-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueBox Build
One trend is to add box build and final assembly to your product offering. In this issue, we explore the opportunities and risks of adding system assembly to your service portfolio.
IPC APEX EXPO 2024 Pre-show
This month’s issue devotes its pages to a comprehensive preview of the IPC APEX EXPO 2024 event. Whether your role is technical or business, if you're new-to-the-industry or seasoned veteran, you'll find value throughout this program.
Boost Your Sales
Every part of your business can be evaluated as a process, including your sales funnel. Optimizing your selling process requires a coordinated effort between marketing and sales. In this issue, industry experts in marketing and sales offer their best advice on how to boost your sales efforts.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
Component Specifier
December 31, 1969 |Estimated reading time: 7 minutes
As SMT matures and its end products continue to shrink in size but grow in capability, manufacturers are constantly in need of components that satisfy demanding footprint, reliability and placement requirements. Modern manufacturing techniques are useless if a board's components are out of date, perform poorly or fail to satisfy end-user requirements. To assist manufacturers in this search, SMT Magazine presents Component Specifier, a product section designed to spotlight state-of-the-art active, passive, odd-form and interconnect components.
ACTIVEDevices capable by themselves of controlling voltages and currents to produce gain or switching actions in analog or digital circuits, i.e., reacting to an applied signal, they can change their basic charater.
PASSIVEDevices that do not change their character when electrical impulses are applied, i.e., they provide a single, repeatable reaction.
INTERCONNECTDevices that provide mechanical and electrical union/disconnection and consist of mating plugs and receptacles (sockets) to join PCBs with cables, racks, chassis or other PCBs (stacking); actual connection to the board, however, must be via surface mount-type contacts.
ODD-FORM Devices whose geometrical form factors are singular - but not necessarily unique - such that they must be manually mounted. Their housings (as opposed to their basic functions) are nonstandard as to shape. Examples include many transformers, hybrid circuit structures, fans/blowers, mechanical switching blocks, etc.
ACTIVE
Voltage/Current Threshold Detectors
The HCPL-3700 optocoupler is an optically isolated voltage and current threshold detection device with a sensing input buffer IC coupled to an open collector output that is both TTL and CMOS compatible. The threshold is independent of CTR degradation (LED and temperature) and device-to-device variation. It accepts AC or DC input, and the sensing voltage is programmed by an external current-limiting resistor (range is 5 to 240 V). It comes in three eight-pin DIP packages, through-hole or surface mount. QT Optoelectronics Inc., Sunnyvale, Calif.
PASSIVE
EMI Suppression Capacitor Array
The W3F4 series of SMT feed-through 1206 capacitor arrays contains four elements with a dual common-ground connection suitable for multi-line designs requiring electromagnetic-interference suppression, broadband I/O filtering or Vcc power-line conditioning. The array also comes in the standard 0805 configuration with a number of values in NP0 and x7R ceramic dielectrics. Applications include transceivers, cell phones, laptops and set-top boxes. AVX Corp., Myrtle Beach, S.C.
Y2 Capacitors
Series SMP Y2 capacitors come in 1,000 to 4,700 pF value range with a rated nominal voltage of 250 VAC. Constructed of self-healing metallized impregnated paper, the capacitors exhibit a failure mode tending toward an open circuit. Featuring flexible electrodes that absorb thermal expansion stresses, the capacitors can be packaged on tape for vertical mounting to reduce the footprint. Evox Rifa Inc., Lincolnshire, Ill.
Resettable Fuses
The polymeric positive temperature coefficient (PPTC) resettable surface mount fuses reportedly provide over-current protection in computers, industrial process controls, telecom, portable and consumer electronics. They come in 21 sizes, including: six in microSMD (1210 form factor); eight in miniSMD (1812 form factor); one in midSMD (2018 form factor); two in SMD (2920 form factor); and two in SMD2 (3425 form factor). Raychem Corp., Menlo Park, Calif.
Voltage-controlled Oscillators
The VS-9000 voltage-controlled crystal oscillator comes in a 5 x 7 x 2 mm ceramic/metal package with a pulling range more than 100 ppm. Suitable for telecom products, PCMCIA cards and other high-density applications, their overall size is 9.77 x 13.96 x 4.7 mm. The units feature an optional enable/disable pin for tri-stating output, saving CMOS switching power when the host product is quiescent. They are available from 1 to 70 MHz. Raltron Electronics Corp., Miami, Fla.
Low-ohmic Chip Resistors
The LVC series (low-ohm-value chip) of thick-film current sensing resistors come in standard surface mount packages and feature 1/4, 1/2 and 1 W power ratings. Ohmic values range from 0.05 to 1 W in standard 5 percent tolerance. Case sizes include 1206, 2010 and 2512, with nickel barrier terminals, low TCRs (to ±100 ppm) and operating temperature of -55° to 125°C. The chips come in 8 mm tape on 7" reels. Ohmite Manufacturing Co., Skokie, Ill.
Power Moisture Resistors
Thick- and thin-film power moisture chip resistors are for use in engine controls, navigation systems, and other applications where circuits are exposed to excessive wetness or humidity. They come in 15 thick-film case sizes from 0.030 x 0.020" to 0.250 x 0.125" and in 10 thin-film case dimensions from 0.050 x 0.050" to 0.225 x 0.125". Termination sizes are standard; metalizations include solderable, epoxy and wire bondable. State of the Art Inc., State College, Pa.
Resettable Bus Port Protection
The 1812 series of 2.6 A, surface mount, PTC resettable circuit protection devices are designed specifically for USB ports. Circuits may be protected from over-current conditions in a range of computer and peripheral applications, including Smart Cards, modems, keyboard and mouse ports, printers, and network cards. Package dimensions are 0.179 x 0.127 x 0.050". Littelfuse Inc., Des Plaines, Ill.
Air-core Inductors
MicroSpring inductors measure only 1.4 x 2.2 x 1.4 mm and feature typical Q factors of 200 at 1.8 GHz. Values range from 1.65 to 12.55 Nh. A tight inductance tolerance - as low as 2 percent - is said to favor thermal stability and often eliminate the need for circuit tuning. The inductors feature an acrylic jacket with a flat top suitable for auto placement and reflow or vapor-phase soldering. Coilcraft, Cary, Ill.
High-current Inductors
The HC2 series of surface mount, high-current power inductors use foil technology and feature a compact footprint for high-density circuit packaging. Its frequency range of 1 kHz to 1 MHz is coupled with low DCR/high efficiency. The inductors are suitable for infrared and vapor-phase soldering. For low-voltage applications, the inductors can be used in desktop and laptop computers, as well as high-current DC/DC converters. Cooper Electronic Technologies, St. Louis, Mo.
Multilayer Ceramic Capacitors
This company's series of surface mount, double-layer capacitors reportedly are resistant to damage from reflow oven temperatures. Suitable for backup for µA to mA range (as in microcomputer and RAM applications), the capacitors feature a proprietary separator material for thermal protection. In three values - 0.1f, 5.5 V; 2.2 f, 5.5V; and 2.2 f, 3.5 V - they measure 10.8 x 10.8 x 5.5 mm and are supplied on 24 mm tape. Tokin America Inc., San Jose, Calif.
Attenuators
This company's series of temperature-compensating attenuators is intended for RF and microwave systems in which circuits must compensate for ambient temperature changes. Using thick-film technology, the devices can be used as thermal sensors in a range of applications. As it is often necessary to compensate for temperature-induced gain changes in mixers and amplifiers, these single-chip, totally passive components reportedly can eliminate the need to design active circuitry for this purpose. Methode Development Co., Chicago, Ill.
Frequency Pulling Oscillators
The CFPV series of miniature, surface mount VCXOs are intended for SONET/SDH transmission systems in local PBXs and local- or wide-area networks. The devices are said to provide a high degree of frequency pulling or output frequency control via an applied voltage. This allows degraded incoming signals to be corrected to nominal frequency through a PLL device. Various values provide up to ±100 ppm; packages are six-pad 7.5 x 5.0 x 1.9 mm SMDs. C-MAC Frequency Products, Durham, N.C.
Analog Circuit Precision Resistors
VSM0805 precision chip resistors measure 2.03 x 1.27 mm and feature Precision Bulk Metal foil technology. They have a nominal TCR of less than 5 ppm per °C, are low noise and bear absolute tolerances to ±0.01 percent. These components are suited for analog as well as high-frequency applications and are said to meet the demands of miniaturization. Applications include test and measurement, navigation, process control, automotive, telecom, medical, and robotics. Vishay Intertechnology Inc., Malvern, Pa.
SIP DC/DC Converters
The SWUO series of high-isolation DC/DC converters comes at 0.75 W in SIP. Suitable for I/O board system and subsystem distributed power configurations where low-voltage semiconductors are present, the converters are encapsulated and are said to run without derating or heat sinking over their temperature range. Input voltages range from 5 to 24 V nominal (3,000 VDC isolation); case dimensions are 0.770 x 0.240 x 0.400". Polytron Devices Inc., Paterson, N.J.
INTERCONNECTBoard-to-board Connectors
The 0801 series of low-profile, 0.8 mm-pitch board-to-board connectors features an overall mated height of 6.8 mm. A specially designed bellows-formed contact reportedly resists scooping and stubbing problems. Mating is assisted via integrated mounting bosses; bodies are glass-filled, high-temperature LCP resins. The connectors are said to be useful for palmtop devices, PCS, cell phones, etc. Leoco (USA) Corp., Hayward, Calif.
Panel Mating Connectors
The PanelMate line of low-profile, 1.25 mm-pitch connectors are suitable for tight packaging tasks, including LCD panels, notebook computers, camcorders, digital cameras, mobile phones, etc. The family includes crimp and FPC receptacles and six intermating surface mount headers. With two to 30 circuits, wire-to-board headers feature profile heights as low as 1.03 mm and shielded versions providing EMI protection. Features include blade-style pins, friction locking windows, angled mating lead-ins and a fully shrouded design. Molex Inc., Lisle, Ill.