TPS561201: IC Pd Difference between TPS561208

Part Number:TPS561201

Dear, Sir. 

I tried to simulate TPS561201& TPS561208 using WEBENCH tool. 

The condition is ; 

VIN MIN=12V, VIN MAX=13V

VOUT=5V

IOUT=1A

I can see the difference on IC Pd at IOUT=1A as below. 

TPS561201 : aprox. 0.3W

TPS561208 : aprox. 0.22W

I think both products are operating under same CCM. 

Please give your advice reason why TPS561201's IC Pd is higher than TPS561208. 

Best Regards, 

H. Sakai