Analog Devices / Maxim Integrated ADuM1252 Bidirectional I2C Isolators

Analog Devices / Maxim Integrated ADuM1252 Bidirectional I2C Isolators offer two bidirectional, open-drain channels for applications (such as I2C) that require data to be transmitted in both directions on the same line. To prevent latch-up action, Side 1 outputs comprise special buffers to regulate the logic-low voltage at 0.64V, and the input logic-low threshold is at least 50mV lower than the output logic-low voltage. Side 2 provides conventional buffers that do not regulate the logic-low output voltage. The ultra-low-power Vishay ADuM1252 also provides a disturbance-free bus connection for hot-plug connections on Side 2 by first pre-charging the bus pins and then monitoring the bus state for either an idle bus or detection of an I2C stop condition before connecting Sides 1 and 2.

Featuring independent 1.71V to 5.5V supplies on both sides one and two of the isolator, ADuM1252 operates up to 2MHz. An ultra-low standby current of 21µA per side is ideal for battery-operated systems. Available in an 8-pin narrow SOIC package, these devices are rated for operation at ambient temperatures of -40°C to +125°C.

Features

  • Low VOL(MAX) for greater I2C device compatibility
    • 0.69V for Side 1
    • 0.4V for Side 2
  • Ultra-low power consumption for longer battery life, 142μA (typical) per channel at 400kHz
  • Wide independent VDD1/VDD2 supply range supports more logic voltage levels and allows level shifting, 1.71V to 5.5V for both sides
  • Enhanced hot-swappable Side 2 I/O, initial Side 2 connection occurs at bus idle or stop states to prevent data corruption
  • Bidirectional I2C data transfer up to 2MHz SCL
  • Bidirectional SCL for advanced bus topologies supports clock stretching and multiple controllers across the isolation barrier
  • Strong current sinking enables lower RPULL-UP values for faster bus speeds
    • 5mA for Side 1
    • 50mA for Side 2
  • Robust galvanic isolation of digital signals
    • 445VRMS continuous withstanding (VIOWM), 8-narrow SOIC
    • Withstands ±10kV surge per IEC 61000-4-5
    • 4mm creepage and clearance, 8-narrow SOIC
  • Pending safety and regulatory approvals
    • IEC60747-17, reinforced VIORM narrow SOIC: 630VPEAK
    • UL 1577, 8-narrow SOIC: 3000VRMS for 1 minute
    • IEC/EN/CSA 62368-1
    • IEC/EN/CSA 61010-1
    • CAN/CSA-C22.2 No. 14-18

Applications

  • Isolated I2C/SMBus interfaces
  • Battery management systems
  • Power Over Ethernet (PoE)
  • Motor control systems

Specifications

  • 1.71V to 5.5V supply range
  • 1.48V to 1.65V undervoltage-lockout threshold side
  • 30mV typical undervoltage-lockout threshold hysteresis
  • 5pF typical input capacitance
  • ±10µA leakage current
  • 200kV/µs minimum common-mode transient immunity
  • 2MHz (minimum) maximum data rate
  • -40°C to +125°C operating temperature range
  • +150°C junction temperature

Typical Application Circuit

Application Circuit Diagram - Analog Devices / Maxim Integrated ADuM1252 Bidirectional I2C Isolators

Functional Diagram

Block Diagram - Analog Devices / Maxim Integrated ADuM1252 Bidirectional I2C Isolators

Analog Devices / Maxim Integrated ADuM1252 Bidirectional I2C Isolators