New Industry Products

Advanced Linear Devices Intros ALD110xxx MOSFETS

June 13, 2005 by Jeff Shepard

Advanced Linear Devices Inc. (Sunnyvale, CA) has produced a MOSFET with an effective 0 V turn-on threshold that supports ultra-low power applications such as sensor arrays and medical implants. The zero-threshold MOSFET is based on a floating-gate charge technology. By programming the charge level on the MOSFET gate, the turn-on/turn-off thresholds for the device can be controlled.

Currently, ultra-low power systems offer 0.7 V, give or take 500 mV. With a zero-threshold device, small amplifiers can be built to operate at supply voltages of 0.2 V, and with power dissipation of less than 1 µW. Zero-threshold MOSFETs can alter current analog circuit design. Using the new device like a matched-pair current source, a simple circuit can be constructed to operate with as little as a 20 mV supply. More complicated circuits, using several stages stacked on top of each other, could operate on as little as 0.2 mV or 0.45 mV.

Applications for sub 1 V amplifiers and switches include implantable medical devices, microelectromechanical system sensor arrays, automotive and aviation fail-safe circuits, as well as cell phones. The quad/dual, N-channel matched-pair MOSFETs are level-matched at the factory using a floating-gate charge controller, or electrically programmable analog device (EPAD). The floating gate is poly-silicon embedded in the gate oxide. The charge level on the gate controls the sensitivity of the MOSFET switch, and can be set with the EPAD programming tool.

The EPAD programming can set thresholds from 0.01 V to -0.01 V with an offset voltage of just 2 mV. The zero-threshold MOSFET can be classified as either an enhancement-mode device (when operated above the threshold voltage) or a depletion-mode device (when operated at or below the threshold voltage). The quad and dual MOSFET arrays have part numbers ALD110800 and ALD110900. The gate threshold voltage of the devices is 0.0 V 0.01 V at 1 µA.

Pricing for the ALD110800 and ALD110900 starts at $0.91 each in quantities of 1,000 pieces.