Datasheet Summary
XR- 2277/2278
Dot and Bar Graph Display Generators
GENERAL DESCRIPTION
FUNCTIONAL BLOCK DIAGRAM
The XR-2277 and XR-2278 are 12 point level detector circuits designed for direct interfacing to light emitting diode (LED) moving-dot or bar-graph displays. Each of the circuits is prised of an input buffer amplifier and 12 parators, biased from a resistor string at logarithmic intervals. Accuracy is enhanced by an internal reference. Each parator provides a high impedance current source output which are all very closely matched and simultaneously adjustable with a single external resistor. A control signal applied to the mode select pin determines whether the display is driven in a...