Overview
The SN65HVS885 is an 8-channel digital-input serializer designed by Texas Instruments for high-channel density digital input modules in industrial and building automation systems. Operating from a single 5-V supply, this device accepts field input voltages up to 34 V and provides a serially shifted digital output with reduced voltage ranges of 0-5 V. It is SPI-compatible, allowing easy interfacing with standard microcontrollers. The device features galvanic isolation when used with isolators, protecting the controller side from high-voltage field signals. It also includes an on-chip temperature sensor for overtemperature indication and system safety.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| VCC (Device power input) | -0.5 | 6 | V | |
| VIPx (Field digital inputs) | -0.3 | 36 | V | |
| VID (Voltage at any logic input) | -0.5 | 6 | V | |
| IO (Output current) | -8 | 8 | mA | |
| TJ (Junction temperature) | 170 | °C | ||
| Tstg (Storage temperature) | 150 | °C | ||
| TA (Device operating temperature) | -40 | 125 | °C | |
| fCLK (Clock pulse frequency) | 100 | MHz | ||
| RθJA (Junction-to-ambient thermal resistance) | 35 | °C/W |
Key Features
- Operates from a single 5-V supply
- Accepts field input voltages up to 34 V
- 8-channel digital-input serializer with SPI-compatible interface
- Cascadable for more inputs in multiples of eight
- Field inputs protected to 15-kV ESD
- Output drivers for external status LEDs
- On-chip temperature sensor for overtemperature indication and system safety
- Current limited inputs with adjustable current thresholds
- Internal debounce filters for input signal validation
- Available in a 28-pin HTSSOP package with exposed thermal pad for efficient heat dissipation
Applications
- Industrial PCs
- Digital I/O cards
- High channel count digital input modules
- Decentralized I/O modules
- Building automation systems
Q & A
- What is the operating voltage range of the SN65HVS885?
The SN65HVS885 operates from a single 5-V supply, with a recommended operating range of 4.5 V to 5.5 V.
- What is the maximum voltage that the field inputs can handle?
The field inputs can handle voltages up to 34 V.
- How many channels does the SN65HVS885 have?
The SN65HVS885 is an 8-channel digital-input serializer.
- Is the SN65HVS885 SPI-compatible?
- What kind of thermal protection does the SN65HVS885 have?
The device includes an on-chip temperature sensor that signals a fault condition if the temperature exceeds 150°C and shuts down the device if it exceeds 170°C.
- How can the debounce time be set for the SN65HVS885?
The debounce time can be set using the DB0 and DB1 pins, which allow for selection of 0, 1, or 3 ms debounce times.
- What is the purpose of the HOT pin on the SN65HVS885?
The HOT pin serves as an overtemperature indicator and can be used to trigger an interrupt or visually indicate the device's health using an LED.
- Can the SN65HVS885 be cascaded for more inputs?
- What is the recommended storage temperature range for the SN65HVS885?
The recommended storage temperature range is from -40°C to 150°C.
- What is the junction-to-ambient thermal resistance of the SN65HVS885 in the HTSSOP package?
The junction-to-ambient thermal resistance is 35°C/W.
