MICRF008 QwikRadio Sweep-Mode Receiver General Description Features The MICRF008 QwikRadio UHF receiver is a single-chip Complete UHF receiver on a monolithic chip OOK (on-off keyed) receiver IC designed for remote 300MHz to 440MHz frequency range wireless applications. This device is a true single-chip, Up to 4.8kbps data rate. antenna-in, data-out device, and it is easy to implement. Automatic tuning, no manual adjustment MICRF008 receiver requires very few peripheral passive Very low RF antenna reradiation components. All tunings, RF and IF, are accomplished CMOS logic interface for standard ICs within the IC. Ease of use and minimal parts count translate to cost savings and shorter time to market. Low external part count MICRF008 receiver offers a robust and low-cost solution Replaces superregenerative receivers design for high volume wireless applications. Manufacturability and same performance over the years The MICRF008 sweeps the internal local oscillator at rates Very small PCB area required greater than the baseband data rate. This effectively broadens the RF bandwidth of the receiver to a value Applications equivalent to conventional superregenerative receivers. This allows the MICRF008 to operate with less expensive Garage door and gate openers LC transmitters without additional components or tuning, Security systems even though the receiver topology is still superheterodyne. Remote appliances control In this mode the reference crystal can be replaced with a Toys less expensive 0.5% ceramic resonator. Fan and light control Since all post-detection (demodulator) data filtering is provided on the MICRF008, no external IF filters are required. One of the two internal filter bandwidths must be externally selected based on data rate and code modulation format. Data sheets and support documentation can be found on Micrels web site at: www.micrel.com. Typical Application ANT1 1/8 Monopole U1 80mm MICRF008YM 1 8 REFOSC SEL0 C1 1.8pF 2 7 ANT CAGC +5V 3 6 VDD VSS Y1 3.36MHz L1 C2 4 5 33nH 4.7F CTH DO C3 C4 0.1F 2.2F 433.92MHz Receiver QwikRadio is a registered trademark of Micrel, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MICRF008 Ordering Information Part Number Junction Temperature Range Package Lead Finish MICRF008YM 40C to +85C 8-Pin SOIC Pb-Free Pin Configuration SEL0 1 8REFOSC ANT 2 7 CAGC VDD 3 6 VSS CTH 4 5 DO 8-Pin SOIC (M) Pin Description Pin Number Pin Name Pin Name SOIC-8 1 SEL0 Bandwidth Selection Bit 0 (Digital Input): Sets the desired demodulator filter bandwidth. See Table 1. Internally pulled-up to VDD. 2 ANT Antenna (Input): High-impedance, internally AC-coupled receiver input. Connect this pin to the matching network. See Applications Information for optional band-pass filter information. 3 VDD Positive Supply Input: Connect a low ESL, low ESR decoupling capacitor from this pin to VSS, as short as possible. 4 CTH Data Slicing Threshold Capacitor (External Component): Capacitor extracts the DC average value from the demodulated waveform which becomes the reference for the internal data slicing comparator. See Applications Information for selection. 5 DO Data Output (Output): CMOS-level compatible data output signal. 6 VSS Negative Supply Input: Connect this pin to the RF ground. 7 CAGC AGC Capacitor (External Component): Integrating capacitor for on-chip AGC (automatic gain control). The decay/attack time-constant () ratio is nominally 10:1. See Applications Information for capacitor selection. 8 REFOSC Reference Oscillator (External Component or Input): Timing reference for on-chip tuning and alignment. Connect either a ceramic resonator or a crystal between this pin and VSS, or drive the input with an AC-coupled 0.5VPP input clock. M9999-080108 August 2008 2