2. Functional Description
The TRC101 is a low power, frequency agile, zero-IF, multi-channel FSK transceiver for use in the 315,
433, 868, and 916 MHz bands. All RF and baseband functions are completely integrated requiring only a
single 10MHz crystal as a reference source and an external low-cost processor. Functions include:
•
PLL synthesizer
•
Power Amp
•
LNA
•
I/Q Mixers
•
I/Q Demodulators
•
Baseband Filters
•
Baseband Amplifiers
•
RSSI
•
Low Battery Detector
•
Wake-up Timer/Duty Cycle Mode
•
Valid Data Detection/Data Quality
The TRC101 is ideal for Frequency Hopping Spread Spectrum (FHSS) applications requiring frequency
agility to meet FCC requirements. Use of a low-cost microcontroller is all that is needed to create a
complete data link. The TRC101 incorporates different sleep modes to reduce overall current
consumption and extend battery life. It is ideal for applications operating from typical lithium coin cells.
2.1 TRC101 Typical Application Circuit
Figure 1. Typical Application Circuit
RF Transmitter Matching
The RF pins are high impedance and differential. The optimum differential load for the RF port at a given
frequency band is shown in Table 1.
TABLE 1.
TRC101
Admittance
Impedance (Ohm)
L
315 MHz
1.5e-3 – j5.14e-3
52 + j179
98nH
433 MHz
1.4e-3 – j7.1e-3
27 + j136
52nH
868 MHz
2e-3 – j1.5e-2
8.7 + j66
12.5nH
916 MHz
2.2e-3 – j1.55e-2
9 + j63
11.2nH
4
RFM [ RF MONOLITHICS, INC ]
