Termination without another co-parent in the picture.
You simply want to get your ex off your and your child's backs by terminating their parental rights? Unfortunately, no, you can't. If you have a new spouse or domestic partner who wants to adopt your child, you may be able to have a termination accompanying their adoption. But without that scenario, you can't just terminate the other parent's rights... even if they want to consent.
You sign away your rights and I'll drop the child support.
You can't do this, even if both of you want to. See above. Pennsylvania courts, as of 2011, only terminate parental rights if there is an adoption pending, or if the local courts handle an involuntary termination through a children's services case.
Your spouse/partner wants to adopt your child
If your ex is willing to cooperate, there is a form for voluntary termination of parental rights, which will be filed accompanying your petition for adoption. If your ex is not willing to cooperate, you will have to file a petition for involuntary termination of parental rights along with the adoption papers, but your situation must meet the required criteria for an involuntary termination. These criteria include absence from the child's life and lack of support for a substantial period of time; the criteria are stated in Pennsylvania Consolidated Statutes and can also be found on line (see links).
How about if I Report them to children's services?
You may obtain custody of your child this way, if you did not have custody previously --but this won't lead to termination of your ex's rights. This is also a dangerous game because children's services may also decide to investigate you. One parent's report on the other has led to both parents having children removed from them. The children's services reporting game is fraught with danger -- don't do it, anonymously or otherwise.
Additional resources provided by the author
Title 23 (Domestic Relations), Pennsylvania Consolidated Statutes