general description the max5128 evaluation kit (ev kit) is a fully assembledand tested surface-mount printed-circuit board (pcb) that evaluates the max5128 22k , linear-taper digital potentiometer. the ev kit provides both a mechanicalpushbutton-controlled interface and a microprocessor- controlled interface. the max5128 evaluation system (ev system) consists of the max5128 ev kit and the maxim cmaxqusb+ command module. the ev kit includes windows 98se/2000/xp-compatible software that provides a pro-fessional user interface for exercising the max5128? features. the program is menu driven and offers a graphical user interface (gui) complete with control buttons and a track bar. order the complete ev system (MAX5128EVCMAXQU+) for comprehensive evaluation of the max5128 using a pc. order just the ev kit (max5128evkit+) if the cmaxqusb+ module has already been purchased with a previous maxim ev system. features ? powered and controlled from standard usbinterface (MAX5128EVCMAXQU+) ? 2.7v to 5.25v single-supply operation ? windows 98se/2000/xp-compatible evaluationsoftware ? easy-to-use menu-driven software ? supports pushbutton inputs or cpu-generatedinputs ? fully assembled and tested evaluate: max5128 max5128 evaluation kit/evaluation system ________________________________________________________________ maxim integrated products 1 19-0843; rev 0; 7/07 component list for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. ordering information part temp range ic package command module max5128evkit + 0? to +70?* 8 ?fn (2mm x 2mm) not included MAX5128EVCMAXQU + 0? to +70?* 8 ?fn (2mm x 2mm) cmaxqusb+ windows is a registered trademark of microsoft corp. + denotes a lead-free and rohs-compliant ev kit/ev system. * this limited temperature range applies to the ev kit pcb only. the max5128 ic temperature range is -40? to +85?. note: the maxim cmaxqusb+ command module is required when using the max5128 ev kit software. designation qty description c1 1 0.1? ?0%, 16v x7r ceramiccapacitor (0603) taiyo yuden emk107bj104ma murata grm188r71c104k c2, c3 0 not installed, capacitors (0603) j1 1 dual-row, 2 x 10 right-anglereceptacle ju1 1 2-pin header ju2, ju3, ju4 3 3-pin headers r1, r2 2 100k ?% resistors (0603) r3 1 4.7k ?% resistor (0603) designation qty description sw1, sw2 2 momentary pushbutton switches u1 1 max5128ela+ (8-pin ?fn, 2mm x 2mm) u2 1 dual cmos switch debouncer max6817eut+t (6-pin sot23, 3mm x 3mm) u3 1 dual cmos inverter fairchild nc7wz04p6x (6-pin sc70, 2mm x 2mm) (top mark: z) 4 shunts 1 pcb: max5128 evaluation kit+ downloaded from: http:///
evaluate: max5128 max5128 evaluation kit/evaluation system 2 _______________________________________________________________________________________ quick start recommended equipment before beginning, the following equipment is needed:? max5128 ev system: max5128 ev kitcmaxqusb+ command module (usb cable included) ? user-supplied windows 98se/2000/xp-compatiblepc with a spare usb port ? dc power supply, 5v at 100ma (optional) ? digital multimeter (dmm) note: in the following sections, software-related items are identified by bolding. text in bold refers to items directly from the ev kit software. text in bold and underlined refers to items from the windows 98se/2000/xp operating system. procedure the max5128 ev kit is fully assembled and tested.follow the steps below to verify board operation. caution: do not turn on the power supply until all connections are completed. 1) visit the maxim website (www.maxim-ic.com/evkit- software) to download the latest version of the ev kitsoftware, 5128rxx.zip. save the ev kit software to a temporary folder and uncompress the zip file. 2) install the ev kit software on your computer by run- ning the install.exe program inside the temporaryfolder. the program files are copied and icons are created in the windows start | programs menu. 3) ensure that jumper ju1 (vdd select) of the cmaxqusb+ is set for 5v operation. 4) for pc control, verify that shunts are installed in the following positions: ju1 installed ju2 installed across pins 1-2 ju3 installed across pins 1-2 ju4 installed across pins 2-3 5) connect the ohmmeter across the h and w pads. 6) carefully connect the boards by aligning the 20-pin connector (j1) of the max5128 ev kit with the 20-pin header (p3) on the cmaxqusb+ command module. gently press them together. 7) connect the usb cable from the pc to the ev kit board. a building driver database window pops up in addition to a new hardware found message when installing the usb driver for the first time. ifyou do not see a window that is similar to the one described above after 30s, remove the usb cable from the board and reconnect it. administrator privi- leges are required to install the usb device driver on windows 98se, 2000, and xp. refer to the troubleshooting_usb.pdf document includ- ed with the software if you have any problems dur- ing this step. 8) follow the directions of the add new hardware wizard to install the usb device driver. choose the search for the best driver for your device option. specify the location of the device driver to bec:\program files\max5128 (default installation directory) using the browse button. 9) start the ev kit software by opening its icon in the start | programs menu. the ev kit software main window appears, as shown in figure 1. 10) wait until the program automatically detects the max5128. 11) the max5128 ev kit is ready for evaluation. component suppliers supplier phone website murata mfg. co., ltd. 770-436-1300 www.murata.com taiyo yuden 800-348-2496 www.t-yuden.com note: indicate that you are using the max5128 when contact- ing these component suppliers. downloaded from: http:///
detailed description of software each button of the gui (figure 1) corresponds to acommand used to set the wiper position or to program the device. warning: do not remove the shunts of ju2 or ju3 from their default positions while running the software (seetable 1). wiper control the track bar in the wiper control group box allows the user to change the wiper position between the high-terminal ( h ) and low-terminal ( l ) end points. use the computer mouse, arrow keys, or page-up/page-downkeys to move the track bar between the 128 position points. the wiper position can also be changed byentering a numerical position (0 to 127) in the volatile edit fields. the top volatile field shows the wiper posi- tion with respect to the h end point, while the bottom volatile field shows the wiper position with respect to the l end point. the software calculates the difference between the newnumber entered and the old value and generates the nece ssary up/down pulses to position the wiper to the desired value. nonvolatile programming to program the nonvolatile memory, write the desiredvalue utilizing the gui? wiper control and press the write nv register button. this action will write the cur- rent wiper position to the nonvolatile register of thedevice. the 7-bit nonvolatile memory will retain the value written to it even after power-down. resetting the max5128 the factory reset button programs the volatile and nonvolatile memory to the midscale factory setting.the software forces the wiper to the extreme of the resistor string and generates 64 up/down pulses to position the wiper to midscale. detailed description of hardware the max5128 ev kit supports both mechanical push-buttons and digital inputs to control the potentiometer? wiper position and is configured by setting jumpers ju2 and ju3. by default, the max5128 ic? logic inputs (up and dn) are controlled through the provided soft- ware. install shunts across pins 2-3 for both ju2 and ju3 to control the device? logic inputs through the pushbutton switches (sw1 and sw2). see table 1 for the ev kit? various jumper settings. evaluate: max5128 max5128 evaluation kit/evaluation system _______________________________________________________________________________________ 3 table 1. jumper settings figure 1. max5128 ev kit software main window jumper shunt position description installed* low terminal l shunts to ground ju1 not installed low terminal l floating 1-2* wiper position software controlled ju2, ju3 2-3 wiper position pushbuttoncontrolled (sw1, sw2) 1-2 ev kit requires external powersupply across vcc pad ju4 2-3* ev kit uses the cmaxqusb+command module's power source * default position. downloaded from: http:///
evaluate: max5128 power input the max5128 ev kit requires a 2.7v to 5.25v power sup-ply across the vcc and gnd pads for normal operation. the ev kit can either be powered through the cmax- qusb+ command module? power source or by an external power supply. the ev kit? default setting has ju4 installed across pins 2-3 to utilize the cmaxqusb+ command module? power source (usb powered). configure the command module? vdd select voltage to 3.3v or 5v (jumper ju1) when using the cmaxqusb+ to power the max5128 ev kit. install the ev kit? ju4 jumper across pins 1-2 to use an external power supply. digital interface wiper positioning can be controlled through themomentary pushbutton switches (sw1 and sw2) by installing the jumpers of both ju2 and ju3 across pins 2-3. the debouncer (u2) is provided to eliminate the?ontact bounce?that sw1 and sw2 may exhibit. toggle the sw1 pushbutton to increment the wiper position. toggle the sw2 pushbutton to decrement the wiper position. use the following procedure to program the nonvolatile memory: 1) force up high (hold sw1). 2) force dn high (hold sw2). 3) transition input up from high to low (release sw1) and then release sw2. refer to the digital interface section of the max5128 ic data sheet for a more detailed description.jumper ju1 can also be used to connect the max5128 l pin to the circuit ground, providing a ground refer- ence during evaluation. max5128 evaluation kit/evaluation system 4 _______________________________________________________________________________________ 13 2 ju2 1 32 ju4 up 1 14 in1 6 out1 r1 100k c10.1 f c2open max6817 u2 max5128 u1 vccvcc gnd sw1 3 14 in2 4 out2 sw2 2 5 1 a1 6 y1 u3 nc7wz04p6x vcc vcc vcc vcc h w l vcc gnd 3 a2 4 y2 2 5 7 up 1 v cc 2 h vcc gnd 3 w gnd 6 dn 4 l 5 n.c. 8 13 2 ju3 dn r2 100k c3open ju1 r3 4.7k j1-1 j1-11 j1-13 j1-15 j1-7 j1-5 dn up j1-3 j1-9 j1-2 j1-12 j1-14 j1-16 j1-8 j1-6 j1-4 j1-10 j1 j1-17 j1-19 j1-18 j1-20 figure 2. max5128 ev kit schematic downloaded from: http:///
evaluate: max5128 max5128 evaluation kit/evaluation system _______________________________________________________________________________________ 5 _______________________________________________________________________________________ 5 figure 3. max5128 ev kit component placement guide component side figure 4. max5128 ev kit pcb layout?omponent side downloaded from: http:///
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 2007 maxim integrated products is a registered trademark of maxim integrated products, inc. evaluate: max5128 max5128 evaluation kit/evaluation system figure 5. max5128 ev kit pcb layout?older side downloaded from: http:///
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