Here in this circuit, Zener Diode and Bipolar Transistor are used for automatic overvoltage protection. View All News and Media. Primarily, the HotSwitch device turns on or off the current flow to a power rail as-needed. This is done by using a shunt resistor R1, which is a 1 Ohm shunt resistor with a 2 Watt rating. C4AK Series High Temperature, Long Life DC-Link Film Capacitors The voltage drop depends on the RDSON of a particular MOSFET in use, which is significantly smaller than a PFET. Microsoft is quietly building a mobile Xbox store that will rely on Activision and King games. Circuit breakers also have a small inductive component, so the breaker can be made to trip slowly on overload or very fast on a short circuit. By adding the resistor and the Zener diode of 9.1V, we can clamp the gate-source voltage to a maximum of negative 9.1V, hence the transistor remains safe. The 30A RV Circuit Analyzer Diagnostic Chart provides fault indication for the following wiring faults: Correct Wiring, Open Ground, Open Neutral, Reverse Polarity, Hot/Ground Reversed, No Power. Now, when the voltage supply is higher than the threshold value, Zener breakdown happens and the Zener diode D2 starts conducting. Now, if the supply voltage is more than the Vgs then you have to drop the voltage between the gate terminal and source. The 57 Deluxe power circuit meets all modern legal and electrical code requirements. Zener Voltage Regulator Circuit: This method regulates the input voltage and protects the circuit from over voltage by supplying a regulated voltage,but itdoesn't disconnect the output part when voltage exceeds the safety limits. The electric circuits and components which are used these days give a lot of preference and time to make it as safe as possible. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Introduction to the Python Programming Language, A Practical Guide to Inductors and Inductance. The damage to the component and to the circuit as a whole can be minimized or completely eliminated by providing a protection circuitry in the form of overvoltage protection. At the same time, the devices in Semtechs HotSwitch portfolio provide an enhanced shield against inrush current, overvoltage, under voltage, reverse current, short circuit, and over-temperature faults. Our website is made possible by displaying online advertisements to our visitors. We push innovation to create intelligent power and sensing technologies that solve the most challenging customer problems Our employees are inspired each day to increase stakeholder value through high quality and high value products and services Learn More. Using a Diode is the easiest and cheapest method for Reverse Polarity Protection but it has a problem of power leakage. Components required for making the circuit hardware is mentioned below. Low-cost surplus off-peak electric power is typically It is recommended to use proper MOSFET Heatsink if the load current is larger than 500mA. Below is the LTspice simulation of the circuit using a low-cost LM431 adjustable reference in place of the Zener, so you can set the voltage to the desired value with pot U2. Kind regards JJ Link to pose in question: https://www.electricaltechnology.org/2019/11/simple-overvoltage-protection-circuit-using-zener-diode.html, Your email address will not be published. ULTRA-SAFE EQUIPMENT - Carmtek 30 Amp RV Surge Protector is built from flame-retardant material making it extra safe to use. Required fields are marked *. To protect against possible voltage spikes and transients from destroying the MOSFET, a pair of tranzorb diodes could be added at the input as in Fig. It is little bit costlier than diode but it makes the protection circuit much safer and efficient. Save my name, email, and website in this browser for the next time I comment. During a situation, when the comparator detects the voltage drop across the shunt resistor is 1.01V (this voltage depends on op-amp or comparator accuracies and other factors) the comparator will disconnect the load. For example, lets assume, 1A is set using the potentiometer for triggering the MOSFET into the OFF condition. News For You. Semtech's portfolio of TVS arrays protect data interfaces from secondary lightning surges and cable discharge events. When a fault occurs in any of the zone, then only the circuit breaker in that zone trips. The pcb's provide protection against over voltage, under voltage and over current / short circuits. When the output voltage increases the base-emitter voltage decreases, due to this transistor Q1 conduct less. Reverse Polarity Protection using Diode. D1, D2 and R1 protect against these spikes that might otherwise exceed the LTC4359s 40V to 100V survival rating. Read breaking headlines covering politics, economics, pop culture, and more. Without the cap there is a chance that the output will go negative (negative spike) for a few nanoseconds because the gate resistor needs time to discharge the mosfet gate-source intrinsic capacitance through zener/tranzorb diode. This will increase the source current requirement to achieve the minimum body diode drain-to-source voltage for the charge pump to initiate. Fuses are generally chosen to be rated at 150% of the normal current. Step by Step Procedure with Solved Example, Automatic Street Light Control Circuit using LDR & Transistor BC 547, https://www.electricaltechnology.org/2019/11/simple-overvoltage-protection-circuit-using-zener-diode.html. ul{list-style:none;margin:10px;} Tiny Size-vs-High Specs, this range of RECOMs DC/DC Converters utilizes minimal PCB footprint. Get the latest health news, diet & fitness information, medical research, health care trends and health issues that affect you and your family on ABCNews.com When the battery is installed incorrectly, the NMOS FETs gate voltage is low, preventing it from turning on. Now, there are at least six cameras present in high-end vehicles. Get Free Android App | Download Electrical Technology App Now! Figure 1 below shows the evolution of USB standards with the corresponding data transmission rates. The 50A RV Circuit Analyzer Diagnostic Chart provides fault indication for the following wiring faults: Correct Wiring, Open Ground, Open Neutral, Missing L1, Missing L2, Reverse Polarity, L1 Ground Reversed, L2 Ground Reversed, Open Circuit/No Power. The best way to overcome this problem is to use a stable power across the comparator where the transient changes do not affect the comparators input voltage and the voltage reference. Reverse Polarity Protection. Hence, Q1 does not allows the current to flow through it and protect the Load from exceeded voltage. This flow of current in the opposite direction happens only when the voltage across the terminals exceed the threshold voltage called the Zener voltage. Heatsink (as per the application requirement), 1ohms resistor, 2W (2W maximum of 1.25A load current). The LTC4359 operates from 4V to 80V and withstands an absolute maximum range of 40V to 100V without damage. Get the latest NFL news, NFL rumors, podcasts, free agency updates, trade grades, pedictions, columns, analysis, and more from FanSided. Learn more about Semtech's innovative circuit protection technology platform. "RT1" is the inrush current limiting thermistor (Amphenol CL-60A) placed in the white neutral line. I have used the exact parts as per the diagram and sourced them from Mouser.com and etched a double sided circuit board for it. The design of the circuit is such that the pre-set value of the circuit is the rating of the Zener diode. Low Capacitance RailClamp 4-Line Surge and ESD Protection, 24V ESD and EOS Protection for 4-Line Automotive Applications. Get the latest breaking news across the U.S. on ABCNews.com When used in high current diode applications, theLTC4359 reduces power consumption, heat dissipation, voltage loss and PC board area. A power supply can fail in many ways, but one particularly worrying possibility is that the series regulator element, i.e. 3D Power Packaging for Low Power DC/DC converters. A three-judge panel of the New Orleans-based 5th Circuit Court of Appeals found Wednesday that the CFPBs funding structure violated the Constitutions separation of powers doctrine. A voltage drop of RdsOn ILOAD is seen in the power path. To be able to use the N-MOSFET as a reverse current protector in the high side power path requires a gate voltage greater than the battery voltage to turn the MOSFET on. They are used to generate low-power stabilized power supplies. 1551W Series Watertight Polycarbonate Enclosures. The output (yellow trace) is cutoff when the voltage reaches 15V and turns back on at about 14.4V (for about a 0.6V hysteresis caused by R4). A solution often used is to put a metal oxide varistor (MOV) across the supply. Hi jongmaxwell, The output (yellow trace) is cutoff when the voltage reaches 15V and turns back on at about 14.4V (for about a 0.6V hysteresis caused by R4). Hammonds New Miniature Enclosures for Indoor or Outdoor Use. There are some simple methods to protect the circuit from reverse polarity connection such as using a diode or Diode Bridge or by using P-Channel MOSFET as a switch on HIGH side. When the input voltage is reversed, the diode conducts, causing the fuse to blow. Semicon Media is a unique collection of online media, focused purely on the Electronics Community across the globe. TLP Analysis Doesnt Guarantee Compliance to ESD. Follow, Copyright 2020, All Rights Reserved 2012-2020 by. Semicon Media is a unique collection of online media, focused purely on the Electronics Community across the globe. Here is a great video showing slow-motion tripping. If the supply voltage is less than the Gate-to-Source voltage (Vgs) of P-channel MOSFET then you only need the MOSFET without diode or resistor. One single connecting port's name that is ingrained in our life is Universal Serial Bus or USB in short. C1 ensures spikes caused by switching transients dont trigger the SCR. It is a very common transistor and is used as an exemplar of an NPN transistor. A comparably sized P-channel MOSFET will have a higher RdsOn and hence higher power losses but can be implemented with simpler drive circuitry comprising a zener diode and a resistor. Culture is often originated from or attributed to a specific region or location. And, if you are designing for an automotive application, you need to ensure that your design meets the requirements of appropriate standards such as ISO7637-2. The Zener diode is chosen to be slightly higher; in this case, 15V. The post says The capacitor between gate and source is added to ensure the circuit works well when there is a rapid change in input voltage polarity. Short-circuit protection, Reverse polarity protection, and over/under voltage protection are some of the protection circuits that are used to protect any electronic appliance or circuit from any sudden mishappenings. It is either made up of silicon or germanium material and doped with either positively or negatively charged material. Selector Guides, FemtoBuck DC-DC Regulators and Controllers, LoRa They are also used to protect circuits from overvoltage, and electrostatic discharge. Copyright 2022Circuit Digest. The pinout for a FMMT718 is given in a tabular form below. At the same time, the devices in Semtechs HotSwitch portfolio provide an enhanced shield against inrush current, overvoltage, under voltage, reverse current, short circuit, and over-temperature faults. The overcurrent part is R19 and Q9. But bridge rectifier consists of four diodes, hence the amount of power waste will be twice of the power waste in the above circuit with single diode. If that is not possible by physical means, you need to include some electronic reverse current protection. 1551W Series Watertight Polycarbonate Enclosures. Get the latest breaking news across the U.S. on ABCNews.com Adding to this list of circuits, in this article, we will learn how to design Protection circuits, like reverse polarity protection, short-circuit protection and over/under voltage protection, Overvoltage protection is a power supply features which cutoffs the supply whenever input voltage exceeds the preset value. Using a Diode is the easiest and cheapest method for Reverse Polarity Protection but it has a problem of power leakage. It detects electrical surges and secures the downstream subsystem by disconnecting the load from the power source. All rights reserved. Blockingdiodes are commonly placed in series with supply inputs for the purpose of ORing redundant power sources and protecting against supply reversal. This method of measuring current is called Shunt Resistor Current Sensing, you can also check other current sensing methods which can also be used to detect over current. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device.A common mnemonic is ACID, for "anode current into device". Circuit breakers also have a small inductive component, so the breaker can be made to trip slowly on overload or very fast on a short circuit. While performing amplification applications, it receives an analog signal via collectors and another signal is applied to its base. The maximum continuous drain current, ID, rating must exceed the maximum continuous load current. IBT can offer Lithium Ion cells with protection circuit modules (PCM) factory fitted to the cell. The body diode voltage for a MOFET typically decreases as the ambient temperature increases. transistor or FET may fail in such a way that it becomes a short circuit. Omrons new G5PZ-X PCB relay comes in a compact package with 20 A at 200 VDC rated load, Tiny Size-vs-High Specs, this range of RECOMs DC/DC Converters utilizes minimal PCB footprint, Hammonds New Miniature Enclosures for Indoor or Outdoor Use, KEMET's C4AK series film capacitors feature long life and high voltage, Murata's ultra-thin, high-efficiency, 72 W charge pump modules support 48 V Bus architecture, WORM cards are complete solutions to restore security against threats of data altering or removing, Designed to perform in high-flex, high-torsion, and continuous flex applications, Nordic Semiconductor presents the Nordic Thingy:53 rapid prototyping platform based on the nRF5340. Your email address will not be published. For more than 50 years, Semtech's Protection Products Group has been on the forefront of developing cutting-edge circuit protection solutions to safeguard the various circuit buses, ports, connectors, and interfaces found in consumer products and electronic systems. Submitted by RJayapal on Tue, 08/28/2018 - 15:08. In proper working state, the base terminal of transistor Q2 is high which causes that transistor to turn OFF. Omrons new G5PZ-X PCB relay comes in a compact package with 20 A at 200 VDC rated load, Tiny Size-vs-High Specs, this range of RECOMs DC/DC Converters utilizes minimal PCB footprint, Hammonds New Miniature Enclosures for Indoor or Outdoor Use, KEMET's C4AK series film capacitors feature long life and high voltage, Murata's ultra-thin, high-efficiency, 72 W charge pump modules support 48 V Bus architecture, WORM cards are complete solutions to restore security against threats of data altering or removing, Designed to perform in high-flex, high-torsion, and continuous flex applications, Nordic Semiconductor presents the Nordic Thingy:53 rapid prototyping platform based on the nRF5340. As it is carrying the full load current, it should take it, perhaps a 5W type. The pinout can be seen in the below image. The 57 Deluxe power circuit meets all modern legal and electrical code requirements. However, for this project, the MOSFET is used without a Heatsink. We will always receive an output voltage less than or equal to the rating of the Zener diode. In a simple alternating current (AC) circuit consisting of a source and a linear time-invariant load, both the current and voltage are sinusoidal at the same frequency. They can be classified as follows: A crowbar circuit (shown in Figure 1) can protect your device from overvoltage. Typically, the voltage at the input side is such that several volts are dropped across the series regulator element. Another form of overvoltage that occurs is a transient spike on the power line. Adding to this list of circuits, in this article, we will learn how to design Therefore the variable resistor is set for a 1V output. Inserting the N-MOSFET in the ground circuit will introduce a ground shift that may not be acceptable in all applications. Now, lets talk about the power loss in the circuit, when the transistor is ON the resistance between drain and source is almost negligible but to be more accurate you can go through the datasheet of the P-Channel MOSFET. Omrons new G5PZ-X PCB relay comes in a compact package with 20 A at 200 VDC rated load, Tiny Size-vs-High Specs, this range of RECOMs DC/DC Converters utilizes minimal PCB footprint, Hammonds New Miniature Enclosures for Indoor or Outdoor Use, KEMET's C4AK series film capacitors feature long life and high voltage, Murata's ultra-thin, high-efficiency, 72 W charge pump modules support 48 V Bus architecture, WORM cards are complete solutions to restore security against threats of data altering or removing, Designed to perform in high-flex, high-torsion, and continuous flex applications, Nordic Semiconductor presents the Nordic Thingy:53 rapid prototyping platform based on the nRF5340. The main difference is the way in which the regulator voltage is applied to the base of the transistor. When the input voltage reaches 15V, the Zener conducts, setting up a voltage across R2. In the circuit 3 I dont get why C8 is needed? The crowbar protection circuit is one of the most used overvoltage protection circuits. With its wide operating voltage range, the ability to withstand reverse input voltage, and high temperature rating, the LTC4359 satisfies the demanding requirements of both automotive and telecom applications. Introduction to Semtechs SurgeSwitch Devices, Digi-key at Embedded World 2022 with Semtech Corporation, Semtech Shield Protection - Products Overview, Semtech Automotive Protection Solutions (AEC-Q100), New HotSwitch devices expand Semtechs robust offering of protection solutions to provide a, Semtechs SurgeSwitch product line offers 30% reduced clamping, 80% smaller package size and, Semtechs EClamp8052P combines common-mode noise filtering and high-performance, low-capacitance, HotSwitch is a new product line of devices from Semtech with an integrated load switch, The U.S. Department of Transportation (USDOT) and the National Highway Traffic Safety, Since its initiation in the early 20th century, the automotive industry has evolved, One single connecting port's name that is ingrained in our life is Universal Serial Bus, Wi-Fi technology has become ubiquitous in our highly connected society. Hammonds New Miniature Enclosures for Indoor or Outdoor Use. a{text-decoration:none;} The SHDN pin may be either driven high or left open to enable the LTC4359. Original equipment manufacturers (OEMs) have been using X-ray machines to detect unreliable solder joints. Semicon Media is a unique collection of online media, focused purely on the Electronics Community across the globe. How?? ULTRA-SAFE EQUIPMENT - Carmtek 30 Amp RV Surge Protector is built from flame-retardant material making it extra safe to use. ESD gun test tells us YES or NO, but TLP can help us to understand WHY and HOW. A pioneer in power management ICs across networking and industrial power, handheld power and automotive applications, Semtech leads the quest to enable a new class of greener, smarter and smaller end products. The GATE amplifier (see Block Diagram) senses across IN and OUT and drives the gate of the MOSFET to regulate the forward voltage to 30mV. Find latest news from every corner of the globe at Reuters.com, your online source for breaking international news coverage. Culture (/ k l t r /) is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups. This can be a dangerous situation as an over-current condition could damage the power supply. A Zener Voltage Regulator protects the circuit from overvoltage and also regulates the input supply voltage. This circuit not only protects the load side circuit but also regulates the input supply voltage to maintain a steady voltage. Below is the LTspice simulation of the circuit using a low-cost LM431 adjustable reference in place of the Zener, so you can set the voltage to the desired value with pot U2. USB specification has evolved over 25 years from USB 1.0 in 1996 to the most recent version, USB4. Semtechs TVS protection devices safeguard automotive data-line circuits from ESD and other overvoltage transients. The TZ1 and TZ2 are not required for the LM74610-Q1. F1 is the typical 250v 2 amp slow blow mains fuse (use 250v 1 amp fuse for 240 volt mains). padding-left:35px; Some of these events can result in large overcurrent levels flowing in the motor drive power circuits. A second MOSFET is required for load switching applications. ULTRA-SAFE EQUIPMENT - Carmtek 50 Amp RV Surge Protector is UL Tested. If the full voltage appeared on the output, then it could damage many of the ICs that are in the circuit and are being powered. The LTC4359 replaces diodes in these applications with a MOSFET to reduce both the voltage drop and power loss associated with a passive solution. Both breakdown types occur in the device the only difference being, Zener effect is predominant in lower voltages whereas, the avalanche breakdown happens at higher voltages. Table 3 shows the examples of recommended MOSFETs to be used with the LM74610: The LTC4359 is a positive high voltage, ideal diode controller that drives an external N-channel MOSFET to replace a Schottky diode. When you have questions, our experts have answers. The output shows a reverse voltage. Circuit has error. . There is another form of reverse polarity that occurs when you are not expecting it. The working of the circuits given above is also dependent on the voltage drop of each transistor. 3D Power Packaging for Low Power DC/DC converters, 1551W Series Watertight Polycarbonate Enclosures, C4AK Series High Temperature, Long Life DC-Link Film Capacitors, Xtra-Guard Continuous Flex-Rated Industrial Ethernet Cable, Nordic Thingy:53 IoT Prototyping Platform. Circuit breakers also have a small inductive component, so the breaker can be made to trip slowly on overload or very fast on a short circuit. News For You. A list of components required for the overcurrent protection circuit is listed below. There are many different ways to protect your circuit from overvoltage. In our previous protection circuit tutorials we have designed many basic protection circuits that can be adapted into your circuit, namely, Over Voltage Protection, Short-Circuit Protection, Reverse polarity protection, etc. Zener diode is a type of diode that allows current to flow through it in both the directions unlike a normal diode which allow current flow only in one direction which is from anode to cathode. Thousands of customers worldwide rely on our diverse product portfolio and world class technology roadmap for solutions in low power wireless communications, optical data transport, video broadcasting, power management, circuit protection, touch sensing, and more. 2N2222 is very common bipolar NPN transistor, mainly used for general purpose low-power amplifying or switching application. All rights reserved. When pulled low the SHDN pin turns off most of the internal circuitry, reducing the quiescent current to 9A and holding the MOSFET off. The FPD COMP (Fast Pull-Down Comparator) quickly responds to this condition by turning the MOSFET off in 300ns, thus minimizing the disturbance to the output bus. 2. I have built circuit 4 and it does not work for me. An anode is an electrode of a polarized electrical device through which conventional current enters the device. You just have to connect the gate terminal of the MOSFET to the ground. Also, solder it to greatly increase their ability to shed heat (but do not do this with RF components!). a lot of valuable information. But this needs to have an appropriate current rating. Figure 1 shows how a system is protected by a HotSwitch device. Do not reverse the positive (+) and negative (-) terminals. It is advisable to use a dedicated current sense amplifier for accurate current sensing related issues. Hence, this could apply to non-battery operated devices as well, and is likely to apply to automotive electronics. Committed to providehelpful electronic circuits schematics and related electronicdesign information. Short-circuit protection, Reverse polarity protection, First, we consider the working of the circuit when the power supply is working properly. Semtech's PerSe technology intelligently senses human presence for optimized connectivity and enhanced user experience. We can make an overvoltage protection circuit using a Zener diode and Bipolar transistor in two methods. Each protection scheme safeguards a defined area known as a protection zone. Temperature logger running on Raspberry Pi, Testing the MH-Z19 Infrared CO2 Sensor Module, Everything You Want to Know About Raspberry Pi GPIO: But Were Afraid to Ask, Datalogger example using Sense Hat, InfluxDB and Grafana, 50 Raspberry Pi Linux Bash commands youll actually use. The presence of a MOS channel within its structure forms a low potential barrier for the majority carriers, thus SBRs forward bias operation at low voltage is similar to Schottky diode. Bla. VERTICAL MARKETS, Circuit This makes the base terminal of Q2 which was earlier high to ground. When Q2 is turned OFF, the transistor Q1s base terminal is low and it starts conducting. How do I choose the right ESD protection solution? The semiconductor industry is producing leadless packages of integrated circuits (ICs) to make room for the enormous number of electronic components and meet modern-day vehicles' safety and reliability requirements. So, we can calculate the power loss in circuit like below: Lets assume the current flow through the transistor is 1A. ULTRA-SAFE EQUIPMENT - Carmtek 30 Amp RV Surge Protector is built from flame-retardant material making it extra safe to use. Explore our top resources to help you learn more about LoRa devices and the LoRaWAN standard or bring a LoRa-based solution to market. In this case, the circuit could be well beyond economic repair. Here the Preset voltage value is the rating of the Zener. It detects electrical surges and secures the downstream subsystem by disconnecting the load from the power source. Find the latest U.S. news stories, photos, and videos on NBCNews.com. Power supply 12V (minimum) or as per the voltage is required. First, we consider the working of the circuit when the power supply is working properly. When Q2 is turned OFF, the transistor Q1s base terminal is low and it starts conducting. C4AK Series High Temperature, Long Life DC-Link Film Capacitors (each). Explorehow SurgeSwitch provides highly efficient protection against EOSand ESD events. For more than 25 years, Semtech Protection, Overview with Principal Solutions Architect,, At embedded world 2022, on the Digikey booth,, The Semtech Shield brand offers protection, Learn all about electrostatic discharge (ESD), Download the Semtech Automotive Protection, Semtech Introduces the HotSwitch Platform for, Semtech Unveils SurgeSwitch System Transient, Semtech Announces EClamp Device To Solve. This in turn reduces the output voltage, keeping the output voltage almost constant. When this reaches the trigger voltage of the SCR (less than 1V), the SCR fires, creating a short circuit across the input, which causes the fuse to blow. If this occur, then the full unregulated input voltage would appear across the output. As this is an op-amp based overcurrent protection circuit, it will have an op-amp as the driving unit. In automotive applications, theLTC4359operates through load dump, cold crank and two-battery jumps, and it survives reverse battery connections while also protecting the load. You can also protect your device from this back EMF using a reversed diode across the inductance, as shown in figure 7. Note that you must leave a lead length on components expected to run a bit warm, and increase the area of the PCB land. However, many Zener diodes rely instead on avalanche breakdown. By varying the voltage at its input with R6, you can set the trigger voltage, providing a lot more flexibility. Reverse polarity protection is the easiest to achieve. In a previous article, we looked at voltage regulators and how to limit electrical current. Guarding LVDS Devices in Automotive Vehicles, Semtech Celebrates Innovation, Earth Day and Every. If the load current is reduced, the GATE amplifier drives the MOSFET gate lower to maintain a 30mV drop. Microsofts Activision Blizzard deal is key to the companys mobile gaming efforts. The output capacitor Cout is recommended to protect the immediate output voltage collapse as a result of line disturbance. Related Post:Automatic Doorbell with Object Detection By Arduino. Overvoltage protection is a power supply features which cutoffs the supply whenever input voltage exceeds the preset value. Good Day, I am currently doing my Final year engineering project, and would like to use the overvoltage circuit displayed on the website in my design. Please consider supporting us by disabling your ad blocker. When the battery is installed incorrectly, the PMOS FETs gate voltage is high, preventing it from turning on. Depending on the load current the shunt resistor produces a voltage drop across which can be calculated using Ohms law. So you cannot say for sure if the IC is adequately bonded to the PCB or not.