TLE4275-Q1 – Voltage Regulator

With the increase in technology, more compact devices which are optimized in size are widely manufactured and used. Today for our applications we make use of very sensitive devices such as microprocessors and controllers. Under these conditions when voltage fluctuations occur even in one circuit, the whole device can get damaged. Voltage regulators such as TLE4275-Q1 are required to prevent such voltage fluctuations.

Voltage regulators are devices which can output a regulated voltage when there are voltage fluctuations in the circuit. These are used as reference voltage sources. There are both positive voltage regulators and negative voltage regulators.

What is TLE4275-Q1?

TLE4275-Q1 is a low dropout voltage regulator. It is a monolithic IC. This device can regulate voltages up to 45V to a 5V output voltage. TLE4275-Q1 can drive load up to 450mA. When over temperature is detected the temperature protection circuit present in the device turns off the device to protect it from damaged caused by high temperatures.

For stability and high transient responses, external capacitors are used along with the IC. Operating junction temperature is -400C to 1500C. The output current of TLE4275-Q1 is 5mA. Under recommended operating conditions the minimum input voltage is 5.5V

Block Diagram

TLE4275-Q1 block diagram contains over temperature protection circuit, overload protection circuit.

Block diagram of TLE4275-Q1
Block diagram of TLE4275-Q1

Regulated Output


The device gives a regulated output of 5V, which can be drawn using OUT pin. A current limitation is given to the output. During the initial powerup, to control the initial current through the pass element, this regulator has soft start incorporated.

Power on Reset (RESET)

RESET is output with an external pull up resistor to the regulated supply. Until the regulator load voltage exceeds an approximate 4.65V and the power on Reset delay has expired, the reset output remains low.

Reset Delay Timer (DELAY)

Before the reset terminal is asserted high, an external capacitor on this DELAY terminal sets the timer delay. To trip an internal comparator, the external capacitor should be charged until the voltage exceeds the threshold value. The external capacitor is charged with the help of a constant output current.

Low voltage Tracking Mode

The regulator drops out of regulation during low input voltages. At this condition, the output voltage tracks input minus a voltage based on the load current and switch resistance. This eliminates the need of using a boost converter during cold-crank conditions.

How to Use?

Depending on the type of application, various values of external components are used along with TLE4275-Q1 voltage regulator IC. In order to prevent the reset during fast load steps, large output capacitors are used.

Circuit Diagram of TLE4275
Circuit Diagram of TLE4275

For better load transients, a low-ESR ceramic capacitor with a dielectric of type X5R or X7R is recommended. Before beginning the design process some of the parameters should be determined.

Such as Input voltage range, output voltage range, output current rating, output capacitor, power-up reset delay time. For the circuit above an input voltage range from 4 to 40V is used. Here the output voltage is 5V.

Output current rating is 400mA and the output capacitor range is from 10 to 500µF. For the output capacitors used in the circuit, the ESR range is 1mΩ to 20Ω and DELAY range is from 100pF to 500nF. The incorporated temperature protection circuit turns off the device at over temperature.

The input supply given to the device should be well regulated. It is recommended to add an electrolytic capacitor of 47µF and a ceramic by-pass capacitor at the input if the input supply is located more than a few inches away from the IC.

Pin Configuration

The TLE4275-Q1 voltage regulator is available as 5-Pin TO-263-KTT package, 5-Pin TO-252-KVU package and 20-Pin HTSSOP-PWP package.KTT and KVU packages have similar pin configuration.

Pin Diagram of TLE4275
Pin Diagram of TLE4275

Pin configuration for KTT and KVU package is as follows-

  • Pin-1 is the input pin IN. It is connected to the ground with the help of a ceramic capacitor.
  • Pin-2 is the Reset output pin RESET. This is also known as Open-collector Output.
  • Pin-3 is the ground pin GND. This pin is internally connected to Heat sink.
  • Pin-4 is the delay rest pin DELAY. To set delay time with this pin, it is connected to ground using a capacitor.
  • Pin-5 is the output pin OUT. This pin is connected to ground using a capacitor greater than 22µF.

Pin Configuration for 20-Pin PWP package is as follows-

  • Pin-1 is the reset output pin RESET.
  • Pin-3 is the reset delay pin DELAY.
  • Pin-4 is the output pin OUT.
  • Pin-8 is the ground pin GND.
  • Pin-19 is the input pin IN.
  • Pin-2,5,6,7,9,10,11,12,13,14,15,16,17,18,20 are NC pin which doesn’t have any connections.


Specifications of TLE4275-Q1 are as follows-

  • TLE4275-Q1 is a monolithic IC.
  • It is a very low dropout voltage.
  • It has very low power consumption.
  • This device is useful for automotive applications.
  • TLE4275-Q1 has an output voltage of 5V.
  • It has a short-circuit proof circuit.
  • Power-On and Undervoltage Reset is provided.
  • Reset low-level output voltage is less than 1V.
  • TLE4275-Q1 has reverse polarity-proof.
  • TLE4275-Q1 also has over temperature and overload protection circuits.
  • It contains an external delay capacitor to program the rest delay.
  • TLE4275-Q1 is available as a 5-pin TO package.
  • TLE4275-Q1 can regulate the input voltage of 45V.


Applications of TLE4275-Q1 are as follows-

  • The TLE4275-Q1 voltage regulator is suitable and qualified for automotive applications.
  • This device is also useful as a Cluster.
  • Body control modules use TLE4275-Q1 low dropout voltage regulator.
  • Heating ventilation and Air conditioning (HVAC) uses a TLE4275-Q1 voltage regulator.

Alternative IC

Some of the IC that can be used as an alternative to TLE4275-Q1 voltage regulator is TLE720M05, TLV1117, TL431, SN74LVC1G08 etc…

TLE4275-Q1 is a fixed output voltage regulator. There are also some other voltage regulator IC’s present in the market that has an adjustable voltage version. In such devices, using external voltage divider circuit, output voltages can be adjusted.

Datasheet provided by Texas Instrumentation contains further electrical characteristics of TLE4275-Q1 under different operating conditions. In which of your application was TLE4275-Q1 voltage regulator helpful?

Image Source: Texas Instrumentation