TXM-433-RM Linx Technologies Inc, TXM-433-RM Datasheet - Page 7

• Manufacturer Part Number: TXM-433-RM
• Description: TRANSMITTER RF 433MHZ
• Manufacturer: Linx Technologies Inc
• Series: RMr

Specifications of TXM-433-RM

• Frequency: 433MHz
• Applications: ISM, Remote Monitoring, Telemetry
• Modulation Or Protocol: ASK, OOK
• Data Rate - Maximum: 10 kbps
• Power - Output: -4dBm ~ 4dBm
• Current - Transmitting: 6mA
• Data Interface: PCB, Through Hole
• Antenna Connector: Through Hole
• Voltage - Supply: 5.9 V ~ 9 V
• Operating Temperature: -10°C ~ 55°C
• Package / Case: SIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -
• Memory Size: -
• Other names: TXM-433-RM-R

M O D U L ATION REQUIREMENTS
D ATA CODING
BASIC REMOTE CONTROL EXAMPLE
fi g u re 8: Basic wireless encoder circ u i t
The RM transmitter has a DC to 10 KHz modulation bandwidth and will accept
direct analog (AFSK) or digital data. A modulation lowpass filter (10 KHz @
-6 dB, 1st order) is used intern a l l y.
Digital data is normally input to pin 5 in a serial stream at CMOS logic leve l s
such as those from a microprocessor or encoder IC. The maximum data ra t e
is 10Kbps. The pin should always be dri ven with a voltage common to the
supply voltage present at pin 3 (Vcc). Under no condition should the vo l t a g e
at the data pin be allowed to exceed the supply voltage (Vcc).
Once a reliable RF link has been established, the challenge becomes how to
most effe c t i vely tra n s fer data across it. Since the transmit and receive
modules have no internal digital coding/decoding, a user has tremendous
f l exibility to send many types of analog and digital data. It is important to
understand, howeve r, that some intelligent transmission structure must be
u s e d . This is true for seve ral reasons. The first and most significant is that
there must be some way to distinguish an intended transmission from
i n t e r ferers and ambient noise. In addition, it is generally not possible to hold
DC levels across an RF link, therefo r e, transitions must take place at
m i n i mum interva l s.
It is, of course, a simple task to also accomplish application-specific data
encoding and tra n s fer using a microprocessor. I n ex p e n s i ve micros such as
the Microchip PIC series make an excellent choice for this task.
If you do not have a microprocessor on-board your product and you want to
send control signals such as a key press, switch closing, or low - rate data,
consider using an encoder and decoder IC chipset. These chips take care of
all encoding, error checking, and decoding functions and are ava i l a ble from
L i n x . An example of such an application is shown below.
This is an example of a basic remote control design utilizing a Holtek
encoder/decoder IC. When a key is pressed at the tra n s m i t t e r, a corresponding
pin at the receiver goes high. This basic circuit can be easily modified to suit
a broad range of applications, and clearly demonstrates the ease of using and
i n t e r facing the Linx modules.
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