Trimming analog circuits with solid-state devices

Although simple and inexpensive, trimming potentiometers can be awkward to reach or readjust in large systems. A new alternative is an electrically programmable analog device, called an Epad. The small floating-gate MOS device is programmed with an inexpensive instrument working with a PC. It may be configured to provide a trimmable voltage or resistance, which will hold its setting indefinitely or may be reprogrammed.