Power Electronics
Spotlight on Passives

Spotlight on Passives

Multilayer Capacitors

The EVC series of multi-layer monolithic ceramic capacitors (MLCCs) from Murata Electronics features higher ripple-current capabilities, high voltage and large capacitance per volume, lower ESR and ESL compared to film and aluminum electrolytic capacitors (better surge suppression), and high operating temperature assurance.

For example, the maximum-rated capacitor in this series has a voltage rating of 630 Vdc and an effective capacitance of 12 µF at 400 Vdc. The allowable ripple current is 20 Arms at 20 kHz, with a dielectric withstanding voltage of 750 V and maximum operating temperature of 125°C. The case size is 32 mm × 40 mm × 3.7 mm for capacitors with 250-Vdc, 400-Vdc and 630-Vdc ratings or 16 mm × 20 mm × 3.7 mm for a 35-Vdc rated MLCC.
Murata Electronics
Kyoto, Japan


Ultra-Thin Supercapacitors

Tecate Industries' CAP-XX ultra-thin G Series of general-purpose supercapacitors consists of single-cell and dual-cell versions. The RoHS-compliant parts boast low impedance and a very low profile. The supercapacitors offer long-life performance at up to 2.3 V in the single-cell versions and 4.5 V in the dual-cell configurations, with two cells connected in series.

The GW Series features a 28.5-mm × 17-mm footprint and combines high capacitance (up to 0.4 F at 4.5 V) with ESR as low as 60 mµ in a thin (0.9-mm to 2.9-mm) package. The GS Series features a 39-mm × 17-mm footprint and combines high capacitance (up to 0.7 F at 4.5 V) with ESR as low as 34 mV in the same thin package. Pricing starts at $3.06 each in quantities of 1000.
Tecate Industries
San Diego


400-F Supercapacitors

A supercapacitor from Illinois Capacitor provides 400 F at 2.7 V in a 25-mm × 62-mm package. The 407DCN2R7K has an equivalent series resistance of 3 mµ at 120 Hz with a load life of 87,600 hr at 25°C with 100% of rated voltage.
Illinois Capacitor
Lincolnwood, Ill.


Polymer Capacitors

Nichicon's F11 series of capacitors uses layered-aluminum construction, conductive polymer electrolyte and a three-terminal design all in a molded package. This structure decreases the magnetic field and inductance at ultrahigh frequency, so the part achieves excellent impedance characteristics over a wide frequency range. The layered-aluminum design of the F11 series provides the ultralow ESR and ESL over a wide frequency range needed in today's high-performance LSI.

With a voltage range of 2.5 V to 6.3 V and a capacitance range of 47 µF to 2400 µF, the F11 series' operating temperature range is -55°C to 105°C. The capacitors come in two sizes: 16.7 mm × 12.1 mm × 2.5 mm and 8.5 mm × 5.3 mm × 2 mm. Both sample and production quantities are available.
Schaumburg, Ill.


HID Lighting Capacitors

Cornell Dubilier's series of HID lighting capacitors are rated for 60,000 hr life at 100°C. The Type DL capacitors' catalogued capacitance values range from 5 µF to 75 µF with a voltage range from 120 Vac to 400 Vac.

The Type DL capacitors are packaged in cylindrical plastic cases ranging from 30 mm to 50 mm in diameter and 55 mm to 117 mm in length. Pricing starts at $1 each.
Cornell Dubilier
New Bedford, Mass.


Thin-Film Resistor Networks

A series of hermetically sealed thin-film resistor networks from TT electronics BI Technologies Electronic Components Division meets a number of military qualifications. The thin-film resistor networks are hermetically sealed in nitrogen-filled package cavities. The networks feature a resistance range from 10 Ω to 1 MΩ, with absolute tolerances to less than ±0.05% and ratio tolerance to less than ±0.01%. TCRs are less than ±25 ppm/°C, with TCR tracking to less than ±5 ppm/°C (±1 ppm/°C is also available).

Available with hot solder dip, tin-lead plate and gold-plate finishes, the thin-film resistor networks come in through-hole DIP and surface-mount packages. Pricing starts at $35 each in quantities of 50.
BI Technologies
Fullerton, Calif.


RoHS-Compliant Resistors

Stackpole Electronics has added to its lead-free/RoHS-compliant resistor offering. The LC series, a resistor network series, is available with 4 to 13 pins and circuit types of bussed and isolated resistors in a low-profile SIP package. The series is available in a power rating of 0.125 W per element, in resistance values from 30 kΩ to 100 kΩ, in tolerances of 1% and 2% and a TCR of 100 ppm. Typical pricing for the LC series starts at $34 each in quantities of 1000.
Stackpole Electronics
Raleigh, N.C.


Thick-Film Resistors

A thick-film resistor from Vishay Intertechnology combines an extremely low resistance with tight tolerances and low TCR for current-sensing applications. The CRCW….-EL thick-film power resistor offers a resistance range from 10 mΩ to 100 mΩ, with tight tolerances of ±1% and ±5%. The resistor features TCR of ±100 ppm/K, ±200 ppm/K, ±300 ppm/K, ±400 ppm/K and ±600 ppm/K over an operating temperature range of -55°C to 155°C. The resistor features a special metal glaze on high-quality ceramic with a protective overglaze.

The RoHS-compliant resistor offers lead-free solder contacts on a nickel barrier layer, with pure tin plating providing compatibility with both lead-free and lead-containing soldering processes. The device is offered in three case sizes: the 0.1-W 0603, the 0.125-W 0805 and the 0.25-W 1206. Pricing starts at $0.08 each in 1000-piece quantities.
Vishay Intertechnology
Malvern, Pa.


Polypropylene Capacitors

From Electronic Concepts, the 5MPF series of polypropylene capacitors for ac applications feature the company's Fuseac technology to protect the capacitors against fault conditions. An internal fuse electrically disconnects when the capacitor's hot spot reaches a defined temperature and prevents deforming of the case.

These capacitors feature dry film construction and come in cylindrical cans with radial terminals and a mounting bolt. Capacitance ranges from 10 µF to 250 µF with standard tolerances of ±3% and ±5%.

AC working voltage ratings at 85C are 300 Vac, 600 Vac and 900 Vac at 60 Hz. Operation is specified over the -40°C to +85°C range.
Electronic Concepts
Eatontown, N.J.


Tantalum Capacitors

AVX's TPM Series now includes D and low-profile Y case-sized multi-anode, mirror-configuration tantalum capacitors. The symmetrical design reduces the ESL to 1 nH, half that of standard D case-sized devices. The low ESL enables a resonant frequency up to 500 kHz (mirror D case), delivering more efficient filtering in dc-dc power switching converters.

The mirror anode configuration also reduces the height of the tantalum capacitors from 4.3 mm (E case) to 3.1 mm (D case) with further reductions down to 2 mm maximum height (Y case). Typical pricing for the TPM mirror tantalum capacitor starts at $2 each in quantities of 1000.
Myrtle Beach, S.C.


High-Power Resistors

From IMS, the N-Series of high-power resistors and terminations on AlN offers unmatched power handling and flexibility in meeting specific circuit requirements.

The N-Series is available in cases 0505 to 3725, thicknesses 0.015 in., 0.025 in. or 0.040 in., and multiple termination styles, including single wrap to groundpad, center stripe, extended wrap or single sided with backplane for added power dissipation.

Standard resistance range is 10 Ω to 2 kΩ with tolerances to 2%. N-Series resistors and terminations are available with RoHS-compliant platinum silver, pre-tinned platinum silver or wire-bondable gold terminals, making them ideal for any application operating above 10 W.
Portsmouth, R.I.


Charging Resistors

From Epcos, the J20X series of charging resistors employ a PTC ceramic construction that enables them to be self-protecting despite their small size. The family consists of three products — the J201, J202 and J204 products — whose specifications are listed in the table. These resistors overcome a key limitation of ohmic resistors that are typically used to limit current when charging capacitors. Those resistors can fail if the capacitor short circuits or a relay malfunctions when short circuiting the capacitor. These faults can subject ohmic resistors to fatally high power levels.

In contrast, when the J20X series of resistors is subjected to a fault, the temperature and inherent resistance of the PTC ceramic increases in line with the increased ohmic losses and limits the current to a safe level. Typical applications include industrial power supplies, frequency converters and UPS systems in the power range from 500 W to 50 kW. In such applications, a link-circuit capacitor is used to smooth the generated dc voltage or as an energy-storage device in the link circuit. Unit pricing is approximately $2.35 each in quantities up to 5000.
Munich, Germany


Precision Surface-Mount Resistors

TT electronics IRC's PPC Series combines the precision of a thin-film resistor with the power-handling capabilitiess of a thick-film resistor. The component merges the high-surge capability (up to 1500 W for 1 ms) of IRC's CHP Series with tolerances to 0.1% at TCRs of 25 ppm/°C.

Available in 1206, 2010, 2512 and 3610 package sizes, the cylindrical surface-mount PPC Series resistor features maximum power ratings of ⅛ W, ½ W, 1 W and 2 W, with working voltages of 200 V, 300 V, 350 V and 500 V, respectively. Resistance ranges from 100 Ω to 10 kΩ, with tolerances down to ±0.1% and TCRs of ±25 ppm/°C.

Pricing for the PPC Series surface mount precision power resistor starts at $0.35 each in quantities of 2500. Lead time is from stock to 8 weeks.
TT electronics IRC
Corpus Christi, Texas


Military SMPS Stacked Capacitors

KEMET's military-grade ceramic stacked capacitors are intended for high-reliability switch-mode power supply and pulse-energy applications. The SMPS Stacked Capacitors are qualified to Military Performance Specification MIL-PRF-49470 and DSCC Drawing 87106. Their low ESR and ESL make them ideally suited for input and output filtering of power-supply applications as well as snubber applications.

The capacitors are available in case codes 3, 4 and 5 (larger case codes 1, 2 and 6 will be available in the third quarter of this year), X7R dielectric, and voltage ratings from 50 Vdc up to 500 Vdc, and capacitance values up to 47 µF. The chip stack is horizontal and the leadframe attachment is a high-temperature solder. They are also available in unencapsulated (unpotted bare chips) or encapsulated (potted assembly) styles.

With an operating temperature range between -55°C and 125°C, and with capacitance shift limited to ±15% over that range, the SMPS Stacked Capacitors are an excellent choice for electrical applications, general-purpose applications and high-frequency power-supply circuits.
Greenville, S.C.


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