LTS-5325CTB-P LED Digital Tube Datasheet - 0.56 Inch Character Height - Blue - 3.8V Forward Voltage - 70mW Power Consumption - Simplified Chinese Technical Documentation

1. Product Overview

LTS-5325CTB-P na'urar haɗawa ta saman (SMD) ce, wacce aka ƙera don nuna alamar lamba ɗaya. Babban aikinta shine samar da bayyanannun lambobi ko iyakantattun alamomin haruffa masu haske a cikin na'urorin lantarki. Babban fasahar ta ta dogara ne akan InGaN (Indium Gallium Nitride) blue LED guntu wanda aka girma akan sapphire substrate, wannan fasahar sananniya ce don samar da ingantaccen haske mai haske. Na'urar tana amfani da allon launin toka don samun bambanci mai girma, kuma tana amfani da fararen kayan sashi don yada haske, wanda ke haifar da kyakkyawan bayyanar haruffa.

1.1 Key Features and Advantages

• Digital Size:It adopts a large character height of 0.56 inches (14.22 mm), ensuring excellent visibility even from a long distance.
• Segment Quality:Provide continuous, uniform segments to achieve consistent and professional visual output, without gaps or irregularities.
• Energy Efficiency:Low power consumption design, suitable for battery-powered applications or those emphasizing energy efficiency.
• Optical Performance:Provides high brightness and high contrast, ensuring clear readability even in well-lit environments.
• Viewing Angle:Provide a wide viewing angle, allowing clear reading of the display content from different positions.
• Reliability:Thanks to solid-state reliability, with no moving parts, it has a long service life and is resistant to shock and vibration.
• Quality Control:Devices are graded (binned) according to luminous intensity to ensure brightness levels remain consistent within specified ranges for particular orders.
• Environmental Compliance:The packaging is designed lead-free and complies with the RoHS (Restriction of Hazardous Substances) directive.

1.2 Device Configuration

This is a common cathode display. The specific model LTS-5325CTB-P indicates a blue (B) display with a right-side decimal point (DP). The common cathode configuration simplifies circuit design when using microcontrollers or driver ICs that sink current.

2. Technical Parameters: In-depth and Objective Interpretation

This section provides a detailed and objective analysis of the device's operational limits and performance characteristics under specified conditions.

2.1 Absolute Maximum Ratings

These are stress limits that must not be exceeded under any conditions, as doing so may cause permanent damage to the device. Operation should always remain within the recommended operating conditions detailed subsequently.

• Power consumption per segment:Maximum 70 mW. This is the total electrical power (current * voltage) that can be safely converted into light and heat within a single segment.
• Peak forward current per segment:Maximum 30 mA, but only under pulse conditions (1/10 duty cycle, 0.1 ms pulse width). This rating applies to brief high-current pulses, not continuous operation.
• Continuous forward current per segment:A 25°C, maximum 25 mA. When ambient temperature (Ta) exceeds 25°C, this current derates linearly by 0.28 mA per °C increase. For example, at 85°C, the maximum continuous current is approximately: 25 mA - [0.28 mA/°C * (85°C - 25°C)] = 25 mA - 16.8 mA = 8.2 mA.
• Operating and storage temperature range:-35°C to +105°C. The device can be stored or operated over this full range.
• Soldering temperature:Can withstand 260°C soldering iron for 3 seconds. The soldering iron tip must be placed at least 1/16 inch (≈1.6 mm) below the package mounting plane.

2.2 Electrical and Optical Characteristics

These parameters define the typical performance of the device when operating under its recommended conditions (Ta=25°C).

• Average luminous intensity (I_V):At a forward current (I_F) of 10 mA, the range is from 8600 µcd (minimum) to 28500 µcd (typical). This wide range indicates the devices are binned; the specific intensity grade will be specified in the ordering information.
• Forward voltage per chip (V_F):At I_F=5 mA, typical value is 3.8V, maximum value is 3.8V. This is the voltage drop across the LED when it is lit. Designers must ensure the drive circuit can provide this voltage.
• Peak emission wavelength (λ_p):468 nm. This is the wavelength at which the emitted light intensity is highest, located precisely in the blue region of the visible spectrum.
• Dominant Wavelength (λ_d):470 nm. This is the single wavelength perceived by the human eye as representative of the light color, very close to the peak wavelength.
• Spectral Line Half-Width (Δλ):25 nm. This indicates spectral purity; a smaller value means the light is more monochromatic (purer in color). 25 nm is a typical value for standard blue LEDs.
• Reverse current (I_R):At a reverse voltage (V_R) of 5V, maximum 100 µA. This parameter is for test purposes only; the device is not designed for reverse bias operation.
• Luminous intensity matching ratio:A cikin sashin "Ƙananan haske iri ɗaya", mafi girma shine 2:1. Wannan yana nufin hasken sashin mafi haske bai kamata ya wuce sau biyu na hasken sashin mafi duhu ba, don tabbatar da daidaito.
• Tsangwama:An ƙayyade shi zuwa ≤ 2.5%. Wannan yana nufin ɓarkewar haske ko tsangwama na lantarki da ba dole ba tsakanin sassan maƙwabta.

2.3 Electrostatic Discharge (ESD) Protection

LEDs are highly sensitive to electrostatic discharge. The datasheet strongly recommends implementing ESD control measures during handling and assembly to prevent latent or catastrophic damage.

• Personnel should use grounded wrist straps or anti-static gloves.
• All workstations, equipment, and storage facilities must be properly grounded.
• It is recommended to use an ion fan (ion blower) to neutralize the static charge that may accumulate on the surface of plastic packaging due to friction during handling, especially for non-diffusion (N/D) types.

3. Bin System Description

The datasheet clearly states that the devices are "classified according to luminous intensity." This implies the existence of a binning system, although specific bin codes are not detailed in this excerpt. Typically, such systems include:

• Luminous intensity binning:LEDs from a production batch are tested based on their measured light output at a standard test current (e.g., 10 mA) and sorted into different groups (bins). This ensures customers receive LEDs with consistent brightness within predefined ranges (e.g., 8600-12000 µcd, 12000-18000 µcd, etc.). The wide spread from minimum to typical values in the characteristics table (8600 to 28500 µcd) supports this practice.
• Forward Voltage Binning:Although not explicitly mentioned here, LEDs are typically also binned based on forward voltage (V_F) to ensure uniform current distribution when multiple LEDs are connected in parallel.
• Wavelength Binning:For applications with stringent color requirements, LEDs may also be binned based on dominant wavelength or peak wavelength to ensure color consistency. A tight specification (λ_d= 470 nm) indicates a controlled process, but binning may still be performed for high-grade tiers.

4. Performance Curve Analysis

The datasheet includes a "Typical Electrical/Optical Characteristics Curves" section. While specific curves are not provided in the text, these typically include the following curves crucial for design:

• Relative Luminous Intensity vs. Forward Current (I-V Curve):Shows how the light output changes with increasing drive current. It is typically nonlinear, tending to saturate at higher currents.
• Forward Voltage vs. Forward Current:It describes the relationship between voltage and current, which is crucial for designing current-limiting circuits or constant-current drivers.
• Relative Luminous Intensity vs. Ambient Temperature:It shows how the light output decreases as the LED junction temperature increases. This is critical for thermal management in applications.
• Spectral Power Distribution:A chart showing the intensity of emitted light at each wavelength, confirming the blue and spectral width.

Designers should refer to these curves to optimize the drive current for the desired brightness, understand voltage requirements, and plan for thermal effects.

5. Mechanical and Packaging Information

5.1 Package Dimensions

This device complies with specific SMD package dimensions. Key dimensional descriptions include:

• All dimensions are in millimeters, unless otherwise specified, general tolerance is ±0.25 mm.
• Segment area quality standard: Foreign matter ≤ 10 mil, ink contamination ≤ 20 mil, bubble ≤ 10 mil.
• Reflector curvature must be ≤ 1% of its length.
• Burrs on the plastic pins must not exceed 0.14 mm.

Engineers must use the provided dimension drawing (not fully detailed in the text) to create the correct PCB pad pattern.

5.2 Pin Configuration and Polarity

The device uses a 10-pin configuration. Pin 1 is marked in the diagram. The pin arrangement is as follows:

• Pin 1: Segment E Anode
• Pin 2: Segment D Anode
• Pin 3: Common Cathode 1
• Pin 4: Segment C Anode
• Pin 5: Decimal Point (DP) Anode
• Pin 6: Segment B Anode
• Pin 7: Segment A Anode
• Pin 8: Common Cathode 2
• Pin 9: Segment F Anode
• Pin 10: Segment G Anode

The internal circuit diagram shows that all segment anodes are independent, while the cathodes of all segments are internally connected to two pins (3 and 8), which must be connected together on the PCB to form a common cathode.

5.3 Recommended Land Pattern

The recommended PCB land pattern is provided to ensure reliable solder joint formation and proper alignment during the reflow soldering process. This pattern takes into account the package dimensions and solder paste volume requirements.

6. Welding and Assembly Guide

6.1 SMT Welding Instructions

Key Instructions for Surface Mount Assembly:

• Reflow soldering (primary method):
  • Preheating: 120–150°C.
  • Preheating time: maximum 120 seconds.
  • Peak temperature: up to 260°C.
  • Time above liquidus: up to 5 seconds.
• Soldering iron (for repair/rework only):
  • Soldering iron temperature: maximum 300°C.
  • Contact time: maximum 3 seconds per solder joint.
• Critical limitation:The component can withstand a maximum of two reflow process cycles. After the first reflow, the board must be completely cooled to room temperature before the second reflow process (e.g., for double-sided assembly).

6.2 Moisture Sensitivity and Storage

SMD displays are shipped in moisture barrier packaging. To prevent "popcorn" phenomenon (package cracking caused by rapid moisture expansion during reflow), the following storage conditions must be observed:

• Storage:Unopened packaging bags should be stored in an environment with a temperature ≤ 30°C and relative humidity ≤ 60%.
• Exposure time:Once the sealed bag is opened, the moisture absorption process begins. Components have a limited "floor life" under ambient conditions.
• Baking:If components are exposed to environmental humidity beyond their safe limits, they must be baked before reflow to remove moisture. Baking should be performed only once to avoid thermal stress.
  • Components on reels: Bake at 60°C for ≥ 48 hours.
  • Bulk components: Bake at 100°C for ≥ 4 hours or at 125°C for ≥ 2 hours.

7. Packaging and Ordering Information

7.1 Packaging Specifications

This device is supplied in tape and reel format, suitable for automatic surface-mount assembly.

• Carrier Tape:Made of black conductive polystyrene alloy. Dimensions comply with EIA-481-D standard.
• Carrier Tape Dimensions:Includes specific pocket dimensions to securely hold components. Warpage is controlled to not exceed 1mm over a length of 250mm.
• Reel Information:
  • Standard packaging length per 22-inch reel: 44.5 meters.
  • Number of components per 13-inch reel: 700 pieces.
  • Minimum order quantity for remainder/end of reel: 200 pieces.
• Lead Tape and Tail Tape:The reel includes a lead tape (at least 400 mm) and a tail tape (at least 40 mm) for machine feeding.

8. Application Suggestions and Design Considerations

8.1 Typical Application Scenarios

• Test and Measurement Equipment:Digital multimeters, oscilloscopes, power supplies, require clear digital readouts.
• Consumer Electronics:Audio amplifiers, home appliance displays (microwave ovens, ovens), fitness equipment.
• Industrial Control:Panel meters, process indicators, timer displays.
• Automotive Aftermarket:Ga buƙatar ma'auni da na'urorin nuni masu haske sosai.

8.2 Design Considerations

• Current Drive:Always use a constant current driver or a current limiting resistor in series with each segment anode. Based on the supply voltage (V_cc), typical LED forward voltage (V_F~ 3.8V) and required forward current (I_F, for example, to achieve good brightness within limits, take 10-20 mA) to calculate the resistance value. Example: R = (V_cc- V_F) / I_F.
• Thermal Management:Although the power consumption per segment is low, if multiple segments are lit simultaneously for an extended period, especially under high ambient temperatures, ensure sufficient PCB copper area or thermal vias. Remember the current derating rules.
• Microcontroller Interface:For common cathode displays, microcontroller pins typically sink current (acting as ground switches). Use GPIO pins configured as open-drain/low-level output or dedicated LED driver ICs with sufficient current sinking capability. Ensure the total current drawn from the power supply is within its rating.
• ESD protection in the circuit:In the final application, consider adding Transient Voltage Suppression (TVS) diodes or other protective measures on the lines connected to the display, especially if these lines are exposed to the user interface or external connectors.

9. Technical Comparison and Differentiation

Although the datasheet does not directly compare it with other models, based on its specifications, the key differentiators of the LTS-5325CTB-P are:

• Compared to smaller-sized displays (e.g., 0.3-inch):With its larger 0.56-inch character height, it provides superior visibility at long distances.
• Comparison with through-hole LED displays:SMD packaging supports automated assembly, reduces PCB space, and allows for a lower profile height in the final product.
• Comparison with standard brightness LEDs:Its high typical luminous intensity (up to 28500 µcd at 10mA) makes it suitable for applications requiring high brightness.
• Compared to unbinned LEDs:Luminous intensity binning provides designers with more predictable and uniform brightness across all segments and multiple units, which is crucial for professional-looking equipment.

10. Frequently Asked Questions (based on technical parameters)

1. Q: What is the difference between peak wavelength (468 nm) and dominant wavelength (470 nm)?
   A: Peak wavelength is the position of strongest physical light output. Dominant wavelength is the single wavelength that represents the perceived color by the human eye. They are usually close, as shown here, but can differ for some colors. Both confirm this is a blue LED.
2. Q: Can I drive this display with a 5V power supply and a resistor?
   A: Yes. Using a 5V power supply (V_cc) and a typical V_Fvalue of 3.8V, you need a current-limiting resistor. For I_F=10 mA: R = (5V - 3.8V) / 0.01A = 120 Ω. Use the next standard value, such as 120 Ω or 150 Ω. Be sure to verify actual brightness and power consumption.
3. Q: Why are there two common cathode pins (3 and 8)?
   A: This is for current handling and PCB layout flexibility. The total cathode current is the sum of all illuminated segment currents. Having two pins allows this current to be split, reducing the current density per pin and improving reliability. Both pins must be connected to ground on your PCB.
4. Q: The maximum number of reflow cycles is two. What should I do if I need a third rework on the board?
   A: This is strongly discouraged. A third reflow subjects the plastic package and internal connections to excessive thermal stress, significantly increasing the risk of failure. For rework, use a soldering iron (max 300°C, 3 seconds) with extreme care only on the specific solder joints requiring repair, avoiding heating the entire component.
5. Q: How to understand the 2:1 luminous intensity matching ratio?
   A: This means that within a single display unit, under the same driving conditions, the brightness of the brightest segment should not exceed twice the brightness of the darkest segment. This ensures the visual uniformity of the displayed characters.

11. Practical Design and Use Cases

Case: Designing a simple digital voltmeter reading

A designer is creating a 0-30V DC voltmeter using a microcontroller with ADC. The LTS-5325CTB-P is selected for its good readability.

1. Circuit design:The microcontroller's I/O pins are connected to the segment anodes (A-G, DP) through 150 Ω current-limiting resistors (calculated for a 5V system). The two common cathode pins are connected together and attached to a single NPN transistor (e.g., 2N3904) used as a low-side switch, controlled by a microcontroller pin. This allows for multiplexing when needed, but for a single digit, it can be kept constantly illuminated.
2. Software:The microcontroller reads the ADC value, converts it to a voltage, and then maps this value to the correct 7-segment pattern (0-9). The segment data is sent to the corresponding I/O pins.
3. PCB Layout:Use the recommended land pattern from the datasheet for the package. Add thermal relief pads at the pad connections to facilitate soldering. Ensure a robust ground connection for the common cathode.
4. Assembly:The circuit board is assembled using a standard lead-free reflow profile, ensuring the peak temperature does not exceed 260°C. Components undergo only one reflow cycle.
5. Results:The final product displays a clear, bright, and uniform blue voltage reading.

12. Introduction to Working Principle

LTS-5325CTB-P e fa'agaoioia i le mataupu fa'avae o le fa'amalama eletise i totonu o le p-n junction semiconductor. O lona mea fa'agaoioia o le InGaN (indium gallium nitride). Pe a fa'aogaina se voluma sa'o e sili atu i le voluma amata o le diode (pe tusa ma le 3.3-3.8V), e fa'auluina mai le vaega n-type ma le vaega p-type i totonu o le vaega fa'agaoioia. Pe a toe fa'atasi nei ave fe'avea'i, latou te fa'amatu'u atu le malosi i foliga o photon (malamalama). O le tu'ufa'atasiga patino o le u'amea InGaN e fuafua ai le malosi o le va o le fusi, ma fa'amatala ai le umi o le galu o le malamalama e fa'aolaina (lanu) – i lenei fa'ata'ita'iga, o le lanumoana (~470 nm). O le mea fa'avae safaira e maua ai se fa'ata'ita'iga tioata mo le fa'atupuina o vaega InGaN maualuga. O le laulau efuefu ma mea fa'ailoga vaega pa'epa'e e fai ma fa'asalalau ma fa'ateleina le fa'atusatusaga, e fa'atulagaina ai le malamalama e fai ma vaega numera e iloagofie.

13. Fa'asologa o tekinolosi ma le talaaga.

O lenei masini e fai ma sui o se tekinolosi ua matua ma ua lautele le fa'aaogaina. O le fa'aogaina o le InGaN i luga o le safaira e fai ai le LED lanumoana o se faiga masani tau pisinisi. O fa'asologa o tekinolosi fa'aaliga e maua ai le talaaga mo lenei vaega e aofia ai:

• Miniaturization:Although 0.56 inches is a common size, there is a trend towards even smaller, high-brightness SMD digital tubes for ultra-compact devices.
• Efficiency Improvement:Continuous advancements in materials science have improved the luminous efficacy (lumens per watt) of InGaN LEDs, enabling higher brightness at lower currents or reduced thermal loads.
• Integration:There is a trend toward integrating LED displays with their driver ICs and microcontrollers into more complete "smart display" modules, simplifying end-product design.
• Color Options and RGB:Although this is a monochromatic blue light display, the underlying InGaN technology is also the basis for producing green light and, when combined with phosphors, white light LEDs. Full-color RGB displays using miniature SMD LEDs are also becoming more common for more complex graphic displays.
• Alternative Technologies:For certain applications, OLED (Organic Light-Emitting Diode) displays offer advantages in thinness and viewing angles, but may have different lifespan and brightness characteristics compared to such inorganic LEDs.

For digital display applications requiring simple, bright, durable, and preferably SMD assembly, the LTS-5325CTB-P remains a robust, reliable, and cost-effective solution.

Detailed Explanation of LED Specification Terminology

Complete Explanation of LED Technical Terminology

I. Core Indicators of Photoelectric Performance

Terminology	Unit/Representation	Popular Explanation	Why It Is Important
Luminous Efficacy	lm/W (lumens per watt)	The luminous flux emitted per watt of electrical energy, the higher the more energy-efficient.	Directly determines the energy efficiency class and electricity cost of the luminaire.
Luminous Flux	lm (lumen)	The total amount of light emitted by a light source, commonly known as "brightness".	Determine if the lamp is bright enough.
Viewing Angle	° (degree), such as 120°	The angle at which light intensity drops to half, determining the beam's width.	Affects the illumination range and uniformity.
Color Temperature (CCT)	K (Kelvin), e.g., 2700K/6500K	The warmth or coolness of light color; lower values are yellowish/warm, higher values are whitish/cool.	Determines the lighting atmosphere and suitable application scenarios.
Color Rendering Index (CRI / Ra)	No unit, 0–100	The ability of a light source to reproduce the true colors of objects, Ra≥80 is recommended.	Affects color fidelity, used in high-demand places such as shopping malls and art galleries.
Color Tolerance (SDCM)	MacAdam Ellipse Steps, e.g., "5-step"	Quantitative indicator of color consistency, smaller step value indicates better color consistency.	Ensure no color difference among luminaires from the same batch.
Dominant Wavelength	nm (nanometer), e.g., 620nm (red)	Wavelength values corresponding to colored LED colors.	Determine the hue of monochromatic LEDs such as red, yellow, and green.
Spectral Distribution	Wavelength vs. Intensity Curve	It shows the intensity distribution of light emitted by an LED across various wavelengths.	It affects color rendering and color quality.

II. Electrical Parameters

Terminology	Symbols	Popular Explanation	Design Considerations
Forward Voltage	Vf	Minimum voltage required to turn on an LED, similar to a "starting threshold".	The driving power supply voltage must be ≥ Vf, and the voltage adds up when multiple LEDs are connected in series.
Forward Current	If	The current value that allows the LED to emit light normally.	Constant current drive is commonly used, where the current determines brightness and lifespan.
Maximum Pulse Current	Ifp	Peak current that can be withstood in a short time, used for dimming or flashing.	Pulse width and duty cycle must be strictly controlled, otherwise overheating damage.
Reverse Voltage	Vr	The maximum reverse voltage that an LED can withstand; exceeding it may cause breakdown.	A cikin da'ira, ya kamata a hana haɗin baya ko kuma ƙarfin lantarki mai ƙarfi.
Thermal Resistance	Rth (°C/W)	The resistance to heat flow from the chip to the solder joint. A lower value indicates better heat dissipation.	High thermal resistance requires a stronger cooling design; otherwise, the junction temperature will increase.
Electrostatic Discharge Immunity (ESD Immunity)	V (HBM), such as 1000V	Anti-static strike capability, the higher the value, the less susceptible to damage from static electricity.	Anti-static measures must be implemented during production, especially for high-sensitivity LEDs.

III. Thermal Management and Reliability

Terminology	Key Indicators	Popular Explanation	Impact
Junction Temperature	Tj (°C)	The actual operating temperature inside the LED chip.	For every 10°C reduction, the lifespan may double; excessively high temperatures cause lumen depreciation and color shift.
Lumen Depreciation	L70 / L80 (hours)	The time required for brightness to drop to 70% or 80% of its initial value.	Directly defines the "useful life" of an LED.
Lumen Maintenance	% (e.g., 70%)	Percentage of remaining brightness after a period of use.	Characterizes the ability to maintain brightness after long-term use.
Color Shift	Δu′v′ or MacAdam Ellipse	The degree of color change during use.	Affect the color consistency of the lighting scene.
Thermal Aging	Material performance degradation	Degradation of packaging materials due to prolonged high temperature.	May lead to decreased brightness, color shift, or open-circuit failure.

IV. Encapsulation and Materials

Terminology	Common Types	Popular Explanation	Characteristics and Applications
Package Type	EMC, PPA, Ceramic	The housing material that protects the chip and provides optical and thermal interfaces.	EMC offers good heat resistance and low cost; ceramic provides excellent heat dissipation and long lifespan.
Chip structure	Front-side, Flip Chip	Chip Electrode Layout Method.	Flip-chip offers better heat dissipation and higher luminous efficacy, suitable for high-power applications.
Phosphor coating	YAG, silicate, nitride	Covered on the blue light chip, partially converted into yellow/red light, mixed into white light.	Different phosphors affect luminous efficacy, color temperature, and color rendering.
Lens/Optical Design	Flat, Microlens, Total Internal Reflection	Optical structure on the encapsulation surface, controlling light distribution.	Determines the emission angle and light distribution curve.

V. Quality Control and Binning

Terminology	Grading Content	Popular Explanation	Purpose
Luminous Flux Grading	Codes such as 2G, 2H	Grouped by brightness level, each group has a minimum/maximum lumen value.	Ensure uniform brightness for products within the same batch.
Voltage binning	Codes such as 6W, 6X	Grouped by forward voltage range.	Facilitates driver power matching and improves system efficiency.
Color Grading	5-step MacAdam Ellipse	Group by color coordinates to ensure colors fall within a minimal range.	Ensure color consistency to avoid uneven colors within the same luminaire.
Color temperature binning	2700K, 3000K, etc.	Grouped by color temperature, each group has a corresponding coordinate range.	To meet the color temperature requirements of different scenarios.

Six, Testing and Certification

Terminology	Standard/Test	Popular Explanation	Meaning
LM-80	Lumen Maintenance Test	Long-term illumination under constant temperature conditions, recording brightness attenuation data.	Used to estimate LED lifetime (combined with TM-21).
TM-21	Standard for Life Projection	Projecting the lifespan under actual use conditions based on LM-80 data.	Providing scientific lifespan prediction.
IESNA standard	Standard of the Illuminating Engineering Society	Covers optical, electrical, and thermal testing methods.	Industry-recognized testing basis.
RoHS / REACH	Environmental certification	Ensure the product does not contain harmful substances (e.g., lead, mercury).	Conditions for access to the international market.
ENERGY STAR / DLC	Energy Efficiency Certification	Energy efficiency and performance certification for lighting products.	Yawan da ake amfani da shi a cikin sayayyar gwamnati da ayyukan tallafi, don haɓaka gasar kasuwa.