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How LT4363IMS-2#PBF Surge Suppression IC Protects Loads from Overvoltage

If you use an electronic device, one of things you want to look out for is the voltage rating. Depending on a number of factors, the device might go beyond the recommended voltage and that could pose a serious threat to the functionality.

However, you may be able to stop the damage from even happening if you are intentional with the device selection. Today, consumer electronics are equipped with surge suppression ICs. These are dedicated Integrated Circuits (ICs) or chops integrated or embedded into the electronic devices to help regulate the voltage.

If you are looking for one of the best out of the rest, we recommend LT4363IMS-2#PBF. It is a surge suppression IC with a current limit. It would be able to withstand higher voltages, thereby, protecting your consumer electronics the more.

How Surge Suppression ICs Work

These are dedicated ICs or electrical devices attached inside consumer electronics to aid the voltage regulation process. The integration of a surge suppression IC is a critical element that aids the fight against damaging devices when the current or power supply surges or increases astronomically.

Surge suppression ICs also belong to circuit protection ICs; a broader category of Integrated Circuits (ICs) designed to offer additional protection to electrical circuits, which are susceptible to hazards, such as static discharges.

What Makes LT4363IMS-2#PBF Unique?


No doubt, LT4363IMS-2#PBF is not the only surge suppression IC out there. However, it possesses some remarkable features, which come together to make it one of the most sought-after.

Below are some of the unique features of this surge protector:

1. Load protection from Higher Voltage Transients

One of the banes of consumer electronics’ voltage regulation is the inability to regulate even the highest of voltages. In that essence, it might be impossible to keep the surge suppressor active for the higher voltage surges.

LT4363IMS-2#PBF offers a higher voltage transient, in the sense that it keeps the loads safe. For example, the protector monitors the significant drop in voltage between the OUT and SNS pins. This regulation goes a long way to helping LT4363IMS-2#PBF figure out when the loads are dwindling, voltage-wise.

When the consumer electronics is overloaded, it is also in the place of LT4363IMS-2#PBF to keep the device functional. To do this, it first regulates or controls the gates of the external, N-Channel MOSFET. This regulation paves the way for the surge protector to regulate the output when the device is in overvoltage operation.

2. Reverse Input Protection

Although LT4363IMS-2#PBF’s primary function is to work as a surge suppression IC; it can also perform other functions. Note that in terms of voltage regulation, it can be both ways. For example, the voltage might surge, leading to overvoltage. It might also drop significantly, thereby, leading to undervoltage.

Either way, the idea is that the voltage might not be favorable for the device’s continual operations. Therefore, it makes sense to see that LT4363IMS-2#PBF uses a reverse input protection.

It is a protective mechanism in place to protect the target device or consumer electronic from undervoltage and overvoltage. For example, when the device’s voltage is below the UV threshold, the external MOSFET wouldn’t be allowed to turn on. Likewise, the MOSFET wouldn’t be allowed to turn on if the input supply voltage exceeds the OV threshold.

For that to work perfectly, LT4363IMS-2#PBF’s regulator mechanism, the use of two (2) precision comparators is required. These comparators help to monitor and keep an eye on the potentials or supply voltage values of the Undervoltage (UV) and the Overvoltage (OV) conditions.

3. Excellent Fault Detection and Management

LT4363IMS-2#PBF detects faults in the voltage process and manages the same effectively. For example, when the consumer electronic is subjected to overvoltage, the IC tends to limit the output to a safe value, until the loads become functional.

The voltage regulation is also added by a timer, which is inversely proportional to the MOSFET stress. The idea is to turn off the MOSFET, only after it has been confirmed that the FLT pins “pulled low”; a form of confirmation that the Overvoltage (OV) condition persists.

4. Higher Overvoltage Resistance

LT4363IMS-2#PBF’s surge suppression IC withstands the consumer electronics from suffering much damage due to overvoltage. To make this work perfectly, it uses a higher overvoltage resistance; capable of resisting up to 100 volts with the VCC Clamp.

LT4363IMS-2#PBF Attributes

Here are some of the attributes of this surge suppression IC:

Voltage – WorkingBetween 4 volts and 80 volts
Voltage – Clamping272V Adj
Mounting TypeSurface-mount
Type of Technology UsedExternal Switch
Number of Circuits1

LT4363IMS-2#PBF’s Pins

LT4363IMS-2#PBF supports up to ten (10) pins, with each of these contributing to the IC’s functionalities. These are some of the pins and how they function:

5. TMR

The full name is Fault Timer Input. It helps to detect or find out the faults on time. For excellent performance, the TMR pin has to be connected to the via a capacitor to establish a connection between the ground and the pin.

The core functions include setting the times for:

  • Cool down periods
  • Early fault warning
  • Fault turn-off


This is the Shutdown Control Input. It is a dedicated pin for shutting down the device and putting it in a low-current mode.

Upon activation, the SHDN pin keeps the device function, rather than exposing it to overcurrent. It needs to be enabled to a threshold of 0.4V to function optimally.

Note that the part or device can be turned back on from the low-current mode if the SHDN pin is pulled above 2.1 volts. Doing that allows the internal current source to turn the part on.

7. FB

It is called the Voltage Regulator Feedback Input. It is a critical pin that helps the device to underscore the current voltage supply.

The FB is to be connected to the center tap of the resistive divider, which is further connected between the Ground (GND) and the OUT pin.

The other supported pins are:

  • Open Collector Fault Output (FLT)
  • Current Sense Output (SNS)
  • Undervoltage Comparator Input (UV)
  • N-Channel MOSFET Gate Drive Output (GATE)
  • Overvoltage Comparator Input (OV)
  • Positive Supply Voltage Input (VCC)
  • Output Voltage Sense Input (OUT)
  • Device Ground (GND)


You need a consumer electronics assuring of the highest performances? Think of the one that integrates the LT4363IMS-2#PBF; a robust surge suppression IC capable of withstanding up to 100 volts of current surges.