MAX1479

19-3726; Rev 0; 5/05 MAX1479 Evaluation Kit General Description The MAX1479 evaluation kit (EV kit) allows for a detailed evaluation of the MAX1479 ASK/FSK transmitter. It enables testing of the device’s RF performance and requires no additional support circuitry. The RF output uses a 50Ω matching network and an SMA connector for convenient connection to test equipment. A reverse polarity SMA is also included to connect to a 1/4 wave whip antenna. The EV kit can also directly interface to the user’s embedded design for easy data encoding. The MAX1479EV kit comes in two versions: a 315MHz version and a 433.92MHz version. The passive components are optimized for these frequencies. These components can easily be changed to work at RF frequencies from 300MHz to 450MHz. For easy implementation into the customer’s design, the MAX1479EV kit also features a proven PC board layout, which can be easily duplicated for quicker time-tomarket. The EV kit Gerber files are available for download at www.maxim-ic.com. ♦ Proven PC Board Layout ♦ Proven Components Parts List ♦ Multiple Test Points Provided on Board ♦ Available in 315MHz or 433.92MHz Optimized Versions ♦ Adjustable Frequency Range from 300MHz to 450MHz* ♦ Fully Assembled and Tested ♦ Can Operate as a Stand-Alone Transmitter with Included Battery *Requires component changes. Features Evaluates: MAX1479 Ordering Information PART MAX1479EVKIT-315 MAX1479EVKIT-433 TEMP RANGE -40°C to +85°C -40°C to +85°C IC PACKAGE 16 Thin QFN 16 Thin QFN Component List DESIGNATION QTY C1, C6 (315MHz) 2 DESCRIPTION 15pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H150J 6.8pF ±0.5pF, 50V ceramic capacitors (0603) C0G Murata GRM1885C1H6R8D 22pF ±5%, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H220J 10pF ±5%, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H100J 0.01µF ±10%, 50V ceramic capacitors (0603) Murata GRM188R71H103KA01 680pF ±5%, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H681J Not installed L1 (433MHz) 1 DESIGNATION QTY C7, C9 2 DESCRIPTION 0.47µF +80/-20%, 16V ceramic capacitors (0603) Y5V Murata GRM188F51C474Z 220pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H221J 2.2pF ±0.5pF, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H2R2D 1.0pF ±0.5pF, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H1R0D 100pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H101J 3-pin headers Digi-Key S1012-36-ND or equivalent 27nH ±5% inductor (0603) Coilcraft 0603CS-27NXJB 22nH ±5% inductor (0603) Coilcraft 0603CS-22NXJB C1, C6 (433MHz) 2 C8, C11, C12 3 C2 (315MHz) 1 C13 (315MHz) 1 C2 (433MHz) 1 C13 (433MHz) 1 C3, C10 2 C14, C15 2 C4 C5, C16, C18, C19 1 JU1–JU10 L1 (315MHz) 10 1 0 ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX1479 Evaluation Kit Evaluates: MAX1479 Component List (continued) DESIGNATION QTY L2 (315MHz) L2 (433MHz) R1 R2 R3 R4 Antenna (315MHz) 1 1 1 0 1 1 0 DESCRIPTION 22nH ±5% inductor (0603) Coilcraft 0603CS-22NXJB 18nH ±5% inductor (0603) Coilcraft 0603CS-18NXJB 5kΩ potentiometer BC Components SM4W502 0Ω resistor (0603), any, not installed 5.1Ω ±5% resistor (0603), any 0Ω resistor (0603), any 315MHz 1/4-wave whip antenna, not provided Lynx ANT-315-CW-RH 433MHz 1/4-wave whip antenna, not provided Lynx ANT-433-CW-RH RP-SMA connector Linx CONREVSMA001 Battery holder MPD BA2032 Coin-cell battery Panasonic BR2032 Y1 (433MHz) 1 RF_OUT U1 VDD, VSS, ENABLE, DATA_IN, CKOUT 1 1 DESIGNATION QTY REF_IN 1 DESCRIPTION SMA connector top mount, not installed Digi-Key J500-ND Johnson 142-0701-201 SMA connector top mount Digi-Key J500-ND Johnson 142-0701-201 MAX1479ATE Test points Mouser 151-203 or equivalent 5 Y1 (315MHz) 1 Antenna (433MHz) ANTENNA_OUT BAT1 Battery 1 Crystal 9.84375MHz Hong Kong Crystal SSL9843750E03FAFZ800 or Crystek 017000 Crystal 13.56MHz Hong Kong Crystal SSM1356000E03FAFZ800 or Crystek 017001 Shunt (JU1) Digi-Key S9000-ND or equivalent MAX1479 EV kit PC board 1 1 1 — — 10 1 Connections and Setup Component Suppliers SUPPLIER Coilcraft Crystek Hong Kong Crystal Murata PHONE 800-322-2645 800-237-3061 852-2412-0121 800-831-9172 FAX 847-639-1469 941-561-1025 852-2498-5908 814-238-0490 Note: Indicate you are using the MAX1479 when contacting these manufacturers. Quick Start The following procedure allows for proper device evaluation. Required Test Equipment • • • • 2 Regulated power supply capable of providing +3.0V Spectrum analyzer such as the Agilent 8562E Optional ammeter for measuring supply current Power meter such as the Agilent EPM-441A This section provides a step-by-step guide to operating the EV kit and testing the device’s functionality. Do not turn on the DC power until all connections are made: 1) Connect a DC supply set to +3.0V, through an ammeter, to the VDD and VSS terminals on the EV kit. Do not turn on the supply. 2) Connect the RF_OUT SMA connector to the spectrum analyzer. Set the analyzer to a center frequency of 315MHz (or 433.92MHz) and a span of 1MHz. 3) Turn on the DC supply. The spectrum analyzer should display a peak of about +10dBm at 315MHz (or 433.92MHz). 4) Disconnect the spectrum analyzer and connect the power meter instead. Measure the output power and also the current draw. 5) Calculate the efficiency. This is done using the following equation: Efficiency = 10ˆ(POUT/10)/(V x I) For example, for a +10.8dBm output, and a 10.9mA (at 3.0V) current, the efficiency is 37%. _______________________________________________________________________________________ MAX1479 Evaluation Kit Layout Issues A properly designed PC board is an essential part of any RF/microwave circuit. On high-frequency inputs and outputs, use controlled-impedance lines and keep them as short as possible to minimize losses and radiation. At high frequencies, trace lengths that are on the order of λ/10 or longer can act as antennas. Keeping the traces short also reduces parasitic inductance. Generally, 1in of a PC board trace adds about 20nH of parasitic inductance. The parasitic inductance can have a dramatic effect on the effective inductance. For example, a 0.5in trace connecting a 100nH inductor adds an extra 10nH of inductance or 10%. To reduce the parasitic inductance, use wider traces and a solid ground or power plane below the signal traces. Also, use low-inductance connections to ground on all GND pins, and place decoupling capacitors close to all VDD connections. The EV kit PC board can serve as a reference design for laying out a board using the MAX1479. Data Input The MAX1479 EV kit transmits ASK and FSK data with data rates of up to 100kbps (ASK) or 20kbps (FSK). JU2 controls whether the MAX1479 transmits the ASK carrier frequency (or the FSK high frequency), turns off the PA (or transmits the FSK low frequency), or transmits an external data stream. See Table 1. Evaluates: MAX1479 REF_IN External Frequency Input For applications where the correct frequency crystal is not available, it is possible to directly inject an external frequency through the REF_IN SMA (not provided). Connect the SMA to a low-phase-noise generator. The addition of C18 and C19 is necessary (use 0.01µF capacitors). Battery Operation The MAX1479 EV kit can be powered by an external power supply or by the supplied 3V coin-cell battery. Set jumper JU3 to connect pins 2 and 3 for battery operation. RF Output The MAX1479 EV kit includes two SMA connectors for RF output. RF_OUT is a standard SMA and is used to connect the PA output to test equipment. Output is matched to 50Ω. ANTENNA_OUT is a reverse polarity SMA and is used to connect to the 1/4-wave whip antenna (not supplied). Note that resistor R2 (0 Ω ) needs to be added. Detailed Description Power-Down Control The MAX1479 can be controlled externally using the ENABLE connector. The IC draws approximately 0.2nA (at room temperature) in shutdown mode. Jumper JU1 is used to control this mode. The shunt can be placed between pins 1 and 2 to enable the device. Remove the JU1 shunt for external control. See Table 1 for jumper function descriptions. Modulation Mode Input Jumper JU4 sets the mode of transmission. Set jumper JU4 to connect pins 1 and 2 for FSK mode, 2 and 3 for ASK mode. Table 1. JU1 Through JU4 Jumpers Function JUMPER JU1 STATE 1-2 2-3 N.C. 1-2 JU2 2-3 N.C. JU3 JU4 1-2 2-3 1-2 2-3 FUNCTION RF carrier transmit enable Power-down mode External power-down control RF carrier transmit mode (ASK), FSK high frequency (FSK) PA off, PLL ON (ASK), FSK low frequency (FSK) External data transmit External supply operation Battery operation FSK mode ASK mode FSK Frequency Deviation The FSK deviation is set by jumpers JU5 through JU7. The maximum deviation depends on the PC board parasitics. The EV kit max is around 50kHz (315MHz). If very large FSK frequency deviations are desired, use a crystal with a larger motional capacitance and/or reduce PC board parasitic capacitances. One way to reduce parasitic capacitances on the EV kit is to remove C14, C15, and C16 and move the crystal closer to the IC. _______________________________________________________________________________________ 3 MAX1479 Evaluation Kit Evaluates: MAX1479 Table 2. Clock-Divider Settings JUMPER SETTING 1-2 1-2 1-2 JU5 1-2 2-3 2-3 2-3 2-3 JU6 JUMPER SETTING 1-2 1-2 2-3 2-3 1-2 1-2 2-3 2-3 JU7 JUMPER SETTING 1-2 2-3 1-2 2-3 1-2 2-3 1-2 2-3 FUNCTION Max deviation 7/8 x max deviation 3/4 x max deviation 5/8 x max deviation 1/2 x max deviation 3/8 x max deviation 1/4 x max deviation 1/8 x max deviation Clock Output Jumpers JU8 and JU9 set the divider ratio for the clock output. See Table 3 for the settings. I/O Connections Table 5 is a list of all I/O connections. Table 5. I/O Connectors SIGNAL DESCRIPTION RF output External reference frequency input Reverse polarity SMA for 1/4-wave antenna Ground Power-supply input Data input Power-down control Buffered clock output RF_OUT REF_IN ANTENNA_OUT VSS VDD DATA_IN ENABLE CLKOUT Table 3. Clock Divider Settings JUMPER SETTING 1-2 1-2 JU8 2-3 2-3 JU9 JUMPER SETTING 1-2 2-3 1-2 2-3 FUNCTION fXTAL /16 fXTAL /8 fXTAL /4 Logic 0 output Envelope Shaping Jumper JU10 sets envelope shaping for a more gentle turn-on/turn-off of the PA in ASK mode. Set jumper JU10 to connect pins 2 and 3 to allow for envelope shaping. See Table 4 for settings. For additional information and a list of application notes, consult the www.maxim-ic.com website. Table 4. JU10 Jumper Function JUMPER JU10 STATE 1-2 2-3 FUNCTION No envelope shaping Envelope shaping 4 _______________________________________________________________________________________ MAX1479 Evaluation Kit Evaluates: MAX1479 C14 100pF Y1* C15 100pF C19 OPEN REF_IN 1 2 50Ω OUTPUT * C1 C2 C6 C13 L1† L2† AT 315MHz 15pF 22pF 15pF 2.2pF 27nH 22nH 9.84375MHz AT 433.92MHz 6.8pF 10pF 6.8pF 1.0pF 22nH 18nH 13.56MHz C16 OPEN 14 C18 OPEN VDD 1 2 3 XTAL1 XTAL2 15 Y1 †USE WIRE-WOUND INDUCTORS ONLY. C5 OPEN GND 16 VSS JU4 2 MODE U1 MAX1479 VDD DATA_IN 1 2 3 VDD_PA VDD ENABLE 1 2 3 1 2 3 1 2 C12 220pF L2* C4 680pF JU10 6 C9 0.47µF C8 220pF VDD 3 1 C7 0.47µF C11 220pF C10 0.01µF R3 5.1Ω VDD JU3 1 2 3 VDD JU2 DIN R4 0Ω C3 0.01µF BAT1 JU1 4 ENABLE ROUT 7 3 R1 5kΩ L1* C1* CKOUT 5 CLKOUT CLK0 9 CLK1 10 VDD JU7 123 VDD JU6 123 DEV0 11 DEV1 12 VDD PAOUT DEV2 13 8 C13* C2* C6* R2 OPEN RF_OUT 1 2 VDD JU9 123 VDD JU8 JU5 123 ANTENNA_OUT 1 2 123 Figure 1. MAX1479 EV Kit Schematic _______________________________________________________________________________________ 5 MAX1479 Evaluation Kit Evaluates: MAX1479 Figure 2. MAX1479 EV Kit Component Placement Guide— Component Side Figure 3. MAX1479 EV Kit PC Board Layout—Component Side Figure 4. MAX1479 EV Kit PC Board Layout—Solder Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.