TLE4291E Infineon Technologies, TLE4291E Datasheet - Page 9

• Manufacturer Part Number: TLE4291E
• Manufacturer: Infineon Technologies

Specifications of TLE4291E

• Packages: PG-SSOP-14
• Regulator Type: single output
• Output Voltage: 5V
• Accuracy: 2.0 %
• Max. Output Current: 450mA
• Dropout Voltage: 250mV

5
5.1
The output voltage
transistor accordingly. Saturation control as a function of the load current prevents any oversaturation of the pass
element. The control loop stability depends on the output capacitor
the poles/zeros introduced by the integrated circuit. To ensure stable operation, the output capacitor’s capacitance
and its equivalent series resistor ESR requirements given in
maintained. For details see also the typical performance graph “Output Capacitor Series Resistor
Output Current
An input capacitor
Connect the capacitors close to the IC terminals.
Protection circuitry prevent the IC as well as the application from destruction in case of catastrophic events. These
safeguards contain output current limitation, reverse polarity protection as well as thermal shutdown in case of
overtemperature.
In order to avoid excessive power dissipation that could never be handled by the pass element and the package,
the maximum output current is decreased at input voltages above
The thermal shutdown circuit prevents the IC from immediate destruction under fault conditions (e.g. output
continuously short-circuited) by switching off the power stage. After the chip has cooled down, the regulator
restarts. This leads to an oscillatory behavior of the output voltage until the fault is removed. However, junction
temperatures above 150 °C are outside the maximum ratings and therefore reduce the IC lifetime.
The TLE4291 allows a negative supply voltage. However, several small currents are flowing into the IC increasing
its junction temperature. This has to be considered for the thermal design, respecting that the thermal protection
circuit is not operating during reverse polarity condition.
Figure 3
Figure 4
Data Sheet
I(ext),min
Supply
Q,nom
+
V
I
Voltage Regulator
Description Voltage Regulator
Block Diagram Voltage Regulator Circuit
Output Voltage vs. Input Voltage
C
I
I
I
Q
I
”. Also, the output capacitor shall be sized to buffer load transients.
V
C
Q
I
BlockDiagram _VoltageRegulator .vsd
I
is not needed for the control loop stability, but recommended to buffer line influences.
is controlled by comparing a portion of it to an internal reference and driving a PNP pass
I
Diagram_Output-InputVoltage.svg
Q
Saturation Control
Current Limitation
Temperature
Shutdown
dr
9
Reference
GND
Bandgap
d
d
Chapter 4.2
Q
≈
V
C
C
load
I
Q
Q
= 28 V.
, the load current, the chip temperature and
Q
table “Functional Range” have to be
d
d
I
Q
C
Q
Q
≈
Q,max
Regulated
Output Voltage
C
Rev. 1.0, 2011-06-07
Q
-
Voltage Regulator
load
+
V
Q
TLE4291
ESR
LOAD
CQ
vs.