state. No active clamping required by external self-holding circuit (µC)
to keep regulator shut off.
Inhibit: E2 Enable function, active High
Hold: E6 Hold and release function, active Low
Pin Definitions and Functions
Pin
1
2
3
4
5
6
7
Symbol
I
E2
R
GND
D
E6
Q
Function
Input;
block to ground directly at the IC by a ceramic capacitor
Inhibit;
device is turned-ON by High signal on this pin; internal pulldown resistor of 100
kΩ
Reset Output;
open-collector output internally connected to the output via a resistor of
30 kΩ
Ground;
connected to rear of chip
Reset Delay;
connect with capacitor to GND for setting delay
Hold;
see truth table above for function; this input is connected to output voltage across
puliup resistor of 50 kΩ
5-V Output;
block to GND with 22-µF capacitor, ESR < 3
Ω
2
Microchip MCU
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