RK-900-HDTC Radiotronix, RK-900-HDTC Datasheet - Page 9

• Manufacturer Part Number: RK-900-HDTC
• Description: RF Modules & Development Tools Rapid Developmnt Kit
• Manufacturer: Radiotronix

Specifications of RK-900-HDTC

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Circuit Description
A simplified block diagram of the EWD-HDTC module is shown in Figure 2.
The module contains an internal antenna switch, and can operate in one of four modes:
TX, RX, sleep, and shutdown.
In transmit mode, the local oscillator (LO) is switched to the power amp (PA), generating
the transmit carrier. The PLL provides closed-loop frequency control of the carrier. The
incoming data stream is used to frequency modulate the carrier. Modulation is precisely
controlled by the PLL by switching between two reference frequencies corresponding to
the two possible states of the data input line. Data can be transmitted in NRZ or
Manchester form. The control block contains a built-in Manchester encoder, simplifying
the requirements of the external microcontroller.
In receive mode, the module operates like a traditional super heterodyne receiver. The
LO is switched to the receive mixer in order to down convert the incoming RF signal to a
150 kHz intermediate frequency. The IF block amplifies and filters the down converted
signal in preparation for demodulation. Clock extraction and synchronization is
performed on the demodulated data by the control block. The receiver supports NRZ and
Manchester encoded data.
The on-board PLL allows fine-frequency adjustments to be made to the carrier frequency,
eliminating the need for on-board trimmer capacitors and temperature controlled crystal
oscillators.
C:\Radiotronix\Data Sheets\ewd-hdtc.doc - 5 -
ANT PIN
Figure 2 EWD-HDTC Internal Block Diagram
TRANSMIT CHAIN
LNA
MIXER
Receive Chain
LO
BLOCK
IF
PLL
DEMOD
2
3
RSSI
ECLK
EDAT
1/11/2003