19-1296; Rev 2; 1/01 MAX2510 Evaluation Kit Component Suppliers PHONE/ FAX SUPPLIER Features ♦ +2.7V to +5.5V Single-Supply Operation ♦ Allows Testing of Advanced Power Management (four modes): < 1nA Shutdown Receive Transport Standby ♦ 50Ω SMA Connector Interface ♦ Fully Assembled and Tested INTERNET Coilcraft (847) 639-6400/ (847) 639-1469 http://www.coilcraft.com Murata-Erie (814) 237-1431/ (814) 238-0490 http://www.murata.com Sprague (603) 224-1961/ (603) 224-1430 — Ordering Information PART MAX2510EVKIT-SO TEMP. RANGE -40°C to +85°C IC PACKAGE 28 QSOP Component List DESIGNATION QTY DESCRIPTION C1, C3 2 0.01µF capacitors C2 1 330pF ceramic capacitor DESIGNATION QTY DESCRIPTION R3, R11, R17 3 50Ω resistors R4, R7, R8, R14 4 5kΩ resistors R1, R5 2 0Ω shorts (0603) (can be changed to allow for other matching networks) R9 1 Resistor—not installed (for backterminating an interstage filter) R10, R15 2 280Ω 1% resistors R16 1 Resistor—not installed (for adjusting the RSSI output voltage range) C4 1 0.047µF capacitor C6, C8 2 47pF capacitors (0603) C5, C10, C30, C31 0 Not installed C7, C9, C12, C13, C21, C22, C23, C27 8 0.1µF capacitors C14, C15, C17, C19 4 0.001µF capacitors U1 1 MAX2510EEI (28 QSOP) C18, C25 2 10pF capacitors (0603) U2 1 C20, C29 2 0.022µF capacitors 10.7MHz ceramic bandpass filter (ZO = 330Ω), 3-pin through-hole footprint Murata SFE10.7MA5-A C24 1 10µF tantalum capacitor Sprague 293D106X0010C2 RXEN, TXEN 2 3-pin headers (0.1" center) 2 Shunts L2 1 82nH inductor Coilcraft 0805HS-820TKBC None 1 MAX2510EV-SO circuit board None 1 MAX2510EEI data sheet L3, L4 2 47nH inductors Coilcraft 0805HS-470TKBC LO IN, I, Q, RXIN, RXIN, TXOUT, TXOUT, MIXOUT, LIMIN 9 50Ω edge-mount SMA connectors E.F. Johnson 142-0701-801 Note: All resistors, capacitors, and inductors are surfacemount components with an 0805 footprint, unless otherwise specified. Filter U2 and the various jumpers are through-hole mounted. ________________________________________________________________ Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. Evaluates: MAX2510 General Description The MAX2510 evaluation kit (EV kit) simplifies testing of the MAX2510 low-power IF transceiver with limiter/ received-signal-strength indicator (RSSI) and quadrature modulator. This EV kit allows simple evaluation of all chip functions in a 50Ω test environment. Evaluates: MAX2510 MAX2510 Evaluation Kit _________________________Quick Start The following section provides instructions for operating the EV kit as an IF transceiver. The RF ports (RXIN, RXIN, TXOUT, and TXOUT) are matched to 50Ω at 240MHz, and the second IF is configured for 10.7MHz operation. The EV kit and the MAX2510 can be configured for operation at other frequencies (see the Detailed Description section and the MAX2510 data sheet). Test Equipment Required This section lists the test equipment recommended for verifying operation of the MAX2510. It is intended only as a guide; some substitutions may be possible. • Two RF-signal generators capable of delivering at least 0dBm of output power up to 500MHz (HP8656B, HP8648A, or equivalent). One generator is required for the local oscillator (LO) source in both transmit (Tx) and receive (Rx) modes. The other is required for the Rx input signal in Rx mode. Connections and Setup This section provides step-by-step instructions for getting the EV kit up and running in both Tx and Rx modes. Tx Mode Perform the following steps to set up the EV kit in Tx mode: 1) Make the DC connections: set the power supply to 3V, and connect it to the VCC and GND terminals on the EV kit. Set one of the voltage sources to 1.4V, and connect it to VBIAS. Set the other voltage source to 2V, and connect it to the gain-control terminal (marked GC). 2) Set the part in Tx mode by putting 3-pin jumper TXEN in the “high” position, and jumper RXEN in the “low” position. 3) The supply current should be near 30mA. If this is not the case, check the voltage on the TXEN and RXEN test points. The TXEN voltage should be at VCC, and the RXEN voltage should be at ground. • An RF spectrum analyzer that can cover the transmitter’s output frequency range, as well as a few harmonics (HP8560E, for example). 4) Connect TXOUT to the spectrum analyzer using an SMA cable. Terminate TXOUT with a 50Ω SMA terminator. • A baseband-signal generator that can produce two outputs in quadrature (sine and cosine waves) at levels of approximately 500mVp-p. This is necessary to evaluate the transmitter’s sideband suppression. The HP8904A/Opt. 002 generator provides sine and cosine outputs at frequencies up to 600kHz. For differential operation, TXOUT and TXOUT can be combined using a balun. Connect the balun’s output to the spectrum analyzer. Set the spectrum analyzer to 240MHz center frequency with a 1MHz total span. • Optional: An RF 180° hybrid combiner or balun (Anzac H-9 or equivalent). This is used for differential coupling into the RXIN, RXIN connections on the receiver or the TXOUT, TXOUT connections on the transmitter. If a balun is not available, these inputs and outputs can be evaluated in a single-ended configuration, at a slight performance cost. • A voltmeter for measuring the RSSI output voltage. • An oscilloscope for observing the limiter output signals. • A power supply that can provide up to 50mA at +2.7V to +5.5V. • Two 0V to 5V adjustable voltage sources for providing gain-control (GC) pin voltage and the VBIAS voltage for the I and Q inputs. • Two 50Ω SMA terminators • Several 50Ω SMA cables 2 5) Connect the local oscillator (LO) signal source to the LO SMA connector. Set the frequency to 240MHz and the amplitude to -13dBm. You will see a small amount of LO signal present at the center of the spectrum-analyzer display. 6) Set both channels of the baseband-signal generator to deliver sine waves at 500mVp-p at a frequency of 100kHz. To achieve maximum sideband suppression, be sure that there is a precise 90° phase difference between these two sinusoidal signals. Connect the first signal to the I input. You will see a double sideband signal (DSB) on the spectrum analyzer at 240MHz, with the lower sideband at (240MHz - 100kHz) and the upper sideband at (240MHz + 100kHz). Connect the other signal to the Q input. If the phase difference is set correctly, you will see a cancellation of the sidebands. Which sideband is canceled depends on which input leads the other in phase. Swapping the I and Q connections at the board’s input suppresses one or the other sideband. Leave the part set to transmit the upper sideband (USB) when finished. The rest of these instructions assume the _______________________________________________________________________________________ MAX2510 Evaluation Kit 7) The USB output power should be approximately 0dBm with GC = 2V. Test the GC function by slowly lowering the voltage on the GC pin from 2V to 0V. You will see at least a 40dB change in USB power over this voltage range. 8) When the transmitter is working properly, you may wish to test other features, such as shutdown mode (both TXEN and RXEN jumpers set to “low”. The I and Q inputs can be adjusted to check transmitter gain over frequency, VBIAS voltage, etc. Rx Mode This section describes how to connect and use the MAX2510’s receiver section. 1) Remove the I and Q input signal sources to prevent crosstalk into the receiver during Rx-mode measurements. The GC and VBIAS voltage supplies have no function in Rx mode. 2) Switch the part into Rx mode by moving the RXEN jumper to the “high” position and the TXEN jumper to the “low” position. 3) Change the LO frequency to equal the desired Rx frequency minus 10.7MHz. This provides a 10.7MHz downconverted signal into the off-chip filter (a 10.7MHz bandpass type). For a 240MHz Rx frequency, the LO frequency should be (240 - 10.7 = 229.3 MHz). Leave the LO power level at -13dBm. 4) Connect RXIN to a second RF-signal generator using an SMA cable. Terminate RXIN with 50Ω. For differential operation, connect the signal generator to RXIN and RXIN through a balun. Set this generator’s frequency to 240MHz at -30dBm of output power. 5) Connect an oscilloscope to the limiter outputs LIMOUT and LIMOUT. A 2-channel oscilloscope with low-capacitance probes is ideal. The signals from LIMOUT and LIMOUT should be approximately 600mVp-p and out-of-phase with each other. 6) Connect a voltmeter to the RSSI test pad in the upper-left corner of the EV kit to monitor the RSSI output voltage. For -30dBm of RXIN power, the RSSI voltage should be 1.8V. Lower the input power in 10dBm steps, observing the decrease in RSSI output voltage of about 20mV per 1dB change in input power. Return the power level to -30dBm. 7) Observe that the signals at LIMOUT and LIMOUT remain at constant level over the RXIN power range. Advanced System Power-Management Features Besides the Tx and Rx modes previously mentioned, the MAX2510 supports two other operating modes: shutdown and standby. Bring both TXEN and RXEN jumpers to the “low” position, putting the part in shutdown mode and reducing the supply current to 2.0µA (typical). To enter standby mode, bring both TXEN and RXEN jumpers to the “high” position. This reduces the supply current to about 0.5µA while leaving the VREF generator active (for fast switching into receive mode). _______________Detailed Description The following section covers the EV kit’s circuit design in detail. (See the MAX2510 data sheet for additional information.) Baseband Inputs The I, I, Q, and Q pins comprise the quadrature modulator’s baseband inputs. They require external DC biasing to set a common-mode level of approximately 1.4V. On the EV kit, this voltage is provided by external resistors and a voltage supply (VBIAS). The I and Q pins are AC coupled to SMA connectors, which induces a highpass cutoff of approximately 300Hz. The I and Q pins are biased to the common-mode voltage and AC grounded. Test points on the EV kit allow flexible access to these pins if the application requires differential drive. Transmitter Output The MAX2510’s Tx outputs (TXOUT and TXOUT) are high-impedance open collectors; therefore, external inductors are used for proper biasing. DC-blocking capacitors are used to connect to these outputs. The inductors and capacitors act only to provide biasing; they do not set the output impedance. For single-ended applications, terminate TXOUT with a 50Ω terminator. Alternatively, replace L4 with a 0Ω short. Refer to the MAX2510 data sheet for more information on matching this port. Receiver Input The Rx inputs (RXIN and RXIN) require an impedancematching network for optimum performance. The Rx inputs are matched to 240MHz on the EV kit as shipped. The input matching network comprises a series capacitor from each Rx input SMA connector to the part, as well as a shunt inductor across RXIN and RXIN. The EV kit layout provides space for additional components: one series element on each side and a _______________________________________________________________________________________ 3 Evaluates: MAX2510 transmitter is set in USB mode and the lower sideband (LSB) is the suppressed sideband. If the application requires LSB, reverse the relevant instructions. The EV kit also accommodates differential I and Q inputs. (Refer to the Detailed Description section.) Evaluates: MAX2510 MAX2510 Evaluation Kit shunt element across the inputs. The additional series elements have been replaced by 0Ω shorts, and the additional shunt element is not installed. Refer to the MAX2510 data sheet for more information on designing a matching network for this port. Receiver Output The receive downconverter mixer’s output appears at the MIXOUT pin (a current source that can drive a 165Ω load to 2Vp-p). The MIXOUT pin is terminated with a net 330Ω (R10 + R11) for proper match to the bandpass filter (ZO = 330Ω). Therefore, the net load at MIXOUT is 330Ω 330Ω = 165Ω. The EV kit design allows separate testing of the MAX2510’s Rx mixer and limiter sections for testing the Rx mixer only. Coupling capacitor C20 is used to connect the node between R10 and R11 to an external SMA connector (MIXOUT). For these tests, the filter (U2) must be removed, and R10 replaced with a 140Ω resistor. This network has some attenuation, but presents the correct impedance to the MIXOUT pin and provides a nearly 50Ω output impedance for measurement. The attenuation is 11.2dB. Limiter Input The MAX2510 EV kit can be modified to allow separate testing of the limiter only, similar to the receive mixer in the previous section. The filter (U2) must be removed. This allows the limiter SMA connector to be used as a direct input to the limiter. ______________________Layout Issues A good PC board is an essential part of an RF circuit design. The EV kit PC board can serve as a guide for laying out a board using the MAX2510. Rx Inputs and Tx Outputs The layout of the RXIN and RXIN input matching network should be layed out symmetrically to provide the best input balance if used as a differential input. The TXOUT and TXOUT biasing networks should also be layed out symmetrically to present an equal load impedance on each pin. Baseband Inputs The MAX2510’s I, I, Q, and Q inputs are high impedance; take care to minimize potential unwanted coupling into these pins. The easiest way to accomplish this is to keep the trace length to a minimum. Power-Supply Decoupling Each VCC node on a PC board should have its own 0.047µF decoupling capacitor. This minimizes supply coupling from one section of the MAX2510 to another. A star topology for the supply layout, in which each VCC node on the MAX2510 circuit has a separate connection to a central VCC node, can further minimize coupling between sections of the MAX2510. Limiter Output The downconverted, limited signal appears at the LIMOUT and LIMOUT pins as a 1.2Vp-p differential voltage (600mVp-p per side). For single-ended use, the unused side can be left open. The limiter outputs can deliver this voltage across a load as low as 250Ω. 4 _______________________________________________________________________________________ GC RSSI LO SMA R16 OPEN C6 LIMOUT SMA LIMOUT SMA R2 0Ω R13 0Ω 47pF C8 C4 0.047µF C1 0.01µF R3 47pF 50Ω C3 0.01µF C2 300pF TP2 TP1 VCC LIMIN SMA R6 0Ω 28 U1 VREF 1 JU8 2 TXEN 3 VCC HIGH LOW HIGH LOW 19 3 2 1 21 VIL Q Q I I TXOUT TXOUT RXIN RXIN 17 18 16 15 23 24 22 25 C15 0.001µF Q C5 OPEN R9 OPEN R5, 0Ω R1, 0Ω MIXOUT SMA 27 VCC MIXOUT C20 0.022µF JU9 RXEN C14 0.001µF VCC VCC 12 11 13 14 20 GND R10 280Ω R11 50Ω MAX2510 2 RXEN VA GND 26 C21 0.1µF C17 50Ω 1 LIMOUT LIMOUT TXEN GND LO LO GND VCC GC RSSI CZ CZ LIMIN R12 0Ω 10 9 6 7 8 5 4 3 2 1 C29 0.022µF R15 280Ω 3 U2 C25 10pF R4 5kΩ C12 0.1µF I C2 10µF R8 5kΩ C7 0.1µF L4, 47nH C10 OPEN C31, 20pF C30, 20pF L3, 47nH L2 82nH C18 10pF GND VCC R14 5kΩ Q I C19 0.001µF RXIN SMA RXIN SMA C22 0.1µF R7 5kΩ C27 0.1µF VBIAS C13 0.1µF C9 0.1µF TXOUT SMA VCC TXOUT SMA C23 0.1µF VCC Q SMA I SMA Evaluates: MAX2510 MURATA FILTER SFE10.7MA5-A MAX2510 Evaluation Kit Figure 1. MAX2510 EV Kit Schematic _______________________________________________________________________________________ 5 Evaluates: MAX2510 MAX2510 Evaluation Kit 1.0" 1.0" Figure 2. MAX2510 EV Kit PC Board Layout—Top Silkscreen and Pad Placement Figure 3. MAX2510 EV Kit PC Board Layout—Component Side (layer 1) 1.0" Figure 4. MAX2510 EV Kit PC Board Layout—Ground Plane (layer 2) 6 _______________________________________________________________________________________ MAX2510 Evaluation Kit Evaluates: MAX2510 1.0" 1.0" Figure 5. MAX2510 EV Kit PC Board Layout—Power-Supply Routing (layer 3) Figure 6. MAX2510 EV Kit PC Board Layout—Bottom Silkscreen and Pad Placement 1.0" Figure 7. MAX2510 EV Kit PC Board Layout—Bottom (solder side) (layer 4) _______________________________________________________________________________________ 7 Evaluates: MAX2510 MAX2510 Evaluation Kit NOTES 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.