about Electronics help me!

about Electronics help me!
Design a 40% duty cycle square wave generator circuit with an adjustable
frequency of between 1 to 10 KHz.The output should have an adjustable linear output
voltage range of between 0 to 5 V and be capable of supplying a current of 150 mA
throughout the voltage range.Your design should include a circuit schematic and
provide complete specification of all components used in the design.Your design
description should show all calculations you have made to size the components and
provide all justifications why you have chosen the design and component
specifications.