NTE1508

The NTE1508 is a monolithic integrated circuit in an 18Lead DIP type package that senses analog voltage levels and drives 10 LEDs, providing a linear analog display. A single pin changes the display from a moving dot to a bar graph. Current of NTE1508 drive to the LEDs is regulated and programmable, eliminating the need for resistors. This feature is one that allows operation of the whole system from less than 3V. The NTE1508 contains its own adjustable reference and accurate 10step voltage divider.

The low biascurrent input buffer accepts signals down to GND, or V, yet needs no protection against inputs of 35V above or below GND. The buffer NTE1508 drives 10 individual comparators referenced to the precision divider. Indication nonlinearity can thus be held typically to 1/2%, even over a wide temperature range. Versatility was designed into the NTE1508 so that controller, visual alarm, and expanded scale functions are easily added on to the display system. The circuit can drive LEDs of many color, or lowcurrent incandescent lamps. Many NTE1508s can be "chained" to form displays of 20 to over 100 segments. Both ends of the voltage divider are externally available so that 2 drivers can be made into a zerocenter meter.

The NTE1508 is very easy to apply as an analog meter circuit. A 1.2V fullscale meter requires only 1 resistor and a single 3V to 15V supply in addition to the 10 display LEDs. If the 1 resistor is a pot, NTE1508 becomes the LED brightness control When in the dot mode, there is a small amount of overlap or "fade" (about 1mV) between segments. This assures that at no time will all LEDs be "OFF", and thus any ambiguous display is avoided. Various novel displays of NTE1508 are possible. Much of the display flexibility derives from the fact that all outputs are individual, DC regulated currents. Various effects can be achieved by modulating these currents.

The individual outputs of NTE1508 can drive a transistor as well as a LED at the same time, so controller functions including "staging" control can be performed. The NTE1508 can also act as a programmer, or sequencer.