RFM31B Datasheet, PDF (10/63 Pages) List of Unclassifed Manufacturers – ISM RECEIVER

RFM31B
2. Functional Description
HopeRF's RFM31B are highly integrated, low cost, 433/868/915MHz wireless ISM receivers module .
The wide operating voltage range of 1.8–3.6V and low current consumption makes the RFM31B an ideal
solution for battery powered applications.
The RFM31B uses a single-conversion mixer to downconvert the 2-level FSK/GFSK/OOK modulated
receive signal to a low IF frequency. Following a programmable gain amplifier (PGA) the signal is converted to the
digital domain by a high performance  ADC allowing filtering, demodulation, slicing, and packet handling to be
performed in the built-in DSP increasing the receiver’s performance and flexibility versus analog based
architectures. The demodulated signal is then output to the system MCU through a programmable GPIO or via the
standard SPI bus by reading the 64-byte RX FIFO.
A high precision local oscillator (LO) is generated by an integrated VCO and  Fractional-N PLL synthesizer. The
synthesizer is designed to support configurable data rates, output frequency and frequency deviation .
The RFM31B is designed to work with a microcontroller to create a very low cost system. Voltage regulators are
integrated on-chip which allows for a wide operating supply voltage range from +1.8 to +3.6V. A standard 4-pin
SPI bus is used to communicate with an external microcontroller. Three configurable general purpose I/Os
are available. A complete list of the available GPIO functions is shown in "8. Auxiliary Functions" and includes
microcontroller clock output, Antenna Diversi ty, Antenna Switch, POR, and various interrupts. A complete list
of the available GPIO functions is shown in "RFM31B Register Descriptions.”
C3
C4
C5
100 p 100 n 1 u
X1
30 MHz
GP1
GP2
VDD
VDD_RF
1
SCLK
15
GP3
C1
NC
2
SDI
14
RFp
3
RF31B
SDO
13
GP4
GP5 ^{Microcontroller}
L1
RXn ₄
VDD_D
12
NC ₅
11 ^NC
C2
C6
1u
RFM31B module
VSS
,
Figure 1.RFM31B Application Example
Tel: [phone] Fax: [phone] E-mail: [e-mail] http://www.hoperf.com
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