PIC18F4520-1/P PIC18F4520-E/ML PIC18F4520-E/P PIC18F4520-E/PT PIC18F4520-E/PTH PIC18F4520-I PIC18F4520-I/ML PIC18F4520I/P PIC18F4520-I/P PIC18F4520-I/PH