RT1206BRD073K4L

Product overview – RT1206BRD073K4L

RT1206BRD073K4L is a YAGEO RT series high precision, high stability thin film chip resistor in a 1206 (3216 metric) surface‑mount package. It provides a resistance of 3.4 kΩ with a tight tolerance of ±0.1% and a rated power of 0.25 W (1/4 W) at 70 °C.

The RT series spans multiple case sizes (0100, 0201, 0402, 0603, 0805, 1206, 1210, 2010, 2512), all based on the same thin film technology and lead‑free terminations. RT1206BRD073K4L sits in the middle of this portfolio as a 1206 device, balancing power handling with PCB area, and is suitable for a wide range of precision circuits in converters, printing equipment, server boards, telecom systems and consumer electronics.

With halogen‑free epoxy and RoHS‑compliant materials, RT1206BRD073K4L aligns with modern environmental and regulatory requirements while supporting long‑term stability in demanding electronic systems.

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2.

Core electrical specifications of RT1206BRD073K4L

RT1206BRD073K4L belongs to the RT thin film high‑precision family characterized by:

- Resistance value: 3.4 kΩ

- Tolerance options in the RT series: from ±0.01% to ±1% (RT1206BRD073K4L specifically is ±0.1%, code “B”)

- Power rating at 70 °C (RT1206): 0.25 W (1/4 W)

- Temperature Coefficient of Resistance (TCR) options in the RT series: 5, 10, 15, 25, 50 ppm/°C (coded A–E)

- Maximum continuous working voltage: determined by √(P × R) or the series’ specified limit, whichever is lower

For RT1206BRD073K4L, the rated working voltage can be approximated using the formula defined for the RT series:

V = √(P × R) = √(0.25 W × 3400 Ω) ≈ √850 ≈ 29 V rms or DC, limited further if the series maximum working voltage for 1206 is lower.

This combination of tolerance and thin film technology allows RT1206BRD073K4L to support precise gain setting, reference divider networks and other analog front‑end roles where tight matching and low drift are needed.

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3.

Thin film construction and materials of RT1206BRD073K4L

RT1206BRD073K4L follows the standard RT series thin film construction:

- High‑grade ceramic body provides mechanical strength and thermal stability.

- Internal metal electrodes are formed at each end of the chip.

- A resistive thin film layer bridges the electrodes; its value is set by deposition and then laser‑trimmed to achieve the specified resistance.

- A protective coating covers the resistive layer, providing environmental and handling protection.

- The resistance value is printed on the body according to the RT marking scheme for this size.

- External matte tin terminations form the solderable interfaces to the PCB.

In practical terms, this architecture supports low noise, stable resistance and predictable behavior over time and temperature. For example, in a precision ADC driver stage where gain accuracy needs to be maintained across years of operation, the ceramic substrate and thin film layer of RT1206BRD073K4L can help keep offset and gain errors under control compared with thicker‑film alternatives.

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4.

Package size, dimensions and PCB footprint considerations for RT1206BRD073K4L

RT1206BRD073K4L uses the 1206 package from the RT series, with a nominal size of 3.2 mm × 1.6 mm (3216 metric). The RT series datasheet associates each outline code (0100 to 2512) with specific mechanical dimensions shown in its outline and dimension tables (table 1 and figure 5). RT1206BRD073K4L corresponds to the RT1206 outline.

Key implications for PCB design with RT1206BRD073K4L include:

- Sufficient pad length to support robust solder joints while managing current flow and thermal dissipation.

- Adequate spacing to neighboring components, especially in high‑density designs, to respect creepage/clearance and reflow behavior.

- Matching the footprint to the recommended land pattern given in the separate “Chip resistors mounting” datasheet referenced for the RT series.

In a real‑world example, a power supply feedback divider with multiple RT1206BRD073K4L‑class components may be laid out with slightly extended pads to improve heat spreading and mechanical strength, while keeping trace stubs short to reduce noise pickup and parasitics.

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5.

Power rating, rated voltage and derating behavior of RT1206BRD073K4L

Within the RT series, the power rating is defined as a function of case size at an ambient temperature of 70 °C:

- RT0100: 1/32 W

- RT0201: 1/20 W

- RT0402: 1/16 W

- RT0603: 1/10 W

- RT0805: 1/8 W

- RT1206: 1/4 W

- RT1210: 1/4 W

- RT2010: 1/2 W

- RT2512: 3/4 W

RT1206BRD073K4L, as an RT1206 device, is rated at 0.25 W at 70 °C.

Rated voltage for RT1206BRD073K4L is given by:

V = √(P × R) or the maximum working voltage specified by the RT series, whichever is lower, where:

- V is the continuous DC or AC (rms) working voltage

- P is the rated power (0.25 W for RT1206)

- R is the resistance in ohms (3.4 kΩ for RT1206BRD073K4L)

The RT series includes a derating curve (figure 6) showing maximum dissipation as a percentage of rated power versus ambient temperature (Tamb). Above 70 °C, allowable power decreases linearly until reaching zero at the upper temperature limit defined by the RT series.

In use, if RT1206BRD073K4L is mounted near heat‑generating components, such as MOSFETs or power inductors, the effective ambient temperature at the resistor may be higher than the system ambient. Designers typically calculate dissipation (P = V²/R or I²R) in RT1206BRD073K4L and then apply the derating curve to ensure that the actual power remains comfortably below the derated limit.

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6.

Precision, TCR options and value coding in the RT series including RT1206BRD073K4L

RT1206BRD073K4L is part of a broad precision range in the RT series, which offers:

Tolerance codes

- L: ±0.01%

- P: ±0.02%

- W: ±0.05%

- B: ±0.1%

- C: ±0.25%

- D: ±0.5%

- F: ±1%

RT1206BRD073K4L uses the tolerance code “B”, corresponding to ±0.1%.

TCR (Temperature Coefficient of Resistance) codes

The RT series defines TCR options from 5 ppm/°C to 50 ppm/°C, abbreviated as:

- A = 5 ppm/°C

- B = 10 ppm/°C

- C = 15 ppm/°C

- D = 25 ppm/°C

- E = 50 ppm/°C

These TCR options allow matching RT1206BRD073K4L‑class components to the temperature stability needs of the target circuit. For precision voltage references or instrumentation amplifiers, lower‑ppm options can be selected, while less demanding applications may choose 25–50 ppm/°C for cost or availability reasons.

Resistance value coding

For the global part number format of the RT series, the resistance is encoded with 2–4 characters, using R/K/M as decimal points. The specific example for RT1206BRD073K4L follows this scheme:

- “3K4” in the part number indicates 3.4 kΩ

In E‑series terms, RT1206BRD073K4L’s 3.4 kΩ value is part of the precision range defined by E‑24/E‑96/E‑192 systems, where the series itself notes that E‑192 values are available on request. This structured coding and series coverage makes it straightforward to build fine‑stepped resistor ladders or matched networks around RT1206BRD073K4L.

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7.

Marking scheme and identification for RT1206BRD073K4L in the RT series

The RT series defines different marking rules by size and E‑series classification:

- RT0100 / RT0201 / RT0402 and any resistance value not in E‑24 / E‑96 series: no marking.

- RT0603: uses up to 3‑digit markings, with special handling of some E‑24 values (10/11/13/15/20/75) indicated by a short bar under the marking letter.

- RT0805 / RT1206 / RT1210 / RT2010 / RT2512:

- 4‑digit marking for either E‑24 or E‑96 values.

- First three digits: significant figures.

- Fourth digit: number of trailing zeros.

RT1206BRD073K4L, as a 1206 device in the RT series, follows the 4‑digit marking system. For example, a 10 kΩ RT1206 device would be marked “1002” (100 × 10² Ω). The precise printed marking corresponding to 3.4 kΩ depends on the internal E‑series code mapping but adheres to the same 4‑digit rule.

For more detailed marking options (including special series variants), YAGEO refers to a separate “Chip resistors marking” datasheet. For board‑level inspection, automated optical inspection (AOI) systems can use these 4‑digit codes to verify that RT1206BRD073K4L or similar parts have been correctly placed and oriented.

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8.

Environmental compliance and reliability features of the RT series and RT1206BRD073K4L

RT1206BRD073K4L benefits from the RT series’ environmental and reliability characteristics:

- RoHS compliant: the RT series uses lead‑free materials, compatible with lead‑free soldering processes.

- Halogen‑free epoxy: helps reduce environmentally hazardous substances and supports compliance with halogen‑related environmental directives and internal corporate standards.

- No forbidden materials used in production: supports adherence to various hazardous substance restriction lists beyond core RoHS rules.

- High component and equipment reliability: derived from the thin film technology, ceramic substrate, protective coatings and controlled terminations.

In practice, these attributes make RT1206BRD073K4L suitable for applications where regulatory compliance and long‑term field performance must be documented, such as telecom infrastructure or high‑availability server systems.

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9.

Typical applications and use cases for RT1206BRD073K4L within the RT series

The RT series, including RT1206BRD073K4L, is targeted at precision roles across several application domains:

- Converters: RT1206BRD073K4L can serve in feedback networks for DC‑DC converters or as gain‑setting resistors in ADC/DAC support circuitry, where ±0.1% tolerance reduces the spread of gain or setpoint.

- Printing equipment: precision resistors like RT1206BRD073K4L can stabilize sensor interfaces, head driver circuits and power monitoring functions over temperature and time.

- Server boards: RT1206BRD073K4L can be used for power rail sense lines, reference dividers and current monitoring circuits, supporting controlled voltage margins and accurate telemetry.

- Telecom: baseband and RF base‑station boards often require precise biasing and gain control; RT1206BRD073K4L’s thin film stability and fine tolerance can be used in such bias networks.

- Consumer: high‑end audio, imaging or measurement devices may use RT1206BRD073K4L where consistency between units and low drift improve user experience and product calibration.

For example, in a telecom power supply, a pair of RT1206BRD073K4L devices can form a high‑precision divider feeding a supervisor IC, ensuring that undervoltage/overvoltage thresholds remain tightly controlled despite temperature swings and long service life.

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10. Ordering information and part-number structure for RT1206BRD073K4L in the RT series

The RT series uses a global part number structure that encodes key parameters of devices such as RT1206BRD073K4L. The part number is composed of fields representing:

1) Size

- Codes include RT0100, 0201, 0402, 0603, 0805, 1206, 1210, 2010, 2512.

- RT1206BRD073K4L uses “RT1206” to denote the 1206 size.

2) Tolerance

- Single‑letter code (L, P, W, B, C, D, F) as described earlier.

- RT1206BRD073K4L uses “B” for ±0.1%.

3) Packaging type

- Specific letters indicating packaging style, as defined in the RT series.

4) Temperature Coefficient of Resistance (TCR)

- A, B, C, D, E for 5, 10, 15, 25, 50 ppm/°C, respectively.

5) Taping reel code

- Indicates tape/reel size and packaging quantities, with some exceptions noted for certain size/TCR/tolerance combinations (e.g., 0805 TC50 1% in 13" reel uses code 02; 0603 TC50 1% in 13" reel uses 03; 2512 TC15 7" reel uses 35; 2010 TC15 7" reel uses 31).

6) Resistance value

- 2–4 characters, using R/K/M as decimal points. For example, “56R” would represent 56 Ω, “3K4” represents 3.4 kΩ as in RT1206BRD073K4L.

- Detailed rules appear in the “Resistance rule of global part number” table in the RT series documentation.

7) Default code

- A field used for internal defaults and series definition.

An example provided by the RT series for a different part is:

RT0603DRE0756RL: an RT0603 resistor, TC50, 56 Ω, ±0.5% tolerance, in a 7" tape reel.

RT1206BRD073K4L fits the same schema, with the size, tolerance, TCR, packaging and resistance appropriately encoded. This standardization simplifies cross‑referencing and managing part libraries in CAD and ERP systems.

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11.

Mechanical robustness and test requirements for RT1206BRD073K4L and the RT series

RT1206BRD073K4L is covered by the RT series’ test methods and requirements, summarized in tables 4 and 5 of the product specification. These cover:

- General performance tests as aligned with IEC 60115‑8, including:

- Visual and mechanical inspection

- Resistance measurement

- Short‑time overload

- Temperature cycling

- Load life tests

- Bending endurance for sizes 0100 through 2512 (table 5), demonstrating how the RT series—including RT1206BRD073K4L—responds to PCB flexing and mechanical stress.

While the detailed numeric limits and procedures are listed in the RT series tables, the presence of these standardized tests indicates that RT1206BRD073K4L is evaluated against defined criteria for resistance change, mechanical integrity and solder joint durability under typical handling and operating conditions.

In a practical assembly scenario, where long PCBs might flex during depanelization or installation, the bending performance data for RT1206BRD073K4L’s 1206 package helps guide panel design, depanelization methods and board support during soldering and testing.

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12.

Conclusion – positioning RT1206BRD073K4L within high‑precision designs

RT1206BRD073K4L combines the RT series’ thin film precision with the widely used 1206 footprint, delivering 3.4 kΩ at ±0.1% tolerance and 0.25 W rated power at 70 °C. Halogen‑free, RoHS‑compliant construction, stable TCR options, and a standardized global part numbering system enable flexible deployment across converters, printing systems, server boards, telecom infrastructure and advanced consumer electronics.

Through its ceramic‑based thin film structure, defined derating behavior, and documented test regime, RT1206BRD073K4L offers a predictable, controllable resistor element for designs that demand consistent electrical characteristics over time and temperature.

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Frequently Asked Questions (FAQ)

Q1. What are the key electrical parameters of RT1206BRD073K4L that need to be checked during selection?

A1. RT1206BRD073K4L provides 3.4 kΩ resistance with ±0.1% tolerance in a 1206 package, rated at 0.25 W at 70 °C. The rated working voltage is determined by V = √(P × R) or the series maximum working voltage, whichever is lower. When selecting RT1206BRD073K4L, it is useful to confirm resistance, tolerance, TCR option, power rating and calculated working voltage against circuit requirements.

Q2. How does the power rating of RT1206BRD073K4L relate to ambient temperature in my design?

A2. RT1206BRD073K4L is rated at 0.25 W at 70 °C ambient. Above 70 °C, the RT series derating curve (figure 6) reduces the allowable power linearly until the upper temperature limit is reached. For example, if the ambient near RT1206BRD073K4L is significantly above 70 °C due to nearby hot components, the permissible dissipation must be reduced accordingly, and the actual P = I²R or V²/R should be kept below that derated value.

Q3. What kind of temperature coefficient (TCR) options are available for RT1206BRD073K4L within the RT series?

A3. The RT series offers TCR codes A, B, C, D, E representing 5, 10, 15, 25 and 50 ppm/°C respectively. RT1206BRD073K4L belongs to this family and can be specified with one of these TCR options, depending on the exact suffix in the global part number. For temperature‑sensitive precision circuits, lower‑ppm variants of RT1206BRD073K4L can be chosen.

Q4. How is the 3.4 kΩ value of RT1206BRD073K4L encoded in its part number?

A4. The RT series uses a resistance field in the global part number with 2–4 characters, where R/K/M denotes the decimal point. For RT1206BRD073K4L, “3K4” represents 3.4 kΩ. This scheme is common across the RT series and allows straightforward interpretation of resistance values from the part number.

Q5. What marking can I expect on the body of RT1206BRD073K4L?

A5. As a 1206 device in the RT series, RT1206BRD073K4L uses a 4‑digit marking scheme shared with RT0805, RT1210, RT2010 and RT2512 sizes. The first three digits represent significant figures and the fourth digit is the multiplier (number of zeros). The exact numeric marking for 3.4 kΩ follows this rule. AOI and inspection processes can use this 4‑digit code to verify correct placement.

Q6. Is RT1206BRD073K4L suitable for lead‑free and environmentally regulated designs?

A6. Yes. The RT series, including RT1206BRD073K4L, is RoHS compliant and uses halogen‑free epoxy. The datasheet notes that no forbidden materials are used in the products or production. This supports compliance with major hazardous substance and environmental standards and simplifies integration into regulated products.

Q7. Can RT1206BRD073K4L be used in high‑reliability or safety‑critical applications?

A7. RT1206BRD073K4L is designed for general‑purpose applications under normal operation and usage conditions, including converters, printing equipment, server boards, telecom and consumer products. The general legal disclaimer from YAGEO emphasizes that specific high‑reliability domains—such as aerospace, atomic energy, aviation, medical life‑support, military, power generation control, traffic signal and similar applications—require direct consultation with YAGEO. RT1206BRD073K4L is not positioned by the datasheet as a dedicated high‑reliability or safety‑critical component.

Q8. How does RT1206BRD073K4L behave under mechanical stress, such as PCB bending?

A8. The RT series includes mechanical robustness data, including a bending test table (table 5) covering sizes 0100 to 2512, which encompasses RT1206BRD073K4L. These tests evaluate how resistance changes and mechanical integrity are maintained when the PCB is flexed. While specific numerical limits are in the RT series tables, the inclusion of RT1206 in these bending tests shows that RT1206BRD073K4L is qualified for typical PCB flexing during handling and assembly, provided recommended mounting and panelization guidelines are followed.

Q9. What mounting and soldering guidelines apply to RT1206BRD073K4L?

A9. For RT1206BRD073K4L, YAGEO refers to the dedicated “Chip resistors mounting” datasheet that provides recommended footprints and soldering profiles. This includes land pattern dimensions, reflow temperature profiles and guidelines for wave or reflow soldering. Adhering to these recommendations helps ensure consistent solder joints and minimizes mechanical or thermal stress on RT1206BRD073K4L during assembly.

Q10. How is the packaging of RT1206BRD073K4L defined and what quantities are available?

A10. RT1206BRD073K4L follows the RT series packing style and quantity rules summarized in table 3 of the product specification, which cover paper and embossed tape options and standard reel sizes. Some special combinations (e.g., 0805 TC50 1% on 13" reels) have specific packing codes. RT1206BRD073K4L uses a packing type and taping reel code encoded in its global part number, ensuring consistent reel format and quantity for automated assembly. Detailed tape and reel dimensions are provided in the separate “Chip resistors packing” datasheet.

Q11. How should I calculate whether RT1206BRD073K4L can handle a specific voltage in my circuit?

A11. For RT1206BRD073K4L, use the rated power (0.25 W for RT1206) and resistance (3.4 kΩ) to calculate the rated working voltage: V = √(P × R). This gives approximately 29 V. Compare the planned operating voltage with this value and also with any maximum working voltage specified for the RT series. The actual operating voltage must not exceed the lower of these limits, and the resulting power dissipation must also respect derating above 70 °C.

Q12. What are typical application examples where RT1206BRD073K4L provides advantages over lower‑precision resistors?

A12. RT1206BRD073K4L’s ±0.1% tolerance and thin film stability make it advantageous in:

- Voltage feedback dividers for converters, where small tolerance reduces output voltage spread.

- Gain‑setting networks in amplifiers, where precision improves gain accuracy and channel matching.

- Sensor signal conditioning, where stable resistance over time and temperature maintains calibration.

Compared with broader‑tolerance thick film resistors, RT1206BRD073K4L reduces the need for per‑unit calibration and allows tighter design margins.

Q13. Are there matching values in other case sizes if RT1206BRD073K4L’s 1206 footprint is not suitable?

A13. The RT series covers multiple sizes—0100, 0201, 0402, 0603, 0805, 1206, 1210, 2010, 2512—built on the same thin film technology and ordering logic. While RT1206BRD073K4L itself is the 1206 implementation at 3.4 kΩ, equivalent 3.4 kΩ parts with similar tolerance and TCR can be found in other RT case sizes using the same global part number structure, allowing footprint changes while keeping electrical characteristics aligned.