High-voltage Super Mox resistors meet the precision temperature stability requirements of high-accuracy and high-voltage systems
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High-voltage Super Mox resistors meet the precision temperature stability requirements of high-accuracy and high-voltage systems, combining a proprietary noninductive resistance system and designed to achieve low temperature coefficient, low voltage coefficients, high stability and increased high operating voltages.

With a resistance range from 1kohm to as high as 100Gohm on all models and tolerances of 0.05, 0.1, 0.25, 0.5, 1, 2, 5, 10%, the Super Mox low-TC precision high-voltage resistors are designed to meet the demanding requirements of high voltage power supplies, electron microscopes, X-ray systems, high resolution CRT displays and geophysical instruments.

Available with temperature coefficients of 5, 10, 15, 25, 50 and 100ppm/C, the resistors have a silicone conformal coating, gold plated leads and a standard operating temperature of -55 to +225C, although an extended temperature range to 350C is available.

High-voltage Super Mox resistors meet the precision temperature stability requirements of high-accuracy and high-voltage systems
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High-voltage Super Mox resistors meet the precision temperature stability requirements of high-accuracy and high-voltage systems, combining a proprietary noninductive resistance system and designed to achieve low temperature coefficient, low voltage coefficients, high stability and increased high operating voltages.

With a resistance range from 1kohm to as high as 100Gohm on all models and tolerances of 0.05, 0.1, 0.25, 0.5, 1, 2, 5, 10%, the Super Mox low-TC precision high-voltage resistors are designed to meet the demanding requirements of high voltage power supplies, electron microscopes, X-ray systems, high resolution CRT displays and geophysical instruments.

Available with temperature coefficients of 5, 10, 15, 25, 50 and 100ppm/C, the resistors have a silicone conformal coating, gold plated leads and a standard operating temperature of -55 to +225C, although an extended temperature range to 350C is available.

Rugged surface mount devices are specifically designed for surge/pulse applications and for circuits subject to extreme thermal cycling
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Power resistors handle hot duties
Providing design engineers with economical power resistors with high temperature capabilities, both power wirewound and film resistors are available for high volume applications

Providing design engineers with rugged surface mount devices specifically designed for surge/pulse applications and for circuits subject to extreme thermal cycling, TT Electronics IRC Wire and Film Technologies Division offers two versions of its popular cylindrical surface mount resistors. Designated the HSF Series and SMC Series, respectively, the cylindrical surface mount resistors approach wirewound performance levels in each area while providing OEMs with significant cost savings.

Both devices utilise IRC’s MetalGlaze thick film resistive elements on cylindrical ceramic substrates, which provide better heat dissipation, improved solderability and improved surge/pulse capabilities.

The two series are optimised for different applications.

The HSF Series features an unspiralled thick film element that offers three times the surge rating of IRC’s standard CHP Series, or as much as 10 times the rating of a conventional flat chip 2512 component.
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Designed to fit within the footprint of a standard 2512 chip, the HSF Series saves a significant amount of board space versus a comparable rated wirewound device.

The HSF Series resistors feature a power rating of 1W at 70C and a working voltage of 350V.

Resistance values of 5.9, 11, 27, 68 and 270ohm are offered, with a tolerance of +/-10%, and TCRs to +/-50ppm/C.

Maximum operating temperature is +150C.

IRC will also produce devices in custom resistance values to meet customer requirements.

The SMC Series resistors are designed to provide maximum thermal compliance for use in applications that are subject to extreme temperature cycling.

Metal caps fitted on the terminals of the cylindrical resistor body give the SMC Series devices exceptional thermal compliance, relieving stresses created from the TCE (thermal coefficient of expansion) mismatch between the ceramic component and the FR4 circuit board.

Designed to fit within industry standard 2512 and 3610 footprints, the SMC Series devices are ideal for automotive, power supply and industrial applications that require a surface mount resistor with superior surge and thermal characteristics.

The SMC Series resistors have a maximum power rating of 1W at 70C for the 2512 package and 2W at 70C for the 3610 size.

Resistance range is 1ohm to 2.0Mohm, with standard tolerance to +/-5%, and TCRs to +/-50ppm/C.

Maximum operating temperature is +150C.

IRC will also produce devices outside these specifications to meet customer requirements.

Typical pricing for the HSF and SMC Series resistors is approximately $0.18 each in quantities of 10,000.

Lead time is from stock to 4 to 6 weeks.

Welwyn Components has expanded its current sense resistor offering with the launch of the ULR series, its lowest ohmic value resistor, to minimise power consumption
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In response to demand for more energy efficient products, TT Electronics Welwyn Components has expanded its current sense resistor offering with the launch of the ULR series, its lowest ohmic value resistor, to minimise power consumption. The ULR series has been designed for current sensing in power electronic systems and the resistors are available in 1 to 3W power ratings, with a wide ohmic range starting from as low as 500uohm.

Products in the economical, low-inductance ULR series are surface mounted to maximise board space, making them well-suited to the industry trend for smaller products and are ideal for power supplies, DC/DC convertors and miniature electric motor control devices.

The series is RoHS compliant, has an ambient temperature range of -55 to +170C and the higher rated resistors feature a PCB clearance gap to maximise the thermal performance.

In addition, the series boasts a low temperature coefficient of 50ppm/C, essential for those involved in constructing devices and circuits for the detection of currents.
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Current sensing products are among the fastest growing resistive products in the industry today.

Direct resistive sensing remains the lowest cost method of generating a voltage proportional to current flow and submilliohm products to reduce the associated power loss.

John Graham, Marketing and Sales Director said: ‘Welwyn’s investment in the new ULR series comes in response to an increased demand for current sensing resistors as the world becomes more focused on energy efficiency’.

Power resistors are housed in a TO-220 style package and feature low thermal impedance and high insulation resistance for demanding applications
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Providing design engineers with high-power low-inductance devices in transistor-style packages, TT Electronics IRC Advanced Film Division has extended its MHP Series power resistors with 20 and 35W devices. Designated the MHP-20 and MHP-35, the highly stable power resistors are housed in a TO-220 style package and feature low thermal impedance and high insulation resistance for demanding applications.

According to Gary Bleasdell, Thick Film Business Unit Director for IRC’s Advanced Film Division, the MHP Series 20W and 35W resistors feature a package size that is much smaller than comparable wirewound devices of similar wattage ratings.

‘These resistors have an inherently lower inductance value than wirewound resistors, and because the MHP Series devices are designed for heatsink mounting, the equivalent wirewound resistors would need to be four to five times larger to achieve similar power ratings’, said Bleasdell.

‘The noninductive design, along with the high power levels and small package size, make the resistors ideal for applications involving high frequency and high speed pulse’.
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Additional applications for the MHP Series resistors include load resistors, motor control and drive circuits, switch mode power supplies, automotive electronics, industrial power equipment, UPS Systems and industrial computers.

The MHP-20 resistors feature inductance values of less than 50nH, and are available in power ratings of 10 and 20W, with a resistance range from 0.01ohm to 51kohm (10W ranges from 220ohm to 51kohm; 20W ranges from 0.01 to 220ohm).

Both the 10 and 20W resistors feature a thermal resistance of 5.9C/W, standard tolerances of +/-1 and +/-5%, and TCRs from 100 to 250ppm/C.

The MHP-35 resistors feature inductance values of less than 50nH and are available in power ratings of 20 and 35W, with a resistance range from 0.01ohm to 51kohm (20W ranges from 220ohm to 51kohm; 35W ranges from 0.01 to 220ohm).

Thermal resistance for the resistors is 3.3C/W, with standard tolerances of +/-1 and +/-5%, and TCRs from 100 to 250ppm/C.

IRC will also produce devices outside these specifications to meet customer requirements.

Both the MHP-20 and MHP-35 power resistors are RoHS-compliant.

Pricing for the MHP-20 and MHP-35 resistors is $1.80 each in quantities of 1000.

Lead time is from stock to 6 to 8 weeks.

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Providing design engineers with a thermally efficient high current resistor in a surface mount package, TT Electronics BI Technologies SMT Division has developed a noninductive power resistor rated up to 20W. Designated the SMHP Series, the resistor is housed in a small, thin TO-263 package suitable for high density PCB installation.

According to Jim Rieley, Sales Director for BI Technologies’ SMT Division, the TO-263 style package offers extremely low thermal resistance.

‘The SMHP Series resistors are thermally enhanced and the design of the package allows them to be directly mounted to a heatsink’, Rieley said.

‘Because the design provides complete thermal flow throughout the device, the resistors are being specified for applications in automotive electronics, switch-mode power supplies, and high frequency snubber and pulse handling circuits’.
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The surface mount power resistors are also ideal for high precision CRT colour video amplifiers, pulse generator load resistors, inrush current protection, and bleeder resistors.

The SMHP Series device is an extension of the company’s MHP Series through-hole resistors.

The MHP Series noninductive high power resistors are available in five power ratings (20 to 140W) and three TO-style package types, including TO-126, TO-220 and TO-247.

The SMHP Series resistors are rated for 20W power dissipation, with resistance ranges from 0.01 to 220ohm with values to 51kohm available.

TCRs range from 50 to 250ppm/C, with tolerances of +/-5 and +/-1%.

Maximum operating voltage is 500V and dielectric withstanding voltage is 2000V DC.

Thermal resistance is 3.3C/W from the resistor’s ‘hot spot’ to the package’s metal flange and operating temperature range is -55 to +155C.

BI Technologies will also produce devices outside these specifications to meet customer requirements, with comprehensive application engineering and design support available for customers worldwide.

Typical pricing for the SMHP Series resistors is US $1.00 to $1.60, depending on resistance value.

Samples are available immediately for engineering evaluation and customer prototypes.

Providing design engineers with a resistor suitable for extremely high operating temperatures, TT electronics IRC Advanced Film Division has developed a series of tantalum nitride chip resistors rated for operation at 200C. Designated the PFC-HT Series, the chip resistors use IRC’s proprietary TaN film self-passivating resistive element technology, and feature a wraparound nonleaching termination style, with either gold-plated or 100% tin (lead-free) versions specifically designed to enable the devices to operate at elevated temperatures. According to Jerry Seams, Applications Engineering Manager for IRC’s Advanced Film Division, the PFC-HT Series chip resistors were designed for use at extremely high temperatures such as down-hole oil drilling sensing equipment.

‘In addition to designing the resistor itself for high-temperature operation, the challenge also included developing a method to attach to the PC board at such temperature extremes’, said Seams.

‘The resistors are available with either 100% tin or gold-plated terminations that will not reflow at 200C, enabling engineers to use epoxies and solders designed for high temperature applications’.

In addition to the down-hole sensor measurement applications for which they were designed, Seams continued, the PFC-HT Series devices are also suitable for automotive engine compartment and aerospace applications.

Available in industry standard 0603, 0805 and 1206 chip sizes, the PFC-HT Series chip resistors have voltage and power ratings of 33.3V/62.5mW, 50V/100mW and 100V/125mW, respectively.

Resistance range is from 10ohm to 85kohm, with tolerances to +/-1%.

The resistors have absolute TCRs from +/-25 to 100ppm/C, with an operating temperature range from -55 to +200C.

Pricing for the PFC-HT Series devices is $0.30 each in quantities of 10,000.

Lead time is from stock to 8 to 9 weeks.

Providing design engineers with a surface mount power resistor designed to facilitate thermal management, TT electronics’ BI Technologies SMT Division has developed a moulded SOIC-style package with a metal lead frame that features an integral heatsink directly under the resistor element. Designated the SMP Series, the noninductive power resistors are rated for up to 5W and are available in a two-resistor x 2W configuration. According to Jim Rieley, Sales Director for BI Technologies’ SMT Division, the moulded package and lattice-style metal lead frame are specifically designed to minimise the thermal resistance along each axis.

‘This package design increases the resistor’s ability to dissipate heat, as well as its ability to withstand pulses of longer duration’, explained Rieley.

In addition, a metal heatsink directly under the resistive element forms a centre solderable area on the bottom of the package that is electrically isolated from the resistor, Rieley continued.

‘Soldering this central area to the printed circuit board is the most efficient method of dissipating heat from the device’.

The SMP Series resistors are suitable for a variety of applications, including high frequency emitter resistors in switching power supplies, high precision CRT colour video amplifiers, high frequency snubber and pulse handling circuits, pulse generator load resistors and inrush current protection, as well as bleeder resistors.

The SMP Series resistors are offered in power ratings of 2, 3 and 5W, and are available in configurations of one resistor x 5W, one x 3W, one x 2W and two x 2W.

Resistance range is 0.1ohm to 10kohm with tolerances of +/-1.0 and +/-5.0%.

Typical TCR is +/-100ppm/C at 10ohm and above.

Maximum operating voltage for the SMP Series resistors is 50V DC, with dielectric withstanding voltage at 250V DC.

Operating temperature range is -55 C to +155C.

The SOIC package power resistors measure 11.30 x 11.30mm, with a board mounted profile of 2.39mm thick.

BI Technologies will also produce devices outside these specifications to meet customer requirements, with comprehensive application engineering and design support available for customers worldwide.

Typical pricing for the SMP Series resistors starts at $0.70 in quantities of 500.

Lead times are from stock to 8 weeks.

Samples are available immediately for engineering evaluation and customer prototypes.

Providing design engineers with a high power flameproof resistive device capable of handling overload conditions, TT electronics IRC Wire and Film Technologies Division has developed a series of power wirewound resistors with high temperature ceramic shells, in power ratings up to 60W. Designated the PW and PWR Series, the resistors are available in both axial and radial lead configurations. According to Keith Chipman, Product Manager at IRC’s Wire and Film Technologies Division, the PW and PWR Series resistors are specifically designed for power applications and are excellent at handling overloads.

‘The resistors feature high-temperature ceramic shells with inorganic fill materials to create a flameproof construction’, said Chipman.

‘Additionally, the PW Series can be ordered with TCRs as high as +5500ppm/C, making them ideal to protect circuits from thermal runaway or circuits that require temperature compensation’.

Applications for the PW and PWR Series devices include power electronics circuits as inrush, pulse or protection resistors; voltage dividers, bleeders, current limiters, and load banks.

They are specified in power supplies, motor controllers, white goods and automotive applications.

The PW Series resistors, with power ratings from 2 to 25W in axial lead configurations and 20 to 60W in radial terminal configurations, are available in resistance values ranging from 0.10ohm to 30kohm at standard tolerances of +/-10% or +/-5%.

TCRs range from +300 to +5500ppm/C.

The PWR Series resistors are radial leaded (vertical) devices with power ratings from 3 to 10W, and resistance values ranging from 0.10ohm to 18kohm, with standard tolerances of +/-10 or +/-5%.

The PW/PWR Series resistors are constructed using alloy resistance wire wound on glass-fibre substrates, packaged in high temperature ceramic shells with fireproof inorganic encapsulate material.

PC board standoffs are optional on the PW Series devices.

IRC will also produce devices outside these specifications to meet customer requirements.

Typical pricing for the PW Series resistors ranges from $0.15 to $0.20 in quantities of 10,000.

Pricing for the PWR Series is $0.43 in quantities of 10,000.

Lead time for both devices is from stock to 4 to 6 weeks.

Providing medical electronics and hybrid design engineers with an ultraminiature resistor chip that delivers precision and stability over time and temperature fluctuations, TT electronics IRC Advanced Film Division has extended the resistance range of its wire bondable chip resistors to 1Mohm while maintaining the TCR at +/-25ppm/C. Designated the WBC Series, the resistors combine IRC’s tantalum nitride thin film technology with silicon substrate processing to produce devices just 20mil square. According to Dr Debasis Roy, Director of IRC Advanced Film Division’s Thin Film Business Unit, IRC is the only resistor supplier to develop a 1Mohm precision resistor in such a miniature package with TCRs as low as +/-25ppm/C.

‘In addition to a variety of hybrid circuit applications, the 1MW resistance value makes the chip resistors suitable for battery-operated implantable applications in medical electronics such as cardiac pacemakers and defibrillators’, he said.

‘Our proprietary TaNSil process produces an ultrastable self-passivating tantalum nitride resistance element on silicon that provides exceptional stability, power dissipation and precision for these types of applications’.

‘The higher resistance range enables the devices to withstand higher surge conditions’.

The wire bondable chip resistors are available in 0202 and 0303 chip sizes, with optional gold backside metallisation available.

The 0303 two-resistor centre-tapped chips can be used in feedback circuits of amplifiers, where ratio matching, high power and close tracking between two resistors is critical.

The WBC Series wire bondable resistor chips feature a power rating of 250mW at 70C, with a rated operating voltage of 100V.

Resistance range is 10ohm to 1Mohm, with absolute tolerances to +/-0.1% and ratio tolerances (0303 chip) to +/-0.05%.

Absolute TCRs are +/-25ppm/C, with tracking TCRs to +/-2ppm/C.

Operating temperature range is -55 to +150C.

As with all IRC products, devices outside these specifications can be produced to meet specific customer requirements.

Pricing for the WBC Series resistors typically starts at $1.00 in quantities of 1000 pieces.