Evaluates: MAX31180 MAX31180 Evaluation Kit General Description Features The MAX31180 evaluation kit (EV kit) is a fully assembled Easy Evaluation of the MAX31180AUA+ and tested PCB to evaluate the MAX31180 spread- +3.3V Single-Supply Operation spectrum crystal multiplier. The EV kit operates from a Low Peak Cycle to Cycle 75ns Jitter Typical single 3.3V supply and the onboard crystal provides a Configurable Clock Multiplier 25MHz clock signal. The EV kit also provides header Selectable Spread Spectrum Magnitude pins to configure the clock frequency multiplier, the Proven PCB Layout magnitude of the spread spectrum, and a means to Fully Assembled and Tested disable the spread spectrum feature. An SMA connector for the clock output is included to easily facilitate the connection of test equipment. EV Kit Contents Ordering Information appears at end of data sheet. Assembled circuit board, including MAX31180AUA+ MAX31180 EV Kit Board Photo 319-100028 Rev 0 7/17MAX31180 Evaluation Kit Evaluates: MAX31180 8) Remove the jumper from PDN and leave it open. This Quick Start position of the PDN sets the device to the Power-Up Required Equipment and Accessories mode and disables the spread spectrum. The spec- One DC Power Supply capable of supplying +3.3V trum analyzer shows a CW tone signal at 25MHz. One multimeter for measuring the current 9) Set the jumper on PDN on the position connected to V (1). This position of the PDN enables the CC One spectrum analyzer Spread Spectrum. One SMA cable 10) Set the jumper on SMSEL on the position connected MAX31180 EV kit to GND (0). This position of the SMSEL set the device to the 0.5% Spread Spectrum mode. The spectrum Procedure analyzer shows a spread spectrum centered at 25MHz The EV Kit is fully assembled and tested. Follow the steps and about 250KHz bandwidth ( 0.5%). below to verify board operation: 11) By setting the SMSEL and CMSEL at the positions Note: To configure the PDN, SMSEL, and CMSEL 3-pin showed on Table 1, you can also see the spread headers, set the jumper to the right side of the header for spectrums at 50MHz (2 x CLOCK) and 100MHz (4 x 0 position and left side for the 1 position. CLOCK), each with 1.0% and 1.5%. 1) Place the EV kit on a nonconductive surface to ensure that nothing on the PCB is shorted to the Detailed Description workspace. The MAX31180 is a spread-spectrum clock generator 2) With the output set to +3.3V and disabled, with low jitter, selectable clock multiplier, selectable connect the positive terminal of the DC supply dither magnitude, and capable of accepting a 16MHz through a Mutimeter to the red (V /+3.3V) and CC to 33.4MHz crystal connected to the X1 and X2 pins. In negative terminal to black (GND) banana jacks of this EV kit, the mounted 25MHz crystal can be replaced the MAX31180 EV kit. and alternately, an external 16MHz to 33.4MHz clock can be applied to X1 in place of the crystal. In this setup, 3) Connect an SMA Cable to the MAX31180 CLOCK X2 would be left open. Using the CMSEL input, the user OUTPUT SMA Connector of the MAX31180 EV kit selects whether the crystal or clock input is multiplied and connect the other end of the cable to the by 1, 2, or 4. The MAX31180 is capable of generating spectrum analyzer. spread-spectrum clocks from 16MHz to 134MHz. 4) Set the jumper on PDN on the position connected to The PLL can dither the output clock about its center GND (0). This position of the PDN set the device to frequency at a user-selectable magnitude. Using the the Power-Down mode. SMSEL input, the user selects the dither magnitude. 5) Set the jumper on CMSEL on the position connected The PDN input can be used to place the device into a to GND (0). This position of the CMSEL set the low-power standby mode where the SSO output is three- Device Output to the 1 x CLOCK mode (25MHz). stated. If the PDN pin is open, the SSO output is active but 6) Set the center frequency of the spectrum analyzer to the spread-spectrum dithering is disabled. The spread- 25MHz (1 x CLOCK), reference level to 20dBm, and spectrum dither rate is fixed at f /992 to keep the dither IN span = 10MHz. rate above the audio frequency range. On power-up, the 7) Turn on the power supply. The supply current should output clock (SSO) remains three-stated until the PLL be about 0mA and no signal present on the reaches a stable frequency (f ) and dither (f ). SSO DITHER spectrum analyzer. Maxim Integrated 2 www.maximintegrated.com