About TT Electronics Welwyn Components
We design and manufacture a full portfolio of resistor technologies as well as a wide portfolio of hybrid microcircuits and mutli-chip modules. Our product offering is comprehensive, with an ohmic value range spanning 18 decades, and many innovations in the field of high power steel resistors, safety-qualified fusing resistors and high energy surge tolerant parts. Designers rely on our components for critical products from energy meters to motor drives.
Technical Resources
| Technical Resource | Download |
|---|---|
| Resistors Short Form Brochure | Download |
| Circuit Protection Application Note | Download |
| Current Sense Application Note | Download |
| Energy Metering Application Note | Download |
| Glass Sealed Ultra-High Value Resistors Application Note | Download |
| High Current Shunt Capabilities | Download |
| High Speed Digital Data Terminations Application Note | Download |
| High Voltage Application Note | Download |
| Lighting Circuits Application Note | Download |
| Medical Application Note | Download |
| Planar Surge Resistors Application Note | Download |
| Replacement of CHP & HSF with Flat Chip Resistors | Download |
| Resistor Capacitor Chip Network Application Note | Download |
| Resistors for Welding Power Supplies Application Note | Download |
| Lead Form Capability | Download |
| UL Recognised Fusible Resistors Application Note | Download |
| WDBR Series Application Note | Download |
| Wirewound Pulse & Overload Application Note | Download |
| PS002 – Packing Specification Axial Resistors (IRC Origin) | Download |
| PS001 – Packing Specification General Purpose Chip Resistors | Download |
| Technical Note TN001: Advice on Storage Conditions for Fixed Resistors | Download |
| Technical Note TN005 – EIA Standard Values for Resistors | Download |
| Technical Note TN007 – Instant Access to Life Cycle and Obsolete Product Data Online for TT | Download |
| Technical Note TN002: Instant Access to RoHS, REACH, Conflict Mineral and Other Compliance Data Online | Download |
| Technical Note TN004: Methods for Marking Values on Resistors | Download |
| Technical Note TN006: Recommended Layouts for SMD Resistors | Download |
Product Range
COTS Alternative to MIL-PRF-55342
TT Electronics provides an established high-reliability alternative to the US DoD MIL-PRF-55342 specification.
CR series chip resistors have been manufactured at TT Electronics’ Bedlington UK site for over 40 years. With four million component hours of load test data, we are well placed to supply into high-reliability applications. For example, approvals to European standards EN140401-802 and IECQ-CECC40401 support defence and aerospace applications, whilst tringent custom screening supports trans-oceanic cable repeater applications with 30+ year lifetimes.
| EIA Case Size | Power Rating P 70°C (W) | Max Working Voltage (V) | Resistance Range (Ω) | Tolerance (±%) | TCR (±ppm/°C) |
|---|---|---|---|---|---|
| 0603 | 0.1 | 75 | 1R0 – 10M | 0.1, 0.25, 0.5, 1, 2, 5 | <10R: 400 |
| 0805 * | 0.125 | 150 | 1R0 – 100M | 0.1, 0.25, 0.5, 1, 2, 5 | 10R–1M0: 100 |
| 1206 | 0.25 | 200 | 1R0 – 100M | 0.1, 0.25, 0.5, 1, 2, 5 | 10R–1M0: 100 |
| 2010 | 0.5 | 400 | 1R0 – 1M0 | 0.1, 0.25, 0.5, 1, 2, 5 | >1M0: 250 |
| 2512 | 1 | 500 | 1R0 – 1M0 | 0.1, 0.25, 0.5, 1, 2, 5 | >1M0: 250 |
* MIL case size 0705
Product Documentation
New high-power, low-resistance shunt resistors for precision current sensing
The surface-mount LRMAH2512 high-power shunt resistors from TT Electronics deliver precision and surge-resistant current measurement. With a 6W power rating, and AEC-Q200 approval, the metal alloy LRMAH2512 can be used in motor control, power supply, and battery management. Values are down to 200µΩ at 1% tolerance, and TCR is down to 50ppm/°C.
For more infomation, please contact
sales@charcroft.com.
Product Documentation
ULR2N Metal Element Inverse Chip Resistors
ULR2N is the latest addition to TT Electronics’ portfolio of metal element current sense shunt resistors. It is designed in inverse format with terminations on the long sides, which gives good resistance to thermal and board flex stresses and supports the use of wide current traces. With a precision of down to 1% tolerance and 170ppm/°C, ULR2N offers a choice of 5 ohmic values from 1 to 3mΩ. Rated at 2W, this product is suitable for sensing currents at levels up to 45A, and is therefore in many cases restricted only by the current carrying capacity of the PCB traces. The bulk metal technology used for these parts gives high energy capacity for current surge events, compared to film or foil alternative technologies.
Applications
- Power supplies
- Motor control
- Actuator control
- DC-DC convertors
Benefits
- Low ohmic values support high energy efficiency in the end product
- Inverse format allows current traces to be kept wide, avoiding a current crowding hotspot and improving product reliability
- Bulk metal technology withstands high current surges for improved reliability
Features
- Inverse 1020 chip format
- Values from 1 to 3mΩ
- Down to 1% tolerance and 170ppm/°C
- High surge bulk metal technology
- AEC-Q200 pending
Market Segments
- Automotive
- Industrial
- Medical
Product Documentation
LRMA Series
LRMA Series: Low Resistance Metal Alloy Resistor
Applications
- Resistance range 0.5mΩ to 500mΩ
- High temperature operation to 170°C
- Low thermal EMF version
- High power version
- Current sensing for power electronics
- RoHS compliant & halogen free
- AEC-Q200 qualified
Product Documentation
MFC Series of Metal Foil Chip Resistors
MFC Series is the latest addition to TT Electronics’ portfolio of surface mount resistors for compact current sensing functions.
With AEC-Q200 qualification available and in six sizes from 0402 to 2512, the MFC Series offers a broad range of options in the 2 to 200mΩ range.
Precision to ±0.5% and ±50ppm/°C is available and the metal foil technology combines the heat spreading properties of a ceramic substrate with the surge tolerance of a bulk metal alloy resistance element.
Applications
- Automotive DC-DC conversion
- DC motor control
- Actuator control
- Power supply monitoring
- Portable device BMS
- LED drivers
Benefits
- Compact footprint minimises PCB area.
- Metal foil on ceramic technology has better surge tolerance than thick-film, enhancing product reliability.
- Metal foil on ceramic technology has lower self-heating than thick-film or metal strip, enhancing product reliability.
- High precision and low TCR frees up error budget to enable precision requirements to be relaxed elsewhere in the design.
Additional Features
- Power ratings up to 2W
- Value range R002 to R200
- Trimmed to full range of E24 values
- Additional integer milliohm values
- Surge tolerant metal foil
Market Segments
- Automotive
- Industrial
- Medical
Product Documentation
APC – Anti-Sulphur Precision Chip Resistors
APC is the latest addition to TT Electronics’ portfolio of surface mount resistors qualified for use in environments exposed to sulphur-bearing gasses. Tested to both ASTM-B-809-95 and the newer EIA-977 standards, this offers designers of high precision analogue circuits an accurate and stable resistor which will remain reliable in polluted environments. With nineteen combinations of size, sulphur protection grade and power range, APC covers a broad range of resistance requirements at tolerances down to ±0.05% and TCRs to ±10ppm/°C.
Applications
- Automotive battery management
- Roadside monitoring
- Vehicle maintenance equipment
- Industrial process control
- Industrial process control
- Portable test & measure
- Generator sets
- Process monitoring in rubber, wine, petrochemicals & waste
Benefits
- Demonstrated sulphur resistance gives high reliability and so reduces field failure costs.
- High precision and low life drift frees up error budget to enable precision requirements to be relaxed elsewhere in the design.
Features
- Tested to EIA-977 & ASTM-B-905-95
- Precision to ±0.05% and ±10ppm/°C
- AEC-Q200 qualified option
- High stability of ohmic value
- 4R7 to 1M5 and 0402 to 2512
- Two sulphur protection grades
- Higher power option
Market Segments
- Automotive
- Industrial
- Instrumentation
Product Documentation
ULR3N – Metal Element Inverse Chip Resistors
ULR3N is the latest addition to TT Electronics’ portfolio of metal element current sense shunt resistors. It is designed in inverse format with terminations on the long sides, which gives good resistance to thermal and board flex stresses and supports the use of wide current traces.
With a precision of down to 1% tolerance and 100ppm/°C, ULR3N offers a choice of 15 ohmic values from 100μΩ to 3mΩ. Rated at 3W, this product is suitable for sensing currents at levels up to 170A, and is therefore in most cases restricted only by the current carrying capacity of the PCB traces. The bulk metal technology used for these parts gives high energy capacity for current surge events, compared to film or foil alternative technologies.
Applications
- Power supplies
- Motor control
- Actuator control
- DC-DC convertors
Benefits
- Ultra-low ohmic values support high energy efficiency in the end product.
- Inverse format allows current traces to be kept wide, avoiding a current crowding hotspot and improving product reliability.
- Bulk metal technology withstands high current surges for improved reliability.
Features
- Inverse 1225 chip format
- Values from 100μΩ to 3mΩ
- Down to 1% tolerance and 100ppm/°C
- High surge bulk metal technology
- AEC-Q200 pending
Market Segments
- Automotive
- Industrial
- Medical
Product Documentation
DPCR – Defibrillator Pulse Chip Resistors
DPCR is the latest addition to TT Electronics’ portfolio of thick-film surface mount resistors for high surge energy applications. It has been developed specifically to withstand the surge energy of medical defibrillators. By preventing electrical energy from being diverted into sensitive monitoring equipment connected to the patient, it avoids any reduction in the effectiveness of defibrillation, whilst also protecting the equipment.
Qualified against defibrillator surge standards, it has also been characterised to Electro-Static Discharge (ESD) standards, shortening time to market for medical equipment designers. Standard in common values 10kΩ (requires two pieces in parallel), 20kΩ and 51kΩ, other E24 values up to 100kΩ are available on request.
Applications
- External defibrillators
- Portable defibrillators (AED)
- Heart monitors (ECG)
- Neurological monitors (EEG)
- Blood flow monitors (impedance plethysmography)
- Any electrically connected medical devices
- Cables for connecting above monitors
Benefits
- Single component solution leads to reduction in total footprint and faster assembly.
- Characterisation to application specific surge tests shortens equipment development time.
Features
- Tested to IEC 60601-2-27 at 5kV peak
- Tested to IEC 61000-4-2, Level 4 ESD
- Values 20K and 51K standard at 5%
- High stability of ohmic value
Market Segments
- Medical
Product Documentation
IGN Series Pyrotechnic Igniter Devices
IGN series offers precision-engineered solutions for electro-pyrotechnic ignition systems. The IGN line leverages decades of thin film design experience to produce customized solutions that provide fast, reproducible ignition. These products are based on two electrical igniter categories – thermal igniters and percussive igniters. The latter are also known as exploding foil initiators or “slappers”.
- Fast, reliable initiation of pyrotechnic applications
- 0603 chip thermal igniters
- Percussive “slapper” igniters
- Standard designs available for customer experimentation
- Custom design service
Applications
- Detonators for quarrying
- Detonators for mining
Benefits
- Fully custom product
- Fast initiation
- High repeatability of performance
Features
- Standard 0603 & custom chip sizes
- Thermal ignitors
- Percussive igniters
- High reliability TaN film
- RoHS compliant without exemptions
Product Documentation
WCM High Pulse Carbon Film MELF Resistors
WCM is the latest addition to TT Electronics’ portfolio of surface mount high pulse resistors. The cylindrical MELF format gives the maximum film area in a compact footprint, and the use of carbon film technology results in far higher capacity for surge energy than is found in metal film versions. The high pulse performance makes this product ideal for circuit protection in data and power lines. Available in 0207 and 0204 sizes and with a high power option at a 1W rating, WCM offers a wide ohmic range from 7R5 to 10M.
Applications
- Surge protection on data lines
- Surge-proof line monitoring
- Circuit breakers
- Process controllers
- Power quality monitors
- Solar inverters
Benefits
- Saves PCB area compared to multiple component solutions to achieve the same pulse performance
- Maximised film area avoids current crowding and high voltage gradients, improving reliability
Features
- 1.2/50μs surge voltage up to 10kV
- Peak power up to 800W for 1ms
- 5s overload voltage up to 700V
- Good humidity 85%RH, 85°C performance
- Compact footprint
Market Segments
- Industrial
- Consumer
Product Documentation
GBCN – Green Thick Film Chip Arrays
GBCN is the latest addition to the TT Electronics range of green thick film resistor products. It is essentially a variant of BCN designed using green thick film materials which are completely free of Pb (lead) and its compounds.
This allows the product to be RoHS compliant without relying on exemptions which may be withdrawn in the future.
The part contains an array of four isolated resistor elements in a 1206 footprint. It is ideal for use in pull-up, pull-down, level shift and termination functions in digital circuits and in compact analogue circuits.
Applications
- Digital bus bias & termination
- Compact analogue designs
- Process controllers
- Body control modules
- Medical devices
Benefits
- Single component solution leads to reduction in total footprint and faster assembly.
- Complete absence of Pb compounds supports future-proof environmental compliance.
Features
- Free of Pb and its compounds
- RoHS compliant without exemptions
- Four elements in one chip
- Reduced interconnect inductance
- AEC-Q200 qualified
Market Segments
- Industrial
- Automotive
- Medical
Product Documentation
EBW8518 – E-Beam Welded Shunt
EBW8518 is a busbar-mounted shunt resistor for high current measurements in the hundreds of amps range.
This product is an electron beam welded resistance element sandwiched between large copper terminals with optional tin plating. A variety of voltage sense terminal styles may be made available as custom options.
Precision applications can make use of the 1% tolerance, 100ppm/°C TCR, 1µV/°C thermal EMF and separate ground pins to reduce errors.
Applications
- Busbar current sense
- Energy metering
- Welding power supply
- HEV battery management
Benefits
- Low measurement error frees up the designer’s error budget
- Low ohmic values reduce power loss
- Low self-heating reduces equipment temperature and improves reliability
Features
- Robust electron beam welded technology
- Low values to 50µO
- Low thermal EMF
- Low measurement inductance
- AEC-Q200
Market Segments
- Industrial
- Automotive
Product Documentation
HDSC – High Energy Double Sided Chip Resistors
HDSC is the latest addition to our range of pulse withstanding chip resistor products. It is essentially a variant of DSC with no laser trimming applied. This maximises the level of surge performance available in a single-sided flat chip design.
Available in four sizes from 0805 to 2512, HDSC withstands up to 6.5kV peak for a 1.2/50µs surge and up to 6kW for a 0.1ms pulse. It is ideal for protection and discharge applications in compact power supplies and power control circuits where a resistance tolerance of 5% is adequate.
Applications
- Power supplies
- Circuit breakers
- Motor drives
- Medical monitor input protection
Features
- Takes 1.2/50µs surge voltage up to 6.5kV
- Peak power up to 6kW for 0.1ms
- 2s overload ratings up to 9.4W
- High stability & reliability<0.1%
Market Segments
- Industrial
- Medical
Product Documentation
TJC – Thermal Jumper Chip
TJC is designed to provide a thermally conductive pathway with electrical isolation. It may be used as a thermal management solution for cooling PCB hotspot areas.
TJC is made from aluminium nitride, which has around 5 times the thermal conductivity of alumina. As well as providing electrical isolation, it also has a greater thermal conductivity than the equivalent footprint of 70µ copper, and so gives a better thermal connection than an uninterrupted trace.
Applications
- Power supplies
- Power amplifiers
- RF amplifiers
- Laser diode cooling
Features
- High thermal conductivity
- Electrically isolated
- Aluminium nitride (AlN) ceramic chips
- Compact thermal management<0.1%
- Low capacitance
Market Segments
- Industrial
- Medical
- Aerospace
Product Documentation
WIN-T0402 Water Insoluble Nitride Thin Film Precision Resistors
WIN-T0402 adds a new smaller size to the existing three sizes of the WIN series. This allows our new generation to be used in more compact applications, such as server power supplies, process control, safety critical systems, exposed telecom systems, portable medical products, and aerospace COTS.
Applications
- Server power supplies
- Process control
- Safety critical systems
- Exposed telecom systems
- Portable medical products
- Aerospace COTS
Features
- Precision 0.1%, 25ppm/°C
- TaN thin film technology
- Inherent moisture protection
- Typical 85°C, 85%RH biased humidity, 2000 hr <0.1%
- Typical moisture resistance stability ±100ppm
Market Segments
- IT systems
- Industrial
- Medical
- Aerospace
Product Documentation
UPCA164 Ultra Precision Chip Array
UPCA164 is an ultra-precision chip array which incorporates four resistor elements in a compact 1206 footprint. This is a nichrome film precision part, like the existing PCA but with a threefold improvement in temperature stability.
Applications
- Test and Measurement
- Data loggers
- Industrial automation
- Multi-channel sensors
Features
- 4 elements on a 1206 chip
- Ultra-precision thin-film part
- Matching tolerance ±0.05%
- Tracking TCR ±5ppm/°C
- Custom variants with multiple ohmic values available
Market Segments
- Instrumentation
- Industrial
- Medical
Product Documentation
GHVC Series – Green High Voltage Chip Resistors
GHVC is the industry’s first high voltage chip resistor which is completely free of Pb and its compounds and therefore is RoHS compliant without exemption.
GHVC is the latest addition to our range of high voltage chip resistor products. It is essentially a variant of HVC designed using green thick-film materials which are completely free of Pb (lead) and its compounds. This allows the product to be RoHS compliant without relying on exemptions which may be withdrawn in the future. Available in three sizes from 1206 to 2512, GHVC has LEVs in the range 1 to 3kV and withstands up to 7kV peak for a 1.2/50µs surge. It is ideal for high voltage sensing and protection in compact power supplies, circuit breakers and medical monitors.
Applications
- Power supplies
- Circuit breakers
- Medical monitor input protection
Features
- Free of Pb and its compounds
- RoHS compliant without exemptions
- Limiting element voltage up to 3kV
- Overload voltage up to 4kV
- Takes 1.2/50µs surge voltage up to 7kV
- Anti-sulphur terminations standard
Market Segments
- Industrial
- Medical
Product Documentation
WSHR Series – Ultra Low Profile Steel Heaters
Features
- Ultra low profile <2mm
- Up to 400°C operating temperature
- Uniform temperature distribution
- Low thermal mass
- Single fixing mountable
Applications
- Enclosure heaters for exposed environments
- Chemical & food processing
- Sealing & printing
- Medical humidifier
Benefits
- Low profile allows space-saving integration which is not possible with bulky wirewound or PTC alternatives.
- Wide area heating is possible with a single element, avoiding the cost of multiple elements or heat spreaders.
Market Segments
- Industrial
- Medical
Product Documentation
MFC4320 – Metal Foil on Ceramic Chip Resistors
Features
- High power 5W
- High stability foil on ceramic
- Values R002 to R05 at 1% tolerance
- TCR down to ±30ppm/°C
- Low temperature rise
Applications
- Power supplies
- DC-DC convertors
- Motor invertors
- HVAC systems
- Lighting drivers
Benefits
- Low ohmic values to R002 minimise power loss.
- Low TCR improves the temperature stability of the circuit.
- Metal foil on ceramic technology has better surge tolerance than thick-film, enhancing product reliability.
- Metal foil on ceramic technology has lower self-heating than thick-film or metal strip, enhancing product reliability.
Market Segments
- Industrial
- Medical
Product Documentation
WDBR Series - UL Recognised Low Profile Power Resistors
WDBR-UL series is a thick film on steel power resistor with UL recognition. It has been developed based on the existing WDBR product which itself has been successfully used in the field for over ten years. The creepage and clearances and power ratings have been assessed in accordance with the requirements of UL508.
Our Advantage
For circuit designers who need to design UL approved systems containing power resistors in highly compact enclosed assemblies with heatsink-based thermal management, we provide WDBR-UL which provides a far lower volume solution than competing encased wirewound products and a faster route to safety certification.
Applications
- Motor drive invertors
- Dynamic braking, inrush current limiting, snubber
- Electronic assembly heater Element
- Over-voltage protection in wind turbines
Benefits
- Low profile allows space-saving integration which is not possible with bulky wirewound alternatives
- UL recognition eases the compliance burden for UL approved end uses
Features
- UL508 certified – UL file E238661
- Ultra-low profile – thickness <2mm
- Rated power up to 1.4kW
- Overload power up to 13kW
- Isolation to 2.5kV
- 12R to 150R in 5 size options
Market Segments
- Industrial
CR0603 - High Reliability Thick-Film Chip Resistors
CR series is a thick film chip resistor designed for high reliability applications. Until now there have been four standard sizes for solder terminations and CR0603 adds a fifth, smaller size to the range. With the same value range 1R0 to 10M, CR0603 provides a high reliability component in compact circuits where footprint is critical.
Applications:
- Sub-sea repeaters
- Mainframe systems
- Hi-rel systems
Benefits:
- Screened resistor enhances reliability and reduces field failures.
- Thick-film element has higher surge tolerance than thin-film, also improving reliability.
Features:
- CECC40401 release option
- High temperature and overload 100% screening available
- Tolerance down to 0.1%
- Gold wire bond or solder terminations
- Zero-ohm link available
Market Segments:
- Aerospace
- Military
- Medical
- Industrial
- Communications
HR0603 - High Value Thick-Film Chip Resistors
HR series is a thick film chip resistor designed for high ohmic value applications. Until now there have been two standard sizes for solder terminations and HR0603 adds a third, smaller size to the range. With the value range 10M to 20G, HR0603 provides a stable, high ohmic value component in compact circuits where footprint is critical.
Applications:
- High gain amplifiers
- Infra-red & glass break sensors
- Smoke & gas monitors
- Medical monitors
Benefits:
- Single high value resistor enhances reliability and reduces field failures compared with a multi-chip solution
- Thick-film element has higher voltage surge tolerance than thin-film, also improving reliability
Features:
- Ohmic values up to 20G
- Tolerance down to 5%
- Gold wire bond or solder terminations
Market Segments:
- Aerospace
- Military
- Medical
- Industrial
LRMAP5930 Series Low Resistance Metal Alloy Power Resistors
Product Specifics:
- Resistance range 0.2mΩ to 2mΩ
- Excellent long term stability
- High power rating up to 15W
- Current sensing for power electronics
- AEC-Q200 qualified
- Request Sample
Product Documentation
WMHP-HS Series
The WMHP-HS is a PCB mounting heatsink tailored for WMHP series power resistors. It is a compact and lightweight thermal management solution with a small PCB footprint. It can accommodate both TO-220 and TO-247 package styles, thus covering the whole range of WMHP ratings from 20 to 100W.
Product Specifics:
- For TO-220 and TO-247 packages
- Ideal for use with WMHP series power resistors
- Ridged fins for higher surface area with low mass
- Low thermal resistance
- Black anodised finish
- Solderable pins for robust PCB mounting
For circuit designers who need to manage temperature rise in compact power electronic assemblies we provide WMHP-HS which provides more effective cooling with lower mass than the key competing part (Ohmite)
