■ ULN2003 Drive Circuit

 It is  a  NPN Darlington transistor array drive IC used to control multiple output. 

● This single IC can control 7 output from microcontroller, we can easily control output.

● A Darlington transistor (also known as Darlington pair) achieves very high current amplification by connecting two bipolar transistors in direct DC coupling so the current amplified by the first transistor is amplified further by the second one.

● The resultant current gain is the product of those two components of transistor. 

》FEATURES-

● It has 16 pin IC. Out of two ground and common pic IC.

● Contains 7 high-voltage and high current Darlington pairs

● Each pair is rated for 50V and 500mA

● Input pins can be triggered by +5V

● All seven Output pins can be connected to gather to drive loads up to (7×500mA) ~3.5A.

● Can be directly controlled by logic devices like Digital Gates, Arduino, PIC etc.

》 Circuit diagram-

》Application-

● drive the stepper motor 

● blinking the bulb 

● Working of drive circuit-