TXC100

TXC100 RFM | Alldatasheet

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Technical content

Electrical Characteristics

Complies with Directive 2002/95/EC (RoHS) I. Product Overview TXC100 is a rugged, single chip OOK/ASK/FSK Transmitter IC in the 300-450 MHz frequency range. This chip is highly integrated and has all required RF functions including a complete PLL circuit and power amplifier, thus requiring very few external components. The TXC100 is feature rich and is very small in size with high output power and low current consumption and is ideal for various short range wireless applications in the industrial, automotive and consumer markets. II. Key Features Operating Frequency Range: 300-450 MHz Modulation Types: OOK/ASK/FSK Operation supply voltage: 2.1V - 3.6V High Date rate: ASK: 100 kbps FSK: 20 kbps Low current consumption: ASK mode: 7 mA typical FSK mode: 10 mA typical Low Stand by current: < 1 nA Adjustable Output power: -10dBm to +10dBm Adjustable FSK Shift Programmable Clock Output Very Low external component count Extended temperature range: -40°C to +125°C. Small Package: 3X3 mm 16-pin TQFN package Standard 13 inch reel, 2500 pieces III. Popular applications Active RFID tags Automated Meter reading Wireless sensor nodes Home Automation Security systems Tire pressure monitoring Remote keyless entry Automobile Immobilizers Sports & Performance monitoring Wireless Toys Medical equipment Command & Control systems RF Monolithics, Inc.

4441 Sigma Road

Dallas, Texas 75244 (800) 704-6079 toll-free in U.S. and Canada www.rfm.com Email: info@rfm.com Characteristics Sym Min Typical Max Units Operating Frequency fo 300 450 MHz Modulation Types OOK/ASK/ FSK ASK Data Rate 100 Kbps FSK Data Rate Kbps Peak RF Output Power dBm Standby Current nA Supply Voltage Range VDD 2.1 3.6 Vdc Operating Temperature Ta -40 +125 oC Characteristics Sym Min Typical Max Units Crystal Frequency fc fo/32 MHz Load Capacitance Cl pF Tolerance Tol ppm 3x3mm package

IV. TXC100 Block Diagram and Typical Application Circuit 315MHz Band 433MHz Band 100pF 100pF 100pF 100pF C33 DNP DNP C43 DNP DNP 1uF 1uF .01uF .01uF 220pF 220pF 100pF 100pF 680pF 680pF C10¹ 15pF 6.8pF C11¹ 22pF 1pF C12¹ 15pF 6.8pF C13 1uF 1uF C14 .01uF .01uF C15 220pF 220pF C16¹ 2.2pF 1pF L1¹² 27nH 22nH L2¹² 22nH 18nH 9.84375MHz 13.5600MHZ ¹Matched to 50 Ohms ²Use wirewound inductors ONLY 3Use for External Reference Input DNP - Do Not Populate Modulation Control Mode Select (ASK / FSK) RF Control Mixer Filter OSC PA PA Output /32 Shape D0 D1 D2 Mode Input TX Data Input VDD PA CLK CLK1 CLK0 XTAL1 REFEXT/XTAL2 XTAL DRV LOGIC C10 C11 C12 C16 PIN 4 ENABLE INPUT PIN 16 GND BIAS C13 C14 C15 VCC Table 1: Component Values for Typical Application Circuit

VI. Pin Description V. Pin Configuration Pin Name

Description

VDD is the supply voltage for the PLL and Logic. Bypass as close as possible to pin with 1µF, .01µF, 220pf. ModeSel Mode Select enables the chip to be set in ASK or FSK mode Low: ASK mode High: FSK mode ASK, FSK Mode Selection The Mode Select pin (2) sets the transmit mode of the device. A logic low sets the mode to ASK modulation. A logic high sets the device to FSK modulation. In ASK mode, data driven onto the DataIN pin (3) gates the internal power amplifier. A data “High” turns the power amplifier on and thus drives the RF signal to the antenna. A data “Low” turns off the power amplifier. In FSK mode, data driven onto the DataIN pin shifts the carrier frequency by the amount programmed through the DEV[2..0] pins (13,12,11). A data “Low” performs no shift. The frequency of a data “Low” in FSK mode is the same frequency of a data “High” in ASK mode. The FSK deviation is achieved by pulling the crystal frequency. See Crystal Reference section (pin 15) for more details. The maximum deviation for the 315MHz band and 433MHz band is approximately 55 kHz and 80 kHz, respectively. DataIN Data Input enables the turning on and off of the Power Amplifier in ASK mode and selection of high or low frequency in FSK mode. Low (ASK mode): Power Amplifier off High (ASK mode): Power Amplifier on Low (FSK mode): Low frequency High (FSK mode): High frequency Stdby Standby enables selection of low power shutdown/standby mode Low or if left unconnected: Sets device in Standby mode High: Sets device in Ready for transmission mode Note: Lowest current consumption achieved when all config pins at Logic Low. Standby Mode The Standby pin (4) sets the device in low power shutdown, pulling only 0.2nA. When the device is brought out of standby with a logic “High”, it is ready for operation within 200us. The Standby pin has an internal pull-down resistor so this pin can be pulled low or left unconnected. The 200us turn-on time is due to crystal start-up. An optimally matched crystal will minimize this turn-on time. See Crystal Reference section (pin 15) for details on crystal load matching. BOTTOM VIEW 3x3mm VDD ModeSel DataIN Stdby ClkOut VDDPA ESOut PAOut Dev1 Dev0 Clk1 Clk0 Dev2 Xtal1 Xtal2/REF IN GND

Clock output is a buffered version of the crystal frequency which may be used to drive external logic or a microprocessor. The frequency is programmable thru pins 9 (Clk0) and 10(Clk1) as below: NB: fc = (Crystal Frequency) VDDPA Supply voltage for the Power amp. Bypass as close as possible to the pin with a .01µF and 220pf capacitor. ESOut Envelope-Shaping Output controls the on/off ramp time of the power amp in ASK mode. This reduces the spectral width of the output signal when modulated. Placing a small resistor in series with the output, as close as possible to the chip to minimize circuit parasitics, will enable control of output power. A potentiometer may be used to adjust the output power to the desired level. Bypass as close to the pin as possible with a 680pF and 220pF capacitor. Note: By using the ESOUT pin there is approx a 0.6dB drop in max output power. Spectral Shaping/Output Power Adjust The ESOUT pin (7) can serve a dual function. Use of the ESOUT pin will allow for a softer turn-on/turn-off of the power amplifier resulting in reduced spectral spreading of the ASK signal. Inserting a series resistor between the ESOUT pin and the pull-up inductor will allow for adjustment of the carrier output power. Typically a resistance of 5K Ohms or less will allow adjustment down to -10dBm. PAOut The envelope-shaping resistor allows for a turn on / turn-off of the Power Amp in ASK mode. Power-Amplifier Output. - Requires a DC path to the supply voltage, thru a series inductor which can be part of the output matching network to an antenna Power Amplifier The power amp is an open-drain, Class C amplifier with optimal impedance at PAOUT (pin 8) of about 250 Ohms. A matching network can optimize the output to drive typical 50 Ohm antennas. An output matching network with component values is shown in the Typical Application Circuit (section IV). Additionally, the matching network aids in suppressing carrier harmonics to aid in compliance testing. 10, 9 Clk[1..0] See description for Pin 5 13, 12, 11 FreqDev[2..0] Frequency Deviation configuration pins set the amount of deviation desired between data logic states in FSK mode. Frequency deviation is programmable through pins 13, 12, 11 as below: Note: Deviation values are approx for properly loaded crystal. Crystal characteristics and loading will differ with other manufacturers. Xtal1 External Crystal input 1 presents a capacitance of 3pF to GND in ASK and FSK(DataIN=0V) mode. Additional circuit parasitics add to the package capacitance which increases the presented load to about 4.5pF. Xtal2/REFIN External Crystal input 2 presents a capacitance of 3pF to GND in ASK and FSK(DataIN=0V) mode. Additional circuit parasitics add to the package capacitance which increases the presented load to about 4.5pF. External Ref Input enables a custom frequency to be applied to obtain the desired transmit frequency. Unconnected Xtal1 input must be bypassed with a .01µF capacitor and additional .01µF series capacitance should be added into External Reference input. Crystal Reference The crystal drive circuit in the TXC100 is designed to present a 3pF load to GND to the reference crystal. Including PCB parasitic capacitances, this increases to about 4.5pF. In ASK mode, the full 3pF load is applied to the crystal allowing it to oscillate at the desired frequency. In FSK mode, a portion of the 3pF load is removed in response to a data logic “High” applied to the DataIN (pin 2) and the programmed frequency deviation pins DEV[0..2] (13,12,11). For larger frequency deviations use a crystal with larger motional capacitance or reduce PCB parasitic capacitance as much as possible. NOTE: Use a crystal with the same load capacitance as that presented by the TXC100. If not, additional matching will be necessary to achieve the desired carrier frequency and the added matching will reduce the desired FSK deviation. GND Ground. Connect to system ground. Note: The exposed ground pad is the power amp ground. It must be connected to system ground thru a low inductance path. Clk0 Clk1 ClkOut fc/4 fc/8 fc/16 DEV ∆ DEV 2 DEV 1 DEV 0 .125 x max .250 x max .375 x max .500 x max .625 x max .750 x max .875 x max max

VII. Absolute Maximum Ratings VIII. DC Electrical Characteristic (Typical values taken at VDD = +3.0V, TA = +25°C, unless otherwise noted) Parameter Symbol Limit Values Unit Min Max Operating Temperature TO -40 +125 Junction Temperature TJ -40 +150 Storage Temperature TS -60 +150 Supply Voltage – Vdd to GND VS -0.3 V All pins to GND -0.3 Vdd + 0.3 V Note: Maximum ratings must not be exceeded under any circumstances and can cause permanent damage to the IC Limit Values Characteristic Sym Notes min typ max Unit Test Conditions Supply Voltage VDD 2.1 3.6 V Current Consumption 0.2 TA = +25 deg C 120 300 TA = +85 deg C Standby ISTDBY 700 1600 nA TA = +125 deg C 2.9 4.3 PA off, Data=0V (ASK) 10.7 50% duty cycle (ASK) 10.5 17.1 mA Data=+VDD (FSK and ASK)

315 Mhz Band

3.3 4.8 PA off, Data=0V (ASK) 7.3 11.4 50% duty cycle (ASK) Supply IDD 1,4 18.1 Data=+VDD (FSK and ASK)

433 Mhz Band

0.25 V Data Input High VIH VDD-0.25 V Max Input Current II 15.5 µa Digital Outputs Output Voltage Low VOL 0.25 V Clkout, Load = 10pF Output Voltage High VOH VDD-0.25 V Clkout, Load = 10pF

IX. AC Electrical Characteristic (Typical values taken at VDD = +3.0V, TA = +25°C, unless otherwise noted) Notes: 1. 10kHz, 50% duty cycle 2. Dependent on PCB parasitic trace capacitance and crystal parameters. 3. Dependent on crystal parameters. 4. Transmit Efficiency, RF Output Power, and Supply Current are heavily dependent on proper output matching and PCB layout. 5. No Envelope Shaping. Limit Values Parameter Sym Notes min typ max Unit Test Conditions PLL Performance VCO Gain KVCO 280 MHz/V -75 -74 Freq Offset = 100kHz -98 -98 dBc/Hz Freq Offset = 1MHz Loop BW BW 300 kHz Reference Spur -40 dBc -56 -52 dBc -56 -65 dBc fundamental mode, AT Tolerance ppm Internal Load Capacitance pF Clock Output Frequency CLKOUT FXTAL/N MHz Determined by CLK1 and CLK2 System Characteristics Frequency Range 300 450 MHz 12.2 16.1 TA = -40C, VDD = +3.6V 6.1 12.4 TA = +25C, VDD = +3.0V Output Power 2.7 5.3 dBm TA = +125C, VDD = +2.1V into 50Ω matched load Start-up time tON 160 µs STDBY to Tx Rise Time tr 300 ns FSK (50% Duty Cycle) Max Data Rate 100 kbps ASK (50% Duty Cycle) Frequency Deviation (FSK) kHz DEV[2..0]=111 η=POUT/(VDDxIDD) 50% duty cycle Power ON/OFF Ratio -77 dB ASK Mode Frequency Stability vs. VDD ∆dfVDD kHz Frequency Stability vs. Temp ∆dfTA TBD kHz -40°C to +85°C

Supply Voltage vs Supply Current 2.2 2.4 2.6 2.8 3.2 3.4 3.6 3.8 Supply Voltage, V Supply Current, mA mA @ 315MHz X. Typical Operating Characteristics Supply Voltage vs Supply Current 2.2 2.4 2.6 2.8 3.2 3.4 3.6 3.8 Supply Voltage, V Supply Current, mA mA @ 433.92MHz Supply Voltage vs Output Power 2.2 2.4 2.6 2.8 3.2 3.4 3.6 3.8 Supply Voltage, V Output Power (Po), dBm dBm @ 315MHz Supply Voltage vs Output Power 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Supply Voltage, V Output Power, dBm dBm @ 433.92MHz Output Power vs Supply Current Output Power (Po), dBm Supply Current, mA mA @ 315MHz Output Power vs Supply Current Output Power, dBm Supply Current, mA mA @ 433.92MHz

Supply Current and Output Power vs ESout Resistor 0.1 100 1000 10000 Resistor, Ohms Supply Current, mA -16 -14 -12 -10 Output Power, dBm Power Current f = 315MHz Supply Current and Output Power vs ESout Resistor 0.1 100 1000 10000 Resistor, Ohms Supply Current, mA -16 -14 -12 -10 Output Power, dBm Power (dBm) Current (mA) f = 433.92MHz Voltage vs Modulation Current 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Voltage, V Current, mA 315MHz,FSK,50% DC 315MHz,ASK,50% DC Supply Voltage vs Modulation Supply Current 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Supply Voltage, V Supply Current, mA 433.92MHz,FSK,50% DC 433.92MHz,ASK,50% DC

XI. Theory of Operation Introduction The TXC100 is a crystal-referenced transmitter designed to operate in the 315/433 MHz frequency spectrum. The carrier and crystal reference relation is given by: fC = fXTAL * 32 It is capable of supporting OOK/ ASK and FSK data transmissions at 100kbps and 20kbps, respectively. The output power is adjustable from -10dBm to +10dBm thru a resistor at the ESOUT (pin 7). The FSK frequency deviation is programmable with up to eight different deviation values. The IC also provides a buffered clock output of the reference crystal for use by an external processor. The clock output is also programmable. Frequency Synthesizer The frequency synthesizer is simply a Phase Locked Loop circuit with a loop bandwidth of 300 kHz. The PLL contains a phase detector, charge pump, VCO, integrated loop filter, ÷32 clock divider, and crystal oscillator drive circuit. The internal PLL is self contained and requires no external components for filtering or dividing. Only a reference crystal is needed. 50Ω Output Matching When properly matched, the TXC100 can output up to +12 dBm into a 50Ω load. The output is an open-drain configuration which requires a pull-up inductor for proper internal biasing. The pull-up inductance serves to provide biasing for the power amplifier and is a high frequency choke to reduce unwanted coupling back into the power supply. Maximum power transfer occurs when the output is closely matched to 250Ω. For best performance use wirewound inductors instead of chip inductors. Wirewound inductors provide lower insertion loss as opposed to chip inductors. See Typical Application Circuit (section IV) for topology and matching component values. PCB Layout Considerations PCB layout is critical to proper and consistent operation. Always use controlled impedance lines from the PAOUT (pin 8). For a .062” thick FR4 board a 50Ω impedance line is approximately .110” wide. Component spacing is critical as well. Keep all output matching components as close together as possible to minimize stray inductance and capacitance that can detune the matching network. Keep ground planes at least a board thickness away from the signal output leading to the antenna or RF connector.

Antenna Layout Considerations Most compact wireless designs have the need for a small, compact antenna. Typically, loop antennas are the ones of choice since they can be designed into tight spaces. Loop antenna design can become fairly lengthy and detailed discussion is beyond the scope of this datasheet. The object here is to provide a “rule of thumb” approach to achieve an appropriate starting point. Empirical data will provide the best path to take. The circumference of the antenna should be less than λ/4 so that the antenna appears inductive. For this, a series matching capacitor is used to tune out the inductance of the antenna, since the antenna appears inductive. The capacitor may be located at the feed point of the antenna or at the “grounded” end. The capacitor may be a variable type or several fixed values may be attempted until an optimal match is reached. The use of a good network analyzer is essential for proper matching and maximum power transfer. For additional information on antenna design see the Application Notes section of our website: http://www.rfm.com/corp/apnotes.htm. XII. Typical Test Circuit

© 2005 RF Monolithics, Inc. TXC100 012706 Dallas, Texas 75244 (800) 704-6079 toll-free in U.S. and Canada Email: info@rfm.com www.rfm.com www.wirelessis.com Package Dimensions – 3x3mm 16-pin TQFN Package BOTTOM VIEW 1.50 1.50 0.5 TYP. 0.23 TYP. 0.5 TYP. 0.23 TYP. 0.40 0.40 PIN 1 Indicator TOP VIEW SIDE VIEW 3.00 3.00

0.75 MAX

0.25 0.50 0.0~0.05 SEATING PLANE PIN # 1 (all values in mm)