MICRF011BM

MICRF011 QwikRadiotm Receiver/Data Demodulator Preliminary Information General Description The MICRF011, an enhanced version of the MICRF001, is a single chip OOK (ON-OFF Keyed) Receiver IC for remote wireless applications, employing Micrel’s latest QwikRadiotm 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 MICRF011 is a true single-chip radio receiver, it is extremely easy to apply, minimizing design and production costs, and improving time to market. The MICRF011 is a functional and pin equivalent upgrade to the MICRF001, providing improved range, lower power consumption, and higher data rate support when in FIXED mode. The MICRF011 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 MICRF011 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 MICRF011 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. All post-detection (demodulator) data filtering is provided on the MICRF011, 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 and code modulation format. 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—2.4 mA at 315MHz Fully pin compatible with MICRF001 Very low RF re-radiation at the antenna Direct CMOS logic interface to standard decoder and microprocessor ICs Extremely low external part count Applications • • • Garage Door/Gate Openers Security Systems Remote Fan/Light Control IMPORTANT: Items in bold type represent changes from the MICRF001 specification. Differences between the MICRF001 and -011 are identified in table 2, together with design considerations for using the -011 in present MICRF001 designs. Typical Operating Circuit 385.5 MHz, 1200 bps OOK RECEIVER Micrel Inc. • 1849 Fortune Drive San Jose, Ca 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com MICRF011 QwikRadio tm Micrel Ordering Information Part Number MICRF011BN MICRF011BM Temperature Range -40°C to +85°C -40°C to +85°C Package 14-Pin DIP 14-Pin SOIC Pin Configuration (DIP and SOIC) Pin Description Pin Number Pin Name 1 2/3 SEL0 VSSRF 4 ANT 5 VDDRF 6 VDDBB 7 CTH 8 9/10 DO VSSBB 11 CAGC 12 13 SEL1 REFOSC 14 SWEN December 1998b Pin Function Programs desired Demodulator Filter Bandwidth. This pin in internally pulled-up to VDD. See Table 1. This pin is the ground return for the RF section of the IC. The bypass capacitor connected from VDDRF to VSSRF should have the shortest possible lead length. For best performance, connect VSSRF to VSSBB at the power supply only (i.e., keep VSSBB currents from flowing through VSSRF return path). This is the receive RF input, internally ac-coupled. Connect this pin to the receive antenna. Input impedance is high (FET gate) with approximately 2pF of shunt (parasitic) capacitance. For applications located in high ambient noise environments, a fixed value band-pass network may be connected between the ANT pin and VSSRF to provide additional receive selectivity and input overload protection. (See “Application Note 22, MICRF001 Theory of Operation”.) This pin is the positive supply input for the RF section of the IC. VDDBB and VDDRF should be connected directly at the IC pins. Connect a low ESL, low ESR decoupling capacitor from this pin to VSSRF, as short as possible. This pin is the positive supply input for the baseband section of the IC. VDDBB and VDDRF should be connected directly at the IC pins. This capacitor extracts the (DC) average value from the demodulated waveform, which becomes the reference for the internal data slicing comparator. Treat this as a low-pass RC filter with source impedance of 118kohms (for REFOSC frequency ft=4.90MHz). Note that variation in source resistance with filter selection no longer exists, as it does for the MICRF001. (See “Application Note 22, MICRF001 Theory of Operation”, section 6.4). A standard ± 20% X7R ceramic capacitor is generally sufficient. Output data pin. CMOS level compatible. This is the ground return for the baseband section of the IC. The bypass and output capacitors connected to VSSBB should have the shortest possible lead lengths. For best performance, connect VSSRF to VSSBB at the power supply only (i.e., keep VSSBB currents from flowing through VSSRF return path). Integrating capacitor for on-chip receive AGC (Automatic Gain Control). The Decay/Attack time-constant (TC) ratio is nominally set as 10:1. Use of 0.47µF or greater is strongly recommended for best range performance. See “Application Note 22, MICRF001 Theory of Operation” for further information. Programs desired Demodulator Filter Bandwidth. This pin in internally pulled-up to VDD. See Table 1. This is the timing reference for on-chip tuning and alignment. Connect either a ceramic resonator or crystal (mode dependent) between this pin and VSSBB, or drive the input with an AC coupled 0.5Vpp input clock. Use ceramic resonators without integral capacitors. Note that if operated in FIXED mode, a crystal must be used; however in SWP mode, one may use either a crystal or ceramic resonator. See “Application Note 22, MICRF001 Theory of Operation” for details on frequency selection and accuracy. This logic pin controls the operating mode of the MICRF011. When SWEN = HIGH, the MICRF011 is in SWP mode. This is the normal (default) mode of the device. When SWEN = LOW, the device operates as a conventional single-conversion superheterodyne receiver. (See “Application Note 22, MICRF001 Theory of Operation” for details.) This pin is internally pulled-up to VDD. 2 MICRF011 MICRF011 QwikRadio SEL0 SEL1 1 0 1 0 tm Micrel Demodulator Bandwidth (Hz) SWP Mode 5000 2500 1250 625 1 1 0 0 FIXED Mode 10000 5000 2500 1250 Table 1 Nominal Demodulator (Baseband) Filter Bandwidth vs. SEL0, SEL1 and Mode No . 1. Design Change Local Oscillator sweep range reduced 2X. Affects SWP mode only. 2. Local Oscillator sweep rate reduced 2X. Affects SWP mode only. 3. IF Center Frequency reduced 2X. Affects both modes SWP and FIXED. IF Bandwidth reduced 2X. Affects both modes SWP and FIXED. FIXED mode Demod Filter cutoff frequencies increased 2X. Affects FIXED mode only. CTH Pin Impedance 118kΩ @ ft=4.90 MHz [see Note 4]. Affects both modes SWP and FIXED. 4. 5. 6. Retrofit Design Action Reconsider Tx/Rx Frequency Alignment Error Budget, per App. Note 22. If alignment tolerances cannot be met, consider: (1) tighten ceramic resonator tolerance, (2) replace ceramic resonator with crystal, or (3) not to upgrade to -011 Impacts SWP mode maximum data rate. If data rate constraint cannot be met, consider (1) reduce system data rate by 2X, or (2) not to upgrade to -011 Factor this change into Tx/Rx Frequency Alignment Error Budget. FIXED mode users of -001 must change crystal frequency. Factor this change into Tx/Rx Frequency Alignment Error Budget. For FIXED mode only, choose next lower filter frequency (via control pins SEL0/1), to maintain same range performance Recompute appropriate value of CTH capacitor, and change value on PCB Table 2 MICRF001/011 Change List and Design Retrofit Guidelines December 1998b 3 MICRF011 MICRF011 QwikRadio tm Micrel ABSOLUTE MAXIMUM RATINGS Operating Ratings 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 Supply Voltage (VDDRF, VDDBB)..................4.75V to 5.5V Ambient Operating Temperature (TA)..........-40°C to +85°C Package Thermal Resistance θJA (14 Pin DIP)........90°C/W Package Thermal Resistance θJA (14 Pin SOIC)...120°C/W This device is ESD sensitive: Meets Class 1ESD test requirements (Human body Model, HBM), in accordance with MIL-STD-883C, Method 3015. Do not operate or store near strong electrostatic fields. Use appropriate ESD precautions. Electrical Characteristics Unless otherwise stated, these specifications apply for Ta=-40°C to 85°C, 4.75