There are actually some sources that use the term 'Chobham' to refer to any type of 3rd generation composite armour.

 

More correctly 'Chobham' is a series of ceramic composite armour packages developed at the British armour research centre at Chobham Common, Surrey. This armour package is used on the M1 tank series, Challenger 1 and Challenger 2 tanks. The M1A1HA and M1A2 variants add a layer of depleted uranium.

The Leopard 2 uses a 'perforated' armour package - multiple plates of steel interspaced with composites and ceramic polysteryne foam. The Leopard 2 then underwent a series of armour upgrades with successive marks to the current Leopard 2A6 or 2A7+ standards.

 

h**p://en.wikipedia.org/wiki/Perforated_armour

"This armour package is used on the M1 tank series, Challenger 1 and Challenger 2 tanks"

True about all facts except for the Challenger 2. it uses the 2nd generation upgraded/enhanced version of Chobham called Dorchester, Currently the Challenger is the only tank to field this armour package, the Abrams (and variants) still use the older first generation Chobham variant