RFM213W Datasheet, PDF (10/20 Pages) List of Unclassifed Manufacturers – Low-Cost Consumer Electronics Applications

5. Functional Descriptions
RFM213W
RFI
GND
VDD
GND
I-MXR
LNA
Q-MXR
LO GEN
LDOs
Bandgap
POR
Image
Rejection
Band-pass
Filter
I-LMT
RSSI
SAR
AGC
(G)FSK/OOK
DEMOD
AFC & AGC
VCO
Q-LMT
Loop
Filter
PFD/CP
26 MHz
DIVIDER
AFC & Σ-Δ Modulator
VCON VCOP
nRSTO
Radio
Controller
3-wire SPI
LPOSC
XOSC
EEPROM
XIN XOUT
Figure 10. Functional Block Diagram
CSB
SCL
SDA
CLKO
DOUT
5.1 Overview
The RFM213W is an ultra low power, high performance, low-cost (G)FSK/OOK stand-alone RF receiver for various 300 to 480
MHz wireless applications. It is part of the CMOSTEK NextGenRF^TM family, which includes a complete line of transmitters,
receivers and transceivers. The chip is based on a fully integrated, low-IF receiver architecture. The low-IF architecture facilitates
a very low external component count and does not suffer from powerline - induced interference problems. The synthesizer
contains a VCO and a low noise fractional-N PLL with an output frequency resolution of 24.8 Hz. The VCO operates at 2x the
Local Oscillator (LO) frequency to reduce spurious emissions. Every analog block is calibrated on each Power-on Reset (POR) to
the internal reference voltage. The calibration helps the device to finely work under different temperatures and supply voltages.
The baseband filtering and demodulation is done by the digital demodulator. The demodulated signal is output to the external
MCU via the DOUT pin. No external MCU control is needed in the applications.
The 3-wire SPI interface is only used for configuring the device. The configuration can be done with the RFPDK and the USB
Programmer. The RF Frequency, symbol rate and other product features are all configurable. This saves the cost and simplifies
the design, development and manufacture. Alternatively, in stock products of 433.92 MHz is available for immediate demands
with no need of EEPROM programming. The RFM213W operates from 1.8 to 3.6 V so that it can finely work with most batteries
to their useful power limits. The receive current is only 4.3 mA while achieving -111 dBm receiving sensitivity (FSK @ 433.92 MHz
F_RF, 9.6 ksps SR). The RFM213W receiver together with the CMT2113A transmitter enables an ultra low cost RF link.
5.2 Modulation, Frequency Deviation and Symbol Rate
The RFM213W supports FSK/GFSK demodulation with the symbol rate from 0.1 to 100 ksps, as well as the OOK demodulation
with the symbol rate from 0.1 to 40 ksps. The supported deviation of the (G)FSK modulation ranges from 1 to 200 kHz. The
device continuously covers the frequency range from 300 to 480 MHz, including the license free ISM frequency band around 315
MHz and 433.92 MHz. The internal frequency synthesizer contains a high-purity VCO and a low noise fractional-N PLL with an
output frequency resolution of 24.8 Hz. See the table below for the demodulation, frequency and symbol rate information.
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