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Logic ICs Operate With Slowly Changing Input Signals

PCIM 2012 Nuremberg: Toshiba Electronics Europe (TEE) expanded its TC74VHC family of very-high-speed logic with a range of ICs that combine Schmitt trigger inputs with voltage-tolerant output capabilities. The new TC74VHCV logic series allows the logic ICs to function with slowly changing input signals. It also enables interface functionality between systems that use separate power supplies.

Compared to the original design, the output structure of the new TC74VHCV series was modified to enable power-down protection of the output pins. It prevents backflow current from the main to a sub-board in cases where the sub-board power supply is disconnected.

The company also integrated a Schmitt-trigger function into the input stage of the TC74VHCV series. It allows the logic ICs to operate with very slow or distorted input signals—a common occurrence in industrial applications that use long connection lines.

Due to the Schmitt trigger function, the allowable input voltage slope of 0ns to 20ns per volt for the standard TC74VHC series was extended to 0ns to 1000ns per volt for the TC74VHCV series. As a result, the latter will find homes in a wide variety of industrial and consumer applications.

The TC74VHCV lineup includes hex and octal inverters, buffers, transceivers, latches and flip-flops. Devices can operate with power supplies ranging from 1.8V to 5.5V, and they feature a large fan-out capability due to the minimum 16mA output current.

Packaging options include the standard TSSOP (TC74VHCVxxxFT) or the smaller VSSOP (TC74VHCVxxxFK) for applications with limited available board space.

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