MAX44205EVKIT#

Evaluates: MAX44205 MAX44205 Evaluation Kit General Description The MAX44205 evaluation kit (EV kit) provides a proven design to evaluate the MAX44205, low-noise, lowdistortion fully differential operational amplifier (op amp), suitable for driving high-resolution SAR ADCs such as the MAX11905 family of devices. Quick Start Required Equipment ●● MAX44205 EV kit ●● ±5V, 100mA dual DC power supply ●● Low-distortion differential-output signal generator (i.e., Audio Precision 2700, Stanford Research DS360) ●● 2-channel oscilloscope Benefits and Features ●● Two SMA cables of equal length ●● Fully Differential Amplifier with 130dBc THD Procedure ●● +2.7V to +13.2V Supply Voltage Range The EV kit is fully assembled and tested. Follow the steps below to verify the board operation: 1) Verify that all shunts are in their default positions, as shown in Table 1. 2) Connect the ±5V supply to the VS+, VS-, and GND test points, respectively. 3) Use the SMA cables and connect the 10kHz, 6.6Vp-p sine, differential input from the signal generator to the INP and INM SMAs on the EV kit. 4) Turn on the power supplies. 5) Use the oscilloscope and monitor the differential output at jumper JU6. The EV kit PCB comes installed with a MAX44205ATC+ in a 12-pin, 3mm x 3mm TQFN package with an exposed pad. ●● Output-Voltage Clamps to Prevent Overranging ADC ●● Adjustable Output Common-Mode Voltage ●● Evaluate 20-Bit SAR ADC + MAX44205 Amplifier (refer to the MAX11905 EV Kit) ●● Proven PCB Layout ●● Fully Assembled and Tested Ordering Information appears at end of data sheet. 19-7058; Rev 0; 9/14 Evaluates: MAX44205 MAX44205 Evaluation Kit Table 1. Jumper Functions (Ju1–Ju5) JUMPER JU1 JU2 JU3 JU4 JU5 SHUNT POSITION DESCRIPTION 1-2* Normal operation 2-3 SHDN. MAX44205 is in shutdown mode. 1-2* VCLPH is connected to VS+. 2-3 External VCLPH. Apply a voltage no greater than (VS+) + 0.42V at the EXT_VCLPH test point. 1-2* VCLPL is connected to VS-. 2-3 External VCLPL. Apply a voltage no greater than (VS-) + 0.54V at the EXT_VCLPL test point. Not installed User-supplied VOCM. Apply (VS-) + 1.2V to (VS+) - 1.2V at the VOCM test point. Installed* VOCM is connected to GND. Not installed* Disconnects VS- from GND. Installed Connects VS- to GND. *Default position. Note: Jumper JU6 has no shunt; it is used for probing only. Detailed Description of Hardware The MAX44205 EV kit provides a proven design to evaluate the MAX44205, low-noise, low-distortion, fully differential op amp, suitable for driving highresolution SAR ADCs such as the MAX11905 family of devices. Features of the EV kit include jumpers for SHDN control, VCLPH/VCLPL voltage-clamping options, and input for output common-mode voltage (VOCM). The EV kit is meant to work using dual supplies where the voltage between VS+ and VS- is +2.7V to +13.2V. Shutdown Mode (SHDN) Jumper JU1 controls the shutdown mode of the device. The device is in normal operation when the shunt is installed in the 1-2 position on jumper JU1. To place the device in shutdown mode, install a shunt in the 2-3 position on JU1. If the shunt on JU1 is removed, the device is pulled internally to VS+. This option also allows a pulse to be sent through the SHDN SMA. Clamping Voltage (VCLPH and VCLPL) Jumpers JU2 and JU3 allow the options to connect to the VS+ and VS- supply rails or external supplies (Table 1). When the device is driving an ADC, connect VCLPH to the reference voltage of the ADC and VCLPL to the minimum input voltage (or ground). Output Common-Mode Voltage (VOCM) common-mode voltage from (VS-) + 1.2V to (VS+) - 1.2V at the VOCM test point. Adjusting the Gain Adjust the gain by replacing R1–R4 on the EV kit with appropriate resistors. The gain (AV) is as follows: A= V R3 R4 = R1 R2 When selecting resistors, use 0.1% tolerance and 10ppm parts when possible. Input Termination Resistors The EV kit has 49.9Ω termination resistors populated at the R7 and R8 pads at the IN+ and IN- inputs. These resistors should be removed or replaced appropriately to match the impedance of the signal source. Input Filter for ADC Replace R5, R6, and populate C12 appropriately when driving a high-resolution ADC like the MAX11905. Additional capacitance can be installed at the C17 and C18 pads. Refer to Driving a Fully Differential ADC section in the MAX44205 IC data sheet. Component List Refer to file “evkit_build_bom_max44205_evkit_a.csv” attached to this PDF for component information. Jumper JU4 sets the output common-mode voltage to 0V. If the shunt is removed, apply the desired output www.maximintegrated.com Maxim Integrated │  2 www.maximintegrated.com f mc f mc T R S Q hmo T R S Q unbl T R S Q hml T R S Q r gc m P P P P itS unbl Q P qW SXMX OMPD qQ qX qV SXMX OMPD qP r gc m OMPD OMPD OMPD Pj SMXXj Pj bX OMPt e PO PR P PP PQ ur J X Q itP Q ur J R ubkog r gc m OMPD nodm bPO OMPD qS Pj tP r gc m R mMbM l ‘ wSSQOT‘ s bJ ur J hmL ubkog S nt s J unbl U nt s L ubkok hmJ ur L do f mc V ubkok W T ur L qPQ POOj P bPP nodm qR Pj Q P bPS POt e O qU itU O qT bPR OMPt e qPP nodm qPO nodm ur J P bS POt e bPW nodm bPV nodm itQ Q ubkog R bP OMPt e ur J bPQ nodm bT OMPt e nt s o f mc Q S R T nt s l Q S R T ur J P P bV POt e dws ~ubkog f mc ur L P P itT itR Q ubkok R bR POt e Q bU OMPt e bQ OMPt e ur L bPT POt e ur L bW POt e dws ~ubkok bPU OMPt e MAX44205 Evaluation Kit Evaluates: MAX44205 Figure 1. MAX44205 EV Kit Schematic Maxim Integrated │  3 Evaluates: MAX44205 MAX44205 Evaluation Kit 1” Figure 2. MAX44205 EV Kit Component Placement Guide— Component Side 1” Figure 3. MAX44205 EV Kit PCB Layout—Component Side www.maximintegrated.com 1” Figure 4. MAX44205 EV Kit PCB Layout—Solder Side 1” Figure 5. MAX44205 EV Kit Component Placement Guide— Solder Side Maxim Integrated │  4 MAX44205 Evaluation Kit Evaluates: MAX44205 Ordering Information PART TYPE MAX44205EVKIT# EV Kit www.maximintegrated.com Maxim Integrated │  5 Evaluates: MAX44205 MAX44205 Evaluation Kit Revision History REVISION NUMBER REVISION DATE 0 9/14 DESCRIPTION Initial release PAGES CHANGED — For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2014 Maxim Integrated Products, Inc. │  6