19-3726; Rev 0; 5/05 MAX1479 Evaluation Kit 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. Features ♦ 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. Ordering Information PART TEMP RANGE IC PACKAGE MAX1479EVKIT-315 -40°C to +85°C 16 Thin QFN MAX1479EVKIT-433 -40°C to +85°C 16 Thin QFN Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION C7, C9 2 0.47µF +80/-20%, 16V ceramic capacitors (0603) Y5V Murata GRM188F51C474Z 6.8pF ±0.5pF, 50V ceramic capacitors (0603) C0G Murata GRM1885C1H6R8D C8, C11, C12 3 220pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H221J 1 22pF ±5%, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H220J C13 (315MHz) 1 2.2pF ±0.5pF, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H2R2D C2 (433MHz) 1 10pF ±5%, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H100J C13 (433MHz) 1 1.0pF ±0.5pF, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H1R0D C3, C10 2 0.01µF ±10%, 50V ceramic capacitors (0603) Murata GRM188R71H103KA01 C14, C15 2 100pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H101J C4 1 680pF ±5%, 50V ceramic capacitor (0603) C0G Murata GRM1885C1H681J JU1–JU10 10 3-pin headers Digi-Key S1012-36-ND or equivalent L1 (315MHz) 1 27nH ±5% inductor (0603) Coilcraft 0603CS-27NXJB L1 (433MHz) 1 22nH ±5% inductor (0603) Coilcraft 0603CS-22NXJB C1, C6 (315MHz) 2 15pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H150J C1, C6 (433MHz) 2 C2 (315MHz) C5, C16, C18, C19 0 Not installed ________________________________________________________________ Maxim Integrated Products 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. 1 Evaluates: MAX1479 General Description Evaluates: MAX1479 MAX1479 Evaluation Kit Component List (continued) DESIGNATION QTY DESIGNATION QTY DESCRIPTION L2 (315MHz) 1 22nH ±5% inductor (0603) Coilcraft 0603CS-22NXJB L2 (433MHz) 1 18nH ±5% inductor (0603) Coilcraft 0603CS-18NXJB R1 1 5kΩ potentiometer BC Components SM4W502 R2 0 0Ω resistor (0603), any, not installed R3 1 5.1Ω ±5% resistor (0603), any R4 1 0Ω resistor (0603), any Antenna (315MHz) 0 315MHz 1/4-wave whip antenna, not provided Lynx ANT-315-CW-RH Antenna (433MHz) 1 433MHz 1/4-wave whip antenna, not provided Lynx ANT-433-CW-RH ANTENNA_OUT 1 RP-SMA connector Linx CONREVSMA001 BAT1 1 Battery holder MPD BA2032 Battery 1 Coin-cell battery Panasonic BR2032 DESCRIPTION REF_IN 1 SMA connector top mount, not installed Digi-Key J500-ND Johnson 142-0701-201 RF_OUT 1 SMA connector top mount Digi-Key J500-ND Johnson 142-0701-201 U1 1 MAX1479ATE VDD, VSS, ENABLE, DATA_IN, CKOUT 5 Test points Mouser 151-203 or equivalent 1 Crystal 9.84375MHz Hong Kong Crystal SSL9843750E03FAFZ800 or Crystek 017000 Y1 (433MHz) 1 Crystal 13.56MHz Hong Kong Crystal SSM1356000E03FAFZ800 or Crystek 017001 — 10 Shunt (JU1) Digi-Key S9000-ND or equivalent — 1 MAX1479 EV kit PC board Y1 (315MHz) Connections and Setup Component Suppliers SUPPLIER PHONE FAX Coilcraft 800-322-2645 847-639-1469 Crystek 800-237-3061 941-561-1025 Hong Kong Crystal 852-2412-0121 852-2498-5908 Murata 800-831-9172 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 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. 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. Table 1. JU1 Through JU4 Jumpers Function JUMPER JU1 JU2 JU3 JU4 STATE FUNCTION 1-2 RF carrier transmit enable 2-3 Power-down mode N.C. External power-down control 1-2 RF carrier transmit mode (ASK), FSK high frequency (FSK) 2-3 PA off, PLL ON (ASK), FSK low frequency (FSK) N.C. External data transmit 1-2 External supply operation 2-3 Battery operation 1-2 FSK mode 2-3 ASK mode 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. 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 (0Ω) needs to be added. 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. 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 Evaluates: MAX1479 Layout Issues Evaluates: MAX1479 MAX1479 Evaluation Kit Table 2. Clock-Divider Settings JUMPER SETTING JU5 JUMPER SETTING JUMPER SETTING FUNCTION 1-2 1-2 1-2 Max deviation 1-2 1-2 2-3 7/8 x max deviation 1-2 2-3 1-2 3/4 x max deviation 1-2 2-3 2-3 5/8 x max deviation JU6 2-3 1-2 JU7 1-2 1/2 x max deviation 2-3 1-2 2-3 3/8 x max deviation 2-3 2-3 1-2 1/4 x max deviation 2-3 2-3 2-3 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 Table 3. Clock Divider Settings JUMPER SETTING JUMPER 1-2 1-2 JU8 2-3 2-3 JU9 SIGNAL SETTING FUNCTION DESCRIPTION RF_OUT RF output 1-2 fXTAL /16 REF_IN External reference frequency input 2-3 fXTAL /8 ANTENNA_OUT Reverse polarity SMA for 1/4-wave antenna 1-2 fXTAL /4 VSS Ground 2-3 Logic 0 output VDD Power-supply input DATA_IN Data input ENABLE Power-down control CLKOUT Buffered clock 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 4 STATE FUNCTION 1-2 No envelope shaping 2-3 Envelope shaping _______________________________________________________________________________________ MAX1479 Evaluation Kit C15 100pF Y1* C19 OPEN REF_IN 1 50Ω OUTPUT 2 C16 OPEN 14 XTAL1 XTAL2 15 AT 315MHz AT 433.92MHz C1 15pF 6.8pF C2 22pF 10pF C6 15pF 6.8pF C13 2.2pF 1.0pF L1† 27nH 22nH L2† 22nH 18nH Y1 9.84375MHz 13.56MHz C5 OPEN VDD GND JU4 * †USE WIRE-WOUND INDUCTORS ONLY. C18 OPEN 1 2 3 2 MODE VSS 16 U1 R3 5.1Ω MAX1479 VDD DATA_IN 1 2 JU2 VDD 3 1 C7 0.47µF C11 220pF 4 BAT1 6 ENABLE 3 ROUT 7 3 1 2 3 R1 5kΩ C9 0.47µF JU10 C8 220pF C3 0.01µF C12 220pF C4 680pF 1 2 CKOUT L1* L2* C1* 5 1 2 3 R4 0Ω VDD JU1 JU3 DIN VDD_PA 1 2 VDD VDD C10 0.01µF 3 ENABLE Evaluates: MAX1479 C14 100pF CLKOUT PAOUT CLK0 CLK1 DEV0 DEV1 DEV2 9 10 11 12 13 VDD VDD VDD JU7 JU9 JU5 1 2 3 1 2 3 VDD 1 2 3 RF_OUT 1 8 C13* C2* 2 C6* R2 OPEN ANTENNA_OUT 1 2 VDD JU8 1 2 3 JU6 1 2 3 Figure 1. MAX1479 EV Kit Schematic _______________________________________________________________________________________ 5 Evaluates: MAX1479 MAX1479 Evaluation Kit 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.