555 timer ics texas instruments sa555p this texas instruments sa555p has a high output current capability sinking or sourcing 200ma which is ttl compatible it is able to operate in astable or monostable mode the output is fully compatible with cmos ttl and mos it uses a single supply from 45vdc to 16vdc it is pin compatible and functionally interchangeable with the ne555 texas instruments sa555p linear ic precision timer dip8