It depends how clean cut you want your consumption to be. If you want to consume the sun and all of the planets then it is not as easy as you might think.
A small black hole relative to the size of the sun and stationary with respect to the sun would fall directly into it and provided it was big enough not to evaporate quickly, would eventually consume the sun, the larger the mass the faster the consumption. But that would leave all the planets orbiting a black hole and the method of solar destruction would be complex.
An approach from 100AU would generate enormous velocities and the black hole would pass right through the sun and out of the other side. At some point gravity would decelerate the hole relative to the sun sufficiently to draw it back into the sun and the process would repeat itself but each time the hole would be heavier and the sun lighter.
The time this would take and the number of passes made would depend very much on the mass of the black hole relative to the sun and the “height” from which it fell. The black hole would eventual consume the sun, but the sun would probably be destabilised first. This would lead either to gravitational collapse due to reduced thermonuclear forces pushing the sun outward or more likely a nova type explosion due to reduced gravity of the sun.
A small black hole relative to the size of the sun but with angular velocity respect to the sun, would fall into an orbit around the sun. Depending on its size and orbit it might deflect some planets into interstellar space or collide with them and consume them, but the celestial mayhem might take a long time to play out.
If a large black hole is used relative to the size of the sun the effects would be similar except the effects would be more violent and more pronounced. But again it would be difficult to destroy the solar system in its entirety. Planets might be ejected into interstellar space, dragged into the hole or remain in a modified orbits around it. But it is unlikely they would all be destroyed and certainly not on the time scales that you are interested in.
It would take a truly massive black hole to disrupt all of the planets by tidal forces. Would this count? If it would and you’re interested the calculation could be made.
