What is a VD (Voltage Detector)? Various uses

What is a VD (Voltage Detector)?

As the name suggests, a VD (Voltage Detector) is a product that monitors voltage.
It is also called a voltage detector, voltage monitoring IC, reset IC, etc.
The reason it is called a reset IC is that the VD (voltage detector) is used to monitor POWER SUPPLIES voltage of the microcontroller, and when it detects a power-on reset at startup or an abnormal voltage, it outputs a reset signal to prevent the microcontroller from operating normally (running out of control).
This column will help you understand the main applications of voltage detectors (VDs). We hope it will be useful when considering protection and control in circuit design.

VD (Voltage Detector) Applications

1. Reset when the voltage drops

In the case of a microcontroller that operates at 3.3V, such as the one mentioned above, the microcontroller may not operate correctly at a voltage other than 2.97V to 3.63V (±10%).
The reset IC detects a voltage drop while the microcontroller is operating normally and outputs a reset signal.

2.Reset cancellation at POWER SUPPLIES on

After the input voltage reaches or exceeds the operating voltage of the microcontroller, the microcontroller waits for the internal clock to stabilize and the register initialization to complete. This is called the release delay time.
During this time, if there is no drop in the input voltage, a reset release signal is sent to the microcontroller.
This allows the microcontroller to start up safely.

The length of the release delay time is determined by the microcontroller specifications, and is usually between several tens and several hundred ms.

3. Battery voltage monitoring

When the battery is low, the voltage drops rapidly.
If this voltage drop exceeds the operating voltage of the downstream system, it may cause malfunction.

By monitoring the battery voltage using a reset IC, a reset can be applied before the battery voltage falls outside the operating voltage range of the downstream system.
This makes it possible to prevent malfunctions in downstream systems.

4. Built-in reset function and dual monitoring function in the microcontroller

Many microcontrollers also have a built-in reset function.
However, in devices that require high reliability, such as automotive and industrial equipment, safety measures are sometimes taken to increase safety by using an external reset IC as a backup in case the microcontroller malfunctions and the reset function does not work.

5. Reset when voltage rises

In devices that require high reliability, such as automotive and industrial equipment, it is necessary to monitor not only voltage drops but also voltage increases.

The voltage and range detected by a VD (voltage detector) can be shown in one diagram...

Voltage and area detected by VD (Voltage Detector)

If you are looking for VD products, whether they are in or outside of the above areas, please feel free Inquiry. Nexty Electronics will be happy to assist you with your selection.