MICRF002

Features:

` Complete UHF receiver on a monolithic chip
` Frequency range 300 to 440 MHz
` Typical range over 200 meters with monopole antenna
` Data rates to 2.5kbps (SWP), 10kbps (FIXED)
` Automatic tuning, no manual adjustment
` No Filters or Inductors required
` Low Operating Supply Current-240 mA at 315MHz (10:1 Duty Cycle)
` Shutdown Mode for Duty-Cycle Operation in excess of 100:1
` Wakeup Function to Enable External Decoders and Microprocessors
` Very low RF re-radiation at the antenna
` CMOS logic interface to standard decoder and microprocessor ICs
` Extremely low external part count


Application

· Automotive Remote Keyless Entry
· Long Range RFID
· Remote Fan/Light Control
· Garage Door/Gate Openers


Pinout




Specifications

Supply Voltage (VDDRF, VDDBB)..................................+7V
Voltage on any I/O Pin.......................VSS-0.3 to VDD+0.3
Junction Temperature..........................................+150°C
Storage Temperature Range..............-65°C to + 150°C
Lead Temperature (soldering, 10 seconds).......+ 260°C


Description

The MICRF002, an enhanced version of the MICRF001 and MICRF011, is a single chip OOK (ON-OFF Keyed) Receiver IC for remote wireless applications, employing Micrel's latest QwikRadio^tm technology. This device is a true "antenna-in, data-out" monolithic device. All RF and IF tuning is accomplished automatically within the IC, which eliminates manual tuning and reduces production costs. Receiver functions are completely integrated. The result is a highly reliable yet extremely low cost solution for high volume wireless applications. Because the MICRF002 is a true single-chip radio receiver, it is extremely easy to apply, minimizing design and production costs, and improving time to market.

The MICRF002 provides two fundamental modes of operation, FIXED and SWP. In FIXED mode, the device functions like a conventional superheterodyne receiver, with an (internal) local oscillator fixed at a single frequency based on an external reference crystal or clock. As with any conventional superheterodyne receiver, the transmit frequency must be accurately controlled, generally with a crystal or SAW (Surface Acoustic Wave) resonator.

In SWP mode, the MICRF002 sweeps the (internal) local oscillator at rates greater than the baseband data rate. This effectively "broadens" the RF bandwidth of the receiver to a value equivalent to conventional super-regenerative receivers. Thus the MICRF002 can operate with less expensive LC transmitters without additional components or tuning, even though the receiver topology is still superheterodyne. In this mode the reference crystal can be replaced with a less expensive ± 0.5% ceramic resonator.

The MICRF002 provides two feature enhancements over the MICRF001/011, (1) a Shutdown Mode, which may be used for dutycycle operation, and (2) a "Wakeup" function, which provides a logical indication of an incoming RF signal. These features make the MICRF002 ideal for low and ultra-low power applications, such as RKE and RFID.

All post-detection (demodulator) data filtering is provided on the MICRF002, so no external filters need to be designed. Any one of four filter bandwidths may be selected externally by the user. Bandwidths range in binary steps, from 0.625kHz to 5kHz (SWP mode) or 1.25kHz to 10kHz (FIXED mode). The user only needs to program the appropriate filter selection based on data rate of MICRF002 and code modulation format.