What is TRC101？

TRC is a highly integrated single chip, zero-IF, multi-channel, low power radio frequency (RF) transceiver. It is an ideal fit for low cost, high volume, two way short-range wireless applications for use in the unlicensed 300-1000 MHz frequency bands. All critical RF and baseband functions are completely integrated in the chip, thus minimizing external component count and simplifying and speeding design-ins. Use of a low cost, generic 10MHz crystal and a low-cost microcontroller is all that is needed to create a complete link. The TRC101 also incorporates different sleep modes to reduce overall current consumption makes it ideal for various short ranges radio applications.

Pin Configuration

Pin	Part name	Pin out description
1	SDI	SPI data in
2	SCK	SPI data clock
3	nCS	Chip select input- Selects the chip for an SPI data transaction. The pin must be pulled ‘low’ for a 16- bit read or write function.
4	SDO	SPI data out
5	nIRQ	Interrupt request output- The receiver will generate an active low interrupt request for the microcontroller on the following events:ü The TX register is ready to receive the next byte ü The FIFO has received the preprogrammed amount of bits ü Negative pulse on the interrupt input pin nINT ü Power-on reset ü Wake-up timer timeout ü FIFO overflow/TX register underrun ü Supply voltage below the preprogrammed value is detected
6	Dta/nFSei	Data in- When the internal TX register is not used, this pin may be used to manually modulate data from an external host processor. If the internal TX register is enabled, this pin must be pulled high. When using the internal Rx FIFO, this pin must be pulled low to select the FIFO. This pin is used to select the internal registers when reading and writing.Data out- When the internal FIFO is not used this pin is used in conjunction with pin 7 (which is recovered clock) to receive data FIFO select- When reading the FIFO, this pin selects the FIFO and the first bit appears on the next clock. Use this pin in conjunction with Pin 7.
7	CR/FINT/FCAP	Recovered clock output- When the digital filter is used (Baseband Filter Register, Bit [4]) and FIFO disabled (Configuration Register, Bit [6]), this pin provides the recovered clock from the incoming data.FIFO INT- When the internal FIFO is enabled (configuration register, Bit [6]), this pin acts as a FIFO Full interrupt indicating that the FIFO has filled to its pre-programmed limit (FIFO configuration register, Bit [7..4]). External data filter capacitor- When the Analog filter is used (Baseband Filter Register, Bit [4]), this pin is the raw baseband data that may be used by a host processor for data recovery. The external capacitor forms a simple Low-pass filter with an internal 10KOhm series resistor. The capacitor value may be chosen for a Max data rate up to 256kbps Note: check bit [6], bit [7..4], bit [4] in TRC101 datasheet
8	ClkOut	Optional host processor clock output
9	Xtal/Ref	Xtal- Connects to a 10MHz series crystal or an external oscillator reference. The circuit contains an integrated load capacitor (See configuration register in datasheet) in order to minimize the external component count. The crystal is used as the reference for the PLL, which generates the local oscillator frequency. The accuracy requirements for production tolerance, temperature drift and aging can be determined from the maximum allowable local oscillator frequency error. Whenever a low frequency error is essential for the application, it is possible to “pull” the crystal to the accurate frequency by changing the load capacitor value.Ext Ref- an external reference such as oscillator, may be connected as reference source. it is connected via a 0.01uF
10	nRESET	Reset output with internal pull up
11	GND	System ground
12	RF_P	RF Diff I/O
13	RF_N	RF Diff I/O
14	VDD	Supply voltage
15	RSSIA	Analog RSSI output- The Analog RSSI can be used to determine the actual signal strength. The response and settling time depends on an external filter capacitor. Typically, a 1000pF capacitor will provide optimum response time for most applications.
16	NINT/DDet	nINT- This pin may be configured as an active low external interrupt to the chip. When logic ‘0’ is applied to this pin, it causes the nIRQ pin 5 to toggle, signaling an interrupt to an external processor. Reading the first four (4) bits of the status register (in datasheet) tells the source of the interrupt. This pin may be used as a wake-up event from sleep.Valid data detector output- this pin may be configured to indicate valid data when the synchronous pattern recognition circuit indicating potentially real incoming data

Features

Modulation: FSK (Frequency hopping spread spectrum capability)
Frequency range is 300-1000 MHz and high sensitivity is -105 dBm with high data rate of up to 256kbps
Low current consumption of RX current is 8.5mA
Wide operating supply voltage of 2.2 to 5.4 V, and a low standby current of 0.2uA
Programmable analog/digital baseband filter, output RF power, input LNA gain and CLK output frequency
Transmit/receive FIFO and standard SPI interface
Automatic antenna tuning circuit
Support for multiple channels: [315/433 Bands] 95 Channels (100kHz), [868 Band] 190 Channels (100kHz) and [915 Band] 285 Channels (100kHz)
Power saving sleep mode
Very few external components requirement, and small size 16-pin TSSOP package

TRC101 functional description

It is for use in 315, 433, 868 and 916 MHz bands. All the RF and basebands function is completely integrated requiring only a single 10MHz crystal as reference source and an external low cost processor. The functions include; PLL synthesizer, power amplifier, LNA, I/Q mixers, I/Q demodulators, baseband amplifiers, RSSI, Low battery detector, wake-up timer/duty bicycle mode and valid data detection or data quality.

The TRC101 is ideal for frequency hopping spread spectrum applications requiring frequency agility to meet FCC requirements. The use of low cost microcontroller is all that is needed to create a complete data link. It incorporates different sleep modes to reduce overall current consumption and extend battery life. It is ideal applications operating from typical lithium coin cells.

How TRC101 work?

In RF transmitter matching, the RF pins are of high impedance and differential, for example, at 916 MHz frequency band, the impedance is (9+j63) Ohm and inductance L of 11.2nH. This is seen as antenna load by RF pins as maximum power transfer. Antennas ideally suited for this world is a dipole, folded dipole and loop. TRC101 is designed to drive a differential output such as a dipole antenna or a loop. Optimal PCB layout is much important, and for optimal transmit and receive performance, the trace lengths at the RF pins must be kept as short as possible. Using small surface mount components like 0402 or 0603 will yield best performance as well as keep RF port compact. Make all RF connections short and direct. (Check TRC101 block functional characteristics in the datasheet)

TRC101 typical applications circuit

Applications

Wireless modules and mesh sensors
Low power two way telemetry systems
Medical equipment
Sports and performance monitoring
Automobile immobilizers
Security systems
Home and industrial automations
Automated meter reading
Active RFID tags
Two way remote keyless entry

TRC101 Related Products Prices

Parts	Mfr.	Description	Stock	Prices
TRC101	Murata Electronics	RFIC TRANCEIVER DEVELOPMENT KIT	3500	$1.314 Lowest
TRC105	RF Monolithics, Inc	300-510 MHz RF Transceiver	1850	$2.914 Lowest
TRC104	RF Monolithics, Inc	2.4 GHz RF Transceiver	44	RFQ