Evaluates: MAX2837 MAX2837 Evaluation Kit Connections and Setup General Description The EV kit is fully assembled and factory tested. Follow the The MAX2837 evaluation kit (EV kit) simplifies test- instructions below to test the device. This section provides ing of the devices receive and transmit performance step-by-step instructions for getting the EV kit up and in WiMAX applications operating in the 2.3GHz to running in all modes. See Figure 1 for EV kit connections: 2.7GHz ISM band. The EV kit provides 50 SMA connectors for all RF and baseband inputs and outputs. 1) Connect the PC to the INTF3000 interface board Differential-to-single-ended and single-ended-to-differential using the USB-A male to USB-B male cable. On the line drivers are provided to convert the differential I/Q base- INTF3000, remove jumper JU1 and connect a DC band inputs and outputs to single-ended. supply set to 3.3V to the VPULL connector. Connect the 25-pin connector of the INTF3000 (J4) directly to Features the 25-pin connector on the EV kit (J18). On-Board Line Driver and Voltage Reference 2) With the power supply turned off, connect the +3.3V power-supply to VBAT and VCCAUX. Connect the 50 SMA Connectors on All RF and Baseband Ports power-supply ground to the header labeled GND1. PC Control Software Available at 3) With the power supply turned off, connect the +5V www.maximintegrated.com/evkitsoftware) power supply to the +5V test point and the -5V power supply to the -5V test point. Connect the power- Quick Start supply ground to the header labeled GND2. Connect all the power-supply grounds together. Recommended Test Equipment 4) Set the RXBBBUF jumper across pins 1-2 to enable This section lists the recommended test equipment to the RX baseband buffers. verify the operation of the MAX2837. It is intended as a guide only and substitutions may be possible. 5) Set the VCCVCO jumper across pins 2-3, VCCVCO1 jumper across pins 1-2, VCCVCO2 jumper across MAX2837 EV kit pins 2-3, and VBAT LDO jumper across pins 2-3 to INTF3000+ interface board utilize the three on-board LDOs to regulate the VBAT DC supply capable of delivering +5V and 250mA of voltage to +2.85V. continuous current 6) Turn on the +3.3V power supply, and the +5V and DC supply capable of delivering -5V and 250mA of -5V power supplies. continuous current 7) Make sure there are no jumpers across headers DC supply capable of delivering +3.3V and 250mA of labeled RXEN, TXEN and JPSHDNB so that these continuous current enables can be controlled through the software. Two HP8648s or equivalent signal sources capable of 8) Adjust the TX common-mode potentiometer (R36) generating 0dBm up to 3GHz until measuring 0.9V common-mode voltage at the Two HP or equivalent arbitrary waveform generators VCM test point (see Figure 1 for locations). One HP8561E or equivalent RF spectrum analyzer 9) Install and run the MAX2837 control software from with a minimum 100kHz to 3GHz frequency range HERE. One TDS3012 or equivalent oscilloscope with 200MHz 10) In the Enables panel of the software, check the bandwidth EN SPI box to enable the 3-wire interface. PC laptop or tablet with Microsoft Windows XP , 11) In the Synth panel of the software, set the LO Windows 7, 8 OS and a USB port frequency to 2500MHz. USB-A male to USB-B male cable 12) In the Registers panel of the software, set ENABLE to 1 and RXENABLE and TXENABLE to 0 to put the IC into standby mode. The supply current should be around 35mA. Windows and Windows XP are registered trademarks and registered service marks of Microsoft Corporation. 19-0966 Rev 2 1/16Evaluates: MAX2837 MAX2837 Evaluation Kit Receive Mode Layout Considerations 1) Set the signal generator to accurately deliver The EV kit can serve as a guide for board layout. -100dBm at 2502MHz. Connect the output of the Keep PCB trace lengths as short as possible to signal generator to RXRF port of the EV kit. minimize parasitic inductance. Also, keep decoupling 2) Connect either the RXBBI or RXBBQ baseband output capacitors as close to the IC as possible with a direct to a spectrum analyzer. Set the center frequency to connection to the ground plane. 2MHz and the span to 1MHz. Other recommended Power-Supply Layout spectrum analyzer settings are: Res BW of 3kHz, To minimize coupling between different sections of the Attenuation of 40dB, and Ref Level of 30dB. IC, use a star power-supply routing configuration with 3) In the Registers panel of the software, set ENABLE a large decoupling capacitor at a central V node. and RXENABLE to 1 and TXENABLE to 0 to activate CC The V traces branch out from this node, each going the receive path. The current should be around 94mA. CC to a separate V node in the circuit. Place a bypass 4) In the RX panel of the software, toggle both the LNA CC capacitor as close to each supply pin as possible. This gain enable and the baseband VGA enable to be arrangement provides local decoupling at each V SPI. Set both of the gain controls to max. CC pin. Use at least one via per bypass capacitor for a low- 5) Turn on the RF signal source. The output CW tone at inductance ground connection. Do not share the capacitor 2MHz should be approximately -2dBm. ground vias with any other branch. Transmit Mode 1) Connect the spectrum analyzer to the TXRF port. Set the center frequency to 2500MHz and the span to 5MHz. Other recommended spectrum analyzer settings are: Res BW of 10kHz, Attenuation of 10dB and Ref Level of 0dB. 2) Connect a 2MHz sinusoid to TXBBI and a 2MHz sinusoid with a 90 phase shift (or a cosine) to TXBBQ. Set the input amplitude of each channel to 90mV . RMS 3) In the Registers panel of the software, set ENABLE and TXENABLE to 1 and RXENABLE to 0 to activate the transmit path. The current should be around 146mA. 4) In the TX panel of the software, toggle TX VGA Gain to SPI. Set it to -3dB from the max gain. 5) In the TX panel of the software, set the TX Mixer V2I gain to -5.5dB (this is also the default setting). 6) Turn on the baseband signal sources. The output at 2502MHz should be approximately -1dBm. The LO leakage at 2500MHz should be around -27dBm and sideband suppression at 2498MHz should be around -39dBm. Maxim Integrated 2 www.maximintegrated.com