Legendsemi LHE2700FQG

LHE2700 is a single-chip solution designed as a HART FSK half-duplex modem compliant with HART physical layer requirements. The device integrates all necessary filtering, signal detection, modulation, demodulation, and signal generation functions, requiring minimal external components. Its precision internal oscillator significantly reduces board space, making it an ideal choice for loop-powered applications in master/slave configurations. With a maximum supply current of 112 μA, it is well suited for low-power loop-powered applications. The transmit waveform consists of phase-continuous 1200 Hz and 2200 Hz sine waves. The device includes a precise carrier detect circuit and uses a standard UART interface.

• Fully integrated FSK modem compliant with HART standard
• 1200 Hz and 2200 Hz sinusoidal frequency shift keying frequencies
• Maximum supply current 112 μA in receive mode
• Suitable for intrinsically safe applications
• Integrated receive bandpass filter
• Minimal external components required
• Clock optimized for various system configurations
• Ultra-low power crystal oscillator (58 μA maximum)
• External CMOS clock source
• Precision internal oscillator
• Buffered HART output with additional drive capability
• 8 kV HBM ESD rating
• 2.7 V to 5.5 V supply voltage
• 1.71 V to 5.5 V interface levels
• -40℃ to +125℃ operating temperature range
• 4 mm × 4 mm QFN package
• HART physical layer standard compliant
• UART interface

• Field transmitters
• HART multiplexers
• PLC and DCS analog I/O modules
• HART network connections