FRAM-based non-volatile state savers

The state saver is as simple to use as a D-type flip-flop. It operates like conventional logic, but stores and retains the logic state in the absence of power, simplifying the design of system control functions. The non-volatile state saver is ideal for diverse applications such as switch interfaces, relay drivers, LED drivers, recording error flags, power down state detection, non-volatile counters, tamper indicators, door open indicators, motor on/off control, DIP switch replacement, and jumper replacement, among others.

“The non-volatile state saver is a fundamental building block that most engineers can use in their designs,” says Ramtron Vice President Mike Alwais. “The FM1105 and FM1106 are the first in a new line of unusual and novel products that use FRAM technology. Non-volatile storage applied to logic is a revolutionary concept, which has yielded a unique product that can remember stored output values without a battery. Any change in state is automatically recorded in a non-volatile ferroelectric latch. This function is possible due to the fast writes and extremely high endurance of the underlying ferroelectric memory technology.”

The low-power non-volatile state saver provides continuous access to non-volatile system settings without reading a memory or consuming dedicated processor I/O pins. It enables storage of signals that may change frequently and without notice, and it allows the non-volatile storage of system settings without the system overhead and extra pins of a serial memory.

The FM1105 operates from 4.5V to 5.5V at a low operating current of less than 15µA, while changing state continuously at 1KHz. The FM1106 operates from 2.7V to 3.6V and boasts a low operating current of less than 5µA, while changing state continuously at 1KHz. Both devices offer an unlimited number of state changes, can run up to 1 MHz, and operate over the industrial temperature range (-40 degrees C to +85 degrees C). Visit www.ramtron.com/statesaver for more product details.

The non-volatile state saver is ideal for setting the correct state of a relay or switch. During normal operation, the system sets the state saver to control the relay. When power fails, the state saver remembers the last state and restores it automatically and immediately on power up. This allows the relay to power up in the correct state – on or off as the application requires. As a switch replacement, for example DIP switches or jumpers, the non-volatile state saver allows software to alter switch settings and still have continuous access to the signals even on power up.

Many systems need to capture the indication that an error has occurred. This may be a dangerous condition, a fault with equipment, or other status information. The non-volatile state saver is the easiest and fastest way to capture and preserve such an event during a power outage. The system indicates the occurrence of an error state to the non-volatile state saver. This state will be stored on power down and restored automatically on power up. The indication is continuously available and can be used as a control signal, unlike having the data stored in a memory.

Engineering samples of the FM1105 and FM1106 are available now. The device is packaged in an 8-pin SOT23 that is RoHS-compliant. Unit pricing starts at $0.36 for quantities of 10,000 units.