Overview
The SN65HVD1780P, produced by Texas Instruments, is a fault-protected RS-485 transceiver designed for robust and reliable communication in harsh environments. This device combines a differential driver and a differential receiver, operating from a single power supply, making it suitable for half-duplex (two-wire bus) communication. It is fully compliant with ANSI TIA/EIA 485-A standards and can operate with both 3.3-V and 5-V supplies, catering to various application needs.
The SN65HVD1780P is characterized over a wide temperature range from -40°C to 125°C and is pin-compatible with the industry-standard SN75176 transceiver, allowing for drop-in upgrades in most systems. The device features internal ESD protection, fault protection up to ±70 V, and receiver failsafe mechanisms to ensure reliable operation under various fault conditions.
Key Specifications
| Parameter | Value | Unit | Conditions |
|---|---|---|---|
| Signaling Rate | Up to 115 kbps | kbps | |
| Number of Nodes | Up to 320 | ||
| Supply Voltage | 3.3 V to 5 V | V | |
| Operating Temperature | -40°C to 125°C | °C | |
| ESD Protection | ±16 kV (Human Body Model) | kV | |
| Fault Protection | Up to ±70 V | V | |
| Driver Differential Output Rise/Fall Time | 50 ns (RL = 54 Ω, CL = 50 pF) | ns | VCC > 4.5V and T < 105°C |
| Driver Propagation Delay | 55 ns (RL = 54 Ω, CL = 50 pF) | ns | |
| Receiver Enable/Disable Time | 300 ns / 10 μs | ns / μs |
Key Features
- Fault Protection: The device is designed to survive overvoltage faults, including direct shorts to power supplies, mis-wiring faults, connector failures, cable crushes, and tool mis-applications up to ±70 V.
- ESD Protection: Internal ESD protection circuits protect the transceiver bus terminals against ±16 kV human body model (HBM) electrostatic discharges.
- Receiver Failsafe: The receiver output remains logic high under bus-idle, bus-short, or open bus conditions, ensuring reliable operation in various fault scenarios.
- Hot-Plugging Capability: The device supports hot swap or hot pluggable applications with power-up and power-down glitch-free operation and default disabled input and output pins.
- Wide Common-Mode Voltage Range: Suitable for multipoint applications over long cable runs with a wide common-mode voltage range.
- Low Power Operation: Can operate with a 3.3-V supply with reduced driver output voltage for low-power applications.
Applications
The SN65HVD1780P is commonly used in various applications requiring robust and reliable RS-485 communication, including:
- Industrial Automation: For control and monitoring systems in industrial environments.
- Building Automation: For HVAC, lighting, and security systems.
- Medical Devices: For communication in medical equipment where reliability and fault tolerance are critical.
- Aerospace and Defense: For communication in harsh environments requiring high reliability and fault protection.
- Automotive Systems: For communication in vehicle networks, especially in the automotive qualified version (SN65HVD1780-Q1).
Q & A
- What is the operating temperature range of the SN65HVD1780P?
The operating temperature range is from -40°C to 125°C.
- What are the supply voltage options for the SN65HVD1780P?
The device can operate with supply voltages ranging from 3.3 V to 5 V.
- How many nodes can be connected on a bus using the SN65HVD1780P?
Up to 320 nodes can be connected on a bus.
- What is the maximum signaling rate supported by the SN65HVD1780P?
The maximum signaling rate is up to 115 kbps.
- Does the SN65HVD1780P have built-in ESD protection?
Yes, it has internal ESD protection circuits that protect against ±16 kV human body model (HBM) electrostatic discharges.
- What is the fault protection capability of the SN65HVD1780P?
The device can survive bus pin faults up to ±70 V.
- Is the SN65HVD1780P suitable for hot-plugging applications?
Yes, it supports hot swap or hot pluggable applications with power-up and power-down glitch-free operation.
- How does the receiver failsafe mechanism work in the SN65HVD1780P?
The receiver output remains logic high under bus-idle, bus-short, or open bus conditions, ensuring reliable operation in various fault scenarios.
- Is the SN65HVD1780P pin-compatible with other industry-standard transceivers?
Yes, it is pin-compatible with the industry-standard SN75176 transceiver.
- Can the SN65HVD1780P be used in automotive applications?
Yes, there is an automotive-qualified version (SN65HVD1780-Q1) available for high-reliability automotive applications.
