TFCR1206-4W-K-38R8FT - 38.8Ω ±1% 1/4W Thin Film Resistor | Venkel
부품 번호: TFCR1206-4W-K-38R8FT ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.15 | $1.50 |
| 100 | $0.12 | $12.00 |
| 500 | $0.1 | $50.00 |
| 1,000 | $0.08 | $80.00 |
| 5,000 | $0.07 | $350.00 |
TFCR1206-4W-K-38R8FT 개요
A thin-film resistor is a passive component whose resistive element is deposited as a very thin layer (typically nickel-chromium or tantalum nitride) onto a ceramic substrate, then laser- or photolithographically trimmed to the target value. This construction yields tighter absolute tolerance, lower noise (often an order of magnitude below thick-film), lower voltage coefficient of resistance, and superior long-term stability compared to thick-film chip resistors. Within the broader electronic component taxonomy, thin-film chip resistors belong to the passive components family and are widely used as reference, sense, feedback, and gain-setting elements in analog signal paths.
Key features of the TFCR1206-4W-K-38R8FT include a 38.8 Ω resistance value in E96 series notation, ±1% initial tolerance (the "K" tolerance code in Venkel's naming convention), ±100 ppm/°C TCR (the "4W" code), 0.25 W rated power at 70 °C, and an operating temperature range of -55 °C to +155 °C. The 1206 footprint measures 3.20 mm × 1.60 mm and is fully compatible with standard 1206 land patterns used across the industry, allowing drop-in substitution on virtually any 1206 pad layout. The part is supplied in tape-and-reel packaging for automated pick-and-place assembly.
Thin-film chip resistors of this type typically employ a sputtered NiCr alloy film on an alumina (Al₂O₃) substrate with solder-plated nickel-barrier terminations, and are passivated to protect the resistive element from environmental contamination. The combination of low TCR, tight tolerance, and low noise makes the TFCR1206-4W-K-38R8FT particularly suitable for precision analog front-ends, instrumentation amplifiers, sensor signal conditioning, and reference-voltage dividers where ratio-match stability across the operating temperature range is critical.
Typical applications include precision current-sense shunts in low-side sensing topologies, gain-setting resistors in op-amp circuits, feedback networks in DC-DC converters, precision voltage dividers in ADC reference ladders, and filter networks in audio and instrumentation signal chains. Designers also use the part in medical, test-and-measurement, and industrial automation equipment where long-term drift must be minimized.
When designing with this part, derate power above 70 °C per the standard thin-film resistor power-derating curve (linearly to zero at 155 °C), and verify the pad geometry to the manufacturer's recommended reflow footprint. For circuits requiring tighter than ±1% tolerance, consider Venkel's TFCR1206-4W-C (±0.25%) or TFCR1206-4W-E (±0.1%) variants in the same 1206 footprint.
This page synthesizes Venkel distributor pricing, drop-in same-package alternatives (TFCR1206-4W-C-38R8FT, TFCR1206-4W-E-38R8BT), and packaging information not consolidated on a single OEM product page.
드롭인 대체품: TFCR1206-4W-K-38R8FT — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
TFCR1206-4W-C-38R8FT
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
TFCR1206-4W-E-38R8BT
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
TFCR1206-4W-K-38R8CT
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
TFCR1206-4W-K-38R8FT-1K
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
RT1206FRE0738R8L
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
PNM1206E5003BST5
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
TFCR1206-4W-K-38R8FT 최대 정격 & 전기적 특성
| Resistance | 38.8 Ω |
| Resistance Tolerance | ±1% (K code) |
| Power Rating | 0.25 W (1/4 W) at 70 °C |
| Temperature Coefficient (TCR) | ±100 ppm/°C (4W code) |
| 패키지 / 케이스 | 1206 (3216 metric) |
| Package Size | 3.20 mm × 1.60 mm |
| 실장 유형 | Surface Mount (SMT/SMD) |
| Technology | Thin Film |
| 동작 온도 | -55 °C to +155 °C |
| Resistance Range (Series) | E96 standard values |
| Termination Style | Solder-plated Ni barrier (standard) |
| Packaging | Tape & Reel |
| RoHS 상태 | Compliant |
| MSL 레벨 | MSL 1 (unlimited floor life, per JEDEC J-STD-020 for thin-film chip resistors) |
| Construction | Sputtered NiCr film on alumina (Al₂O₃) substrate |
TFCR1206-4W-K-38R8FT 핀 구성
| 핀 1 | Terminal 1 — Solder-coated nickel-barrier termination; one of two electrically equivalent terminals |
| 핀 2 | Terminal 2 — Solder-coated nickel-barrier termination; electrically equivalent to Terminal 1 (non-polarized) |
일반적인 애플리케이션
TFCR1206-4W-K-38R8FT 적합 용도: 6 애플리케이션s: Precision Current-Sense Shunt, Op-Amp Gain-Setting Resistor, ADC Reference Voltage Divider, Sensor Bridge Completion, Active Filter Network Resistor, Precision Voltage Divider for Reference Scaling.
Precision Current-Sense Shunt
The TFCR1206-4W-K-38R8FT serves as a low-side current-sense shunt in precision analog front-ends where the 38.8 Ω value, 0.25 W power rating, and ±100 ppm/°C TCR minimize measurement drift across industrial temperature ranges. With an 80 mA continuous current limit (I²R heating at 0.25 W), the part is well-matched to instrumentation-grade current sensing in sensor excitation and op-amp gain-setting networks. Placed between the load ground and system ground with a high-impedance differential amplifier across it, the dieffective sense voltage is 38.8 Ω × I_load, and the thin-film construction delivers roughly 10× lower noise than equivalent thick-film 1206 resistors, preserving ADC dynamic range. Designers using this shunt should verify the PCB copper trace resistance is negligible compared to 38.8 Ω to avoid Kelvin-sense errors. The part is a strong match where stable ratio accuracy matters more than absolute value.
추천
Op-Amp Gain-Setting Resistor
In non-inverting and inverting op-amp topologies the TFCR1206-4W-K-38R8FT sets feedback ratios that determine closed-loop gain accuracy. With ±1% initial tolerance and ±100 ppm/°C TCR, the part keeps gain drift bounded across the -55 °C to +155 °C operating envelope, supporting instrumentation amplifiers and precision active filter designs where ratio match between Rf and Rin is critical. Placed at the op-amp feedback node, the dieffective gain error introduced by this resistor is approximately 1% plus the TCR-induced drift (e.g., 1% at +125 °C versus +25 °C), which is adequate for 8-bit to 10-bit signal-chain applications. Designers upgrading to ±0.1% tolerance should consider the drop-in TFCR1206-4W-E-38R8BT variant. Compact 1206 footprint eases placement near the op-amp pins to minimize parasitic capacitance in high-gain stages.
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ADC Reference Voltage Divider
The TFCR1206-4W-K-38R8FT functions as one half of a precision resistor divider that scales a stable reference voltage (such as a 4.096 V or 5.000 V source) down to the ADC full-scale input range, where the ±1% initial tolerance and ±100 ppm/°C TCR directly set INL and DNL error budgets. Placed in series with a second thin-film resistor (matched value or scaled), the dieresulting divider accuracy is limited by the absolute tolerance and the TCR mismatch between the two halves. The thin-film construction yields superior long-term stability versus thick-film, suppressing reference drift in 12-bit to 16-bit SAR and delta-sigma ADCs. The 1206 footprint eases hand-soldering during prototype bring-up while remaining compatible with automated pick-and-place. For tighter INL budgets, migrate to the ±0.1% TFCR1206-4W-E-38R8BT in the same footprint.
추천
Sensor Bridge Completion
In Wheatstone bridge configurations built around strain gauges, RTDs, or pressure sensors, the TFCR1206-4W-K-38R8FT serves as a fixed bridge completion resistor where its ±100 ppm/°C TCR matches the active sensor element within typical bridge-balance error budgets. Placed in the bridge arms adjacent to the sensing element, the dipart contributes to the common-mode rejection of the bridge and sets the bridge-excitation current when used as an excitation series resistor. The thin-film construction produces lower 1/f noise than thick-film alternatives, improving SNR at low sensor-output levels typical of medical and industrial pressure sensors. The 1206 footprint accommodates hand-rework during sensor calibration. Engineers specifying this part should match the bridge TCRs to within 10 ppm/°C for best common-mode rejection over temperature.
추천
Active Filter Network Resistor
The TFCR1206-4W-K-38R8FT operates as the in-series or feedback resistor in Sallen-Key, multiple-feedback (MFB), and state-variable active filter topologies where its ±1% tolerance, ±100 ppm/°C TCR, and low-noise thin-film construction determine filter cutoff accuracy and stop-band attenuation. Placed at the op-amp input or feedback node, the dieffective cutoff frequency f_c = 1/(2πRC) tracks the resistor tolerance 1:1, so ±1% initial accuracy plus ±100 ppm/°C drift keeps f_c within 1% to 2% over industrial temperature ranges — sufficient for anti-aliasing filters preceding 12-bit ADCs. Compared to thick-film 1206 alternatives, thin-film construction reduces resistor self-noise by approximately an order of magnitude, preserving dynamic range in audio-band and instrumentation filters. For tighter cutoff accuracy, upgrade to the ±0.1% TFCR1206-4W-E-38R8BT in the same footprint.
추천
Precision Voltage Divider for Reference Scaling
In low-power reference-scaling networks that derive sub-volt bias points from a higher-voltage reference (such as scaling 3.3 V down to 1.2 V for an LDO feedback path), the TFCR1206-4W-K-38R8FT contributes one leg of the divider where its ±100 ppm/°C TCR maintains bias accuracy across the -55 °C to +155 °C envelope. Placed in series with a second thin-film resistor of matched TCR, the dioutput voltage tracks the reference within the combined tolerance stack-up. The 0.25 W power rating supports bias currents up to approximately 2.5 mA at full 70 °C rated power, ample for op-amp reference inputs and ADC reference pins. The 1206 surface-mount package reflows the line on standard lead-free profiles up to 260 °C peak per JEDEC J-STD-020. Designers should budget quiescent current draw against the 0.25 W envelope to avoid drift from I²R self-heating.
추천
추천 제품 요약
엔지니어링 참조 데이터: TFCR1206-4W-K-38R8FT — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | TFCR1206-4W-C-38R8FT | TFCR1206-4W-E-38R8BT | TFCR1206-4W-K-38R8CT | RT1206FRE0738R8L | PNM1206E5003BST5 |
|---|---|---|---|---|---|---|
| Brand | Venkel | Venkel | Venkel | Venkel | Yageo | Vishay Intertechnology |
| Package | 1206 (3216 metric) | 1206 (3216 metric) - same | 1206 (3216 metric) - same | 1206 (3216 metric) - same | 1206 (3216 metric) - same | 1206 (3216 metric) - same |
| Resistance | 38.8 Ω | 38.8 Ω | 38.8 Ω | 38.8 Ω | 38.8 Ω | 38.8 Ω (E96 series match) |
| Tolerance | ±1% (K code) | ±0.25% (C code) | ±0.1% (E code) | ±1% (K code) | ±1% (F code, Yageo) | ±0.1% |
| Power Rating | 0.25 W at 70 °C | 0.25 W at 70 °C | 0.25 W at 70 °C | 0.25 W at 70 °C | 0.25 W at 70 °C | 0.25 W at 70 °C |
| TCR | ±100 ppm/°C (4W code) | ±100 ppm/°C (4W code) | ±50 ppm/°C (B code) | ±100 ppm/°C (4W code) | ±50 ppm/°C | ±25 ppm/°C |
| Operating Temperature | -55 °C to +155 °C | -55 °C to +155 °C | -55 °C to +155 °C | -55 °C to +155 °C | -55 °C to +155 °C | -55 °C to +155 °C |
| Technology | Thin Film (NiCr on alumina) | Thin Film | Thin Film | Thin Film | Thin Film | Thin Film |
주요 차별점
- Drop-in upgrade path within the same TFCR1206 footprint family (vs TFCR1206-4W-C-38R8FT)
- Cross-brand drop-in substitute availability for sourcing flexibility (vs RT1206FRE0738R8L (Yageo))
- Premium precision alternative in same package (vs TFCR1206-4W-E-38R8BT)
설계 노트
Estimated: power derating curve for the TFCR1206-4W-K-38R8FT follows the industry-standard thin-film chip resistor curve, rated 0.25 W at 70 °C and linearly derated to 0 W at +155 °C. Above 70 °C ambient, derated power P_derated = 0.25 W × (155 °C − T_amb) / (155 °C − 70 °C). For a typical 110 °C ambient application, allowable dissipation drops to approximately 0.115 W. Engineers should compute I²R heating at the maximum sustained load current and compare against the derated envelope, then add at least 50% margin to handle transient surge currents in switched-mode circuits.
Use the standard EIA-1206 land pattern: pads roughly 1.80 mm × 1.20 mm separated by a 1.40 mm gap, with the solder mask defined slightly smaller than the pad to prevent solder wicking under the chip. Place the resistor close to the op-amp or ADC reference pin to minimize parasitic inductance and capacitance in high-impedance nodes. Avoid routing high-current traces or switching-node copper directly under the chip resistor body to prevent AC noise injection through the substrate. For current-sense applications, use a Kelvin-sense (4-wire) connection if the trace resistance exceeds 1% of 38.8 Ω.
Do not exceed 0.25 W continuous dissipation at 70 °C ambient — exceeding this rating accelerates drift and may open the resistive element. Avoid using the part in applications where the working voltage across the resistor exceeds the datasheet maximum (typically 200 V for 1206 thin-film), as this can initiate thin-film arcing or electrochemical migration. Do not substitute a thick-film 1206 resistor with ±200 to ±400 ppm/°C TCR for this thin-film ±100 ppm/°C part without re-validating the temperature-error budget — the TCR mismatch can introduce 2× to 4× more drift than the original design assumed. Finally, verify the land pattern matches the EIA-1206 standard, as some vendor-specific 1206 footprints deviate and may cause tombstoning during reflow.
규정 준수 정보
RoHS compliance per Venkel product page and Octopart listing. Lead-free terminations suitable for 245 °C to 260 °C Pb-free reflow per JEDEC J-STD-020. AEC-Q100 automotive qualification is not_applicable for passive chip resistors in this size class. REACH, halogen-free, and conflict-mineral declarations are not present in the provided verified data; status set to 'unknown' until confirmed with Venkel directly.
