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Configurable, Isolated 10-bit ADCs for Multi-Range Binary Inputs

Industry's First Integrated Solution for Detection of Multi-Voltage Binary Inputs

Product Details

The MAX14001/MAX14002 are isolated, single-channel analog-to-digital converters (ADCs) with programmable voltage comparators and inrush current control optimized for configurable binary input applications. 3.75kVRMS of integrated isolation is provided between the binary input side (field-side) and the comparator output/SPI-side (logic-side) of the MAX14001/MAX14002. An integrated, isolated, DC-DC converter powers all field-side circuitry, and this allows running field-side diagnostics even when no input signal is present. The 20-pin SSOP package provides 5.5mm of creepage and clearance with group II CTI rating.

These devices continually digitize the input voltage on the field-side of an isolation barrier and transmit the data across the isolation barrier to the logic-side of the device where the magnitude of the input voltage is compared to programmable thresholds. The binary comparator output pin is high when the input voltage is above the upper threshold and low when it is below the lower threshold. Response time of the comparator to an input change is less than 150μs with filtering disabled. With filtering enabled, the comparator uses the moving average of the last 2, 4, or 8 ADC readings. Both filtered and unfiltered ADC readings are available through the 5MHz SPI port, which is also used to set comparator thresholds and other device configuration.

The MAX14001/MAX14002 control the current of a binary input through an external, high-voltage FET. This current cleans relay contacts and attenuates input noise. An inrush comparator monitoring the ADC readings triggers the inrush current, or wetting pulse. The inrush trigger threshold, current magnitude, and current duration are all programmable in the MAX14001 but are fixed in the MAX14002. When the high-voltage FET is not providing inrush current, it switches to bias mode. Bias mode places a small current load on the binary input to attenuate capacitively coupled noise. The level of bias current is programmable between 50μA and 3.75mA in both the MAX14001 and MAX14002. This allows optimization of the tradeoff between noise attenuation and power dissipation.

Design Solution: Isolated ADC with Integrated DC-DC Converter Simplifies Field-Side Circuitry ›

Key Features

  • Enables Robust Detection of Binary Inputs
    • Programmable Input Bias Current Rejects Line Noise
    • 3.75kVRMS of Isolation for 60 Seconds
    • 5.5mm of Creepage and Clearance
    • Group II CTI Package Material
  • Reduces BOM and Board Space Through High Integration
    • 10-bit, 10ksps ADC
    • Binary Threshold Comparators
    • Control Circuit for Driving a Depletion Mode FET
    • Isolation for Both Data and DC-DC Supply
    • 20-SSOP Package
  • Increases Equipment “Up Time” and Simplifies System Maintenance
    • Enables Field-Side Diagnostics
    • Automatic Self-Diagnostics
  • Provides Unparalleled Flexibility
    • Programmable Upper and Lower Input Thresholds
    • Programmable Inrush Current Activation Threshold, Magnitude, and Duration
    • Daisy-Chainable SPI Interface

Applications/Uses

  • Distribution Automation
  • High-Voltage Binary Input (12V–300V)
  • Industrial Control, Multi-Range, Digital Input Modules with Individually Isolated Inputs
  • Substation Automation
Parametric specs for Sensor Interface Devices
Sensor Interface Type Multi-level Binary Input
µC Interface Type Parallel
SPI
# Channels 1
VSUPPLY (V) (min) 3
VSUPPLY (V) (max) 3.6
ISUPPLY (µA) (typ) 4800
Low Power Shutdown No
Oper. Temp. (°C) -40 to +125
Package/Pins SSOP HYBRID/20
Budgetary
Price (See Notes)
$4.86 @1k
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Simplified Block Diagram

MAX14001, MAX14002: Functional Diagram Isolated ADC for Configurable Binary Input Application Circuit. MAX14001, MAX14002: Functional Diagram Zoom icon

Technical Docs

Design & Development

Click any title below to view the detail page where available.

Description

The MAX14001/14002 evaluation system (EV system) provides the hardware and software necessary to evaluate the MAX14001 and MAX14002 isolated, single-channel, analog-to-digital converters (ADCs) with programmable voltage comparators and inrush current control optimized for configurable binary input applications. The MAX14001/ MAX14002 EV kit has Pmod™ compatible connectors for SPI communication. The EV system includes the USB2PMB2 adapter board that receives commands from a PC through the USB cable to create an SPI interface for communication between the software and the MAX14001/MAX14002 on the EV kit.

The EV system includes a graphical user interface (GUI) that provides communication between the target device and the PC. The MAX14001/MAX14002 EV kit has two MAX14001/MAX14002 devices (U1 and U2) that can operate in multiple modes, as shown in Figure 1:

  1. Single Channel mode: The USB2PMB2 adapter connects to connector PMOD1 or PMOD2 on the EV kit, depending on which channel is preferred, allowing differently configured analog inputs with signal conditioning circuitry.
  2. Daisy-Chain mode: The USB2PMB2 adapter connects to connector PMOD1, and DOUT from U1 connects to DIN of U2. Both U1 and U2 are controlled from a single SPI interface.
  3. Dual Channel mode: The USB2PMB2 adapter connects to connector PMOD1 and uses two chipselect signals (CS1 and CS2) to control each chip through a single connector/GUI interface.

View Details

Features

  • Easy Evaluation of the MAX14001/MAX14002
  • EV Kit is USB Powered
  • Daisy-Chainable SPI Interface
  • Internal Voltage Reference or External Voltage Reference
  • Half-Wave Input Rectification Filter or Full-Wave Input Rectification Filter
  • Windows XP®, Windows® 7, Windows 8.1, and Windows 10 Compatible Software
  • Fully Assembled and Tested
  • Proven PCB Layout
  • RoHS Compliant

Description

The MAX14001/14002 evaluation system (EV system) provides the hardware and software necessary to evaluate the MAX14001 and MAX14002 isolated, single-channel, analog-to-digital converters (ADCs) with programmable voltage comparators and inrush current control optimized for configurable binary input applications. The MAX14001/ MAX14002 EV kit has Pmod™ compatible connectors for SPI communication. The EV system includes the USB2PMB2 adapter board that receives commands from a PC through the USB cable to create an SPI interface for communication between the software and the MAX14001/MAX14002 on the EV kit.

The EV system includes a graphical user interface (GUI) that provides communication between the target device and the PC. The MAX14001/MAX14002 EV kit has two MAX14001/MAX14002 devices (U1 and U2) that can operate in multiple modes, as shown in Figure 1:

  1. Single Channel mode: The USB2PMB2 adapter connects to connector PMOD1 or PMOD2 on the EV kit, depending on which channel is preferred, allowing differently configured analog inputs with signal conditioning circuitry.
  2. Daisy-Chain mode: The USB2PMB2 adapter connects to connector PMOD1, and DOUT from U1 connects to DIN of U2. Both U1 and U2 are controlled from a single SPI interface.
  3. Dual Channel mode: The USB2PMB2 adapter connects to connector PMOD1 and uses two chipselect signals (CS1 and CS2) to control each chip through a single connector/GUI interface.

View Details

Features

  • Easy Evaluation of the MAX14001/MAX14002
  • EV Kit is USB Powered
  • Daisy-Chainable SPI Interface
  • Internal Voltage Reference or External Voltage Reference
  • Half-Wave Input Rectification Filter or Full-Wave Input Rectification Filter
  • Windows XP®, Windows® 7, Windows 8.1, and Windows 10 Compatible Software
  • Fully Assembled and Tested
  • Proven PCB Layout
  • RoHS Compliant

Description

The MAX14001 peripheral module provides the hardware to evaluate the MAX14001 isolated ADC to measure two channels of data, line voltage (up to 230V AC or ±325V 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 MAX14001 IC data sheet for detailed information regarding operation of the IC.

The MAX14001PMB has a 12-pin Pmod™-compatible connector for SPI communication. The peripheral module can be used in various ways. Maxim sells a low-cost USB2PMB2 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 12-pin Pmod-compatible connector for SPI communication can be used.

View Details

Features

  • Easy Evaluation of the MAX14001/MAX14002
  • 3.75kVRMS Isolation for Both Data (SPI) and Power (DC-DC Supply)
  • Peripheral Module Is Powered from a Single 3.3V Supply (USB2PMB2 Is USB-Powered), No Field Side Supply Required
  • Measure AC or DC, Voltages Up to 230V AC or ±325V DC and Current Up to 5A
  • Programmable Comparator Output
  • Works With USB2PMB2 Adapter and Munich GUI Software
  • Fully Assembled and Tested
  • Proven PCB Layout
  • RoHS Compliant

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Support & Training

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Filtered Search

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Parameters

Parametric specs for Sensor Interface Devices
Sensor Interface Type Multi-level Binary Input
µC Interface Type Parallel
SPI
# Channels 1
VSUPPLY (V) (min) 3
VSUPPLY (V) (max) 3.6
ISUPPLY (µA) (typ) 4800
Low Power Shutdown No
Oper. Temp. (°C) -40 to +125
Package/Pins SSOP HYBRID/20
Budgetary
Price (See Notes)
$4.86 @1k

Key Features

  • Enables Robust Detection of Binary Inputs
    • Programmable Input Bias Current Rejects Line Noise
    • 3.75kVRMS of Isolation for 60 Seconds
    • 5.5mm of Creepage and Clearance
    • Group II CTI Package Material
  • Reduces BOM and Board Space Through High Integration
    • 10-bit, 10ksps ADC
    • Binary Threshold Comparators
    • Control Circuit for Driving a Depletion Mode FET
    • Isolation for Both Data and DC-DC Supply
    • 20-SSOP Package
  • Increases Equipment “Up Time” and Simplifies System Maintenance
    • Enables Field-Side Diagnostics
    • Automatic Self-Diagnostics
  • Provides Unparalleled Flexibility
    • Programmable Upper and Lower Input Thresholds
    • Programmable Inrush Current Activation Threshold, Magnitude, and Duration
    • Daisy-Chainable SPI Interface

Applications/Uses

  • Distribution Automation
  • High-Voltage Binary Input (12V–300V)
  • Industrial Control, Multi-Range, Digital Input Modules with Individually Isolated Inputs
  • Substation Automation

Description

The MAX14001/MAX14002 are isolated, single-channel analog-to-digital converters (ADCs) with programmable voltage comparators and inrush current control optimized for configurable binary input applications. 3.75kVRMS of integrated isolation is provided between the binary input side (field-side) and the comparator output/SPI-side (logic-side) of the MAX14001/MAX14002. An integrated, isolated, DC-DC converter powers all field-side circuitry, and this allows running field-side diagnostics even when no input signal is present. The 20-pin SSOP package provides 5.5mm of creepage and clearance with group II CTI rating.

These devices continually digitize the input voltage on the field-side of an isolation barrier and transmit the data across the isolation barrier to the logic-side of the device where the magnitude of the input voltage is compared to programmable thresholds. The binary comparator output pin is high when the input voltage is above the upper threshold and low when it is below the lower threshold. Response time of the comparator to an input change is less than 150μs with filtering disabled. With filtering enabled, the comparator uses the moving average of the last 2, 4, or 8 ADC readings. Both filtered and unfiltered ADC readings are available through the 5MHz SPI port, which is also used to set comparator thresholds and other device configuration.

The MAX14001/MAX14002 control the current of a binary input through an external, high-voltage FET. This current cleans relay contacts and attenuates input noise. An inrush comparator monitoring the ADC readings triggers the inrush current, or wetting pulse. The inrush trigger threshold, current magnitude, and current duration are all programmable in the MAX14001 but are fixed in the MAX14002. When the high-voltage FET is not providing inrush current, it switches to bias mode. Bias mode places a small current load on the binary input to attenuate capacitively coupled noise. The level of bias current is programmable between 50μA and 3.75mA in both the MAX14001 and MAX14002. This allows optimization of the tradeoff between noise attenuation and power dissipation.

Design Solution: Isolated ADC with Integrated DC-DC Converter Simplifies Field-Side Circuitry ›

Simplified Block Diagram

MAX14001, MAX14002: Functional Diagram Isolated ADC for Configurable Binary Input Application Circuit. MAX14001, MAX14002: Functional Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal