آر اف (فرکانس رادیویی) و بی‌سیم گیرندهٔ آر‌اف

Product Attributes

Introduction

The MICRF004 QwikRadio™ VHF receiver is a single-chip OOK (on-off keyed) receiver IC for remote wireless applications. This device is a true single-chip, “antenna-in, data-out” device. All RF and IF tuning is accomplished automatically within the IC which eliminates manual tuning production costs and results in a highly reliable, extremely low-cost solution for high-volume wireless applications. The MICRF004 is extremely easy to apply, minimizing design and production costs, and improving time to market. The MICRF004 provides two fundamental modes of operation, fixed and sweep. In fixed mode, the device functions as a conventional superheterodyne receiver with an internal local oscillator operating at a single frequency based on an external reference crystal or clock. Fixed mode is for use with accurately-controlled transmitters utilizing crystal or SAW (surface acoustic wave) resonators. In sweep mode, the MICRF004 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 superregenerative receivers. This allows the MICRF004 to 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 MICRF004 features a shutdown control, which may be used for duty-cycled operation, and a wake-up output, which provides a logical indication of an incoming RF signal. These features make the MICRF004 ideal for low- and ultra-lowpower applications, such as RKE (remote keyless entry) and RFID (RF identification). Since all post-detection (demodulator) data filtering is provided on the MICRF004, no external filters are required. One of the four internal filter bandwidths must be externally selected based on data rate and code modulation format. Bandwidths range in binary steps, from 0.55kHz to 4.4kHz (sweep mode) or 1.1kHz to 8.8kHz (fixed mode).

Features

• Complete VHF receiver on a monolithic chip
• 140MHz to 200MHz frequency range

• 200 meters typical range with monopole antenna

• 2.5kb/s sweep- and 10kb/s fixed-mode data rates
• Automatic tuning, no manual adjustment
• No filters or inductors required
• Low 240μA operating supply current at 150MHz (10:1 duty cycle)
• Shutdown mode for >100:1 duty-cycle operation
• Wakeup for enabling decoders and microprocessors
• Very low RF antenna reradiation
• CMOS logic interface for standard ICs
• Extremely low external part count

Applications

• Automotive remote keyless entry
• Long range RF identification
• Remote fan and light control
• Garage door and gate openers