A Californian Mosfet supplier is claiming a breakthrough in low power, low threshold devices with its factory trimming technique.

Advanced Linear Devices said it has achieved low threshold voltages of 0.20V for N-channel Mosfet pairs matched at the factory.

Threshold voltage and tolerances of ±0.02V are achieved with a patented technique called electrically programmable analogue device technology, which allows Mosfet threshold voltage parameters to be electrically trimmed.

It involves modifying and controlling the threshold voltage of a floating gate Mosfet by injecting electrons with enough energy to jump into the gate layer buried in the device’s oxide layers.

In this way it is possible to increase the gate threshold voltage in millivolt steps over a 2V range. Individual devices or pairs of Mosfets can be trimmed.

Once trimmed, the device voltage and current characteristics are stored in the chip, even when the power to the chip is removed.

The devices are designed for switching and amplifying in low voltage (1V to 10V or ±0.5V to ±5V) or ultra low voltage (less than 1V or ±0.5V) systems. They feature a low input bias current of less than 30pA and low input capacitance.

According to John Skurla, marketing director at ALD, the Mosfets can be biased at or below threshold voltage levels for nanowatt power dissipation.

“Nanopower operation, or circuits that operate on less than a microwatt, has been an elusive goal for the electronics industry,” said Skurla.

“These low power Mosfet arrays can enable the operation of delicate sensors from remote locations for sensitive and critical security applications. Even portable medical devices that are counted on for long operational life can benefit by circuitry with precisely controlled voltages,” he said.

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