Microwave Journal
www.microwavejournal.com/articles/20321-module-isolator-ltm2892

µModule Isolator: LTM2892

July 31, 2013

ltm2892Linear Technology Corp. introduces the LTM2892, a 6-channel SPI/digital or I²C µModule® (micromodule) isolator for 3.3 to 5 V systems. Ground potentials can vary widely in systems, potentially exceeding common mode operating limits, which can interrupt communications, destroy components, and even create hazardous conditions.

The LTM2892 breaks ground loops by communicating across a galvanic isolation barrier that blocks DC current for potential differences of up to 3,500VRMS providing safe, uninterrupted operation. The LTM2892 requires no external components, providing a small, simple µModule solution for isolated data communications.

The LTM2892 is available in two communications interface versions. The LTM2892-I is I²C compatible at up to 400kHz with bidirectional serial data (SDA) plus clock (SCL) and three additional isolated CMOS logic signals that operate at up to 10MHz. The LTM2892-S offers six CMOS digital isolator channels that can be used for general I/O or configured for SPI compliant operation. The six channels include three forward and three reverse directions paths that can all operate at up to 10MHz. When configured for SPI communications, the maximum clock rate is 8MHz for unidirectional communication or 4MHz for round-trip bidirectional operation. All versions include a logic supply pin that provides direct interfacing with low voltage microcontrollers down to 1.62V (SPI) or 3V (I²C)and an ON pin that enables the LTM2892 to be shut down using less than 10µA. Additional features include uninterrupted communications for common-mode transients greater than 50kV/µs and rugged ±15kV ESD HBM across the isolation barrier.

The LTM2892 is offered in a 9mm x 6.25mm surface mount BGA package; all integrated circuits and passive components are housed in this RoHS-compliant µModule package. Pricing starts at $5.95 each in 1,000 piece quantities.

Summary of Features: LTM2892

  • Six-Channel Logic Isolator: 3,500VRMS
  • 3V to 5.5V Supply Operation, Both Sides of Isolated Interface
  • No External Components Required
  • SPI (LTM2892-S) or I²C (LTM2892-I) Options
  • High Common-Mode Transient Immunity: 50kV/µs
  • High Speed Operation:
    • 10MHz Digital Isolation
    • 8MHz/4MHz SPI Isolation
    • 400kHz I²C Isolation
  • 1.62V to 5.5V Logic Supply for Flexible Digital Interfacing
  • ±15kV ESD HBM Across the Isolation Barrier
  • Common Mode Working Voltage: 850VPEAK
  • Low Current Shutdown Mode (<10µA)
  • Small 9mm x 6.25mm x 2.91mm BGA Package

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