Evaluates: MAX14001 MAX14001PMB. General Description. Features. Contents. MAX14001PMB Photo

Transcription

1 General Description The MAX peripheral module provides the hardware to evaluate the MAX isolated ADC to measure two channels of data, line voltage (up to 3V AC or ±35V DC) and load current (up to 5A). All power and communication is with a simple USB cable no separate field side power is required. The integrated DC-DC converter provides power isolation for the system and powers all field-side circuitry. This integrated design reduces the BOM and board dimension for building an isolated ADC system. Refer to the MAX IC data sheet for detailed information regarding operation of the IC. The MAXPMB has a -pin Pmod -compatible connector for SPI communication. The peripheral module can be used in various ways. Maxim sells a low-cost USBPMB adapter board that uses the Munich GUI software for communication through a USB cable. This is not included with this board, but is available from Maxim or one of our distributors. Alternatively, any microcontroller or FPGA with a -pin Pmod-compatible connector for SPI communication can be used. Features Easy Evaluation of the MAX/MAX 3.75kV RMS Isolation for Both Data (SPI) and Power (DC-DC Supply) Peripheral Module Is Powered from a Single 3.3V Supply (USBPMB Is USB-Powered), No Field Side Supply Required Measure AC or DC, Voltages Up to 3V AC or ±35V DC and Current Up to 5A Programmable Comparator Output Works With USBPMB Adapter and Munich GUI Software Fully Assembled and Tested Proven PCB Layout RoHS Compliant Contents MAXPMB, including two MAXs Ordering Information appears at end of data sheet. MAXPMB Photo Pmod is a trademark of Digilent Inc ; Rev ; 3/7

2 Quick Start Required Equipment MAXPMB peripheral module USBPMB adapter board Micro-USB cable Windows XP, Windows 7, Windows 8., or Windows PC with a spare USB port Note: In the following sections, software-related items are identified by bolding. Text in bold refers to items directly from the EV system software. Text in bold and underline refers to items from the Windows operating system. Procedure If the USBPMB adapter is used, download software by following the steps below to get started: ) Visit /evkitsoftware to download the latest version of the Munich_GUI software, version. or later, Munich_GUISetupV..ZIP. ) Save the software to a temporary folder. Unzip the.zip file and double-click the.exe file to run the installer. A message box asking Do you want to allow the following program to make changes to this computer? can appear. If so, click Yes. 3) The installer includes the drivers for the hardware and software. Follow the instructions on the installer and once complete, click Finish. The default location of the software is in the program files directory. ) Connect the MAXPMB Pmod connector X to the connector on USBPMB. 5) Connect the USBPMB to the PC with the Mini-USB cable. Windows should automatically recognize the device and display a message near the System Icon menu indicating that the hardware is ready to use. 6) Once the hardware is ready to use, launch the software. The status bar in the GUI should display Disconnected in the bottom right-hand corner. Go to the Device tab to select the MAXPMB. Detailed Description of Software Connect to Hardware The Device menu has options to search and connect to the hardware. Use the Scan Adapters option to search for the USBPMB modules connected to the PC. If modules are found, the serial numbers of the modules are listed in the USBPMB adapter drop-down list. Select the serial number in the USBPMB s list to connect the software to communicate with that module. The software can only communicate to one module at a time. Sample To start continuous monitoring, click the Sample Continuously button (see Figure ). For a single status, click the Sample Once button. Moving the cursor over the graph area allows the user to select channel type (voltage or current), change scale, zoom, print, or save waveforms. Detailed Description of Hardware The MAXPMB peripheral module has two MAX devices (U and U5). One channel is configured to measure the line voltage with maximum voltage range selected by a resistor chain. The other channel is configured to measure the voltage across a shunt resistor to provide load current. Both AC and DC signals can be measured. No external field side (high voltage) power is required as the MAX has an integrated, isolated DC-DC converter. The complete peripheral module is powered from a single 3.3V supply,, which is called the logic side (or low voltage side). If the USBPMB module is used this takes power from the 5V supply on the USB connector to the PC. The SPIcompatible connector uses two chip-select signals (CS and CS) to control each chip through a single connector/ GUI interface. MAX Isolated ADC The MAX has a free-running, -bit SAR ADC, sampling at ~ksps, that continously updates the data register for each new conversion. If the source being monitored is DC or low-frequency AC (such as 5Hz or 6Hz mains) this sample rate easily meets the Nyquist criteria and, although the two ADCs are not synchronized, the reading can be considered to be simultaneous given the relatively high sample rate. The device digitizes the input voltage on the field side and transmits the data across the isolation barrier to a data receiver on the logic side; which also has a programmable comparator. The host can read the ADC value from the data receiver through the SPI interface. Additionally, the comparator compares the digitized reading to the programmable thresholds and outputs high if data is above the upper threshold, and low if data is below the lower threshold. This hardware feature is extremely use- Windows and Windows XP are registered trademarks and registered service marks of Microsoft Corporation. Maxim Integrated

3 ful for setting real-time trip points, or as demonstrated, it can be used to measure periodic signals. For example, the frequency of the field-side input voltage can be easily calculated using zero-crossing of the comparator output. AC or DC Line Monitor Application To demonstrate the features and ease-of-use of the MAX, this peripheral module shows how to build an isolated ADC and provides software demonstrating how it can be used to measure mains power, such as a V, 6Hz single-phase load or 3V, 5Hz single-phase load, with currents of a few amps. The MAX peripheral module uses two MAXs, one to measure the voltage and another to measure current. The whole board is controlled and powered by the USBPMB adapter that uses the USB power from a PC. The live (L) and neutral (N) lines are input to the board and a fuse on the board protects circuits from large currents. Loads can be connected to the board from the terminal connectors. Logic Versus Field Side The MAXPMB hardware has two channels, one to measure voltage and one to measure current, as well as three power domains with different isolated ground potentials: The logic side or low-voltage side connects to the SPI-compatible Pmod connector, and is powered from a single 3.3V source connected to, referred to logic ground. The current measurement field side, U5 provides field-side power from F, which is nominally 3V and can power circuitry up to 7µA. This single supply is used to power the ADC field side circuitry in addition to the external signal conditioning from ultralow bias MAX65 op amp (U53) and precision voltage reference MAX66 (U5). All signals are referenced to Field Ground or GNDF. The voltage measurement field side, U provides field-side power from F, which is nominally 3V and can power circuitry up to 7µA. This single supply is used to power the ADC field side circuitry, in addition to the precision voltage reference MAX66 (U). All signals are referenced to Field Ground or. Note: GNDF and are floating grounds only and do not have the same potential or provide earthed protection. Shunt Reference The MAX has an integrated voltage reference; however, for this application, which measures AC signals, both the positive and negative values need to be read. Therefore, an external.5v shunt reference MAX66 is used for each ADC with a DC offset of V REF / so the negative part of the AC input is shifted above ground, ensuring the AIN signal input is within the accepted positive voltage range. The control registers within each MAX are set for external voltage reference source and for pin REFIN to be a current source output, which connects to the MAX66. Current Measurement The current ADC measures the voltage across a small mω sense resistor (R5) in the live wire to obtain the live line current value. The MAX accepts and analog input voltage from to +VREFIN. U5 (MAX66) is an ultra-low power shunt.5v voltage reference that draws on µa, which is used instead of the on-chip voltage reference to bias the input AIN at a midpoint to allow AC or positive and negative input signals. U53 (MAX65) is an ultra-low µa supply current op amp with an ultra-low pa input bias current. This op amp is configured as an inverting op amp with a gain of, with its input centered around V REF / or.6v. The amplified voltage across the sense resistor is ±.5mV, allowing head room for the maximum input range of the ADC. Voltage Measurement A voltage divider is used comprising R R6 in conjunction with U voltage reference and R R. This limits the input voltage seen at pin AIN of U to <.5V and centers it around V REF /. The MAX accepts positive voltage inputs at AIN from.5v with respect to AGND, so the sense resistor and resistor dividers need to be selected based on input RMS voltage and maximum RMS. Resistor values are selected so that it is close to but not exceeding the calculated ratio to utilize the full ADC range. R R6 should be larger than MΩ to ensure low current and low power consumption. Pmod-Style Connector The MAXPMB can plug directly into a Pmodcompatible port through X. The pin defintions are SPIcompatible; see Figure for the X pinout. The ADC readings are transmitted to the USBPMB adapter by the SPI interface. Maxim Integrated 3

4 Figure. MAXPMB Software (Munich GUI Tab) Maxim Integrated

5 CURRENT-MEASUREMENT UP TO 5A R5. R59 C5.7UF X 7736 GNDF VOLTAGE-MEASUREMENT UP TO 3V AC OR +/-35V DC 3VAC / +/-35V J OPEN / J OPEN 5VAC / +/-77V J CLOSED / J OPEN VAC / +/-56V J CLOSED / J CLOSED +/-V J CLOSED / J CLOSED / R7 = 68KOHM R7 68K J DNI DNI M M M 3V AC C VP+ = 35V VP- = -35V 68PF R R5 R6 M M DNI M M.UF MAX66AEUR+ OUT GNDF AIN R55 K C56 8PF GNDF C5.UF GNDF F PF GNDF C53 C5.UF PF GNDF GNDF C.UF PF UF UF.7K K SML-PPT K C5 PF.7K TSW-6-8-S-D-RA F R6 R6 8A K K R R R3 M J R53 R5.9K R3 K R K.UF C R56 5.6K F R5 39K U5 MAX C55 PF ISET L GNDF 9 AIN FAULT 8 AGND COUT 7 REFIN CS 6 IC SCLK 5 IFET DIN GATE DOUT 3 9 F GNDF C57 R5 U MAX C7 C3 C.UF PF C58 C8 R57 R7 X R LED R5 F VIN VOUT GND F R C5 R58 U MAX66AEUR+ U5 OUT 3 I.C. GND VOLT-IN F FAULT COUT CS SCLK MOSI MISO FAULT COUT CS SCLK MOSI MISO SCLK MISO MOSI CS FAULT COUT COUT CS A B C C A R6 K GND VOUT A VIN GND B U53 MAX65EWT+ IN+ SHDN OUT C IN- VSS I.C. GND 9 ISET L GNDF 9 3 AIN FAULT 8 AGND COUT 7 REFIN CS 6 IC SCLK 5 IFET DIN 8 GATE DOUT 3 F GNDF MAXPMB Figure. MAXPMB Schematic Maxim Integrated 5

6 Figure 3. MAXPMB PCB Layout SilkscreenTop Figure. MAXPMB PCB Layout Top Figure 5. MAXPMB PCB Layout Bottom Figure 6. MAXPMB PCB Layout Silkscreen Bottom Maxim Integrated 6

7 MAXPMB Bill of Materials ITEM REF_DES DNI/DNP QTY MFG PART # MANUFACTURER VALUE DESCRIPTION CAPACITOR; SMT (); CERAMIC CHIP; 68PF; C - TMK5BJ68KVH TAIYO YUDEN 68PF 5V; TOL=%; TG=-55 DEGC TO +85 DEGC; TC=X5R; AUTO C, C3, C53-3 CGAB3X7RVK5BB TDK.UF CAPACITOR; SMT (); CERAMIC CHIP;.UF; 35V; TOL=%; TG=-55 DEGC TO +5 DEGC; TC=X7R; AUTO 3 C, C5 - C5X7RC3K5BA TDK.UF C, C5, C7, C5, C55, C57-6 GRM555CEJAD; C5CGEJ5BA MURATA; TDK 5 C8, C58 - CLB6KOQNNN SAMSUNG ELECTRONICS UF 6 C5 - C85C7K3RAC; GRMBR7E7KA; CX7RE7K KEMET; MURATA; TDK 7 C5 - GRM55R7EKE MURATA.UF PF 8 C56 - CX7R58KNP VENKEL LTD. 8PF.7UF CAPACITOR; SMT (); CERAMIC;.UF; 6V; TOL=%; TG=-55 DEGC TO +5 DEGC; TC=X7R CAPACITOR; SMT (); CERAMIC CHIP; PF; 5V; TOL=5%; TG=-55 DEGC TO +5 DEGC; TC=CG CAPACITOR; SMT (85); CERAMIC CHIP; UF; 6V; TOL=%; TG=-55 DEGC TO +5 DEGC; TC=X7R CAPACITOR; SMT (85); CERAMIC CHIP;.7UF; 5V; TOL=%; TG=-55 DEGC TO +5 DEGC; TC=X7R; CAPACITOR; SMT (); CERAMIC CHIP;.UF; 5V; TOL=%; MODEL=GRM SERIES; TG=-55 DEGC TO +5 DEGC; TC=X7R CAPACITOR; SMT; ; CERAMIC; 8pF; 5V; %; X7R; -55degC to + 5degC; +/-5% degc MAX. 9 F - 685F8 BEL FUSE 8A FUSE; SMT (6); FAST ACTING; IC=8A; VC=5V LED - SML-PPT ROHM R - CRCWKFK VISHAY DALE K R - ERJ-GNF9C PANASONIC.9K 3 R3, R - CRCW85KFK VISHAY DALE K R5, R55 - ERJ-GNF3 PANASONIC K 5 R7, R57 - MCR6YRTF7 ROHM SEMICONDUCTOR.7K 6 R-R6-6 ERJ-RKF PANASONIC M 7 R5 - PMR8EZPFUL ROHM SEMICONDUCTOR. 8 R5, R58, R59-3 CRCW85ZS; ERJ-6GEYRV; RCJ; RMCF85ZTR VISHAY DALE/PANASONIC/STACKPOLE ELECTRONICS INC 9 R5 - ERJ-GEF39C PANASONIC 39K R53, R5 - CRCW85MFK; RC85FR-7ML VISHAY DALE/YAGEO PHICOMP M R56 - ERJ-GEF56C PANASONIC 5.6K R6, R6 - ERJ-GEFC PANASONIC K 3 R6 - ERJ-GEF3C PANASONIC K U, U5 - MAX MAXIM 5 U, U5 - MAX66AEUR+ MAXIM 6 U53 - MAX65EWT+ MAXIM 7 X - TSW-6-8-S-D-RA SAMTEC SML- PPT MAX 8 X PHOENIX CONTACT 7736 DIODE; LED; SML-P SERIES; ULTRA COMPACT HIGH BRIGHTNESS LED; GREEN; SMT (); VF=.V; IF=.A RESISTOR; ; K OHM; %; PPM;.5W; RESISTOR; ;.9K OHM; %; PPM;.5W; RESISTOR; 85; K OHM; %; PPM;.5W; RESISTOR; ; K OHM; %; PPM;.5W; RESISTOR; ;.7K OHM; %; 5PPM;.5W; RESISTOR; ; M OHM;%; PPM;.W; RESISTOR; 6;. OHM; %; PPM; W; METAL FILM RESISTOR; 85; OHM; JUMPER;.5W; THICK FILM RESISTOR; ; 39K OHM; %; PPM;.5W; 3-LAYER ELECTRODE RESISTOR; 85; M; %; PPM;.5W; THICK FILM RESISTOR; ; 5.6K OHM; %; PPM;.5W; 3-LAYER ELECTRODE RESISTOR; ; K OHM; %; PPM;.5W; 3-LAYER ELECTRODE RESISTOR; ; K OHM; %; PPM;.5W; 3-LAYER ELECTRODE EVKIT PART - IC; MAX; PACKAGE OUTLINE DEVICE: -56; PACKAGE CODE AS-6 MAX66 IC; VREF; UA SOT3 PRECISION SHUNT VOLTAGE AEUR+ REFERENCE; SOT3 MAX6 IC; OPAMP; RAIL-TO-RAIL; KHZ OP AMP WITH 5EWT+ SHUTDOWN; WLP6.9X.3 TSW-6- CONNECTOR; THROUGH HOLE; POST TERMINAL 8-S-D-RA STRIP ASSEMBLY; RIGHT ANGLE; PINS; CONNECTOR; FEMALE; THROUGH HOLE; GREEN PCB TERMINAL BLOCK; STRAIGHT; PINS 9 PCB - MAX_DEMO_A MAXIM PCB PCB:MAX_DEMO_A 3 J DNP CRCW85ZEAHP VISHAY DRALORIC RESISTOR; 85; OHM; %; JUMPER;.5W; THICK FILM 3 J DNP CRCW63ZS; MCR3EZPJ; ERJ- RESISTOR; 63; OHM; %; JUMPER;.W; VISHAY DALE/ROHM/PANASONIC 3GEYR 3 R7 DNP ERJ-RKF683X PANASONIC 68K RESISTOR,, 68K OHM, %, PPM,.65W, NOTE: DNI--> DO NOT INSTALL(PACKOUT) ; DNP--> DO NOT PROCURE Maxim Integrated 7

8 Ordering Information PART MAXPMB# #Denotes RoHS compliant. TYPE Peripheral Module Maxim Integrated 8

9 Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 3/7 Initial release For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit Maxim Integrated s website at. 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. 7 Maxim Integrated Products, Inc. 9