Overview
The SN65HVD21D, produced by Texas Instruments, is a member of the SN65HVD2x family of extended common-mode RS-485 transceivers. These devices are designed to operate in harsh electrical environments and offer superior performance over standard RS-485 transceivers. The SN65HVD21D is particularly suited for applications requiring high node counts and moderate data rates, making it ideal for industrial and commercial communication networks.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage | 4.5 to 5.5 | V |
| Common-mode Voltage Range | –20 to 25 | V |
| Operating Temperature | –40 to 85 | °C |
| Data Rate | Up to 5 Mbps | |
| Number of Nodes | Up to 256 | |
| Cable Length | Up to 150 meters at 5 Mbps | |
| Driver Output Slew Rate | Controlled for reliable switching | |
| Receiver Hysteresis | 100 to 130 mV | |
| ESD Protection | Over 16-kV HBM | |
| Standby Supply Current | 1 µA (maximum) |
Key Features
- Extended common-mode voltage range (–20 V to 25 V) exceeding TIA/EIA-485 requirements.
- Receiver equalization to extend cable length and improve jitter performance.
- High ESD protection (over 16-kV HBM).
- Failsafe receiver for open-circuit, short-circuit, and idle-bus conditions.
- Low standby supply current of 1 µA (maximum).
- Wide receiver hysteresis (100 to 130 mV).
- Controlled driver output slew rate for reliable switching and reduced high-frequency noise emissions.
Applications
- Long cable solutions in factory automation, security networks, and building HVAC systems.
- Severe electrical environments such as electrical power inverters, industrial drives, and avionics.
- Digital motor controllers, remote sensors and terminals, industrial process control, security stations, and environmental control systems.
Q & A
- What is the common-mode voltage range of the SN65HVD21D?
The common-mode voltage range is –20 V to 25 V, more than doubling the TIA/EIA-485 requirement.
- How many nodes can be connected using the SN65HVD21D?
Up to 256 nodes can be connected at moderate data rates.
- What is the maximum data rate supported by the SN65HVD21D?
The SN65HVD21D supports data rates up to 5 Mbps.
- What is the maximum cable length supported by the SN65HVD21D at 5 Mbps?
The maximum cable length is up to 150 meters at 5 Mbps.
- Does the SN65HVD21D have ESD protection?
- What is the standby supply current of the SN65HVD21D?
The standby supply current is 1 µA (maximum)).
- What is the operating temperature range of the SN65HVD21D?
The operating temperature range is –40°C to 85°C).
- Does the SN65HVD21D have failsafe receiver functionality?
- What type of driver output slew rate control does the SN65HVD21D have?
The driver output slew rate is controlled to provide reliable switching and reduce high-frequency noise emissions).
- What is the receiver hysteresis of the SN65HVD21D?
The receiver hysteresis is 100 to 130 mV).
