Overview
The SN65HVD77DGK is a 3.3-V full-duplex RS-485 transceiver produced by Texas Instruments. This device is part of the SN65HVD7x family, which is designed for high-speed data transmission in harsh operating environments. The SN65HVD77DGK combines a differential driver and a differential receiver, operating from a single 3.3-V power supply, making it suitable for multi-point applications over long cable runs.
This transceiver features high levels of ESD protection, including ±12-kV IEC ESD and ±30-kV HBM, and large receiver hysteresis to provide immunity to conducted differential noise. It is available in a small-footprint MSOP package, enhancing its suitability for space-constrained designs.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Supply Voltage (VCC) | -0.5 | 5 | V | |
| Voltage Range at any Bus Pin (A, B, Y, or Z) | -13 | 16.5 | V | |
| Driver Differential Output Voltage Magnitude (|VOD|) | 1.5 | 2 | V | |
| Receiver High-Level Output Voltage (VOH) | 2.4 | VCC-0.3 | V | |
| Receiver Low-Level Output Voltage (VOL) | 0.2 | 0.4 | V | |
| Operating Temperature Range | -40 | 125 | °C | |
| Power Dissipation (PD) at VCC = 3.6 V, TJ = 150°C | 220 | mW (RS-422 load) |
Key Features
- Full-duplex operation with separate input and output pins for driver and receiver.
- High ESD protection: ±12-kV IEC ESD and ±30-kV HBM.
- Large receiver hysteresis (Vhys = 40 mV) for immunity to conducted differential noise.
- No external enabling pins required for SN65HVD77; fully enabled by default.
- Low standby current (< 5 µA) achievable by disabling both driver and receiver.
- Wide common-mode voltage range, suitable for multi-point applications over long cable runs.
- Available in MSOP and SOIC packages for flexibility in design.
- Operates from a single 3.3-V power supply.
- Supports up to 256 nodes on the bus.
Applications
- Industrial automation and control systems.
- Building automation and HVAC systems.
- Medical devices requiring reliable communication.
- Aerospace and defense applications where high reliability is crucial.
- Long-distance data transmission in harsh environments.
- Multipoint data communication networks.
Q & A
- What is the operating voltage range of the SN65HVD77DGK?
The SN65HVD77DGK operates from a single 3.3-V power supply, with a voltage range of -0.5 V to 5 V.
- What level of ESD protection does the SN65HVD77DGK offer?
The device offers high ESD protection, including ±12-kV IEC ESD and ±30-kV HBM.
- What is the maximum operating temperature of the SN65HVD77DGK?
The device operates over a temperature range from -40°C to 125°C.
- Does the SN65HVD77DGK require external enabling pins?
No, the SN65HVD77DGK is fully enabled by default and does not require external enabling pins.
- How many nodes can be supported on the bus with the SN65HVD77DGK?
The device supports up to 256 nodes on the bus.
- What is the typical power dissipation of the SN65HVD77DGK under RS-422 load conditions?
The typical power dissipation is 220 mW at VCC = 3.6 V and TJ = 150°C under RS-422 load conditions.
- What package options are available for the SN65HVD77DGK?
The device is available in MSOP and SOIC packages.
- What is the standby current of the SN65HVD77DGK when both driver and receiver are disabled?
The standby current is less than 5 µA when both driver and receiver are disabled.
- What is the receiver hysteresis of the SN65HVD77DGK?
The receiver hysteresis is 40 mV, providing immunity to conducted differential noise.
- What are some common applications of the SN65HVD77DGK?
Common applications include industrial automation, building automation, medical devices, aerospace, and long-distance data transmission in harsh environments.
