Chip allows isolated USB

By Paul Rako, Technical Editor -- 5/28/2009

Analog Devices’ new ADuM4160 bidirectional isolator provides UL (Underwriter Laboratories) 1577-rated, 5-kV isolation for 1.5 or 12-Mbps USB (Universal Serial Bus)-data lines. The isolator has propagation delay comparable with that of a standard hub and cable. It operates at 250V rms for IEC (International Electrotechnical Commission) 60602-1 CSA (Canadian Standards Association), 600V rms under IEC 60950-1 CSA, and 846V peak for VDE (Verband der Elektrotechnik, Elektronik und Informationstechnik) certification. IEC 60601-1 medical-safely approvals are pending. The device operates from the 5V USB power supply or 3.3V power and provides isolated control of the pullup resistor, allowing the peripheral to control connection timing. The maximum upstream-supply current is 7 mA at 1.5-Mbps data rates and 8 mA at 12-Mbps rates; idle current is 2.5 mA. The unit operates over a −40 to +105°C temperature range.

You can implement a fully isolated USB interface by combining the ADuM4160 data isolator with the ADuM5000 isolated dc/dc-converter IC. Both parts use Analog Devices’ iCoupler isolation technology, which employs on-chip transformers made during die metallization, along with a Kapton polyimide film, to provide the voltage isolation. The high-quality isolation makes the parts suitable for medical, scientific, and industrial applications.

The ADuM4160 is available in a 16-pin, wide-body SOIC with a suggested retail price of $4.89 (1000). ADUM4160EBZ evaluation modules are also available.

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