Analog Devices: CN0188 Reference Design for Low Cost, Level Shifted Low Side Current Monitor for Negative High Voltage Rails

Kit Overview   The EVAL-CN0188-SDPZEVAL-CN0188-SDPZ is a Low Cost, Level Shifted Low Side Current Monitor for Negative High Voltage Rails. The evaluation circuit  monitors current in individual channels of −48 V to better than 1% accuracy. The load current passes through a shunt resistor, which is external to the circuit. The shunt resistor value is chosen so that the shunt voltage is approximately 50 mV at maximum load current.   The measurement result from the AD7171AD7171 is provided as a digital code utilizing a simple 2-wire, SPI-compatible serial interface. The entire circuit operates on a single +3.3 V supply. Optional galvanic isolation is provided by the ADuM5402 quad channel isolator. In addition to isolating the output data, the ADuM5402ADuM5402 digital isolator can also supply isolated +3.3 V for the circuit. The ADuM5402 is not required for normal circuit operation unless galvanic isolation is needed.   This combination of parts provides a accurate high voltage negative rail current sense solution with a small component count, low cost, and low power. The accuracy of the measurement is primarily determined by resistor tolerances and the accuracy of the band gap reference, and is typically better than 1%.   The evaluation circuit uses the EVAL-CN0188-SDPZEVAL-CN0188-SDPZ circuit board and the EVAL-SDP-CB1ZEVAL-SDP-CB1Z System Demonstration Platform (SDP-B) evaluation board (Should be purchased separately). The two boards have 120-pin mating connectors, allowing for the quick setup and evaluation of the circuit’s performance. The EVAL-CN0188-SDPZ board contains the circuit to be evaluated and the SDP evaluation board is used with the CN0188 evaluation software to capture the data from the EVAL-CN0188-SDPZ circuit board.   Key Applications: Metering & Energy Monitoring, Power Supplies

More Development Kits and Tools More Analog Devices Analog Development Kits Analog Devices MCU based Development Kits Development Platforms & Kits element14 Knode

Development Tools

• PC with a USB port and Windows XP or Windows Vista (32-bit), or Windows 7 (32-bit) 
• EVAL-CN0188-SDPZEVAL-CN0188-SDPZ circuit evaluation board 
• EVAL-SDP-CB1ZEVAL-SDP-CB1Z SDP evaluation board

• CN0188 evaluation software 
• Power supply: +6 V, or +6 V “wall wart” 
• Shunt resistor with maximum voltage of 50 mV at the maximum load current. 
• Electronic load

Back to top

Technical Documents

Learning Center

Design Elements

Back to top

Video

Video1

Video2

You don't have permission to edit metadata of this video. Edit media Dimensions x Small Medium Large Custom Subject (required) Brief Description Tags (separated by comma) Video visibility in search results Visible Hidden Parent content Analog Devices: CN0204 Reference Design for Flexible, High Voltage, High Accuracy, Low Drift PLC/DCS Analog Output Module Analog Devices: CN0188 Reference Design for Low Cost, Level Shifted Low Side Current Monitor for Negative High Voltage Rails Poster Upload Preview Ok Cancel

You don't have permission to edit metadata of this video. Edit media Dimensions x Small Medium Large Custom Subject (required) Brief Description Tags (separated by comma) Video visibility in search results Visible Hidden Parent content Analog Devices: CN0235 Reference Design for Fully Isolated Lithium Ion Battery Monitoring and Protection System Analog Devices: CN0225 Reference Design for High Impedance, High CMR, ±10 V Analog Front End Signal Conditioner for Industrial Process Control and Automation Analog Devices: CN0178 Reference Design for Software-Calibrated, 50 MHz to 9 GHz, RF Power Measurement System Analog Devices: CN0202 Reference Design for Flexible, High Accuracy, Low Drift, PLC/DCS Analog Output Module Analog Devices: EVAL-AD7291SDZ Evaluation Board for the AD7291 12-Bit SAR ADC with Temperature Sensor Analog Devices: CN0216 Reference Design for Precision Weigh Scale Design Using the AD7791 24-Bit Sigma-Delta ADC with External ADA4528-1 Zero-Drift Amplifiers Analog Devices: EVAL-AD5790SDZ Evaluation Board for the AD5790 20-Bit Voltage Output DAC Analog Devices: EVAL-AD5421SDZ Evaluation Board for the AD5421 16-Bit, Serial Input, Loop-Powered DAC Analog Devices: CN0271 Reference Design for K-Type Thermocouple Measurement System with Integrated Cold Junction Compensation Analog Devices: CN0206 Refernce Design for Complete Type Thermocouple Measurement System Analog Devices: CN0189 Reference Design for Tilt Measurement Using a Dual Axis Accelerometer Analog Devices: CN0204 Reference Design for Flexible, High Voltage, High Accuracy, Low Drift PLC/DCS Analog Output Module Analog Devices: CN0209 Reference Design for Fully Programmable Universal Analog Front End for Process Control Applications Analog Devices: CN0240 Reference Design for Bidirectional Isolated High-Side Current Sense with 270 V Common-Mode Rejection Analog Devices: CN0229 Reference Design for 4-Channel, Flexible, Configurable, Voltage, and Current Output Circuit for I/O Card and PLC Applications Analog Devices: EVAL-AD5755-1SDZ Evaluation Board for the AD5755-1 16-Bit Voltage Output DAC, Dynamic Power Control, HART Connectivity Analog Devices: EVAL-SDP-CS1Z System Demonstration Platform Controller Board Analog Devices: EVAL-AD5541ASDZ Evaluation Board for the AD5541A Serial-Input, Voltage-Output 16-bit nanoDAC Analog Devices: EVAL-AD5791SDZ Evaluation board for the AD5791 Voltage Output DAC Analog Devices: CN0203 Reference Design for Flexible PLC/DCS Analog Output Module Using AD5750-1 and AD5660-1 Analog Devices: CN0253 Reference Design for A Robust, Low Power, Battery Monitoring Circuit Front End Analog Devices: CN0241 Reference Design for High-Side Current Sensing with Input Overvoltage Protection Analog Devices: EVAL-AD9838SDZ Evaluation Board for the AD9838 Direct Digital Synthesis Analog Devices: EVAL-SDP-CB1Z Evaluation System Controller Board Analog Devices: EVAL-AD7988-5SDZ Evaluation Board for the AD7988-5 Ultra Lower Power 16 bit SAR ADC Analog Devices: CN0234 Reference Design for Single Supply, Micropower Toxic Gas Detector Using an Electrochemical Sensor Analog Devices: CN0261 Reference Design for Optimizing AC Performance in an 18-bit, 250 kSPS, PulSAR Measurement Circuit Analog Devices: EVAL-AD5694RSDZ Evaluation Board for the AD5694(R) Quad Channel Voltage Output DAC Analog Devices: EVAL-AD9837SDZ Evaluation Board for the AD9837 Programmable Waveform Generator Analog Devices: CN0218 Reference Design for 500 V Common-Mode Voltage Current Monitor Analog Devices: ADZS-BRKOUT-EX3 SDP Breakout Board Analog Devices: CN0254 Reference Design for Low Cost, 16-Bit, 250 kSPS, 8-Channel, Isolated Data Acquisition System Analog Devices: CN0255 Reference Design for A Complete Single-Supply, 16-Bit, 100 kSPS PulSAR ADC System Dissipates 8 mW Analog Devices: CN0150A Reference Design for Software Calibrated, 1 MHz to 8 GHz, 60 dB RF Power Measurement System Using the AD8318 Logarithmic Detector Analog Devices: CN0187 Reference Design for Crest Factor, Peak, and RMS RF Power Measurement Circuit Analog Devices: EVAL-AD5780SDZ Evaluation Board for the AD5780 Voltage Output DAC Analog Devices: EVAL-AD7176-2SDZ Evaluation Board for the AD7176-2 Sigma-Delta ADC Analog Devices: CN0194 Reference Design for Galvanically Isolated, 2-Channel, 16-Bit, Simultaneous Sampling, Daisy-Chained Data Acquisition System Analog Devices: CN0188 Reference Design for Low Cost, Level Shifted Low Side Current Monitor for Negative High Voltage Rails Analog Devices: CN0274 Reference Design for Ultralow Power Standalone Motion Switch Analog Devices: CN0251 Reference Design for A Flexible 4-Channel Analog Front End for Wide Dynamic Range Signal Conditioning Poster Upload Preview Ok Cancel

Back to top

Kit Features

Features of EVAL-CN0188-SDPZEVAL-CN0188-SDPZ Current Monitor Evaluation Board:

• Monitors current in individual channels of −48 V to better than 1% accuracy
• Measurement result from the AD7171AD7171 is provided as a digital code utilizing a simple 2-wire, SPI-compatible serial interface
  • Output data rate: 125 Hz
  • Pin-programmable power-down and reset
  • Status function
  • Internal clock oscillator
  • Current: 135 μA
• The shunt voltage is amplified by a factor of 49.7 using U1A, where G = 1 + R3/R2
• The zero-drift  ADA4051-2ADA4051-2 has a low offset voltage (15 μV maximum) and does not contribute significant error to the measurement
  • Very low supply current: 13 μA typical
  • Offset voltage drift: 20 nV/°C
  • High PSRR & CMRR: 110 dB minimum
  • Rail-to-rail input/output
  • Unity-gain stable
• Power supply voltage for the ADR381ADR381, the AD7171AD7171, and the floating zener diode is supplied by the isolated power output (+3.3 V_ISO) of the ADuM5402ADuM5402 quad isolator.
• ADuM5402 Quad-Channel, 2.5 kV Isolators with Integrated DC-to-DC Converter
  • isoPower integrated, isolated dc-to-dc converter Regulated 3.3 V or 5.0 V output
  • Up to 500 mW output power
  • Quad dc-to-25 Mbps (NRZ) signal isolation channels
  • High common-mode transient immunity: >25 kV/μs
• The reference voltage for the AD7171BCPZ-REEL7AD7171BCPZ-REEL7 is supplied by the ADR381 precision band gap reference.
• The ADR381 has an initial accuracy of ±0.24% and a typical temperature coefficient of 5 ppm/°C.
• The input voltage to the AD7171BCPZ-REEL7AD7171BCPZ-REEL7 ADC is converted into an offset binary code at the output of the ADC. The ADuM5402 provides the isolation for the DOUT data output, the SCLK input, and the PDRST input. The code is processed in the PC by using the SDP hardware board and LabVIEW software.

Back to top

Kit Contents

The Analog Devices EVAL-CN0188-SDPZEVAL-CN0188-SDPZ supplied with below contents:

• EVAL-CN0188-SDPZEVAL-CN0188-SDPZ Evaluation Board

Back to top