Low-Power RS-485 Line Driver and Receiver Pairs
1 Features
- Designed for high-speed multipoint Data
transmission over long cables - Operate with pulse durations as low as 30 ns
- Low supply current: 5 mA maximum
- Meet or exceed the requirements of ANSI
standard RS-485 and ISO 8482:1987(E) - 3-State outputs for party-line buses
- Common-mode voltage range of –7 V to 12 V
- Thermal shutdown protection prevents
driver damage from bus contention - Positive and negative output current
limiting - Pin compatible with the SN75ALS180
2 Description
The SN55LBC180, SN65LBC180 and SN75LBC180 differential driver and receiver pairs are monolithic integrated circuits designed for bidirectional data communication over long cables that take on the characteristics of transmission lines. They are balanced, or differential, voltage mode devices that meet or exceed the requirements of industry standards ANSI RS-485 and ISO 8482:1987(E). These devices are designed using the TI proprietary LinBiCMOS™ with the low-power consumption of CMOS and the precision and robustness of bipolar transistors in the same circuit.
| PART NUMBER | PACKAGE(1) | BODY SIZE (NOM) |
|---|---|---|
|
SN75LBC180 SN65LBC180 |
N (PDIP) | 19.3 mm x 63.5 mm |
| D (SOIC) | 8.65 mm x 3.91 mm | |
| RSA (QFN) | 4 mm x 4 mm | |
| SN55LBC180 | RSA (QFN) | 4 mm x 4 mm |
Logic Diagram (positive logic)3 Description (Continued)
The SN55LBC180, SN65LBC180 and SN75LBC180 combine a differential line driver and receiver with 3-state outputs and operate from a single 5-V supply. The driver and receiver have active-high and active-low enables, respectively, which can be externally connected to function as a direction control. The driver differential outputs and the receiver differential inputs are connected to separate terminals for full-duplex operation and are designed to present minimum loading to the bus whether disabled or powered off (VCC = 0). These parts feature a wide common-mode voltage range making them suitable for point-to-point or multipoint data-bus applications.
The devices also provide positive and negative output-current limiting and thermal shutdown for protection from line fault conditions. The line driver shuts down at a junction temperature of approximately 172°C.
The SN75LBC180 is characterized for operation over the commercial temperature range of 0°C to 70°C. The SN65LBC180 is characterized over the industrial temperature range of –40°C to 85°C.
The SN55LBC180 is characterized for operation over the military temperature range of –55°C to 125°C.
