MT SeriesTranscoder
Innovative IC Enables Bi-Directional Remote Control

The revolutionary MT Series Transcoder IC provides unprecedented features for bi-directional remote control and command applications. In the past, encoder and decoder ICs were commonly used to allow the status of inputs, such as switch or button closures, to be sent in one direction across a wireless link. While the MT can perform these basic uni-directional functions with ease, it also allows the bi-directional exchange of information and reception confirmation. When combined with external feedback, the Transcoder can also verify that specified actions have actually taken place. For example, a remote valve might confirm it has fully closed, a nurse call system could indicate “help is on the way”, or an automobile security system would confirm it had armed and in the event of a break-in alert the owner via their system’s keyfob. The MT is even capable of sending variable data such as time, temperature, pressure, or text along with control information.

The transcoder provides eight lines which can be configured as inputs or outputs and individually set for latched or momentary operation. Recognition of the individual outputs can be easily defined for each device by the manufacturer or end user. This allows the creation of user groups, relationships, and permissions. A large twenty-four bit address size makes transmissions highly unique, minimizing the possibility of conflict between multiple devices. An automatic confirmation indicates that the transmission was successfully received. The MT also outputs the ID of the originating transcoder for logging or identification.

In addition to these powerful features, a Serial Interface Engine (SIE) allows the transcoder to be configured and controlled from an external microcontroller or PC. Permissions and users can be configured, modes and functions set and external data added to the transmission stream. A targeting feature allows commands to be directed to specific devices.

The MT is housed in a tiny 20-pin SSOP package, and features low supply voltage, current consumption, and selectable baud rates. Its basic feature set is also compatible with Linx MS Series encoder and decoder ICs. MT Transcoder ICs will be available Q1 2008.

Zetex Semiconductors has added a pair of low voltage PNP transistors to its low saturation high current SOT23FF transistor range. With the footprint of the standard SOT23 package but with a reduced off board height of less than 1mm, the ZXTP25020CFF and ZXTP19020DFF will suit a range of slimline portable product designs.

Helping to reduce component counts and increase power density, the devices serve as cost effective switchers in a variety of portable applications, including linear charging and high side load switching circuits.

By guaranteeing a reverse blocking capability of 7 volts, the ZXTP25020CFF removes the need for a series connected Schottky diode in linear chargers. This saves up to 50% PCB area compared with similar footprint P-channel MOSFETs, which due to their inherent drain-source body diode, require a series Schottky diode.

The SOT23FF package offers an improved thermal resistance of 158oC/W giving a power rating of 0.8W from a 15mm x 15mm PCB area, thereby substantially increasing power density when compared to standard SOT23 solutions. Power dissipation can rise to 1.96W for applications where the equivalent PCB space of 50 x 50mm is available.

In high side switching and load or disconnect switches, the ZXTP19020DFF reduces the voltage drop to just 70mV at 1A and a base drive of 20mA or 140mV at 2A for a 40mA base drive, which can be equated to an equivalent resistance of 70mΩ- in a PCB footprint of 2.5mm x 3mm.

Antenna Factor's new WRT Series antenna is ideally suited for applications such as wireless vending, security, traffic, or power equipment, which require an unobtrusive, tamper-resistant antenna solution. The tiny 19 x 11mm radome installs through a small hole on the product and is anchored by a threaded base. An adhesive foam compression ring is used to resist the elements. The antenna also features an integral counterpoise, which eliminates the need for a proximity ground plane. WRT Series antennas provide favorable performance characteristics and are available in center frequencies of 868MHz, 916MHz and 2.45GHz. The antenna's coax feed is available with SMA or RP-SMA terminations. Alternate connectors and custom colors are available for volume OEM customers

LT Series transceivers operate in the favorable 260 to 470MHz band and are designed for full regulatory compliance and interference immunity, ideally suiting them to domestic as well as export wireless applications. The modules operate over a 2.1 to 3.6VDC range and feature very low power consumption (7.6mA TX, 6.1mA RX, 11.5μA sleep), a wide operational temperature range (-40° to + 85°c) , adjustable transmitter power with up to +10dBm output, and a typical receiver sensitivity in excess of -112dBm.