hello sir,
while i am designing the circuit in proteus software i am getting some doubts, i am giving signal input as 10 to 15V as you said and as of now i am giving 10V and 15V supply from a DC battery in proteus at Vext low and Vext high pins, and i am connected 5V supply at V+ and mode pins what my doubt is what about refout and ref adj pin connections, when i am connecting refout to 3.5K with 9K and adj pin to junction of 3.5K and 9k(as shown in the above exe file) what happen is when i am grounding the 9k no led is glowing but when i am leave the 9k as floating(no ground and no supply) it is working fine , why this is happening.