I don't know of anything that would be anti-personnel, but the Russians have something called the Arena-E active protection system. Mounts in a strip-like ring around the turret of a tank and it used to defeat ATGMs that are inbound on the tank. It fires an explosive charge when the missile gets within detection range and basicaly impacts/destroys the missile or causes premature activation of the warhead before the missile strikes the target.
It's mentioned that in an emergency, the commander of the tank can activate the system manually and explode munitions from the ring. So I guess it would be possible for a tank commander to use it in an anti-personnel manner should infantry be desperate enough to engage a tank in close combat.
Here's a link to a site that tells a little bit about it:
http://defense-update.com/products/a/arena-e.htm