MAX14001 Datasheet, PDF (1/34 Pages) Maxim Integrated Products – Configurable, Isolated 10-bit ADCs for Multi-Range Binary Inputs

MAX14001/MAX14002
EVALUATION KIT AVAILABLE
Configurable, Isolated 10-bit ADCs for
Multi-Range Binary Inputs
General 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. 3.75kV_RMS
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.
Benefits and Features
●● Enables Robust Detection of Binary Inputs
• Programmable Input Bias Current Rejects Line Noise
• 3.75kV_RMS 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
●● High-Voltage Binary Input (12V–300V)
●● Distribution Automation
●● Substation Automation
●● Industrial Control, Multi-Range, Digital Input Modules
with Individually Isolated Inputs
Safety Regulatory Approvals (Pending)
●● UL According to UL1577
Ordering Information appears at end of data sheet.
19-8514; Rev 0; 5/16