MAX5216LPT#

MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter General Description Features The MAX5216LPT evaluation kit (EV kit) enables evaluation of the loop-powered 4–20mA current-loop transmitter with the fault current-limiting capabilities and Highway Addressable Remote Transducer (HART) modem input/output ready, which utilizes the MAX5216 singlechannel, low-power, buffered-output, 3-wire SPI interface 16-bit DAC, the MAX6133 3ppm/°C, low-power voltage reference, the MAX9620 single-channel, zero-drift, high-efficiency op amp with RRIO, and the MAX15007 40V, ultra-low quiescent current LDO. The EV kit also includes Windows XP®, Windows Vista® and Windows® 7-compatible software that provides a simple graphicaluser interface (GUI) for exercising the features of this reference design. ● Wide 12V to 40V Input Supply Range ● Transfer 16-Bit Digital Code to 4–20mA Loop Current ● Offset and Gain Programmable ● < 0.02 % FS Current Error at +25°C ● < 0.1 % FS Current Error Over Temperature Range ● -40°C to +105°C Temperature Range ● 30mA ±20% Resistor-Selectable Current Limiting ● 200µA (typ), 300µA (max) Quiescent Current ● HART Modem Input and Output Ready ● Direct USB Communication through the MAXQ622 Microcontroller ● Windows XP-, Windows Vista-, and Windows 7 (32-Bit)-Compatible Software Ordering Information appears at end of data sheet. ● SPI Interface Terminals ● Proven PCB Layout ● Fully Assembled and Tested Component List DESIGNATION QTY C2, C16 2 C3 C4 DESCRIPTION DESIGNATION QTY 1µF ±10%, 50V X7R ceramic capacitors (0805) Murata GRM21BR71H105KA12 C9, C11, C15, C19, C20, C22, C25 7 1µF ±10%, 16V X7R ceramic capacitors (0603) Murata GRM188R71C105K 1 0.1µF ±10%, 50V X7R ceramic capacitor (0805) Murata GRM21BR71H104KA01 C23, C24 2 18pF ±5%, 50V COG ceramic capacitors (0603) Murata GRM1885C1H180J 1 10µF ±10%, 16V X5R ceramic capacitor (0805) Taiyo Yuden EMK212BJ106KG-T D1 1 Schottky diode (SC79) NXP RB751S40,115 C5, C6, C10, C12–C14, C18, C21 D2 1 TVS diode (SMA) Burns SMAJ36CA 8 0.1µF ±10%, 16V X7R ceramic capacitors (0603) Murata GRM188R71C104K FB1 1 600Ω ferrite bead (0805) API Delevan EMI0805R-600 C7, C8, C17 3 1000pF ±10%, 50V X7R ceramic capacitors (0603) Murata GRM188R71H102KA01 J1 1 Mini-USB type-B, right-angle PC-mount receptacle Hirose UX60A-MB-5ST J2 0 Not installed, 10-pin (2 x 5) header, 0.1in centers Windows, Windows XP, and Windows Vista are registered trademarks and registered service marks of Microsoft Corporation. 19-6689; Rev 0; 5/13 DESCRIPTION MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Component List (continued) DESIGNATION QTY DESIGNATION QTY J3–J7, J9, J11 6 2-pin headers, 0.1in centers Sullins PEC36SAAN R14, R19, R22–R24 5 100Ω ±1%, 1/10W resistors (0603) Panasonic ERJ-3EKF101V J8 1 3-pin header. 0.1in center Sullins PEC36SAAN R20 1 1 2.54mm, 2-position, side-entry terminal block Phoenix Contact 1725656 3.3kΩ ±1%, 1/10W resistor (0603) Panasonic ERJ-3EKF3301V Q1 1 N-channel MOSFET (SOT223) Fairchild NDT014L RS 1 10Ω ±0.1%, 1/10W resistor (0603) Bourns CRT0603BY10R0ELF Q2 1 Bipolar npn transistor (SOT23) NXP MMBT3904,215 TP1 1 R1 1 287kΩ ±0.1%, 1/10W resistor (0603) Panasonic ERA-3AEB2873V Red PC test point, compact 0.06in Kobiconn 151-107-RC TP2 1 Black PC test point, compact 0.06in Kobiconn 151-103-RC TP3–TP13 11 Turret terminal pins Mill-Max 2108-2-00-44-00-00-07-0 J10 DESCRIPTION DESCRIPTION R2 1 24.9kΩ ±0.1%, 1/10W resistor (0603) Susumu RG1608P-2492-B R3 1 2MΩ ±1%, 1/10W resistor (0603) ROYALOHM TC0650F2004T4E U1 1 16-bit VOUT DAC (8 µMAX®) Maxim MAX5216GUA+ R4, R8 2 301Ω ±1%, 1/10W resistors (0603) Panasonic ERJ-3EKF3010V U2 1 Single zero-drift RRIO op amp (5 SC70) Maxim MAX9620AXK+ R5, R12, R18 3 1kΩ ±1%, 1/10W resistors (0603) Panasonic ERJ-3EKF1001V U3 1 R6, R15–R17 4 24.3Ω ±1%, 1/10W resistors (0603) Panasonic ERJ-3EKF24R3V 2.5V, 3ppm/ºC, low-power voltage reference (8 µMAX) Maxim MAX6133A25+ U4 1 100Ω ±0.1%, 1/10W resistor (0603) Panasonic ERA-3AEB101V 3.3V, ultra-low quiescent current, LDO (6 TDFN) Maxim MAX15007AATT+ U5 1 10kΩ ±1%, 1/10W resistors (0603) Panasonic ERJ-3EKF1002V 16-bit microcontroller with USB 2.0 interface (64 LQFP) Maxim MAXQ622G-0000+ Y1 1 12MHz crystal oscillator (HC49US) Citizen HCM49-12.000MABJ-UT — 1 PCB: MAX5216LPT Rev. A R7 R9, R10 R11, R13 1 2 2 49.9kΩ ±1%, 1/10W resistor (0603) Panasonic ERJ-3EKF4992V µMAX is a registered trademark of Maxim Integrated Products, Inc. www.maximintegrated.com Maxim Integrated │  2 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Component Suppliers SUPPLIER PHONE WEBSITE API Delevan 408-865-0344 www.delevan.com Bourns, Inc. 408-496-0706 www.bourns.com Citizen America Corp. 310-781-1460 www.citizencrystal.com Fairchild Semiconductor 888-522-5372 www.fairchild.com Hirose Electric Co., Ltd. 81-3-3491-9741 www.hirose.com Kobiconn 800-346-6873 www.mouser.com/kobiconn Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com NXP Semiconductors 408-474-8142 www.nxp.com Panasonic Corp. 800-344-2112 www.panasonic.com Sullins Electronics Corp. 760-744-0125 www.sullinselectronics.com Susumu International USA 208-328-0307 www.susumu-usa.com Note: Indicate that you are using the MAX5216LPT when contacting these component suppliers. Quick Start Required Equipment ● MAX5216LPT EV kit ● The EV kit board is a plug-n-play device that connects to the PC through a USB-A to Mini-B cable. ● The EV kit is preloaded with the default firmware that communicates with the MAX5216LPT evaluation software. Software can be installed and run on Windows XP, Windows Vista, and Windows 7-based systems. 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 operating system. Procedure The EV kit is fully assembled and tested. Follow the steps below to verify board operation: 1) Visit www.maximintegrated.com/design/tools/ applications/evkit-software/ to download the latest version of the EV kit software, MAX5216LPTGUIVxx. ZIP. Unzip the file and run the setup.exe. Follow the instructions to install the evaluation software on your PC. The program files are copied and icons are created in the Windows Start | Programs menu. 2) Connect the MAX5216LPT to the PC though a USB cable. No additional driver is needed; Windows recognizes the new device as a human interface device (HID) and automatically finds and installs the appropriate driver for it. For more information, check the device properties in: www.maximintegrated.com Figure 1. USB Input Device Properties Device Manager\Human Interface Control\USB Input Device\Properties - > USB\VID_0B6A&PID_1234. See Figure 1. 3) Run the MAX5216LPT.exe program. The application’s GUI appears, as shown in Figure 2. Maxim Integrated │  3 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter RUN BUTTON STOP BUTTON Figure 2. MAX5216LPT GUI Detailed Description of Software The MAX5216LPT EV kit GUI (Figure 2) is active by default. The application checks all the boards with the USB VID/PID 0x0B6A /0x1234 that connected to the PC and indicates them on the right side of the GUI. Up to 16 boards can be connected to the system. Each board has its own unique board index. Select the appropriate board index from the Board index spin box (Figure 3). The EV kit board has to be calibrated first for proper operation. Connect an external 12V to 40V power supply between the LOOP+ (TP1) and LOOP- (TP2) test points or to the J10 connector (see the Figure 13a schematic). www.maximintegrated.com It is strongly recommended to use an isolated power supply. Connect a precision digital voltmeter (DVM) across the precision load. The on-board 100Ω 0.1% R7 resistor can be used as precision load for quick calibration. In this case, remove the J9 shunt and place the DVM across the J9 header. With the 100Ω load, the DVM should display less than 0.350V. This means that the board consumes less than 3.5mA current. Move the track-bar slider to the right until the DVM displays approximately 0.4V. Use the up/down arrow buttons next to Code control spin box to fine tune to an exact 400mV drop across the R7 sense resistor. Type that code into the Calibration Code group box in the field labeled 4mA Code. Maxim Integrated │  4 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter MATCH Figure 3. Select the Board Index in the System with the Multiple Boards Continue the same procedure to find the calibration code for 20mA loop current. The DVM indicates 2.000V across R7 when loop current reaches 20mA. Type in the 20mA code into the Calibration Code group box in the field labeled 20mA Code. The loop current can also be set by typing in a decimal, hexadecimal, or an octal or a binary value in the Code Control spin box (Figure 4). The board accepts codes from 0 to 65535 (216-1) decimal or from 0 to FFFF hex. The notation is displayed on the left side of the box. www.maximintegrated.com Now when the track-bar slider position is changed, the correct current is indicated in the Loop current box of the GUI. The calibration code for 4mA and 20mA loop current can be written on the board itself to avoid calibration procedures in the future, as shown in Figure 5. The same procedure can be continued to find the appropriate code for 24mA loop current, if applicable. Maxim Integrated │  5 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Figure 4. Notation Selection Dialog Box www.maximintegrated.com Maxim Integrated │  6 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Figure 5. MAX5216LPT Board www.maximintegrated.com Maxim Integrated │  7 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Detailed Description of Hardware The MAX5216LPT EV kit board is loaded with the MAX5216, Maxim’s best-in-class lowest power 16-bit DAC (U1), the MAX6133A25 voltage reference (U3), the MAX9620 zero-drift, RRIO high-precision op amp (U2), and the MAX15007 40V low-quiescent current LDO (U4). See the block diagram in Figure 6 and the schematics in Figures 13a and 13b. The on-board MAX6133A25 (U3) provides low temperature drift of 3ppm/°C, low quiescent current, and 2.500V precise voltage reference for the DAC. The MAX5216 (U1) receives a command from the 16-bit MAXQ622 microcontroller (U5) through a 3-wire high-speed SPI bus, which emulates the smart sensor; then its output is divided and converted into the loop current by the MAX9620 (U2) op amp, Q1 power MOSFET, and 10Ω ±0.1% sense resistor (RSENSE). The U1–U3 devices are powered by the MAX15007, a 3.3V low-noise LDO voltage regulator (U4), which gets power from an external power supply. There is a current-limiting circuitry made on the Q2 BJT transistor and sense resistor R6. This circuitry limits the loop current to approximately 30mA, which prevents runaway conditions and damaging an ADC on the programmable logic controller (PLC) side. The Schottky diode (D1) and transient voltage suppressor (D2) are safety devices that protect the transmitter from reverse current flow and overvoltage surge conditions. The U1 device can run at 50MHz clock frequency, but the SPI bus speed is limited to 6MHz on this board by the U5 microcontroller. The evaluation software allows setting the loop current through the full-speed USB 2.0 bus and the U5 microcontroller. The microcontroller is preloaded with the firmware that communicates with the GUI. 3.3V VREF 2.5V U3 U4 MAX6133 MAX15007 R3 2MΩ VDD SMART SENSOR SPI VREF U1 MAX5216 16-BIT, DAC R1 287kΩ U2 MAX9620 301Ω GND RB571S40 4–20mA CURRENT LOOP Q1 NDT014L ∞ LOOP POWER 12V TO 40V Q2 MMBT3904 R6 24.3Ω R2 24.9kΩ RSENSE 10Ω RLOAD DAC Figure 6. MAX5216LPT EV Kit Block Diagram www.maximintegrated.com Maxim Integrated │  8 MAX5216LPT Evaluation Kit Principles of Operation and Key Design Parameters The block diagram shown in Figure 6 allows for the designing of a high-performance, low-power, low component count 4–20mA current-loop transmitter that gives the best result for the price vs. performance solution. The low-power, high-performance components need to be selected to meet the 0.1% current-error requirements of the 4–20mA current loop. The maximum current consumption of the selected components is less than 300µA over -40ºC to +105ºC temperature range. In addition to low power, the 25µV (max) zero-drift input offset voltage over time and temperature of the MAX9620 makes this op amp ideal for the accuracy and stability of this circuitry. The U2 op amp is tracking the voltage drop across the R2 and RSENSE resistors and maintains 0V at both its input nodes. The following equations are used for this circuitry: = I(R2) × I OUT R2 R SENSE I(R2) = I(R1) + I(R3) EQ1 Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter According to Namur NE43 recommendations for failure information transmitted over 4–20mA current loop, the signal range for measurement information is from 3.8mA to 20.5mA, allowing for a small amount of linear overrange process readings. The actual supported range of this board is from 3.2mA to 24.6mA. Solving the EQ4 for R3 having: R2 R3 = VREF × 2.5 = R SENSE × I OUT INIT × Since the cost to maintain the exact 1.945MΩ resistor is too high and is not well suited for the automated production and easy field calibration, it is recommended to use a regular 1% tolerance resistor and regain the accuracy by calibrating out the 4mA offset current and the 20mA fullscale current by the U1 DAC. In this case, some digital codes are used for calibration purposes to maintain the required accuracy. V × CODE I(R1) = REF 65535 × R1 IOUT is the loop current, I(R2) is the current flowing through the R2 resistor, I(R1) is the current flowing through the R1 resistor, and I(R3) is the current flowing through the R3 resistor. In EQ2, we assume that the input current to IN+ and to IN- of U2 is 0. According to EQ1 and EQ2, the initial loop current of 4mA is set by the I(R3) current, while I(R1) is 0. Thus: INIT R2 R SENSE EQ3 Current through the R3 resistor is equal to the U3 output divided by R3, and equation EQ3 can be overwritten as follows: = I OUT INIT VREF R2 × R3 R SENSE www.maximintegrated.com EQ5 The I(R1) = VDAC/R1, where VDAC is the U1 DAC output voltage, and can be overwritten as: EQ2 where: I OUT= I(R3) × 24.9 × 10 3 1.945 × 10 6( Ω ) = 10 × 3.2 × 10 −3 EQ4 EQ6 And: V I(R3) = REF R3 EQ7 Finally, the EQ1 can be overwritten as: 1 R2  CODE I OUT= VREF ×  + ×   65535 × R1 R3  R SENSE EQ8 The error analysis of passive components and VREF of the 4–20mA current-loop transmitter based on EQ8 can be seen in Table 1. Note: The 4–20mA Transmitter Design Calculator/Error Analyzer spreadsheet is available at www.maximintegrated.com/design/tools/calculators/product-design page. It is recommended to use the What-If Analysis/ Goal-Seek feature from the Data tab to find the appropriate code for 4mA, 20mA, and 24mA IOUT. Maxim Integrated │  9 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Table 1. 4–20mA Current-Loop Transmitter Error Analysis COMPONENT TOL (±%) MINIMUM NOMINAL MAXIMUM UNITS VREF 0.04 2.4990 2.5000 2.5010 V R1 0.1 286.71 287 287.29 kΩ R2 0.1 24.88 24.9 24.92 kΩ R3 1 1980.00 2000 2020.00 kΩ RSENSE 0.1 0.00999 0.0100 0.01001 kΩ — — MINIMUM NOMINAL MAXIMUM UNITS 0 0 0 Decimal Zero-scale IOUT 3.07430 3.11250 3.15149 mA 4mA DAC code 2806 2682 2555 Decimal 3.99984 4.00015 3.99999 mA 65535 65535 65535 Decimal 24.69058 24.8024 24.91527 mA Zero-scale DAC code 4mA IOUT Full-scale DAC code Full-scale IOUT 20mA DAC code 20mA IOUT 51314 51025 50734 Decimal 19.99988 20.00007 19.99995 mA 4mA error -0.00410 0.00381 -0.00016 % FS 20mA error -0.00061 0.00035 -0.00026 % FS 63441 63111 62779 Decimal 23.99989 24.00013 24.00002 mA 24mA IOUT DAC code 24mA IOUT Note: Shaded cells indicate TBD. In this case, having the standard 1% tolerance 2MΩ R3 resistor, and setting the U1 to 2682 decimal code, the initial loop current of 4.00015mA is maintained. Note that the total calculated error is much less than the tolerance of the individual components due to it being calibrated out by the high-resolution U1 DAC. The effective number of bits (ENB) for a 4–20mA current-loop transmitter can be calculated as: ENB = There are other sources of error that need to be addressed, such as ±25µV of VOS of the U2 op amp and the temperature coefficients of each component. The typical characterization data of the MAX5216LPT 4–20mA current-loop transmitter is presented in Figures 7–12. The loop current is measured by an Agilent-HP3458A DVM as voltage drop across the loop load /sense resistor of 249Ω. LOG(20mA DAC CODE − 4mA DAC CODE) LOG(2) and based on the data from Table 1, the ENB = 15.56 bits. www.maximintegrated.com Maxim Integrated │  10 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter 0.2 0.02 0.1 12V 0 ERROR (% FS) ERROR (% FS) 0.01 24V -0.01 -0.02 4mA 8mA 12mA 16mA 20mA -0.1 36V 0 10k 20k 0 30k 40k 50k -0.2 60k -40 -20 DAC CODE (DECIMAL) 40 60 80 100 Figure 9. Transmitter Error Change vs. Temperature with 12V Loop Supply 0.2 0.2 0 -0.1 4mA 8mA 12mA 16mA 20mA 0.1 ERROR (% FS) 4mA 8mA 12mA 16mA 20mA 0.1 ERROR (% FS) 20 TEMPERATURE (°C) Figure 7. Transmitter Error at +25ºC -0.2 0 0 -0.1 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) Figure 8. Transmitter Error Change vs. Temperature with 24V Loop Supply www.maximintegrated.com -0.2 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) Figure 10. Transmitter Error Change vs. Temperature with 36V Loop Supply Maxim Integrated │  11 Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter 40 40 35 35 LOOP CURRENT (mA) LOOP CURRENT (mA) MAX5216LPT Evaluation Kit 30 25 20 -40°C +0°C +25°C 12 16 20 24 28 +60°C +85°C +105°C 32 36 25 20 40 12V 16V 20V 24V 28V 32V 36V 40V 30 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) LOOP VOLTAGE (V) Figure 11. Current Limit vs. Loop Voltage Supply Figure 12. Current Limit vs. Temperature MAX5216LPT Extended Features 5) The board is ready for HART interface to exchange data over 4–20mA current loop using the DS8500-KIT HART modem. Simply connect the FSKOUT pin (P2.3) of the modem to TP10, modem’s GND (P2.5) to TP11, and FSKIN pin (P2.2) to TP12. Connect the P2.1 pin (V33) of the DS8500 EV kit board to TP4 (3.3V). Use the digital interface to send and receive the data. Refer to the DS8500 IC data sheet and the DS8500-EV kit data sheet for more info. 1) The board quiescent current is about 200µA (typ), which allows consuming up to 3.4mA by smart sensor. This current can be measured by a DVM connected across R7 while the J7 shunt is removed and U1 code is 0. Removing the J7 shunt eliminates 4mA offset current. 2) The 4mA offset current is independent from the actual current consumption by the smart sensor. An additional 1mA can be added by placing the J11 shunt, but the 4mA offset current (400mV across R7) does not change. 3) The current-limiting condition can be forced by placing the J8 shunt from the default position of 1-2 to position 2-3. The microcontroller on the EV kit board can also be programmed with custom firmware through the J2 JTAG connector (see Table 2). Table 2. JTAG Connector Description (J2) PIN LABEL 1 TCK Test clock 2 GND Digital ground 3 TDO Test data output ● Remove the J3–J5 shunts (see Figure 10 for component placement). 4 N.C. No connect 5 TMS Test mode select ● Connect the SPI lines, CS, SCLK, MOSI, and VGND from TP5–TP8 to the external host controller. Ensure that the input voltage (VIH) is within the spec limit and matches 3.3V level. Note that digital isolation might be necessary for proper operation. 6 RST Reset 7 N.C. No connection 8 +5V +5V from the JTAG debug adapter 9 TDI Test data input ● Send a command to the DAC. 10 GND Digital ground 4) The board can be evaluated over the full SPI bus speed range with an external SPI host controller. To do so, the following board modifications must be made: www.maximintegrated.com FUNCTION Maxim Integrated │  12 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Figure 13a. MAX5216LPT EV Kit Schematic (Sheet 1 of 2) www.maximintegrated.com Maxim Integrated │  13 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Figure 13b. MAX5216LPT EV Kit Schematic (Sheet 2 of 2) www.maximintegrated.com Maxim Integrated │  14 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter 1.0” Figure 14. MAX5216LPT EV Kit Component Placement Guide—Assembly Drawing Top www.maximintegrated.com Maxim Integrated │  15 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter 1.0” Figure 15. MAX5216LPT EV Kit Component Placement Guide—Assembly Drawing Bottom Contact the Support Center at https://support.maximintegrated.com/designdesk/index.mvp for full layout drawings and/or a Gerber file for the MAX5216LPTEVKIT board. www.maximintegrated.com Maxim Integrated │  16 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Ordering Information PART TYPE MAX5216LPT# EV Kit #Denotes RoHS compliant. www.maximintegrated.com Maxim Integrated │  17 MAX5216LPT Evaluation Kit Evaluates: Reference Design of 4 –20mA Loop-Powered Transmitter Revision History REVISION NUMBER REVISION DATE 0 5/13 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. © 2013 Maxim Integrated Products, Inc. │  18