RXM-900-HP-II Linx Technologies Inc, RXM-900-HP-II Datasheet - Page 10

• Manufacturer Part Number: RXM-900-HP-II
• Description: RECEIVER RF 900MHZ 8-CH PACK
• Manufacturer: Linx Technologies Inc

Specifications of RXM-900-HP-II

• Frequency: 902MHz ~ 928MHz
• Sensitivity: -95dBm
• Data Rate - Maximum: 50 kbps
• Modulation Or Protocol: FM, FSK
• Applications: Home / Industrial Automation, Remote Access, Security Alarms
• Current - Receiving: 18mA
• Data Interface: PCB, Through Hole
• Antenna Connector: Through Hole
• Voltage - Supply: 2.7 V ~ 16 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 18-SIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -
• Memory Size: -
• Other names: RXM-900-HP2; RXM-900-HP2

CHANNEL SELECTION
ANALOG OUTPUT
Figure 16: Audio Amplifier
The HP-II receiver module features eight user-selectable channels. The channel
of operation is determined by the state of pins CS0-CS2. Figure 15 shows a
channel-selection table based
on the pins’ states. The on-
board microprocessor performs
all PLL loading functions. This
frees the user from complex
programming requirements and
allows for manual channel
selection via switches in product
designs where a microprocessor
is not used.
The analog output is derived after amplification in the BitPERFECT bit slicer. The
analog output is valid from 50 Hz to 25 KHz, providing an AC signal of about 1V
peak-to-peak. This output should not be used to drive a low-impedance load such
as a speaker. In applications requiring direct drive into a speaker, such as the
transmission of audio, a simple op-amp circuit like the one shown in Figure 16
can be used. In this circuit, the op-amp is used to act as an impedance converter.
NOTE:
A common method of reducing receiver power consumption is to turn the receiver off
via the PDN pin for some time interval and wake the receiver periodically to check for
the presence of a transmitted signal. In order to implement this method with an HP-II
receiver successfully, there are some timing requirements the user must observe
when powering up the receiver to check for channel activity.
At power-up the receiver’s on-board microprocessor will begin its start-up routine as
detailed previously. A 12 mSec time period must be allotted to allow this routine to be
completed. After 12 mSec, the data and RSSI circuits are fully qualified and reliable.
The off-period is determined by the discharge rate of the internal bypass capacitors.
The capacitors must fully discharge to ensure that subsequent power-ups will reliably
restart the microprocessor. This minimum time should be no less than 1 mSec. If the
user is finding that the transmitter is not reliable starting up after power-up, this time
should be increased.
HP Analog Out
READ THIS IF YOU ARE GOING TO PERIODICALLY
POWER-DOWN RECEIVER!!
10K
1uF
2
3
Figure 15: Channel-Selection Table
4-12V
+
-
CS2
6
0
0
0
0
1
1
1
1
4
LM386
8
CS1
0
0
1
1
0
0
1
1
.05uF
10
CS0
250uF
0
1
0
1
0
1
0
1
Channel
0
1
2
3
4
5
6
7
Frequency
903.37
906.37
907.87
909.37
912.37
915.37
919.87
921.37