tle42994 Infineon Technologies Corporation, tle42994 Datasheet - Page 12

• Manufacturer Part Number: tle42994
• Description: Low Dropout Fixed Voltage Regulator
• Manufacturer: Infineon Technologies Corporation

5
5.1
The output voltage
transistor accordingly. The control loop stability depends on the output capacitor
temperature and 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 the table
Range” on Page 10
Capacitor Series Resistor ESR(CQ) versus Output Current IQ” on Page
to buffer load steps it should be sized according to the application’s needs.
An input capacitor
component’s terminals.
A protection circuitry prevents the IC as well as the application from destruction in case of catastrophic events.
These safeguards contain an output current limitation, a reverse polarity protection as well as a thermal shutdown
in case of overtemperature.
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 overtemperature 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 behaviour of the output voltage until the fault is removed. However, junction
temperatures above 150 °C are outside the maximum ratings and therefore significantly reduce the IC’s lifetime.
The TLE42994 allows a negative supply voltage. In this fault condition, 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 conditions.
Figure 6
Data Sheet
Supply
C
I
Block Description and Electrical Characteristics
Voltage Regulator
Voltage Regulator
I
I
C
V
I
BlockDiagram_VoltageRegulator.vsd
Q
is strongly recommended to compensate line influences. Connect the capacitors close to the
I
have to be maintained. For details see also the typical performance graph
is controlled by comparing a portion of it to an internal reference and driving a PNP pass
Saturation Control
Current Limitation
Temperature
S hutdown
12
Reference
GND
Bandgap
Block Description and Electrical Characteristics
V
I
= 22 V.
Q
15. As the output capacitor also has
I
Q
E SR
C
C
Q
, the load current, the chip
}
Regulated
Output Voltage
C
Q
Rev. 1.0, 2008-12-04
TLE42994
“Functional
LOAD
“Output