SN65HVS885 Datasheet, PDF (1/21 Pages) Texas Instruments – 34 V, Digital-Input Serializer for 5V Systems

Typical Size
6.4 mm X 9.7 mm
SN65HVS885
www.ti.com ............................................................................................................................................................................................... SLAS638 – JANUARY 2009
34 V, Digital-Input Serializer for 5V Systems
FEATURES
1
•2 Eight Digital Sensor Inputs
– High Input Voltage up to 34 V
– Selectable Debounce Filters From 0 ms to
3 ms
– Flexible Input Current-Limited – 0.2 mA to
5.2 mA
– Field Inputs Protected to 15-kV ESD
• Single 5V Supply
• Output Drivers for External Status LEDs
• Cascadable for More Inputs in Multiples of
Eight
• SPI-Compatible Interface
• Over-Temperature Indicator
APPLICATIONS
• Industrial PCs
• Digital I/O Cards
• High Channel Count Digital Input Modules
• Decentralized I/O Modules
DESCRIPTION
The SN65HVS885 is an eight channel, digital-input serializer for high-channel density digital input modules in
industrial and building automation. Operating from a 5V supply the device accepts field input voltages of up to
34V. 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 debounce filters.
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.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2009, Texas Instruments Incorporated