International Rectifier Microelectronic Relays Offer Higher Load Current and Lower Contact Resistance Ratings than Older Fax/Modem Relays
"The higher load current and lower contact resistance ratings are especially important for worldwide modem applications in countries
with an older telephone network infrastructure," says Andy Serkuczewski, director of business management and product marketing
for microelectronic relays at International Rectifier. "These telephone networks need the switching capability of up to 125 mA throughout
the normal operating temperature range. Developing a global PCMCIA fax/modem card design requires this higher loop current."
EL SEGUNDO, CA. August 1997 International Rectifier (IR) is expanding their line of specialized telecom microelectronic relays (MERs) for
applications in PCMCIA fax/modem cards, with the new PVO402AP Series. These new devices can accommodate the higher
(125 mA) local loop ratings required in older telephone systems worldwide, as well as lower loop currents typical for modern telephone
networks, making it the universal solution for PCMCIA fax/modem cards.
In addition, since the current standard for such fax/modem cards is the Type II PCMCIA format which is only 5 mm thick
across the outer metal shell, it requires the use of a relay with a total height of no more than 2 mm. The new PVO402AP Series is an
example of a solid-state relay solution that is the only choice for designers, since there are no electromechanical or reed relays that
offer the low-profile package necessary for this application.
The PVO402AP consists of a single-pole, single-throw, normally-open (1 Form A) relay and a ring detector, which is
sometimes described as an AC-input optocoupler. Each of these two functional elements is placed in an isolated and operationally
independent optical cavity (i.e., operation of the relay is independent of the operation of the ring detector). This is a further step in
integrating additional features of a modem's Direct Access Arrangement (DAA) circuitry.
The PVO402AP Series offers a maximum load voltage of ±400 Volts (DC or AC peak) and a maximum load current of 150 mA
(at TAMB up to +40°C) per channel at an RD(ON) of 22 Ohms maximum. The PVO402AP requires only 5 mA of input LED current to
actuate, which makes it TTL and CMOS compatible. High input-to-output optical isolation of 3,750 VRMS allows it to meet worldwide
electrical safety standards and regulations. UL recognition and BABT certification are pending.
The PVO402AP Series relays are packaged in an 8-pin, molded "Thin-Pak" DIP package with "gull-wing" surface-mount
terminals. They are available in standard plastic shipping tubes (50 count) or on tape-and-reel (1,000 per reel). Typical applications
include on/off hookswitch and ring detection in fax/modem DAA circuitry. Despite the fact that these relays have been designed
primarily for PCMCIA applications, they can also be used in the ISA (desktop) formats.
Samples of the PVO402AP are available now, as well as inventory necessary for initial distributor stocking orders. Lead time
for production volume orders is 6 to 8 weeks.
For more information:
Contact the Technical Assistance Center or
your local Sales Rep.
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