The LTM2883 is a complete galvanic 6-channel SPI/Digital or I²C digital µModule isolator with triple rail regulated power for 3.3V and 5V systems provided by an integrated, isolated DC/ DC converter that powers both sides of the interface.  

In industrial systems applications, ground potentials can vary widely, often exceeding the tolerable range, which can interrupt communications or even destroy components. The LTM2883 breaks ground loops by electrically separating communications signals, isolating the logic level interface on each side of an internal inductive isolation barrier that withstands a very large common-mode voltage range up to 2,500VRMS.

The LTM2883’s low EMI isolated DC-DC converter powers the communications interface and provides adjustable 5V, +12.5V, and -12.5V supply outputs, ideal for powering data converters in data acquisition systems. With 2,500VRMS of galvanic isolation, onboard secondary power and a communications interface operating at up to 20Mbps, the LTM2883 requires no external components and provides a simple µModule solution for isolated data communications.

The LTM2883 from Linear Technology is available in two communications interface versions. The LTM2883-I is I²C compliant at up to 400kHz with bidirectional serial data (SDA) plus clock (SCL) and three additional isolated CMOS logic signals that operate at up to 20Mbps.

The LTM2883-S is SPI compliant and offers a total of six CMOS digital isolator communication channels. All channels operate at up to 20Mbps and include three forward direction signals (/CS, SCK and SDI) and three reverse direction signals (SDO, DO1 and DO2). When configured for SPI communications, the maximum clock rate is 8MHz for unidirectional communication or 4MHz for round-trip bidirectional operation.

An onboard 2MHz DC-DC converter powers the LTM2883 and allows each of the three isolated power supply outputs to source up to 20mA over the full operating temperature range. Each supply may be adjusted from its nominal value using a single external resistor. A logic supply pin provides direct interfacing with low voltage microcontrollers down to 1.62V, independent of the main supply, and an ON pin enables the LTM2883 to be shut down using less than 10µA.

Coupled inductors and an isolation power transformer provide 2500VRMS of isolation between the input and output logic interface. This device is ideal for systems where the ground loop is broken, allowing for a large common mode voltage range. Communication is uninterrupted for common mode transients greater than 30kV/µs and rugged ±10kV ESD HBM across the isolation barrier.

The LTM2883 is available in 3.3V or 5V supply voltage versions and is offered in a 15mm x 11.25mm surface mount BGA package; all integrated circuits and passive components are housed in this RoHS-compliant µModule package. Pricing starts at $11.95 each in 1,000 piece quantities.

For more information on the LTM2883 visit www.linear.com/product/LTM2883

Summary of Features of the LTM2883:

  • UL Rated Six Channel Logic Isolator: 2500VRMS
  • UL Recognized File #E151738
  • Isolated Adjustable DC Power:
  • 3V to 5V at Up to 30mA
  • ±12.5V at Up to 20mA
  • No External Components Required
  • High Common-Mode Transient Immunity: 30kV/µs
  • High Speed Operation:
  • 10MHz Digital Isolation (LTM2883-S)
  • 8MHz/4MHz SPI Isolation (LTM2883-S)
  • 400kHz I2C compliant Isolation (LTM2883-I)
  • 3.3V (LTM2883-3) or 5V (LTM2883-5) Operation
  • 1.62V to 5.5V Logic Supply for Flexible Digital Interfacing
  •  ±10kV ESD HBM Across the Isolation Barrier
  • 15mm x 11.25mm x 3.42mm BGA Package

Typical Application

Applications

  • Isolated SPI or I2C Interfaces
  • Industrial Systems
  • Test and Measurement Equipment
  • Breaking Ground Loops

About Linear Technology

Linear Technology Corporation, a manufacturer of high performance linear integrated circuits, was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major public companies in 2000. Linear Technology products include high performance amplifiers, comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery chargers, data converters, communications interface circuits, RF signal conditioning circuits, µModule products, and many other analog functions.  Applications for Linear Technology’s high performance circuits include telecommunications, cellular telephones, networking products such as optical switches, notebook and desktop computers, computer peripherals, video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer products such as digital cameras and MP3 players, complex medical devices, automotive electronics, factory automation, process control, and military and space systems.

Linear Technology (UK) Limited

Tel: +44 (0)1628 477066

E-mail: uksales@linear.com

Web site: www.linear.com

Website for product information:  http://www.linear.com/product/LTM2883