TLE4271G Infineon Technologies, TLE4271G Datasheet - Page 3

• Manufacturer Part Number: TLE4271G
• Description: LDO Regulator Pos 5V 0.55A 8-Pin(7+Tab) TO-263
• Manufacturer: Infineon Technologies
• Type: Linearr

Specifications of TLE4271G

• Package: 8TO-263
• Function: LDO
• Number Of Outputs: 1
• Input Voltage Range: 40 to 6 V
• Output Voltage: 5 V
• Maximum Output Current: 0.55 A
• Output Type: Fixed
• Accuracy: ±2 %
• Typical Dropout Voltage @ Current: 0.35@550mA V
• Operating Temperature: -40 to 150 °C
• Polarity: Positive

Application Description
The IC regulates an input voltage in the range of 5.5 V <
to 26 V it produces a regulated output current of more than 550 mA. Above 26 V the
save-operating-area protection allows operation up to 36 V with a regulated output
current of more than 300 mA. Overvoltage protection limits operation at 42 V. The
overvoltage protection hysteresis restores operation if the input voltage has dropped
below 36 V. The IC can be switched off via the inhibit input, which causes the quiescent
current to drop below 50 A. A reset signal is generated for an output voltage of
V
going edge at the watchdog input within a fixed time, the reset output is set to low. The
delay for power-on reset and the maximum permitted watchdog-pulse period can be set
externally with a capacitor.
Design Notes for External Components
An input capacitor
circuit consisting of lead inductance and input capacitance can be damped by a resistor
of approx. 1
the regulating circuit. Stability is guaranteed at values of
< 3 .
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 a series transistor via a buffer. Saturation control as a function of the load
current prevents any over-saturation of the power element.
If the output voltage decreases below 4.5 V, an external capacitor
discharged by the reset generator. If the voltage on this capacitor
a reset signal is generated on pin 2 (RO), i.e. reset output is set low. If the output voltage
rises above 4.5 V,
V
reset time can be set within a wide range depending on the capacity of
the pull-up resistor at reset output is typically 30 k .
After
enabled and discharges
observed at watchdog input,
low and the watchdog circuit will be disabled.
power-on reset until
If a watchdog pulse will be observed before
circuit will be enabled and
has reached
Semiconductor Group
Q
D
< 4.5 V. The watchdog circuit monitors a connected controller. If there is no positive-
reaches
V
D
has reached the voltage
V
V
DU
DU
in series with
and the reset output will be set high again. The value of the power-on-
, the periodical behavior starts again.
C
C
D
V
I
will be charged with constant current. After the power-on-reset time
D
is necessary for compensation of line influences. The resonant
reaches
C
C
D
D
with a constant current. If there is no positive-going edge
C
C
will be charged too, but reset will not be set low. After
I
D
. An output capacitor
will be discharged down to
V
V
DU
DU
and reset will be set high again.
and reset was set to high, the watchdog circuit is
C
3
D
is discharged down to
C
D
will be charged with the current as at
C
Q
is necessary for the stability of
V
I
C
V
< 36 V to
Q
DWL
. Then reset will be set
22 F and an ESR of
C
V
D
D
V
on pin 4 (D) will be
drops below
DWL
V
C
Qnom
D
, the watchdog
. The value of
= 5.0 V. Up
TLE 4271
1998-11-01
V
DRL
V
D
,