The MAX22192 is an IEC 61131-2 compliant industrial
digital input device with integrated digital isolation. The
MAX22192 translates eight, 24V current-sinking, industrial
inputs to an isolated serialized SPI-compatible output
that interfaces with 1.71V to 5.5V logic voltage. A current-setting
resistor allows the MAX22192 to be configured for
Type 1, Type 2, or Type 3 inputs. For proximity switches,
the field-wiring is verified using the wire break feature.
When wire break is enabled, the active-low LFAULT output is asserted
and a register flag set if the input current drops below
the wire break threshold for more than 20ms. Additional
diagnostics that assert active-low LFAULT include: overtemperature
protection, low 24V field supply, 24V field supply missing,
and CRC communication error.
For robust operation in industrial environments, each input
includes a programmable glitch filter. The filter delay on
each channel can be independently programmed to one
of eight values between 50µs and 20ms, or filter bypass.
The MAX22192 has an isolated 4-pin SPI interface, and
in addition uses isolated active-low LLATCH input for synchronizing
input data across multiple devices in parallel, and isolated
active-low LFAULT output for instantly alerting the host of any
diagnostic issues. The digital signals with a name starting
with L are logic-side signals, and the digital signals with a
name starting with F are field-side signals.
The MAX22192 field-side accepts a single 7V to 65V supply
to the VDD24F pin. When powered by the field supply,
the MAX22192 generates a 3.3V output on the VDD3F pin
from an integrated LDO regulator, which can provide up to
25mA of current for external loads in addition to powering
the MAX22192. Alternatively, the MAX22192 can be powered
from a 3.0V to 5.5V supply connected to the VDD3F
pin. The logic-side of the MAX22192 is powered from a
single 1.71V to 5.5V supply to the VDDL pin to interface
with 1.8V, 3.3V, or 5V logic levels.
The MAX22192 has an isolation rating of 600VRMS for 60
seconds and is available in a 70-pin GQFN package with
2.3mm clearance and creepage. The package material
has a minimum comparative tracking index (CTI) of 600V,
which gives it a group I rating in creepage tables.
Applications
- Industrial Automation
- Process Automation
- Programmable Logic Controllers
