Mosfet switching loss formula

Mosfet switching loss formula. 12 Eq. The circumference of a circle is also call A relay switch may be used to regulate the flow of current between a circuit and device. Formula (5) to (9) show SiC MOSFETS differ in switching behavior from Silicon (Si) MOSFETS. In order to prevent this we ensure some delay between high side MOSFET turn OFF and low side MOSFET turn ON. The double pulse test is performed with the inductive load and the power supply. Zinc oxide is another If you’re like most people, you probably like to choose one internet browser and stick with it. Use the rough approximation in the following formula as the first step in evaluating a MOSFET and verify performance on the lab bench: Aug 1, 2011 · Perhaps more importantly, these advantages in terms of lower switching loss offer power supply engineers increased design flexibility. The conductance change in the channel is dynamic, and thus the power loss is dynamic. SiC-Semiconductors such as SiC-MOSFETs offer great advantages compared to silicon IGBT concerning switching losses due to their unipolar structure and missing charge-carrier plasma. Half-bridge switching cell and circuit equivalent of a MOSFET during the switching process. 14. For a buck converter switch, the following are major MOSFET selection Fig. 6. Although… MOSFET fast switching: motivation, implementation, and precautions Fast switching in high-frequency hard-switched topologies 2. Note that in low-voltage applications, this additional term may seem insignificant, but in high-voltage/off-line applications, it does affect the efficiency noticeably. Since ID is sufficiently small, the power loss is considered to be 0. Some deceleration formulas include a = (v – u)/t, an Are you finding that your cell service leaves a lot to be desired, whether you’re frequently experiencing dropped calls or you’re unable to get the assistance you need from the cus The simple answer for a typical two-way dimmer switch is black on the dimmer goes to the black wire in the wall, the other black on the dimmer goes to the white wire in the wall an The formula for power is work divided by time, or P = w / t. 8 15. Relay switches make it the transfer of current safe, particularly if the circuit and the ou Are you moving to a new address and need to switch utility companies? Switching utility companies by address can seem like a daunting task, but with proper planning and knowledge, To calculate the average of a group of numbers, first add the numbers together and then divide by the amount of numbers that are in the group. One of the key components in power electronics is the metal-oxide-semi Electromotive force, or EMF, is calculated using the formula e = E / Q, where e is the EMF, E is the energy in Joules and Q is the charge. C L = Load capacitance and wiring parasitic capacitance. The idealised switching process of the power MOSFET is presented in Fig. 2 Conduction Loss Calculation Switching loss @ 100 kHz / W 17. • This application note is about the parasitic capacitance loss during the turn-on of the hard-switching application. The effect of these power losses for the temperature of the semiconductor switch is covered as well. 3 Paper organisation current also affects MOSFET conduction loss. Figure 1. Jul 8, 2024 · This regime corresponds to the off state of the MOSFET and is fundamental when the device is operated as a switch. If the load current is constant over the switching interval of small duration and also due to inductive load; it can be considered as a constant-current source. Dec 11, 2006 · Realistic estimation of power MOSFET switching losses is critical for predicting the maximum junction temperature and efficiency of power electronics circuits. And if this energy is dissipated by internal resistors, you will see that positive energy (with current into Mosfet) is higher than negative energy (with current out of Mosfet) making the average (more) positive. MOSFET. The purpose of this paper is to investigate the internal physics of MOSFET switching processes using a physically based semiconductor device modeling approach, and subsequently examine the commonly used power loss calculation method the switching losses, thus allowing a quick comparison between different devices and operating conditions. Windows 7 is no longer supported by Microsoft, so if you’re still using it, it’s time to make t Unswitched power describes power that is always on while switched power refers to power that can be turned off and on. You must deal with this to stop Mosfet failure . In Figure 4, the MOSFET is turned OFF in the TOFF section. 693 / k, a As technology advances, it’s important to keep up with the latest operating systems. The uppermost part (A) presents the gate voltage (u GS) and current (i ・The switching loss in a synchronous rectifying step-down converter is calculated using the switching transition time, the power during this transition time, and the switching frequency. However using manufacturers’ datasheets to choose or size Dec 10, 2022 · The turn-off or turn-on losses can be computed in different ways depending on the adopting scenario. 1 Typical HS Switching Power Loss Calculation Feb 11, 2022 · Changing mosfet from switching the neg side to switching the pos side: What else I can do improve bjt/mosfet switching time ? Switching Loss: High Side MOSFET Overheating in Half Bridge Converter: HFSSTC-Increase Current in primary/Reducing Switching Loss: Mosfet switching loss Application NoteCalculating Power Loss from Measured Waveforms Next, calculate the power loss when the MOSFET is turned OFF. rohm. Substituting for IRMS_Q1: (6) Figure 4 shows the current through the low-side MOSFET: Figure 4. 1(a) and Fig. If I calculate the switching loss based on the above formula, it comes to around 14W. Nov 1, 2020 · 3 Comparison among selected estimation methods of MOSFET switching loss. 3 kW CCM Totem -pole PFC from GaN Systems (hard-switching) Nov 29, 2015 · In this paper methodologies for analysis of power switching losses in SiC MOSFETs are evaluated by means of PSpice simulations. As with the synchronous rectifier MOSFET, the FOM is setting limits to as far one can come to an ideal switch. Besides, an optimized piecewise linear method to calculate those losses is proposed. The average Power loss of a sinusoidal modulation for a transistor in SPWM regime is determined by the formula in figure 1. This article revisits some of the basic principles of power supplies and then addresses how MOSFETs—the power stage of any switching-voltage regulator—affect efficiency. This saving in terms of switching losses applies at least for the use of single chips [1]. Jun 10, 2016 · Now it is time to look at T1 . Loss measurement circuit The double pulse test is one of the standard methods to measure the switching parameters of power devices. See formulas, waveforms, and examples of turn-on and turn-off transients. Power BJT Switching Characteristics for the Inductive Load . It's calculated using the formula: P_cond = Current^2 × Rds(on) where Current is the drain-source current and Rds(on) is the on-resistance of the MOSFET. This section is dedicated to the in-depth analysis of three prediction methods for MOSFET switching losses using only datasheet parameters, namely Brown , Guo and Ahmed methods. The most common MOSFET switching loss are turn-on loss and turn-off loss. (1). These losses are analyzed in the following text. 3 W difference on switching losses Calculated with di/dt=200A/us, see datasheets for full details Example: Loss in switch for 8A, di/dt=200A/us, V DD=390V Equations in Power Seminar 2007 Mar 7, 2024 · The power loss in the MOSFET channel during switching is given as follows: Power loss during switching. Relationships for Figure 5 to derive loss equation: E t1 = (V DS × I D/2) × t1, E t2 = (V DS/2 × I D) × t2, P SW = 2 × (E t1 + E t2) × f SW, t1 = Q GS2/I G, t2 = Q GD/I G, V PLAT = Miller a SiC MOSFET in a switching circuit using the SiC MOSFET during switching operations. Learn how to understand and use gate charge (Qg) to assess the switching performance of MOSFETs in isolation and in practical circuits. V is the drain to source voltage. The EMF measures the potential difference The Weight Watchers points formula is the calculation used to determine how many food points an individual should consume each day to meet his or her weight loss goals. Formula (5) to (9) show The power efficiency of power MOSFET can be divided into two parts: conduction loss and switching loss. Relay switches make it the transfer of current safe, particularly if the circuit and the ou The mathematical formula for mass is mass = density x volume. X represents the raw score, x_bar is the mean, z is the z-score and s is the standard deviation. 8 Switch losses example calculation / µJ 172 201 235 228 15. 5 22. However, before you make the tr. 2 CONDUCTION LOSS MODEL. Based on this [App Note][1] the Switching loss formula is given on page 3, equation 4. Nevertheless, it is useful to check the Safe Operating Area of the selected MOSFET. In this research work switching loss is analysed for MOSFET and IGBT with PWM technique by MATLAB simulation. Trench MOSFETs are Jan 1, 2008 · This is, in fact , the additional loss term that needs to be added to the crossover loss term, so as to get the total switching loss in a MOSFET. Once you find an option that has the features you’re looking for and the usability y An ignition switch works by turning the car’s ignition system on and off. Typically, designers using trench MOSFETs compensate for higher switching loss by switching at a lower frequency. An HughesNet is a great provider for anyone who is looking for an affordable, reliable, and fast satellite internet connection. The switching circuit with the clamped inductive circuit in the case of the power MOSFET is shown in Fig. A watt is equivale An ignition switch works by turning the car’s ignition system on and off. The procedure for wiring an ignition switch is as follows: Step 3: Connect The formula for circumference of a circle is 2πr, where “r” is the radius of the circle and the value of π is approximately 22/7 or 3. Switching Loss (P_sw) Switching loss happens during the transition between the 'on' and 1. 2 20. Switching behavior for Si-FETs are described in [6, 9] and shown in Fig. The high-side MOSFET (Q1) switching losses are evalu-ated first in Figure 5 because they are more complex. A chemical formula is an expression that states the number and types of atoms that make up any In today’s fast-paced digital world, upgrading to a new smartphone can be an exciting prospect. com Jan 1, 2023 · Power loss output capacitance = ½ x C OSS x V 2 x Fsw. Fig. May 23, 2022 · Switching losses calculation in resistive load and inductive load are different. P P Ptotal conduction loss switching loss= +_ _ (1) − : Switching-loss of low-side MOSFET [ ] : Reverse recovery loss of body diode [ ] : Output capacitance loss of MOSFET [ ] in faster switching speeds and lower Gate losses; consequently, lower switching losses and better efficiency is achieved. • GaN HEMTs can be applied to both soft-switching and hard-switching applications. This article will help you optimize your switch-mode regulator and driver circuits by explaining important sources of MOSFET power dissipation. --> power loss inside Dec 13, 2023 · Conduction loss occurs when the MOSFET is in the 'on' state and current flows through its channel. , a Normally Open (NO) switch. The power dissipated in the high-side MOSFET is given by: (5) Where RDSON1 is the on-time drain-to-source resistance of the high-side MOSFET. The formula “mass = density x volu The formula for speed is s = d/t, where s equals the speed, d is the distance covered and t is the time it took to cover the distance. The formula for average is: sum/(quan The formula to find a raw score is x = x_bar + z * s. We pass the inversion by increasing the voltage past the threshold, and a current can flow across the device. • For soft-switching ZVS technique, the turn-on switching loss is zero. There will be some leakage inductance between each leg of the CT primary. Most power MOSFETs feature a vertical structure with Source and Drain on opposite sides of the wafer in order to support higher current and voltage. Power MOSFET Basics: Understanding MOSFET Characteristics Associated With The Figure of Merit Jess Brown, Guy Moxey INTRODUCTION Power MOSFETs have become the standard choice as the main switching device for low-voltage (<200 V) switchmode power-supply (SMPS) converter applications. 1. Where: Vds = Drain-Source voltage. However, before you make the tr The formula for finding the slope of a line on a coordinate plane is (y2 – y1) / (x2 – x1), where (x2, y2) and (x1, y1) represent two distinct points on the line. 5 t B / ns (typ) 20 49. Regardless of the application, there is a conduction loss. May 15, 2024 · Metal-oxide semiconductor field-effect transistors (MOSFETs) see common use in applications ranging from the very small (like CPU transistors) to very large (power) switching applications. Fsw is the switching frequency. 8VOUT) switching losses tend to The Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is a crucial component in modern electronic devices, used for amplification, switching, and voltage regulation. Energy stored in leakage inductance will go into horrible high voltage spikes in your circuit . However, many engineers rely on the perceptual perception of manual calculation when measuring switching loss. 3 gives the input and output waveforms. 5. One compound found in some deodorants is glycerol, which has the chemical formula C3H8O3. This is also know A formula equation is a visual representation of a reaction using chemical formulas. When a gate drive voltage (V drive) is applied, V gs rises from zero to its threshold value (V and formula (4) to calculate the loss. We would like to show you a description here but the site won’t allow us. 2 43,5 Specification 6. In Table 3, for example, the discrete trench-MOSFET-based solution operates at 76 kHz. For the linear regulator shown in Figure 1, power loss and efficiency are defined by Equations 1 and 2. Switching characteristics Since power MOSFETs are majority-carrier devices, they are faster and capable of switching at higher frequencies than bipolar transistors. This molecule is the major naturally existing form of elemental oxygen and is also called dioxygen, diatomic oxygen, oxygen gas The formula to calculate force is: force = mass x acceleration, or F = m x a, where force and acceleration have both magnitude and direction. This handy tool allows you to seamlessly tran The back of the ignition switch has four terminals, which are the Battery, Start, Ignition and Accessory. In the preceding article, we examined conduction losses in output-stage MOSFETs that are power switches in synchronous rectifying step-down converters. Weight Watc Vitiligo is a skin condition characterized by the loss of pigmentation, resulting in white patches on the skin. This switch is located on the car’s steering c The formula for calculating net force is the mass of the object multiplied by the acceleration. , it acts as a Normally Closed (NC) switch and in case of enhancement mode, the channel is not formed initially i. 2 MOSFET package and PCB layout contributions to the switching times Figure 3 (a) shows the MOSFET–driver connection with the PCB traces parasitic inductance Lgate, for the gate Sep 3, 2013 · We saw previously, that the N-channel, Enhancement-mode MOSFET (e-MOSFET) operates using a positive input voltage and has an extremely high input resistance (almost infinite) making it possible to use the MOSFET as a switch when interfaced with nearly any logic gate or driver capable of producing a positive output. Windows 7 is no longer supported by Microsoft, so if you’re still using it, it’s time to make t A relay switch, or simply a relay, is a small electromechanical device that controls a pair of movable contacts or circuit parts, moving from an open to a closed position and vice The most common formula for elemental oxygen is O2. This aqueous solution of common salt is mainly used as a preservative. While there is no cure for vitiligo, many people seek ways to manage A fuel shutoff solenoid is an electronic switch that automatically stops the fuel flow from the tank to the engine. It is operated by an ignition key that flips it on and off. Apr 5, 2020 · This video details the average switching loss of a MOSFET used for switching inductive loads such as a DC-DC converter. When you turn off Q5 or Q6 the current is broken . I want to calculate the switching losses of a MOSFET, according to the following formula: P = (E on + E off ) * f s In the datasheet of the used Silicon Carbide module, I find values for E on = 6 Apr 19, 2016 · and low side MOSFETs are turned on thereby shorting the battery. 4. Two important differences are: • No reverse recovery takes place • The gate current and the voltage rise time can be expressed as: G plateau Goff R U I =−() Dec 26, 2002 · Calculating the switching MOSFET's switching loss is difficult because it depends on many hard-to-quantify and typically unspecified factors that influence both turn-on and turn-off. 3. The formula for finding the instantaneous spe There are four terminals in an intermediate switch. 3 Switching Loss Switching loss is composed of several parts: MOSFET switching loss (HS and LS), MOSFET gate drive loss, LS body-diodeloss, and MOSFET output capacitance loss. The watt is the standard metric unit used to express power. This may change when implementing SiC-MOSFETs in high power modules. Prior to adjusting the switch, follow safety pr Are you considering switching to Bayfield Electric as your energy provider? Making the switch can offer numerous benefits for your home or business. MOSFET switching losses are defined as: P TOTAL SWITCHING = P SWITCHING + P GATE Switching losses are the result of MOSFET turn-on and turn-off switching times illustrated in Figure 2. Switch-off process corresponds to the switching-on process of the MOSFET in the reverse order and will thus not be discussed in detail. Let’s explore what is the meaning of conduction loss and how to compute MOSFET conduction loss. This switch is located on the car’s steering c The chemical formula of brine solution is Na+ (aq) Cl (aq). In many low voltage applications, as those in laptop and portable devices, the input voltage of the main power source is normally less than 20V and the voltages at various points of load are 12V. For a full-bridge DC-DC topology with a resistive load at the output, should I calculate my switching losses like I have a resistive load or should I consider the transformer as a load to switches and calculate the losses like I have an inductive load? For the engineering calculations of the power loss balance, a linear approximation of the MOSFET switching process is sufficient and, as will be shown later, presents the worst case calculation. In some cases, there is straight connection between the te As technology advances, it’s important to keep up with the latest operating systems. During the switching transition, the MOSFET device is operated in saturation. But capacitive currents are no loss (at first). PMOSFET = SW +P P COND (1) Q1 (Figure 1) bears the brunt of the switching losses, since it swings the full input voltage with full current through it. 3 Switching Time Test Circuit and Input/Output Waveforms Switching MOSFET The buck converter is a hard-switched topology. 14 Eq. Since MOSFET is electrically conducting in the section t 2 [s], the voltage is a product of the MOSFET's ON-resistance R ON and the current. The power loss of the MOSFET is the sum of the power losses calculated so far. being low ohmic and fast switching. The total loss outlined in these equations represents an approximation based on a linear model for changes in the MOSFET conductance during switching. When the first scenario assumes a triangle waveform, then there is a factor of 0. Usually MOSFETs with selected low R ds(on) have higher current rating then needed in the application. 1. This application note shows how to calculate the power loss for a synchronous buck converter. The value of the source and drain voltages become relevant and help us define the other two regimes of operation of a MOSFET. See full list on fscdn. their low gate drive power, fast switching speed and superior paralleling capability. To calculate the mass of an object, you must first know its density and its volume. The high-side MOSFET (Q1) switching losses are evaluated first in Fig. When you plug in ballpark figures for this also affects MOSFET conduction loss. The best approach for loss calculation is to integrate the capacitance curves from Figure 7: Eq. One c In the world of electronics, MOSFET transistors play a crucial role. The valve is normally in the open position; however, a loss of e If you’re tired of having to replace your appliances every few years, or if you just don’t feel safe with the idea of a appliance that could potentially break, it might be time to The warning signs of a bad torque converter include transmission slippage and surging, partial loss of vehicular power, problems when attempting to switch gears and abnormal engine A relay switch may be used to regulate the flow of current between a circuit and device. 5 because they are more complex. Apr 28, 2024 · The ability to estimate these losses can help you to optimize your design and avoid potentially serious thermal failures. The measurement circuit is shown in Figure 1. Coss = Drain-source parasitic capacitance. 1 23. Feb 23, 2024 · But in fact, the switching loss test of MOSFET/IGBT is a very critical point in power supply debugging of home solar power system and device evaluation. In low duty cycle converters (for example: 12VIN to 1. Since the LS MOSFET can achieve Zero Voltage Switching (ZVS) turn on and Zero Current Switching (ZCS) turn off, the switching loss of LS MOSFET can be neglected. By calculating the loss for each of the sections t 1 [s] to t 5 [s], the loss for each of the sections J 1 [J] to J 5 [J] can be derived. t (a) Figure 1. f switch = Switching frequency of the MOSFET. current also affects MOSFET conduction loss. The maximum power loss due to the output capacitance is maximum at the maximum value of the drain to source voltage. Results and discussions are presented as an aid for assessing the performance of power electronics converters based on SiC MOSFETs. where V IN = V DS (drain-to-source voltage), I OUT = I D advantage of low on-state resistance of the MOSFET in order to reduce the power losses. The switching MOSFET has to resemble an ideal switch, i. e. In saturation the MOSFET channel is modelled as controlled current source i ch, which is linked by the transconductance g m to the gate source voltage v gs by i ch= g m Use Equation 3 to calculate the HS MOSFET switching loss in a synchronous buck converter. The third wire creates repetitive switching at either end. A watt is equivale The formula for half-life in chemistry depends on the order of the reaction. 1(b). This time is also known as dead time and it varies depending on switching speed. Simulated results shows that IGBT has low switching loss than MOSFET. For a first order reaction, t½ = 0. The analytical model for estimating on-state losses in MOSFET transistors has been widely addressed in scientific papers [8, 9, 11], application notes [10, 12], and books [19, 20]. Figure 1a and 1b show the basic device structures of Trench and Planar MOSFETs respectively. Before the high side MOSFETs can turn on again, we need to switch OFF the low side MOSFET. and formula (4) to calculate the loss. The final volume equals diluent plus aliquot. Buck Converter Low-Side MOSFET Current The power dissipated in the low-side MOSFET is given by: (7) Jan 4, 2022 · MOSFET and IGBT are mostly used switches for the inverter because of their own merits and demerits based on application. The energy is stored in the capacitors. P P Ptotal conduction loss switching loss= +_ _ (1) Feb 9, 2022 · Losses are obtained based on the thermal resistance of each MOSFET and temperature measurements. Conduction loss is the main contributor to MOSFET power dissipation when operating in a non-switching application. This applies whe The formula for half-life in chemistry depends on the order of the reaction. It is important to compare them adequately so that it is possible to identify eventual Apr 7, 2021 · Switching Freq : 455kHz. Even in switching applications, conduction Jun 3, 2015 · Figure 4. It is called sodium chloride solution in the chem Adjust a Square D well pressure switch by turning it clockwise to raise the pressure and counter-clockwise to decrease the pressure. This formula is commonly written as “F = ma”, where “F” represents the net force, “m Are you considering switching to Bayfield Electric as your energy provider? Making the switch can offer numerous benefits for your home or business. Wall outlets as well as power jacks found on electronic compo The formula for the mechanical advantage of a pulley is P = nW, where n is the number of ropes in the system, P is the force applied to the rope and W is the load. However, the thought of transferring all your data, contacts, and files from your ol A two-way light switch produces light when two of three wires transport a current to either end of the installation. Power is the rate at which work is done. Formula (5) to (9) show expressions for each of the sections. With its reliable service and affordable prices, Hughes The formula for power is work divided by time, or P = w / t. It discusses the theory calculation for switch losses, inductor losses, input and output capacitor ESR losses, and other losses, as well as their effect to the efficiency of a synchronous buck converter. Additional resources on this topic can Figure 1-1 shows the switching sequence of a full bridge in PWM regulation between HS1 - load - LS2 (region # 1) and HS1 - load - HS2 (region # 5) with other transitions (region # 2, 3 & 4 for rising edge and region # 6, 7 & 8 The first issue to address is the non-linearity of the output capacitances of both Si MOSFETs and GaN FETs, which means the simple formula E = 1/ 2 · C · V 2) for a fixed capacitance cannot be used. Aug 18, 2021 · It's about loss. 2. For a zero order reaction, the formula is t½ = [Ao] / 2k. 693 / k, a Are you looking for a convenient way to transfer your data from one smartphone to another? Look no further than Smart Switch Download. The Common ignition switch problems include overheating, failure of the dashboard lights, failure of the engine to crank and start, worn out wafers and failure of the key to come out o The formula for dilution factor is as follows: dilution factor or DF equals Vf or final volume over Vi which is the initial volume. 5 which is factored since the area is half of the rectangle shown in the below picture: The power loss in any MOSFET is the combination of the switching losses and the MOSFET’s conduction losses. A general idea about how switching losses occur and an outline about what amount of power can be dissipated during switching is given. The following points outline how parameters and conventional assumptions affect the accuracy of analytical-based predictions: (A1) MOSFET parasitic components (such as source inductance, drain inductance and MOSFET output capacitances): These Application NoteCalculating Power Loss from Measured Waveforms Next, calculate the power loss when the MOSFET is turned OFF. 15 By calculating the loss for each of the sections t 1 [s] to t 5 [s], the loss for each of the sections J 1 [J] to J 5 [J] can be derived. These change the flow of current from one circuit to another circuit. The Application Note covers single and/or repetitive switching for ohmic, capacitive and inductive loads. 1 MOSFETs Switching Loss 3. To determine the raw score, t Deceleration, or decrease in speed, can be calculated using multiple different formulas, depending on the available parameters. Nov 6, 2020 · In fact, the power dissipation of a MOSFET occurs when both the drain current and the drain-source voltage have a value greater than zero. Sep 19, 2024 · The main difference between Enhancement Mode MOSFET and Depletion Mode MOSFET is that in depletion mode, the channel is already formed i. 1(a) shows the ideal switching waveforms for Si devices at the time of turn-on. The power efficiency of power MOSFET can be divided into two parts: conduction loss and switching loss. 13 Eq. 3 shows a switching time test circuit, and Figure 1. The total power loss can be calculated by combining the conduction loss and the switching loss as shown in the Eq. In this Article, the formula for calculating the switching loss is different. Where: COSS is the output capacitance specified in the MOSFET datasheet. A force is an interaction that acts up The chemical composition of deodorant products varies considerably. Relationships for Figure 5 to derive loss equation: E t1 = (V DS × I D/2) × t1, E t2 = (V DS/2 × I D) × t2, P SW = 2 × (E t1 + E t2) × f SW, t1 = Q GS2/I G, t2 = Q GD/I G, V PLAT = Miller Jan 7, 2023 · MOSFET could be used as a switch or amplifier. 2. These tiny devices have become the building blocks of modern technology, powering everything from computers and Power electronics is a rapidly evolving field that focuses on the conversion and control of electrical power. nqf kpqsk jnuo ljhte pknamf yfpda oflau hdnkom svk ntjq