Single-chip solution protects automotive USB 2.0 interfaces

21st September 2016

Nat Bowers

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The TPD3S716-Q1, from Texas Instruments, is a single-chip solution for short-to-battery, short-circuit and ESD protection with an adjustable current-limit for the USB connector’s VBUS and data lines in automotive applications. The integrated data switches provide best-in-class bandwidth for minimal signal degradation while simultaneously providing 18V short-to-battery protection.

The high bandwidth of 1GHz allows for USB2.0 high-speed data rates for applications like Car Play. Extra margin in bandwidth above 720MHz also helps to maintain a clean USB 2.0 eye diagram with the long captive cables that are common in the automotive USB environment.

The short-to-battery protection isolates the internal system circuits from any over-voltage conditions at the V_{BUS_CON}, VD+, and VD– pins. On these pins, the TPD3S716-Q1 can handle over-voltage protection up to 18V for hot plug and DC events. The over-voltage protection circuit provides the most reliable short-to-battery isolation in the industry, shutting off the data switches in 200ns and protecting the upstream circuitry from harmful voltage and current spikes.

The V_{BUS_CON} pin also provides an adjustable current limited load switch and handles short-to-ground protection. The device supports V_BUS currents up to 2.4 A, allowing support for charging USB BC1.2, USB Type-C 5V/1.5A and proprietary charging schemes up to 2.4A. The separate enable pins for data and VBUS allow for both host and client-OTG mode. TPD3S716-Q1 also integrates system level IEC 61000-4-2 and ISO 10605 ESD protection on its V_{BUS_CON}, VD+, and VD– pins removing the need to provide external high voltage, low capacitance diodes.