RFM42B Datasheet, PDF (10/51 Pages) List of Unclassifed Manufacturers – ISM TRANSMITTER

RFM42B/43B
2. Functional Description
HopeRF's RFM42B/43B are highly integrated,low cost,433/868/915MHz wireless ISM transmitters module .
The wide operating voltage range of 1.8–3.6V and low current consumption makes the RFM42B/43B
an ideal solution for battery powered applications.
The RF carrier is generated by an integrated VCO and  Fractional-N PLL synthesizer. The synthesizer is
designed to support configurable data rates, output frequency, frequency deviation, and Gaussian filtering at
433MHz, 868MHz, 915MHz band. The transmit FSK data is modulated directly into the  data stream and can be
shaped by a Gaussian low-pass filter to reduce unwanted spectral content.
The RFM42B’s PA output power can be configured betwee+n1 and +20dBm in 3dB steps, while the RFM43B's
PA output power can be configured between –8 and +13 dBm in 3dB steps.The PA incorporates automatic
ramp-up and ramp-down control to reduce unwanted spectral spreading.
The RFM42B/43B 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 available
in “ RFM42B/43B Register Descriptions.”
2.1. Operating Modes
The RFM42B/43B provides several operating modes which can be used to optimize the power consumption for
a given application.
Table8 summarizes the operating modes of the RFM42B/43B. In general, any given operating mode may be
classified as an active mode or a power saving mode. The table indicates which block(s) are enabled (active) in
each corresponding mode. With the exception of the SHUTDOWN mode, all can be dynamically selected by
sending the appropriate commands over the SPI. An “X” in any cell means that, in the given mode of operation,
that block can be independently programmed to be either ON or OFF, without noticeably impacting the current
consumption. The SPI circuit block includes the SPI interface hardware and the device register space. The 32 kHz
OSC block includes the 32.768 kHz RC oscillator or 32.768 kHz crystal oscillator and wake-up timer. AUX
(Auxiliary Blocks) includes the temperature sensor, general purpose ADC, and low-battery detector.
Mode Name
Digital LDO
Table 8. Operating Modes
Circuit Blocks
SPI 32 kHz OSC AUX
SHUTDOWN
STANDBY
SLEEP
SENSOR
READY
TUNING
TRANSMIT
OFF
(Register contents
lost)
ON
(Register contents
retained)
OFF
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
ON
X
X
X
X
OFF
X
ON
X
X
X
*Note: Using RFM43B at +13dBm usin g recommended reference design.
30 MHz
XTAL
OFF
OFF
OFF
OFF
ON
ON
ON
PLL
OFF
PA
OFF
I_VDD
15 nA
OFF
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
OFF
OFF
ON
450 nA
1 µA
1 µA
800 µA
8.5 mA
30 mA*
Tel: [phone] Fax: [phone] E-mail: [e-mail] http://www.hoperf.com
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