1206 Package 249Ω 0.5W High Power Thick Film Chip Resistor CRH Series SMD

CRH1206F249RP05Z Technical Parameters | 1206 249R 0.5W Ever Ohms High Power Resistor

CRH1206F249RP05Z is a standard part number in the CRH high-power thick film chip resistor series from EVER OHMS (TA-I). It combines an imperial 1206 (metric 3216) package with a nominal resistance of 249Ω, ±1% tolerance, and a 0.5W power rating at 70°C ambient. While conventional 1206 thick film resistors are typically rated at 0.25W, this Ever Ohms 1206 249R 0.5W resistor doubles the power handling within the same footprint — a practical advantage when board space is limited and upgrading to 1210 or 1812 is not an option.

The 249Ω value belongs to the E96 precision series, making it a common choice for feedback dividers, current-sensing branches, snubber networks, and signal conditioning circuits across power supplies, industrial controls, LED drivers, and automotive auxiliary electronics.

Part Number Decoding

Key Electrical Parameters

Parameters are compiled from the public CRH series specification; always verify against the latest official datasheet before mass production.

A frequent miscalculation deserves emphasis: the 200V figure is the component's voltage withstand ceiling. At 249Ω, the real operating boundary is set by power dissipation, not by voltage rating. Above roughly 11V continuous, the 0.5W thermal limit is reached first. This calculation should be documented in the design review.

Derating and Thermal Design

Full 0.5W is available at ambient temperatures ≤70°C. Above 70°C, power derates linearly to zero at 155°C. Enclosed enclosures, still-air conditions, and placements near MOSFETs or transformers require derating checks.

• A typical engineering practice is to keep a 30%–50% power margin, meaning long-term actual dissipation should stay around 0.25W–0.35W.
• PCB layout materially affects temperature rise: enlarge pad copper, provide a copper pour under the component, and avoid thin traces exiting from one side only.
• Drift budgeting: at ±100ppm/°C, a rise from 25°C to 125°C adds roughly ±1% drift; combined with the initial ±1% tolerance, worst-case deviation approaches ±2%. Tighter applications must reserve margin accordingly.

Construction and Reliability

• Alumina substrate: 96% purity alumina conducts heat from the resistive element through the body to the terminations and solder joints, forming an effective thermal path.
• Ruthenium-based thick film element: screen-printed metal glaze paste fired at high temperature, with a larger conductive cross-section than standard 0.25W thick film parts. A glass glaze overcoat provides moisture, corrosion, and abrasion resistance.
• Laser trimming: achieves the ±1% tolerance band with good lot-to-lot consistency suitable for automated production.
• Three-layer termination: inner conductive layer, nickel barrier, and lead-free tin outer plating suppress silver migration and electrode sulfuration — beneficial in sulfur-bearing industrial atmospheres or inside battery packs.
• Soldering compatibility: supports lead-free reflow and wave soldering; reflow peak temperature generally kept within 260°C with dwell time per IPC/JEDEC J-STD-020 and the manufacturer's spec. Resistance to soldering heat complies with IEC 60115-1 test conditions.

For humidity and endurance performance, refer to the official EVER OHMS datasheet; CRH family parts are characterized under 85°C/85%RH long-term loading and high-temperature load life tests with resistance change held within specified limits.

Typical Applications

• Power modules: feedback divider networks, soft-start, and surge suppression in 12W–60W AC-DC/DC-DC converters; 249Ω suits low-current limiting and bleed paths, while the 0.5W headroom absorbs turn-on transients.
• LED drivers: divider and sensing elements in constant-current circuits; the ±100ppm/°C TCR helps maintain current stability across temperature.
• Industrial control: PLC digital input divider/limiter circuits, sensor signal conditioning, relay coil snubbing; thick film construction tolerates vibration and thermal shock well.
• Automotive electronics: signal conditioning and divider networks in on-board chargers and body control modules. Confirm AEC-Q200 qualification for the specific sub-type when used in automotive projects.
• Communications and consumer electronics: bias, divider, and dummy-load circuits in routers, adapters, and fast-charging boards.

Comparison with Standard 1206 Resistors

Replacing an overheating or early-failing 0.25W 1206 249Ω resistor with CRH1206F249RP05Z usually requires no pad or layout change — the most common adoption route for this part.

Purchasing Notes

• Verify the full part number: the "Z" suffix denotes lead-free process; older packaging may use alternate packaging codes such as "S".
• Distinguish CR from CRH: identical packages but different power ratings. Double-check part numbers during kitting and IQC to prevent mixing.
• Evaluate pulse conditions: for circuits with repeated pulse energy, check pulse energy and peak voltage against the safe operating area in addition to continuous power.
• Request compliance documents: RoHS/REACH reports, material declarations, and AEC-Q200 evidence where applicable.
• Plan stock early: 1206 0.5W is a fast-moving item, but E96 precision values carry less on-hand depth than E24 general values.

Recommended Distributors

Sourcing passive components through authorized channels affects both authenticity and lot consistency. Two channels worth engaging:

• Shenzhen Shunhai Technology Co., Ltd. : an authorized distributor of EVER OHMS, covering the full range of thick film and thin film SMD resistors. Based in Longhua, Shenzhen, Shunhai supports samples, BOM kitting, and monthly payment terms — suitable for R&D and production programs requiring genuine parts and stable supply.
• (HuaNian Mall): an online electronic components platform offering stock checks and small-batch ordering across multiple CRH series resistance values, convenient for prototyping, pilot runs, and urgent top-ups.

Before placing volume orders, request the latest datasheet and batch reports from either channel and cross-check them against your design requirements.

Note: Parameters herein are compiled from publicly available EVER OHMS CRH series technical data. Final values are subject to the manufacturer's latest datasheet and the order's technical agreement.