New Industry Products

2x Faster Data and Up to 50% Longer Cables for Motion Control

November 17, 2017 by Paul Shepard

Industrial designers can now achieve 2x faster data rates and extend cable length by up to 50% with MAX22500E, MAX22501E, and MAX22502E RS-485 transceivers from Maxim Integrated Products, Inc.    Applications are expected to include backplane busses, encoder interfaces, field bus networks, industrial control systems, and motion control systems.

With motion control systems requiring more accuracy over longer distances, system designers are challenged to maintain faster data rates and achieve robust communications with longer cables. A production site, for example, may not efficiently function with a slow data rate and short cables as it must transfer accurate information quickly and over a long distance.

The MAX22500E/MAX22501E (half-duplex) and MAX22502E (full-duplex) ESD-protected RS-485/RS-422 transceivers extend the reach of communication up to 100Mbps over 50m. This provides the industry’s fastest data rates for accurate, cost-effective, and robust communication across long cables for a variety of motion control applications.

Block diagram (click on image to enlarge)

The settable pre-emphasis feature within the MAX22500E and MAX22502E enables 2x faster data rates compared to competitive solutions for increased encoder resolution and reduced latency.

Pre-emphasis extends cables up to 50% longer to communicate over longer distances. A large receiver hysteresis (250mV) provides superior robustness to EFT.

In addition, by improving the signal integrity and robustness, system designers can achieve the same level of performance with lower-cost cables. The transceivers operate over the -40 to +125 degrees C temperature range.

Advantages include:

  • Robust communications: Extends the reach to 100Mbps over 50m (or 50Mbps over 100m); Settable pre-emphasis improves data integrity with high data rates; 250mV receiver hysteresis for EFT robustness
  • High Performance: Fastest 100Mbps data rate for higher resolution/accuracy communication; flexible low voltage logic supply interface down to 1.6V; Improved signal integrity enables less expensive cable costs
  • Small Size: Reduced footprint with small 8-, 10-, and 12-pin TDFN packages

"Our solutions offer customers with the flexibility and performance they need to upgrade their systems," said Timothy Leung, Executive Business Manager, Industrial & Healthcare Business Unit at Maxim Integrated.

"For example, they can swap out the IC on their hardware while keeping the same infrastructure. Similarly, end customers can adjust data rates and cable lengths," observed Leung.

Summary of key features

  • High-Speed Operation Over Long Distances
    • Up to 100Mbps Data Rate
    • Integrated Preemphasis Extends Cable Length
    • High Receiver Sensitivity
    • Wide Receiver Bandwidth
    • Symmetrical Receiver Thresholds
  • Integrated Protection Increases Robustness
    • -15V to +15V Common Mode Range
    • ±15kV ESD Protection (Human Body Model)
    • ±7kV IEC61000-4-2 Air-Gap ESD Protection
    • ±6kV IEC61000-4-2 Contact Discharge ESD Protection
    • Driver Outputs are Short-Circuit Protected
  • Flexibility for Many Different Applications
    • 3V to 5.5V Supply Range
    • Low Voltage Logic Supply Down to 1.6V
    • Low 5μA (max) Shutdown Current
    • Available in 12-pin TDFN (3mm x 3mm) Package
    • -40°C to +125°C Operating Temperature Range

Availability and Pricing:

  • The MAX22500E is available in a 10-pin TDFN (3mm x 3mm) package for $3.51 (1000-up, FOB USA) at Maxim's website and select authorized distributors
  • The MAX22501E is available in an 8-pin TDFN (3mm x 3mm) package for $1.79 (1000-up, FOB USA) at Maxim's website and select authorized distributors
  • The MAX22502E is available in a 12-pin TDFN (3mm x 3mm) package for $3.94 (1000-up, FOB USA) at Maxim's website and select authorized distributors
  • The MAX22500EEVKIT#, MAX22501EEVKIT#, and MAX22502EEVKIT# evaluation kits are each available for $95

MAX22502E evaluation kit (click on image to enlarge)

The MAX22502E evaluation kit can be used to demonstrate the functionality of the MAX22502E full-duplex high speed RS-485/RS-422 transceiver with preemphasis functionality. The MAX22502E is a fully assembled and tested PCB that's configurable to operate from a single 3V to 5V supply. The EV kit includes on-board termination for easy point-to-point evaluation.

Features include:

  • Configurable to Operate from a Single 3V to 5V Supply
  • Separate Logic Supply (VL) to Interface with Logic Signals as Low as 1.6V
  • Terminal Block and RJ45 Connectors for Easy RS-485/RS-422 Evaluation
  • Fully Assembled and Tested