The input is all 12V, the output needs to be +15V, -15v, +15V is generated by LTM8056, and -15v is generated by LTM8045, two problems as follow:
1. The power of -15v is not enough. Can the LTM8045 be connected in parallel?
2. The outputs of +15V and -15v are common ground, and both are non-isolated. Is there any output balance or current sharing problem?
1. Paralleled LTM8045's will not share current. For higher power, you can use LTM8049, and that can be setup to share.