Part Number: TL431AQDBZRQ1

Manufacturer: Texas Instruments

Description: IC VREF SHUNT ADJ 1% SOT23-3

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Technical Specifications of TL431AQDBZRQ1

Datasheet  TL431AQDBZRQ1 datasheet
Category Integrated Circuits (ICs)
Family PMIC – Voltage Reference
Manufacturer Texas Instruments
Series Automotive, AEC-Q100
Packaging Tape & Reel (TR)
Part Status Active
Reference Type Shunt
Output Type Adjustable
Voltage – Output (Min/Fixed) 2.495V
Voltage – Output (Max) 36V
Current – Output 100mA
Tolerance ±1%
Temperature Coefficient
Noise – 0.1Hz to 10Hz
Noise – 10Hz to 10kHz
Voltage – Input
Current – Supply
Current – Cathode 700μA
Operating Temperature -40°C ~ 125°C (TA)
Mounting Type Surface Mount
Package / Case TO-236-3, SC-59, SOT-23-3
Supplier Device Package SOT-23-3

TL431AQDBZRQ1 Introduction

If you’re looking for a pin-for-pin replacement for a TL431-Q1 or TL432-Q1, go no further than the TL431LI-Q1 or TL432LI-Q1. These components improve system precision by increasing stability, decreasing temperature drift, and decreasing reference current. The TL431-Q1 has proven to be a widely used and adaptable three-pin adjustable shunt regulator. It has multiple applications as a voltage reference, error amplifier, voltage clamp, or integrated reference comparator.

The TL43x-Q1 is suitable for various applications due to its operability and adjustability to cathode voltages between 2.5 V and 36 V, making it useful in fields as diverse as industry, transportation, communications, and computers. The device’s internal reference and amplifier use the difference between the reference and the virtual internal pin to produce a sink current. You can’t go wrong with the TL43x-Q1 when you need to reference voltage or current, voltage monitoring,  secondary side regulation in flyback SMPSs, zener replacement, and comparator with integrated reference applications since it can run in open-loop or closed-loop modes.

TL431AQDBZRQ1 Description

In place of TL431-Q1 and TL432-Q1, you can use the pin-compatible TL431LI-Q1 and TL432LI-Q1. Increased system accuracy is realized with TL43xLI-Q1 thanks to its superior stability, reduced temperature drift (VI(dev)), and reduced reference current (Iref). The TL431-Q1 is an automotive-grade, adjustable shunt regulator with three terminals and guaranteed thermal stability. Two external resistors allow the output voltage to be adjusted from VREF (about 2.5 V) to 36 V. (see Figure 28). The normal output impedance of this device is 0.2. In many situations where Zener diodes are used, such as in onboard regulation, adjustable power supplies, and switching power supplies, this device is a great alternative because of its active output circuitry, which gives a sharp turnon characteristic. There is no functional difference between the TL432-Q1 and the TL431-Q1; the only difference is the connector for the DBZ package.

TL431AQDBZRQ1 Features

  • A minimal amount of output noise.
  • The typical output impedance is 0.2.
  • From 1 mA up to 100 Ma, it can take a current in the sink.
  • Voltage can be set between VREF and 36 V.

Detailed Description

This component has demonstrated its ubiquity and versatility throughout a broad spectrum of applications, spanning from the transmission of power to the transmission of the signal. This is a result of the fact that its primary components include a precise voltage reference as well as an op-amp, both of which are primary examples of analog building blocks. The TL43x-Q1 is versatile enough to serve as an error amplifier, voltage clamp, single voltage reference, or comparator with integrated reference, among other possible applications. Because the TL43x-Q1 may be used and adjusted to cathode voltages ranging from 2.5 V to 36 V, this component is ideal for use in various end equipment, including those used in computing, telecommunications, and the automotive industries.

A current of at least 1 mA (IMIN(MAX)) needs to be applied to the cathode pin of this device for it to function as a shunt regulator or error amplifier. In this scenario, feedback may be applied from the CATHODE and REF pins to generate an exact copy of the voltage used as the internal reference. Several different reference voltage options are available for purchase, and their initial tolerances range from 0.5% to 1% (at 25°C). These reference choices are indicated in the part number by the letters B (0.5%) or A (1%), respectively (TL431x-Q1).

Feature Description

The TL43x-Q1 contains an internal reference as well as an amplifier. The sink current that is output by the amplifier is determined by the difference between the reference pin and the virtual internal pin. Internal Darlington pair is responsible for the production of the sink current.

When operated with sufficient voltage headroom (at least 2.5 V), the TL43x-Q1 mandates the reference pin to be set to 2.5 V. Cathode current (IKA) is also required. On the other hand, the reference pin can’t just be left floating because IREF needs to be at least 4 A. This is due to the fact that the reference pin is pushed into an NPN, a type of transistor that requires base current to function correctly. The TL43x-Q1 operates as a Zener diode when feedback is applied from the CATHODE and REF pins. This causes the device to regulate to a constant voltage proportional to the amount of current fed into the cathode. The internal amplifier and the reference have entered their appropriate functioning zones.

For this component to be in the correct linear area and provide the needed amount of gain in open loop, servo, or error amplifying implementations, the same amount of current as required in the instance described above involving feedback must be provided. The TL43x-Q1 is unlike other linear regulators; it has an internal compensation system that makes it stable even without an output capacitor between the cathode and the anode.

Device Functional Modes

Open Loop (Comparator) Open loop operation occurs in a TL43x-Q1 device whenever the cathode or current or output voltage is not being fed back in any way to the reference or input pin. if the gadget is given the appropriate amount of cathode current (IKA). With such a high gain in this arrangement, the device is generally utilized as a comparator because of its capabilities. Because it has an integrated reference, the TL43x is the better option when trying to monitor a specific level of a single signal for applications such as undervoltage and overvoltage detection. This is because of the versatility of the device.

● Closed Loop

The TL43x-Q1 is said to be operating in a closed loop whenever the device’s cathode or output voltage or current is fed back in any form to the reference or input pin. Most applications that utilize a TL43x-Q1 do so to manage a constant current or voltage. This device can function as an error amplifier because of the feedback, which computes a portion of the output voltage and adjusts it as necessary to achieve and maintain the required regulation. This is achieved by connecting the voltage at the output pin to the reference pin so that it is equal to the voltage that serves as the internal reference. This connection can be made either by resistive feedback or through direct feedback.


In conclusion, the TL431AQDBZRQ1 voltage reference power management device from Texas Instruments is an excellent choice for maintaining a precise DC voltage despite large power supply variations. Its impressive initial accuracy of 1% and voltage range of 2.495 to 36 V can provide reliable power management for your circuit.

Moreover, ICRFQ offers this top-quality product with excellent service and an array of high-quality goods. Don’t hesitate to upgrade your power system and ensure it can handle the stresses of various uses. Contact ICRFQ today to learn how the TL431AQDBZRQ1 can benefit your application and place your order. Don’t wait longer to improve your power system’s performance with the TL431AQDBZRQ1 from ICRFQ.

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