Data Sheet 2 Rev. 1.1, 2007-09-21
TLE 4276-2
Functional Description
The TLE 4276-2 is a low-drop voltage regulator in a TO package. The IC regulates an
input voltage up to 40 V to
V
Q,nom
= 5.0 V (V50) or adjustable voltage (V). The maximum
output current is 400 mA. The IC can be switched off via the inhibit input, which causes
the current consumption to drop below 10 µA. The IC is short-circuit-proof and includes
temperature protection which turns off the device at overtemperature.
Dimensioning Information on External Components
The input capacitor
C
I
is necessary for compensation of line influences. Using a resistor
of approx. 1 Ω in series with
C
I
, the oscillating of input inductivity and input capacitance
can be damped. The output capacitor C
Q
is necessary for the stability of the regulation
circuit. Stability is guaranteed at values C
Q
≥ 22 µF and an ESR of ≤ 3 Ω within the
operating temperature range.
Circuit Description
The control amplifier compares a reference voltage 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 oversaturation of the power element. The
IC also incorporates a number of internal circuits for protection against:
• Overload
• Overtemperature
• Reverse polarity
