Overview
The STR485LVQT from STMicroelectronics is a low power differential line transceiver designed for data transmission in RS485 applications in half-duplex mode. This component is compatible with both 1.8 V and 3.3 V supplies for data and enable signals, making it versatile for various low-voltage applications. The STR485LVQT features selectable data rates through the SLR pin, allowing for either a fast data rate of up to 20 Mbps or a slow data rate of 250 kbps for extended cable runs. It also includes thermal shutdown protection to prevent excessive power dissipation and a fail-safe receiver to ensure a high output state when inputs are left open, shorted, or idle.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Control Supply Voltage (VL) | 1.65 | - | 3.6 | V |
| Bus Supply Voltage (VCC) | 3.0 | - | 3.6 | V |
| Data Rate (SLR = '0') | - | - | 20 Mbps | - |
| Data Rate (SLR = '1') | - | - | 250 kbps | - |
| Operating Temperature | -40 | - | 105 | °C |
| Number of Transceivers on the Bus | - | - | 256 | - |
| ESD Protection | - | - | ±4 kV HBM, ±8 kV IEC61000-4-2 contact, ±16 kV IEC61000-4-2 air | - |
| Package | - | - | DFN10 (3x3) | - |
Key Features
- Half-duplex RS485 transceiver
- 1.65 V to 3.6 V supply for data and enable signals, 3 V to 3.6 V supply for bus supply
- Selectable data rates: up to 20 Mbps or 250 kbps via SLR pin
- Fail-safe receiver (bus open, idle, or shorted)
- Thermal shutdown protection
- Low quiescent current in shutdown mode
- Extended temperature range: -40 °C to +105 °C
- Available in industry standard DFN10 package
- Bus-pin protection: ±4 kV HBM, ±8 kV IEC61000-4-2 contact discharge, ±16 kV IEC61000-4-2 air discharge
- Compliant with IEC61000-4-4 fast transient burst Class B
Applications
The STR485LVQT is recommended for various applications, including:
- Communications equipment
- Computers and peripherals
- Industrial automation and control systems
Q & A
- What is the operating voltage range for the STR485LVQT?
The STR485LVQT operates with a control supply voltage (VL) of 1.65 V to 3.6 V and a bus supply voltage (VCC) of 3 V to 3.6 V.
- What are the selectable data rates for the STR485LVQT?
The STR485LVQT allows for selectable data rates of up to 20 Mbps or 250 kbps via the SLR pin.
- What is the maximum number of transceivers that can be connected on the same bus?
Up to 256 transceivers can be connected on the same bus.
- What kind of ESD protection does the STR485LVQT offer?
The STR485LVQT offers ESD protection of ±4 kV HBM, ±8 kV IEC61000-4-2 contact discharge, and ±16 kV IEC61000-4-2 air discharge.
- What is the operating temperature range of the STR485LVQT?
The operating temperature range is -40 °C to +105 °C.
- What package type is the STR485LVQT available in?
The STR485LVQT is available in the industry standard DFN10 (3x3) package.
- Does the STR485LVQT have thermal shutdown protection?
Yes, the STR485LVQT includes thermal shutdown protection to prevent excessive power dissipation.
- What is the fail-safe feature of the receiver in the STR485LVQT?
The receiver has a fail-safe feature that guarantees a high output state when the inputs are left open, shorted, or idle.
- Is the STR485LVQT compliant with any specific standards?
Yes, it is compliant with IEC61000-4-4 fast transient burst Class B.
- What is the typical application for the STR485LVQT?
The STR485LVQT is typically used in communications equipment, computers and peripherals, and industrial automation and control systems.
