Modems

AD5700-1BCPZ-R5

AD5700-1BCPZ-R5 - Low Power HART Modem IC | Analog Devices

The AD5700-1BCPZ-R5 is a single-chip HART (Highway Addressable Remote Transducer) FSK half-duplex modem from Analog Devices, designed to comply with the HART physical layer requirements. It integrates all necessary filtering, signal detection, modulation, demodulation, and signal generation functions, requiring minimal external components. The device operates from a 2.7V to 5.5V supply and features an integrated oscillator, eliminating the need for an external crystal. It is available in a compact 24-lead LFCSP-WQ (4x4 mm) package, making it ideal for space-constrained industrial applications. A HART modem is a specialized integrated circuit that enables digital communication over legacy 4-20 mA analog instrumentation loops. It uses Frequency Shift Keying (FSK) to superimpose digital signals on the analog current loop, allowing simultaneous analog and digital communication. The AD5700-1BCPZ-R5 is part of the broader category of industrial communication ICs, which are essential for smart field instruments, process control, and factory automation systems. Key features include a low power consumption of 0.86 mA typical in operating mode, a wide supply voltage range of 2.7V to 5.5V, and an integrated 0.5% accurate oscillator. The device supports HART FSK signaling at 1200 baud and includes a UART interface for easy connection to microcontrollers. It also features a carrier detect output and a modem reset function, simplifying system design. The AD5700-1BCPZ-R5 uses a mixed-signal architecture that combines analog front-end filtering with digital demodulation, ensuring robust performance in noisy industrial environments. The integrated oscillator reduces component count and improves reliability, while the low power consumption makes it suitable for loop-powered devices. The device is specified over the industrial temperature range of -40°C to +125°C. Typical applications include smart transmitters, valve positioners, flow meters, and other HART-enabled field instruments. It is also used in HART multiplexers and gateway modules for process control systems. The device's low power and small footprint make it ideal for loop-powered 4-20 mA transmitters. When designing with the AD5700-1BCPZ-R5, ensure proper decoupling of the power supply and careful layout of the analog front-end to minimize noise. The integrated oscillator eliminates the need for an external crystal, but the supply voltage must be kept within the specified range to maintain oscillator accuracy.