3299W-1-103LF - 10kΩ 25-Turn Cermet Trimmer | Bourns
부품 번호: 3299W-1-103LF ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $1.94 | $1.94 |
| 10 | $1.69 | $16.90 |
| 100 | $1.32 | $132.00 |
| 500 | $1.12 | $560.00 |
| 1,000 | $0.97 | $970.00 |
3299W-1-103LF 개요
A trimming potentiometer (trimmer or trim pot) is a precision variable resistor used for fine-tuning circuit parameters during calibration or production, rather than as a user-adjustable control. Trimmers sit within the broader passive components hierarchy alongside fixed resistors, but offer a settable resistance value via a rotating wiper. The 3299 series uses a cermet (ceramic-metal) resistive element, which provides superior temperature stability, lower noise, and longer rotational life compared to carbon-film alternatives, making this category well suited for industrial, instrumentation, and test equipment designs that demand long-term setpoint stability.
Key features include a sealed construction for protection against flux and contaminants during PCB assembly, a multi-turn (25 turn) drive mechanism protected by Bourns Patent #4,427,966 for vibration-resistant setpoint retention, and a PC-pin through-hole termination with integral standoffs. The series is RoHS compliant (the LF suffix denotes the lead-free, RoHS-compliant version), with operating temperature range typically spanning -55 °C to +125 °C, a temperature coefficient of ±100 ppm/°C, and a rotational life rated for 200 cycles minimum.
The 3299W employs a cermet resistive element deposited on a ceramic substrate and contacted by a precious-metal wiper driven through a planetary gear reduction mechanism. The 25-turn gear ratio provides approximately 38° of wiper travel per external turn, giving roughly 0.1% incremental resolution over the full resistance range and far finer setpoint accuracy than single-turn trimmers, which is essential for calibration-critical circuits where a single turn covers the entire adjustment range.
Typical applications include precision calibration of gain and offset in instrumentation amplifiers, setpoint adjustment in voltage references and DC-DC converter feedback networks, calibration of precision sensor signal-conditioning circuits, and trimming of bridge excitation in load cells and strain gauges. The through-hole PC pin package also suits legacy industrial designs, factory automation equipment, and laboratory instrumentation where long-term stability matters more than board density.
When designing with this part, ensure that adjustment torque remains within the datasheet specification (typically 180 g-cm maximum) and avoid using the wiper as a frequent user control - the 200-cycle rotational life is intended for occasional calibration, not continuous actuation. For surface-mount equivalents the Bourns 3314 or PVG5A series may be considered.
This page synthesizes distributor pricing, drop-in trimmer alternatives sharing the same 3/8 inch square PC-pin footprint, and practical design guidance not found directly on the Bourns datasheet alone.
드롭인 대체품: 3299W-1-103LF — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
3299W-1-103
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
3299W-1-203LF
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
3299W-1-503LF
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
3299W-1-203
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
3299W-1-502LF
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
3269W-1-103LF
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
3299W-1-103LF 최대 정격 & 전기적 특성
| Resistance | 10 kΩ |
| Resistance Tolerance | ±10% |
| Number of Turns | 25 turns |
| Power Rating | 0.5 W (1/2 W) |
| Resistive Element | Cermet |
| Adjustment Type | Top Adjustment |
| Termination Style | PC Pins (Through Hole) |
| 패키지 / 케이스 | 3/8 inch square |
| Sealed Construction | Yes |
| Standoffs | Yes (integral) |
| Temperature Coefficient | ±100 ppm/°C |
| 동작 온도 | -55 °C to +125 °C |
| Rotational Life | 200 cycles minimum |
| 실장 유형 | Through Hole |
| RoHS 상태 | Compliant (LF suffix) |
3299W-1-103LF 핀 구성
| 핀 1 | End Terminal (CCW) — Counter-clockwise end of resistive element |
| 핀 2 | Wiper — Adjustable wiper terminal (connects to screwdriver access slot) |
| 핀 3 | End Terminal (CW) — Clockwise end of resistive element |
일반적인 애플리케이션
3299W-1-103LF 적합 용도: 7 애플리케이션s: Instrumentation Amplifier Gain Calibration, Voltage Reference Setpoint Adjustment, DC-DC Converter Feedback Network, Strain-Gauge Bridge Excitation Trim, Audio Circuit Calibration Trimmers, Sensor Signal-Conditioning Offset Trim, Test & Measurement Equipment Calibration.
Instrumentation Amplifier Gain Calibration
The 3299W-1-103LF serves as the gain-set trimmer in three-op-amp instrumentation amplifier circuits where factory calibration trims out resistor tolerance errors. With its 10 kΩ resistance and 25-turn resolution, it can null offset the feedback resistor mismatch in INA128 or AD620 designs to better than 0.1% accuracy. The cermet element provides ±100 ppm/°C tracking with the surrounding metal-film gain resistors, keeping calibrated gain stable from -55 °C to +125 °C. Unlike SMD trimmers, the through-hole stand-off profile survives vibration and rework without breaking the wiper contact, which is critical for laboratory and field instrumentation that must hold calibration for years.
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Voltage Reference Setpoint Adjustment
Precision shunt references like the TL431, LM4040, and ADR01 use an external resistor divider that must be trimmed in production to hit the target output voltage exactly. The 3299W-1-103LF as the upper divider resistor in a 5.000 V reference trim allows ±100 ppm/°C tracking with the metal-film lower resistor and 25-turn resolution to set output within 1 mV of nominal. The 0.5 W power rating handles continuous dissipation in the divider without drift, and the sealed cermet package keeps the wiper contact clean even when the board is conformally coated for industrial or automotive use. This makes it the factory-calibration trimmer of choice for power-supply output voltage trim and ATE reference designs.
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DC-DC Converter Feedback Network
Non-isolated buck, boost, and SEPIC converter feedback dividers often include a trimmer to set the exact regulated output voltage in production. The 3299W-1-103LF placed in the upper or lower feedback resistor position lets factory calibration trim the output to within 1% of nominal at 10 kΩ of adjustment range, far finer than fixed-resistor selection tolerance. The cermet element's ±100 ppm/°C coefficient tracks with the surrounding 1% metal-film divider resistors, minimizing output voltage drift over temperature. The 0.5 W rating comfortably handles continuous dissipation in 12 V-to-5 V rails at typical feedback currents, and the sealed construction protects the wiper from board-level contamination in industrial power designs.
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Strain-Gauge Bridge Excitation Trim
Load cells and strain-gauge signal conditioners use a Wheatstone bridge excited by a precise voltage or current source whose amplitude must be trimmed to calibrate full-scale output. The 3299W-1-103LF set as the calibration resistor in the excitation regulator or reference trim loop allows factory adjustment to within 0.05% over the 10 kΩ range. Its 25-turn resolution captures the small adjustments needed to compensate for active and dummy gauge mismatch, while the sealed 3/8 inch square package resists moisture and contamination in industrial weighing scales and pressure transducers. The ±100 ppm/°C coefficient matches the bridge completion resistors, so calibration holds across the full -40 °C to +85 °C industrial range typical of process-control installations.
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Audio Circuit Calibration Trimmers
Professional audio designs use 3299W-1-103LF cermet trimmers to calibrate gain stages, balance controls, and bias networks in mixer consoles, microphone preamplifiers, and DI boxes. The 10 kΩ value pairs naturally with op-amp feedback networks such as the NE5532, OPA1612, and SSM2019 where the trimmer nulls offset or trims frequency response. The cermet element introduces less than 1 µV of thermal EMF noise and the 0.5 W power rating lets the wiper sit at the bias point without injecting scratchy artifacts during adjustment. Sealed construction keeps dust out of the wiper contact, so the trimmers remain quiet even after years of partial use - a key requirement for low-noise audio paths.
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Sensor Signal-Conditioning Offset Trim
Thermocouple, RTD, and bridge-type sensor front ends require an offset trim to null the inherent sensor error and amplifier input bias. The 3299W-1-103LF inserted into the reference or offset-correction network of MAX31855, ADS1118, or XTR105 designs lets factory calibration compensate for board-leakage-induced offset to better than 10 µV. The 10 kΩ resistance works directly with the typical 1 µA bias currents of precision front ends without overloading the source, and the 25 turns provide fine-grained adjustment so that calibration does not skip past the optimum setpoint. The ±100 ppm/°C temperature coefficient keeps the trimmed offset stable across the full industrial operating range of the sensor module.
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Test & Measurement Equipment Calibration
Digital multimeters, oscilloscope front ends, and arbitrary waveform generators require periodic calibration adjustments that the 3299W-1-103LF supports as a service-accessible internal trimmer. The 10 kΩ value and 25-turn gear ratio give calibration technicians approximately 0.1% per turn of resolution for nulling gain errors in DAC output stages or scaling reference voltages in ADC input paths. The 0.5 W power rating handles the continuous dissipation typical of always-on reference nodes, while the sealed 3/8 inch square package withstands repeated service entry without contaminating the wiper. Many DMM and calibrator designs use this exact Bourns family for TRIM NV memory backup as well as live cal-point trim.
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추천 제품 요약
엔지니어링 참조 데이터: 3299W-1-103LF — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | 3299W-1-103 | 3299W-1-203LF | 3299W-1-503LF | 3269W-1-103LF |
|---|---|---|---|---|---|
| Brand | Bourns | Bourns | Bourns | Bourns | Bourns |
| Package | 3/8 inch square PC pin (TH) | 3/8 inch square PC pin (TH) - same | 3/8 inch square PC pin (TH) - same | 3/8 inch square PC pin (TH) - same | 3/8 inch square PC pin (TH) - same |
| Resistance | 10 kΩ | 10 kΩ | 20 kΩ | 50 kΩ | 10 kΩ |
| Tolerance | ±10% | ±10% | ±10% | ±10% | ±10% |
| Number of Turns | 25 turns | 25 turns | 25 turns | 25 turns | 25 turns |
| Power Rating | 0.5 W | 0.5 W | 0.5 W | 0.5 W | 0.5 W |
| Resistive Element | Cermet | Cermet | Cermet | Cermet | Cermet |
| RoHS Compliant (LF) | Yes (LF suffix) | No (tin-lead) | Yes | Yes | Yes |
| Adjustment Side | Top | Top | Top | Top | Top |
| Unit Price (qty 1, USD) | $1.94 | ~$1.94 | ~$1.94 | ~$1.94 | ~$2.10 |
주요 차별점
- Sealed 3/8 inch square cermet with 25-turn gear drive (vs Single-turn PVG5A SMD trimmer)
- RoHS-compliant LF finish as standard catalog offering (vs 3299W-1-103 (non-LF))
- Integral standoffs for through-hole flux clearance (vs 3269W-1-103LF)
- Cermet element with ±100 ppm/°C TCR (vs Carbon-film 3292 series)
설계 노트
Do not use the 3299W-1-103LF as a frequently-actuated user control. The 200-cycle rotational life rating is for occasional factory calibration only. If your design needs user-operated volume or contrast, choose a panel-mount potentiometer rated for 10,000+ cycles. Excess actuation also increases wiper contact noise and can permanently drift the setpoint by mechanically wearing the cermet element. Always mechanically lock the trimmer (with RTV or hot-melt glue) after final calibration in production designs.
Provide 0.2 inch clearance between the trimmer body and the PCB by using the integral standoffs - do not push the trimmer all the way down onto the board. This clearance is needed for aqueous wash and rework: without it, the turret-style sealing on the wiper drive can trap flux residue, which causes intermittent wiper contact months later. Match the PC pin footprint to the Bourns recommended 2.54 mm (0.1 inch) hole pattern with pads of 1.6 mm drill / 2.5 mm pad to allow easy hand-soldering and rework.
The 0.5 W power rating is specified at 70 °C ambient and must be derated linearly to 0 W at 125 °C. For continuous dissipation at 10 kΩ with 5 V across it the trimmer only sees 2.5 mW - well within spec - but using the trimmer as a rheostat with high current across pins 1 and 3 can easily exceed the rating. Check worst-case RMS current including any transient inrush. Always use the trimmer in the wiper-to-end configuration when possible to limit current through the wiper contact.
When the 3299W-1-103LF sits in a high-impedance node (e.g. instrumentation amp gain-set pin) keep PCB trace lengths short and guard the node with a driven shield if the source impedance exceeds 1 MΩ. The cermet element adds less than 0.1% non-linearity over the full resistance range so it is well suited to low-distortion audio and precision DC circuits, but the wiper-to-end capacitance is typically 2-5 pF - leave 1 ns of settling time on fast-settling ADC input paths to avoid kickback disturbance during calibration.
규정 준수 정보
RoHS compliant LF suffix per Bourns datasheet; non-LF 3299W-1-103 uses tin-lead finish. Halogen-free status not explicitly stated in the datasheet excerpt; halogen-free information not available from the verified web data. Pb content in LF termination below 0.1% by weight per JEDEC JESD97 paragraph 3.5.
