It's opined in Tom Clancy's book 'Armored Cav', that Chobham is mostly layers of Rolled Homogenous Armor with 2-3 small layers of ceramics. Tanks are fought in three manners, misdirection, brute force on the head of a pin, and with Chemistry professors. The brute force method uses an 'Aluminum Sabotted DU Long-Rod Penetrator', and the Chem tack uses a HEAT round. Basically a javelin of ultra-hot gases/plasma that can penetrate 80 cm of RHA.

The NATO answer to HEAT rounds, and Long-Rod Penetrators, is Chobham. To reduce the penetration of HEAT rounds, thin layers of heat resistant, and brittle ceramics are sandwiched inside thick layers of Depleted Uranium, which address the threat of the Kinetic energy weapons. A 45 CM piece of Chobham plate protects as well as something like 80cm of RHA against penetrators, and 130cm of RHA against HEAT rounds.

see also High-Velocity apfsds for info on the Armor Piercing Aluminum Sabotted Depleted Uranium Long Rod Penetrators (thanks 'The Custodian')