TLE4263_07 Datasheet, PDF (4/19 Pages) Infineon Technologies AG – 5-V Low-Drop Voltage Regulator

TLE 4263
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-saturation of the power element. If the externally scaled down
output voltage at the reset threshold input drops below 1.35 V, the external reset delay
capacitor is discharged by the reset generator. When the voltage of the capacitor
reaches the lower threshold V_DRL, a reset signal occurs at the reset output and is held
until the upper threshold V_DU is exceeded. If the reset threshold input is connected to
GND, reset is triggered at an output voltage of typ. 4.65 V. A connected microcontroller
will be monitored through the watchdog logic. In case of missing pulses at pin W, the
reset output is set to low. The pulse sequence time can be set in a wide range with the
reset delay capacitor. The IC can be switched at the TTL-compatible, low-active inhibit
input. The IC also incorporates a number of internal circuits for protection against:
• Overload
• Overtemperature
• Reverse polarity
Input ^Ι
Temperature
Sensor
Bandgap
Reference
Control
Amplifier
Adjustment
Saturation
Control and
Protection
Circuit
Buffer
W
Watchdog
Q _Output
Reset
Generator
D Reset
Delay
RO Reset
Output
RADJ _Reset
Threshold
INH
Inhibit
GND
GND
AEB03068
Figure 2 Block Diagram
Data Sheet
4
Rev. 2.8, 2007-03-20