TR3005 RFM, TR3005 Datasheet - Page 4

• Manufacturer Part Number: TR3005
• Description: ASH TR 115.2 KBPS 403.5 MHZ
• Manufacturer: RFM
• Series: TRr

Specifications of TR3005

• Frequency: 403.55MHz
• Data Rate - Maximum: 115.2kbps
• Modulation Or Protocol: ASK, OOK
• Applications: ISM
• Power - Output: 0dBm
• Sensitivity: -109dBm
• Voltage - Supply: 2.2 V ~ 3.7 V
• Current - Receiving: 3.8mA
• Current - Transmitting: 7.5mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -10°C ~ 55°C
• Package / Case: SM-20H
• Wireless Frequency: 403.5 MHz
• Operating Supply Voltage: 2.5 V, 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Maximum Data Rate: 115.2 Kbps
• Minimum Operating Temperature: - 10 C
• Modulation: OOK/ASK
• Lead Free Status / RoHS Status: Lead free by exemption / RoHS compliant by exemption
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 583-1090-2

ASH Transceiver Theory of Operation
In tro duc tion
RFM’s am pli fier-sequenced hy brid (ASH) trans ceiver is spe cif i cally
de signed for short-range wire less data com mu ni ca tion ap pli ca tions.
The trans ceiver pro vides ro bust op er a tion, very small size, low
power con sump tion and low im ple men ta tion cost. All crit i cal RF
func tions are con tained in the hy brid, sim pli fy ing and speed ing de -
sign-in. The ASH trans ceiver can be readily con fig ured to sup port a
wide range of data rates and pro to col re quire ments. The trans ceiver
fea tures ex cel lent sup pres sion of trans mit ter har mon ics and vir tu ally
no RF emis sions when re ceiv ing, mak ing it easy to cer tify to short-
range (unli censed) ra dio reg u la tions.
Am pli fier-Sequenced Re ceiver Op er a tion
The ASH trans ceiver’s unique fea ture set is made pos si ble by its
sys tem ar chi tec ture. The heart of the trans ceiver is the am pli fier-
sequenced re ceiver sec tion, which pro vides more than 100 dB of
sta ble RF and de tec tor gain with out any spe cial shield ing or de -
coup ling pro vi sions. Sta bil ity is achieved by dis trib ut ing the to tal RF
gain over time. This is in con trast to a super het ero dyne re ceiver,
which achieves sta bil ity by dis trib ut ing to tal RF gain over mul ti ple
fre quen cies.
Fig ure 1 shows the ba sic block di a gram and tim ing cy cle for an am -
pli fier-sequenced re ceiver. Note that the bias to RF am pli fi ers RFA1
and RFA2 are in de pend ently con trolled by a pulse gen er a tor, and
Delay Line
Out
RFA1 Out
RF Input
Antenna
P1
P2
t
PW1
t
PW2
ASH Receiver Block Diagram & Timing Cycle
SAW Filter
t
PRC
t
PRI
RFA1
P1
RF Data Pulse
Figure 1
Delay Line
Generator
Pulse
SAW
4
that the two am pli fi ers are cou pled by a sur face acous tic wave
(SAW) de lay line, which has a typ i cal de lay of 0.5 µs.
An in com ing RF sig nal is first fil tered by a nar row-band SAW fil ter,
and is then ap plied to RFA1. The pulse gen er a tor turns RFA1 ON
for 0.5 µs. The am pli fied sig nal from RFA1 emerges from the SAW
de lay line at the in put to RFA2. RFA1 is now switched OFF and
RFA2 is switched ON for 0.55 µs, am pli fy ing the RF sig nal fur ther.
The ON time for RFA2 is usu ally set at 1.1 times the ON time for
RFA1, as the fil ter ing ef fect of the SAW de lay line stretches the sig -
nal pulse from RFA1 some what. As shown in the tim ing di a gram,
RFA1 and RFA2 are never on at the same time, as sur ing ex cel lent
re ceiver sta bil ity. Note that the nar row-band SAW fil ter elim i nates
sam pling side band re sponses out side of the re ceiver passband, and
the SAW fil ter and de lay line act to gether to pro vide very high re -
ceiver ul ti mate re jec tion.
Am pli fier-sequenced re ceiver op er a tion has sev eral in ter est ing char -
ac ter is tics that can be ex ploited in sys tem de sign. The RF am pli fi ers
in an am pli fier-sequenced re ceiver can be turned on and off al most
in stantly, al low ing for very quick power-down (sleep) and wake-up
times. Also, both RF am pli fi ers can be off be tween ON se quences
to trade-off re ceiver noise fig ure for lower av er age cur rent con sump -
tion. The ef fect on noise fig ure can be mod eled as if RFA1 is on
con tin u ously, with an at tenu ator placed in front of it with a loss
equiv a lent to 10*log
av er age amount of time RFA1 is ON (up to 50%). Since an
amplifier-sequenced re ceiver is in her ently a sam pling re ceiver, the
over all cy cle time be tween the start of one RFA1 ON se quence and
RFA2
P2
10
(RFA1 duty fac tor), where the duty fac tor is the
Detector &
Low-Pass
Filter
Data
Out