Ceramic resonator boosts frequency to 20 MHz.

With an extended frequency range as high as 20 MHz, the PBRC-B series of ceramic resonators is an alternative to crystals and oscillators. The device's low-profile surface-mount package lends itself to applications where board density and height are limited, such as in portable telephones. The 2-mm-high PBRC-B resonator has frequency ranges from 8.01 to 20 MHz, with a frequency tolerance of ±0.7% and a maximum resonant impedance of 150 ohm. Depending on the frequency selected, a unit costs $0.35 (10,000) typ. AVX Corp, Myrtle Beach, SC. (803) 946-0414.

Cermet trimmers come in sealed housing.

Single-turn, 4-mm trimming potentiometers in the Model 23 series come in a surface-mount package that withstands rigorous IR or convection-reflow processing and cleaning. Standard resistance range is 10 ohm to 2 M-ohm, with a standard resistance tolerance of ±20%. The cermet trimmers, available in both J-lead and gull-wing styles, employ a T cross-slot for positive adjustment. They cost <$1 (1000). BI Technologies, Fullerton, CA. (714) 447-2300.

Substrate combines active and passive components.

The P/Active family combines both active semiconductor components and existing passive integrated networks to produce a range of application-specific network components with computation and communication electronic-system capabilities. The PAC RG Pentium Pro bus-termination resistor network features 50- and 56-ohm terminations for the Intel server chip set, 68-ohm termination for the Intel desktop chip set, and high-speed bus termination. The PAC 1284 communications-port termination features low parasitic inductance and conforms to IEEE 1824 specifications for parallel-port shielding, filtering, and termination. Both units have built-in 2000V ESD protection. The PAC RG and PAC 1284 each cost $0.95 (10,000) and $0.63 (100,000). California Micro Devices Corp, Milpitas, CA. (408) 263-3214.

Tip-and-ring capacitor size reduction.

A reduction in tip-and-ring capacitor chip size now provides space and assembly savings in designs where a through-hole component was used on otherwise all-surface-mount boards. Tip 'N Ring chips act as a filter, allowing the ac ring-signal pulse to pass and block dc battery voltage. The multilayer ceramic technology includes a proprietary wet-buildup proces for a standard surface-mounted part rated at 250V. The chips meet FCC Part 68 requirements, utilize an X7R dielectric, and are available in 1812, 1825, and 2225 standard EIA case sizes. Capacitance values, including 0.22, 0.33, 0.47, and 1.0 µF, depend on case size. A typ chip capacitor with 1825 case size and 0.47 µF costs $0.39 (1000). Dale Electronics Inc, Columbus, NE. (402) 563-6506.

Ceramic resonator comes in lightweight resin case.

A surface-mount ceramic-chip resonator comes in a resin case that weighs Rohm Corp, Electronics Div, Antioch, TN. (615) 641-2020.

Current-sense resistor comes in surface-mount package.

The patented surface-mount design of the SMT low-ohmic current-sensing resistor requires <3 cm² of pc-board space. Part of the ISA-Plan family, the SMT rates at 1W from -55 to +125°C with resistance values from 1 m-ohm to 1 ohm. Available tolerance options include ±2% and ±5%. The device's temperature coefficient of resistance is <50 ppm/°C between 20 and 60°C. A 33-m-ohm SMT with ±5% tolerance costs $0.68 (50,000). Isotek Corp, Swansea, MA. (508) 673-2900.

Power transformers earn CSA certification.

The 241 power transformers in the Two-4-One line have CSA certification to C22.2 #66-1988 for general-purpose and special transformer applications. The chassis-mount transformers have ratings of 2.4 to 100 VA with 2500V rms hipot-dielectric strength and single or dual primaries of 115V or 115/230V at 50/60 Hz. Prices range from $3.98 (100) for a 3-VA unit, to $12.98 (100) for an 8-VA dual-primary transformer. Signal Transformer Company Inc, Inwood, NY. (516) 239-5777.

Surface-mount trimmers meet environmental standards.

Potentiometers with cermet-resistive elements rated from 10 ohm to 2 M-ohm operate within a temperature range of -55 to +125°C. The single-turn devices meet MIL-STD-202 and MIL-R-22097 environmental and performance requirements. The 4-mm open-frame 4H series and the superthin 4M series both have a TC of ±250 ppm/°C and a power rating of 0.1W at 70°C. The 5-mm 4G and 4J series have a TC of 100 ppm/°C and a power rating of 0.25W at 70°C. Respective prices for the 4H open-frame, 4M sealed, 4G sealed gull-wing, and 4J sealed J-lead series are $0.47, $0.79, $0.90, and $0.90 (1000), respectively. Spectrol Electronics Corp, Ontario, CA. (909) 923-3313.

Array squeezes four resistors in 1206-size footprint.

Made of four isolated resistors of the same ohmic value, the ARC241 1206-size array saves board space by replacing four 0603 chips. The 0.063W array offers resistance values between 10 ohm and 1 M-ohm per resistor. Each resistor is rated at 50V dc or rms with 5% tolerance and a temperature coefficient of resistance of ±200 ppm/°C. Arrays are available on standard 8-mm tape. Prices range from $20 to $30 (1000) for avg quantities. Philips Components, Jupiter, FL. (407) 745-3300.

Passive loads deliver 50 to 10,000W.

Loadflex passive loads offer an alternative for test and burn-in applications that work without active loads. Custom units cover a range of 50W to 10 kW at 0 to 600V. Off-the-shelf benchtop and rack-mount loads span 50 to 800W at 0 to 600V at frequencies from dc to 25 kHz. Units in the 6×4×1.5-in. Bullet series of 50W loads fit inside most OEM equipment. In addition to single-input models, Loadflex offers versions with dual and quad inputs. Prices start at $229. Hyberlab Corp, Etobicoke, ON, Canada. (416) 626-3404.

Electrolytic caps span 4.7 to 1000 µF.

The type MXZZ aluminum electrolytic capacitor comes in six voltage ranges, from 6.3 to 50V dc, and in five surface-mount case sizes, including 4×6.3, 5×6.3, 6.3×6.3, 6.3×8, and 8×10.8 mm. The device comes in capacitance values from 4.7 to 1000 µF and operates over a temperature range from -55 to +105°C. Capacitance tolerance can be specified at ±20 or ±10%. Prices start at $0.24 (2000). Tecate Industries Inc, El Cajon, CA. (619) 448-4811.

Surface-mount resistors keep TCR down.

Molded in a surface-mount package, the SMR1D resistor series keeps its nominal temperature coefficient of resistance (TCR) to +0.6 ppm/°C from 0 to +25°C and to -0.6 ppm/°C from +25 to +60°C. Devices have a resistance range from 5 ohm to 33 k-ohm and offer long-term stability of ±0.02%. The power rating at +70°C is 0.25W. Resistors with 0.1% tolerance cost $3.40 (1000). Vishay Resistors, Malvern, PA. (610) 644-1300.