Features

OBSOLETE: For Information Purposes Only. Contact Linear Technology for Potential Replacement.

• UL Recognized File E151738 to UL1577
• Self-Powered Across Isolation Barrier
• 2500VRMS Isolation
• 2.5V Isolated Reference, I_LOAD = 5mA_MAX
• Zero-Cross Output for Line Power
• Dual Differential Input Comparator
• High Input Impedance Comparator

Typical Application

Description

The LTC1531 is an isolated self-powered dual differential comparator. An internal capacitive isolation barrier provides 2500V_RMS of isolation between the comparator and its output. The part provides UL-rated isolated comparisons without the need for an isolated supply since both comparator power and output data are transmitted across the capacitive barrier. The comparator data is transferred differentially across the isolation barrier to provide high common mode voltage and noise immunity. The isolated side can supply a 2.5V reference output to power external sensor circuits such as a thermistor bridge. The dual differential comparator inputs allow for comparison of two differential voltages as well as single-ended voltages. The powered side provides a latched data output as well as a pulsed zero-cross comparator output for controlling a triac. The part is available in a 28-lead SO package.