The MICRF112 is a high performance, easy to use, single chip ASK / FSK Transmitter IC for remote wireless applications in the 300 to 450MHz frequency band. This transmitter IC is a true “data-in, antenna-out” monolithic device.

MICRF112 is high performance in three areas: power delivery, operating voltage, and operating temperature. In terms of power, the MICRF112 is capable of delivering +10 dBm into a 50Ω load. This power level enables a small form factor transmitter (lossy antenna) such as a key fob transmitter to operate near the maximum limit of transmission regulations. In terms of operating voltage, the MICRF112 operates from 3.6V to 1.8V. Many transmitter ICs in the same frequency band stop operating below 2.0V. The MICRF112 will work with most batteries to the end of their useful limits. In terms of operating temperature, the MICRF112 operates from -40°C to +125°C. This wide operating temperature range makes MICRF112 an ideal candidate for the demanding applications such as a tire pressure monitoring system.

The MICRF112 is easy to use. One only needs a reference frequency (RF carrier frequency divided by 32 times) generated from a crystal with a few additional external parts to create a complete versatile transmitter.

The MICRF112 operates with ASK/OOK (Amplitude Shift Keying/On-Off Keyed) UHF receiver types from wide-band super-regenerative radios to narrow-band, high performance super-heterodyne receivers. The MICRF112’s maximum ASK data rate is 50kbps (Manchester Encoding). It operates with FSK receivers as well. The chip is designed to support narrow band FSK (Frequency Shift Modulation) by switching an external capacitor in parallel with the reference crystal. The MICRF112’s maximum FSK data rate is 10kbps.

Data sheets and support documentation can be found on Micrel’s web site at www.micrel.com.