The SN65HVS885 is an eight channel, digital-input serializer for high-channel density
digital input modules in industrial and building automation. Operating from a 5-V supply the device
accepts field input voltages of up to 34 V. In combination with galvanic isolators the device
completes the interface between the high voltage signals on the field-side and the low-voltage
signals on the controller side. Inputs signals are current limited and then validated by internal
With the addition of few external components, the input switching characteristic can be
configured in accordance with IEC61131-2 for Type 1, 2 and 3 sensor switches.
Upon the application of load and clock signals, input data is latched in parallel into
the shift register and afterwards clocked out serially.
Cascading of multiple devices is possible by connecting the serial output of the leading
device with the serial input of the following device, enabling the design of high-channel count
input modules. Multiple devices can be cascaded through a single serial port, reducing both the
isolation channels and controller inputs required.
Input status can be visually indicated via constant current LED outputs. The current
limit on the inputs is set by a single, external, precision resistor. An on-chip temperature sensor
provides diagnostic information for graceful shutdown and system safety.
The SN65HVS885 is available in a 28-pin PWP PowerPAD
package, allowing for efficient heat dissipation. The device is specified for operation at
temperatures from 40°C to 125°C.