19-2907; Rev 1; 11/03 MAX1472 Evaluation Kit Features ♦ Proven PC Board Layout The MAX1472 EV 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. ♦ Fully Assembled and Tested For easy implementation into the customer’s design, the MAX1472 EV 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 Components Parts List ♦ Multiple Test Points Provided On-Board ♦ Available in 315MHz or 433.92MHz Optimized Versions ♦ Adjustable Frequency Range from 300MHz to 450MHz* ♦ Can Operate as a Stand-Alone Transmitter with Included Battery *Requires component changes Ordering Information TEMP RANGE IC PACKAGE MAX1472EVKIT-315 PART -40°C to +85°C 8 SOT23-8 MAX1472EVKIT-433 -40°C to +85°C 8 SOT23-8 Component List DESIGNATION QTY Antenna (315MHz) 0 Antenna (433MHz) DESCRIPTION DESIGNATION QTY 315MHz 1/4 wave whip antenna Lynx ANT-315-CW-RH, not installed C2 (315MHz) 1 22pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H220J 0 433MHz 1/4 wave whip antenna Lynx ANT-433-CW-RH, not installed C2 (433MHz) 1 12pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H120J 1 SMA connector top mount, not installed Digi-Key J500-ND Johnson 142-0701-201 C3, C10 2 0.01µF ±10%, 50V ceramic capacitors (0603) Murata GRM188R71H103KA01 BAT1 1 Battery holder MPD BA2032 C4 1 680pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H681J Battery 1 Coin-cell battery Panasonic BR2032 C5, C16, C18, C19 0 Not installed C6 (315MHz) 1 1 15pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H150J 15pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H150J C6 (433MHz) 1 1 7pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H7R0J 10pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H100J C7 1 0.47µF +80% - 20%, 16V ceramic capacitor (0603) Murata GRM188F51C474Z ANTENNA_OUT C1 (315MHz) C1 (433MHz) DESCRIPTION ________________________________________________________________ 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: MAX1472 General Description The MAX1472 evaluation kit (EV kit) allows for a detailed evaluation of the MAX1472 ASK 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 reversepolarity 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. MAX1472 Evaluation Kit Evaluates: MAX1472 Component List (continued) DESIGNATION QTY DESCRIPTION 2 220pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H221J C14, C15 2 12pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H120J JU1, JU4 2 2-pin headers Digi-Key S1012-36-ND or equivalent JU1 3 Shunts Digi-Key S9000-ND or equivalent JU2, JU3 2 3-pin headers Digi-Key S1012-36-ND or equivalent C11, C12 DESIGNATION R2 QTY 0 DESCRIPTION 0Ω resistor (0603), any, not installed R3 1 5.1Ω resistor (0603), any R4 1 36kΩ ±5% resistor (0603), any REF_IN 1 RP-SMA connector Lynx CONREVSMA001 RFOUT 1 SMA connector top mount Digi-Key J500-ND Johnson 142-0701-201 SW1 1 Switch Panasonic EVQ-PJS04K VDD, VSS, ENABLE, DATA-IN 4 Test points Mouser 151-203 or equivalent U1 1 MAX1472EKA U2 1 ICM7555ISA 1 Crystal 9.84375 MHz Hong Kong Crystal SSL9843750E03FAFZ800 or Crystek 017000 L1 (315MHz) 1 27nH ±5% inductor (0603) Coilcraft 0603CS-27NXJB L1 (433MHz) 1 22nH ±5% inductor (0603) Coilcraft 0603CS-22NXJB L3 (315MHz) 1 22nH ±5% inductor (0603) Coilcraft 0603CS-22NXJB L3 (433MHz) 1 15nH ±5% inductor (0603) Coilcraft 0603CS-15NXJB Y1 (433MHz) 1 R1 1 5kΩ potentiometer BC Components SM4W502 Crystal 13.56MHz Hong Kong Crystal SSM1356000E03FAFZ800 or Crystek 017001 — 1 MAX1472 EV kit PC board Component Suppliers Y1 (315MHz) Connections and Setup Required Test Equipment 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). • Regulated power supply capable of providing +3.0V • Spectrum analyzer such as the Agilent 8562E • Optional ammeter for measuring supply current 4) Disconnect the spectrum analyzer and connect the power meter instead. Measure the output power and also the current draw. SUPPLIER Coilcraft PHONE FAX 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 Quick Start The following procedure allows for proper device evaluation. • Power meter such as the Agilent EPM-441A 2 _______________________________________________________________________________________ MAX1472 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 MAX1472. Detailed Description Data Input The MAX1472 EV kit transmits ASK data with data rates up to 100kbps. JU2 controls whether the MAX1472 transmits CW (jumper pins 1 and 2 connected), an external data stream (no jumper), or train pulses generated by the ICM7555 timer (jumper pins 2 and 3 connected). JU4 controls whether the ICM7555 data is being generated continuously or at the push of SW1. 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 MAX1472 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 MAX1472 EV kit includes two SMA connectors for RF output. RFOUT 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 a 1/4 wave whip antenna . Note that resistor R2 (0Ω) needs to be added. I/O Connections Table 2 lists all I/O connections. Enable Control The MAX1472 can be controlled externally using the ENABLE connector. The IC draws approximately 1nA (at room temperature) in shutdown mode. Jumper JU1 is used to control this mode. The shunt can be placed between pins 1 and 2 for continuous operation. Remove the JU1 shunt for external control. See Table 1 for jumper function descriptions. Table 1. Jumper Functions JUMPER STATE JU1 1-2 JU1 JU2 FUNCTION Table 2. I/O Connectors SIGNAL RFOUT DESCRIPTION RF output REF_IN External reference frequency input ANTENNA_OUT Reverse polarity SMA for 1/4 wave antenna VSS VDD Ground 3.0V power input Normal operation DATA_IN Data input NC External power-down control ENABLE External power-down control 1-2 RF carrier-transmit mode JU2 2-3 Transmit pulse-train mode JU2 NC External data transmit JU3 1-2 External supply operation JU3 2-3 Battery operation JU4 1-2 Continuous data generation JU4 NC Data controlled by SW1 For additional information and a list of application notes, consult the Maxim website, www/maxim-ic.com. _______________________________________________________________________________________ 3 Evaluates: MAX1472 5) Calculate the efficiency. This is done using the following equation: Efficiency = 10 ^ (Pout / 10) / (V x I) where I is in mA. For example, the efficiency is 46.6% for an output of +11dBm, and a current of 9mA (at 3.0V). Evaluates: MAX1472 MAX1472 Evaluation Kit Figure 1. MAX1472 EV Kit * C1 C2 C6 L1 L3 Y1 50Ω OUTPUT AT 315MHz AT 433.92MHz 15pF 7pF 22pF 12pF 15pF 10pF 27nH 22nH 22nH 15nH 9.84375MHz 13.56MHz Y1 * C14 12pF C15 12pF C19 OPEN REF_IN 1 2 C16 OPEN *VALUES AFFECTED BY PC BOARD LAYOUT. 1 VDD 2 C4 680pF C12 220pF RFOUT VDD VDD JU3 U1 C11 220pF C10 0.01µF 6 1 2 JU2 DATA_IN 1 4 PA ENABLE 2 GND V+ 8 ENABLE 5 TRIGGER TRIGGER 2 TRIGGER DISCHARGE 7 U2 ICM7555 R4 36kΩ 3 OUTPUT THRESHOLD 6 TRIGGER C3 0.01µF VDD SW1 4 RESET CONTROL VOLTAGE JU4 Figure 2. MAX1472 EV Kit Circuit Diagram 4 BAT1 3 VDD JU1 ANTENNA_OUT 1 R2 0Ω PAVSS R3 5.1Ω 7 L1 * C2 * L3 * 8 C7 0.47µF MAX1472 DATA C1 * C6 * VSS VDD 3 3 R1 5kΩ XTAL2 C5 OPEN 2 1 VSS XTAL1 C18 OPEN _______________________________________________________________________________________ 5 MAX1472 Evaluation Kit Evaluates: MAX1472 Figure 3. MAX1472 EV Kit Component Placement Guide—Top Silkscreen Figure 4. MAX1472 EV Kit PC Board Layout—Top Copper Figure 5. MAX1472 EV Kit PC Board Layout—Bottom Copper 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.