TLE4263 Datasheet, PDF (4/16 Pages) Siemens Semiconductor Group – 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. If the voltage on the capacitor reaches
the lower threshold V_ST, a reset signal is issued on the reset output and not cancelled
again until the upper threshold V_dT is exceeded. If the reset threshold input is connected
to GND, reset is triggered at an output voltage of 4.5 V. A connected microcontroller is
controlled by the watchdog logic. If pulses are missing, the reset output is set to low. The
pulse sequence time can be set within 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:
q Overload
q Overtemperature
q Reverse polarity
18
Input
Temperature
Sensor
Bandgap
Reference
Control
Amplifier
Adjustment
Saturation
Control and
Protection
Circuit
Buffer
11
Watchdog
12
Output
Reset
Generator
9 _Reset
Delay
3 _Reset
Output
10 _Reset
Threshold
20
Inhibit
4-7, 14-17
GND
AEB01100
Block Diagram
Semiconductor Group
4
1998-11-01