Featured Post

High CMRR Instrumentation Amplifier (Schematic and Layout) design for biomedical applications

on
Instrumentation amplifiers are intended to be used whenever acquisition of a useful signal is difficult. IA’s must have extremely high input impedances because source impedances may be high and/or unbalanced. bias and offset currents are low and relatively stable so that the source impedance need not be constant. Balanced differential inputs are provided so that the signal source may be referenced to any reasonable level independent of the IA output load reference. Common mode rejection, a measure of input balance, is very high so that noise pickup and ground drops, characteristic of remote sensor applications, are minimized.Care is taken to provide high, well characterized stability of critical parameters under varying conditions, such as changing temperatures and supply voltages. Finally, all components that are critical to the performance of the IA are internal to the device. The precision of an IA is provided at the expense of flexibility. By committing to the one specific task of
2

Static 0 to 9 Display using SN7446 and 7490

on
The circuit shown here is a simple Static 0-9 Display can be used in many applications. The circuit is based on 7490 asynchronous decade counter (IC2), a 7-segment display (D1), and a seven-segment decoder / driver IC 7446 (IC1).


The seven-segment display consists of 7 LEDs as 'a' to 'g'. For different LEDs bias, we can show the digits 0 to 9. Seven Segment Displays are of two types, the common cathode and common anode. Like the type of anode anodes of all seven LEDs are attached, while the type common cathode cathodes are all together. The seven-segment display used here is a type common anode. The resistance R1 to R7 are current limiting resistors. IC 7446 is a decoder / driver IC that is used to control the seven segment display.

Work of this circuit is very simple. For each clock pulse output of IC2 BCD (7490) advances a bit. The IC1 (7446) decodes the BCD output for the form of seven segments and controlling the display to indicate the corresponding digit.

Comments

Post a Comment