Analog Devices DS8500 Product Info

• Single-Chip, Half-Duplex Modem Overlays 1200bps FSK Digital Communication on Top of Installed 4mA–20mA Current Loop Infrastructure
• Digital Signal Processing Provides Reliable Input Signal Detection in Noisy Conditions
• Standard Component 3.6864MHz Crystal Reduces System Cost
• Fully Tested and Verified as a HART-Registered Modem IC
• Integrated Solution Requires Minimal Power and Space
  • 2.7V to 3.6V Operating Voltage
  • 285µA (max) Current Consumption
  • Space-Saving, 5mm x 5mm x 0.8mm, 20-Pin TQFN Package
  • Few External Components Required

The DS8500 is a single-chip modem with Highway Addressable Remote Transducer (HART) capabilities. It has been fully tested and verified and has received a HART^® Certificate of Registration. The device integrates the modulation and demodulation of the 1200Hz/2200Hz FSK signal, has very low power consumption, and needs only a few external components due to the integrated digital signal processing. The input signal is sampled by an analog-to-digital converter (ADC), followed by a digital filter/demodulator. This architecture ensures reliable signal detection in noisy environments. The output digital-to-analog converter (DAC) generates a sine wave and provides a clean signal with phase- continuous switching between 1200Hz and 2200Hz. Low power is achieved by disabling the receive circuits during transmit and vice versa. The DS8500 is ideal for low-power process control transmitters.

Applications

• 4-20mA Loop-Powered Transmitters for Temperature, Pressure, Flow, and Level Measurement
• HART Modem Interface Connectivity
• HART Multiplexers