19-2960; Rev 1; 5/05 MAX1473 Evaluation Kit The MAX1473 evaluation kit (EV kit) allows for a detailed evaluation of the MAX1473 superheterodyne receiver. It enables testing of the device’s RF performance and requires no additional support circuitry. The RF input uses a 50Ω matching network and an SMA connector for convenient connection to test equipment. The EV kit can also directly interface to the user’s embedded design for easy data decoding. The MAX1473 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. In addition, the 5kbps data rate received can be adjusted from 0 to 100kbps by changing two more components. For easy implementation into the customer’s design, the MAX1473 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. 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 Receiver with Addition of an Antenna *Requires component changes Ordering Information PART TEMP RANGE IC PACKAGE MAX1473EVKIT-315 -40°C to +85°C 28 TSSOP MAX1473EVKIT-433 -40°C to +85°C 28 TSSOP Component List DESIGNATION QTY DESCRIPTION C1, C2 2 0.01µF ±10% ceramic capacitors (0603) Murata GRM188R71H103KA01 C3 1 1500pF ±10%, 50V X7R ceramic capacitor (0603) Murata GRM188R71H152KA01 C4 1 0.47µF +80% - 20% ceramic capacitor (0603) Murata GRM188F51C474ZA01 DESIGNATION QTY DESCRIPTION C14, C15 2 15pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H150JZ01 C17 0 0.01µF +80% - 20% ceramic capacitor (0603), not installed Murata GRM188R71H103KA01 C21 1 0Ω resistor (0603) 0 1 470pF ±5% ceramic capacitor (0603) Murata GRM1885C1H471JA01 F_IN C5 SMA connector edge mount, not installed Johnson 142-0701-801 C6, C10 2 220pF ±5% ceramic capacitors (0603) Murata GRM1885C1H221JA01 JU1, JU2, JU5, JU6 4 3-pin headers Digi-Key S1012-36-ND or equivalent 1 2-pin header 3 100pF ±5% ceramic capacitors (0603) Murata GRM1885C1H101JA01 JU7 C7, C8, C11 JU3, JU4 0 Not installed 1 Shorted 1 4pF ±0.1pF ceramic capacitor (0603) Murata GRM1885C1H4R0BZ01 JU8 C9 (315MHz) — 5 Shunts (JU1) Digi-Key S9000-ND or equivalent 1 2.2pF ±0.1pF ceramic capacitor (0603) Murata GRM1885C1H2R2BD01 L1 (315MHz) 1 27nH ±5% inductor (0603) Coilcraft 0603CS-27NXJB C9 (433MHz) C12, C20 2 0.1µF ±5% ceramic capacitors (0603) Murata GRM188R71C104KA01 C13, 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: MAX1473 General Description Evaluates: MAX1473 MAX1473 Evaluation Kit Component List (continued) DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION R9 1 1000pF ±10%, 50V X7R ceramic capacitor (0603) Murata GRM188R71H102KA01 1 56nH ±5% inductor (0603) Coilcraft 0603CS-56NXJB RF IN 1 SMA connector top mount Digi-Key J500-ND Johnson 142-0701-201 L3 1 15nH ±5% inductor (0603) Murata LQG18HN15NJ00 TP2, TP4–TP12 0 Not installed 0 SMA connector top mount, not installed Digi-Key J500-ND Johnson 142-0701-201 5 MIX OUT VDD, GND, SHDN, DATA_OUT, TP3 Test points Mouser 151-203 or equivalent R1 R2, R4, R6 1 0 5.1kΩ resistor (0603), any Resistor (0603), not installed 1 R3 0 270Ω resistor (0603), any, not installed Crystal 4.754687MHz Hong Kong Crystal SSL4754687E03FAFZ8A0 or Crystek 016867 R5 1 10kΩ resistor (0603), any R7 1 10pF ±5%, 50V ceramic capacitor (0603) Murata GRM1885C1H100JZ01 Y1 (433MHz) 1 R8 1 10kΩ resistor (0603), any Crystal 6.6128MHz Hong Kong Crystal SSL6612813E03FAFZ8A0 or Crystek 016868 Quick Start Y2 1 10.7MHz ceramic filter Murata SFTLA10M7FA00-B0 The following procedure allows for proper device evaluation. U1 1 MAX1473EUI — 1 MAX1473 EV kit PC board L1 (433MHz) 1 15nH ±5% inductor (0603) Coilcraft 0603CS-15NXJB L2 (315MHz) 1 120nH ±5% inductor (0603) Coilcraft 0603CS-R12XJB L2 (433MHz) Required Test Equipment • Regulated power supply capable of providing +3.3V • RF signal generator capable of delivering from -120dBm to 0dBm of output power at the operating frequency, in addition to AM or pulse-modulation capabilities (Agilent E4420B or equivalent) • Optional ammeter for measuring supply current • Oscilloscope Connections and Setup 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 or RF signal generator until all connections are made: 1) Connect a DC supply set to +3.3V (through an ammeter, if desired) to the VDD and GND terminals on the EV kit. Do not turn on the supply. 2) Connect the RF signal generator to the RF_IN SMA connector. Do not turn on the generator output. Set the generator for an output frequency of 315MHz (or 433.92MHz) at a power level of -100dBm. Set the modulation of the generator to provide a 2kHz 100% 2 Y1 (315MHz) AM-modulated square wave (or a 2kHz pulse-modulated signal). 3) Connect the oscilloscope to test point TP3. 4) Turn on the DC supply. The supply current should read approximately 5mA. 5) Activate the RF generator’s output without modulation. The scope should display a DC voltage that varies from approximately 1.2V to 2.0V as the RF generator amplitude is changed from -115dBm to 0dBm. (Note: At an input amplitude of around -60dBm, this DC voltage will drop suddenly to about 1.5V and then rise again with increasing input amplitude. This is normal; the AGC is turning on the LNA gain reduction resistor). 6) Set the RF generator to -100dBm. Activate the RF generator’s modulation and set the scope’s coupling to AC. The scope now displays a lowpass-filtered square wave at TP3 (filtered analog baseband data). Use the RF generator’s LF OUTPUT (modulation output) to trigger the oscilloscope. 7) Monitor the DATA_OUT terminal and verify the presence of a 2kHz square wave. _______________________________________________________________________________________ MAX1473 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 MAX1473. All required components have been enclosed in a 1.25in ✕ 1.25in square, which can be directly “inserted” into the application circuit. Detailed Description Power-Down Control for continuous shutdown, or pins 1 and 2 for continuous operation. Remove the JU1 shunt for external control. Table 1 describes jumper functions. Power Supply The MAX1473 can operate from 3.3V or 5V supplies. For 5V operation, remove JU7 before connecting the supply to VDD. For 3.3V operation, connect JU7. IF Input/Output The 10.7MHz IF can be monitored with the help of a spectrum analyzer using the MIX_OUT SMA connector (not provided). Remove the ceramic filter for such a measurement and include R3 (270Ω) and C17 (0.01µF) to match the 330Ω mixer output with the 50Ω spectrum analyzer. Jumper JU3 needs to connect pins 1 and 2. It is also possible to use the MIX_OUT SMA connector to inject an external IF as a means of evaluating the baseband data slicing section. Jumper JU3 needs to connect pins 2 and 3. F_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 F_IN SMA connector (not provided). Connect the SMA connector to a function generator. The addition of C18 and C19 is necessary (use 0.01µF capacitors). AGC Control Jumper JU5 controls whether the AGC is enabled. Connect pins 2 and 3 to enable the AGC. Crystal Select Jumper JU2 controls the crystal divide ratio. Connecting pins 1 and 2 sets the divide ratio to 64, while connecting pins 2 and 3 sets the ratio to 32. This determines the frequency of the crystal to be used. Image Rejection Frequency Select A unique feature of the MAX1473 is its ability to vary at which frequency the image rejection is optimized. JU6 allows the selection of three possible frequencies: 315MHz, 375MHz, and 433.92MHz. See Table 1 for settings. Test Points and I/O Connections Additional test points and I/O connectors are provided to monitor the various baseband signals and for external connections. See Tables 2 and 3 for a description. For additional information and a list of application notes, consult the www.maxim-ic.com website. The MAX1473 can be controlled externally using the SHDN connector. The IC draws approximately 1.25µA in shutdown mode. Jumper JU1 is used to control this mode. The shunt can be placed between pins 2 and 3 _______________________________________________________________________________________________________ 3 Evaluates: MAX1473 Additional Evaluation 1) With the modulation still set to AM, observe the effect of reducing the RF generator’s amplitude on the DATA_OUT terminal output. The error in this sliced digital signal increases with reduced RF signal level. The sensitivity is usually defined as the point at which the error in interpreting the data (by the following embedded circuitry) increases beyond a set limit (BER test). 2) With the above settings, a 315MHz-tuned EV kit should display a sensitivity of about -117dBm (0.2% BER) while a 433.92MHz kit displays a sensitivity of about -115dBm (0.2% BER). Note: The above sensitivity values are given in terms of average peak power is 3dB higher. 3) Capacitors C5 and C6 are used to set the corner frequency of the 2nd-order lowpass Sallen-Key data filter. The current values were selected for bit rates up to 5kbps. Adjusting these values accommodates higher data rates (refer to the MAX1473 data sheet for more details). Evaluates: MAX1473 MAX1473 Evaluation Kit Table 1. Jumper Functions SIGNAL DESCRIPTION JUMPER STATE JU1 1-2 Normal operation RF_IN RF input JU1 2-3 Power-down mode F_IN External reference frequency input JU1 NC External power-down control MIX_OUT IF input/output Crystal divide ratio = 32 GND Ground JU2 2-3 FUNCTION Table 3. I/O Connectors JU2 1-2 Crystal divide ratio = 64 VDD Supply input JU3 1-2 Mixer output to MIX_OUT DATA_OUT Sliced data output SHDN External power-down control JU3 2-3 External IF input JU3 NC Normal operation JU4 1-2 Uses PDOUT for faster receiver startup JU4 2-3 GND connection for peak detector filter JU5 1-2 Disables AGC JU5 2-3 Enables AGC JU6 1-2 IR centered at 433MHz JU6 2-3 IR centered at 315MHz JU6 NC IR centered at 375MHz JU7 1-2 Connect VDD to +3.3V supply JU7 NC Connect VDD to +5.0V supply Table 2. Test Points TP 4 DESCRIPTION 2 Data slicer negative input 3 Data filter output 4 Peak detector out 5 +3.3V 6 GND 7 Data filter feedback node 8 Data out 9 Power-down select input 10 VDD 11 AGC control 12 Crystal select Figure 1. MAX1473 EV Kit _______________________________________________________________________________________ MAX1473 Evaluation Kit AT 315MHz AT 433.92MHz 4pF 2.2pF L1 27nH 15nH +3.3V C14 15pF L2 120nH 56nH Y1 4.754689MHz 6.6128MHz Y1 * C15 15pF 1 XTAL2 XTAL1 PWRDN 2 C12 0.1µF C7 100pF 3 4 L3 15nH 5 6 +3.3V C2 0.01µF PDOUT C11 100pF LNAIN DATAOUT VDD5 LNASRC TP4 26 AGND LNAOUT 24 9 23 MIXIN1 DATA_OUT VDD R7 10pF C21 0Ω R6 OPEN JU8 SHORT MIXIN2 C8 100pF DSN 22 21 TP7 C6 220pF DSN 20 TP2 C4 0.47µF R1 TP3 5.1kΩ DFO +3.3V 10 2 11 JU6 12 AGND IFIN2 IR_SEL MIXOUT DGND 14 DV DD C1 0.01µF IN 1 18 C3 1500pF R8 10kΩ +3.3V +3.3V GND 2 3 JU2 1 1 2 Y2 OUT 10.7MHz 3 C5 470pF 19 17 IFIN1 16 XT_SEL 15 AGC_OFF 13 +3.3V TP9 AVDD TP6 3 SHDN TP8 R5 10kΩ 25 MAX1473 OPP 1 DSN 1 2 JU4 3 C13 OPEN 1 2 3 U1 DFFB GND JU1 27 R9 1000pF 8 C10 220pF AVDD DSP 7 +3.3V VDD TP10 28 R2 OPEN L2 * C9 * C20 0.1µF TP5 F_IN VDD VDD +3.3V L1 * C19 OPEN C16 OPEN C18 OPEN RF_IN JU7 Evaluates: MAX1473 * C9 JU5 1 TP12 2 3 TP11 3 R3 JU3 OPEN C17 OPEN MIX_OUT 2 R4 OPEN Figure 2. MAX1473 EV Kit Schematic _______________________________________________________________________________________ 5 Evaluates: MAX1473 MAX1473 Evaluation Kit Figure 3. MAX1473 EV Kit Component Placement Guide— Component Side Figure 4. MAX1473 EV Kit PC Board Layout—Component Side Figure 5. MAX1473 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.