Found 5 alternatives for XC3S1500-4FG456I by Xilinx Inc.. Embedded Fpgas Field Programmable Gate Array — 456-BBGA.
IC FPGA 264 I/O 456FBGA
IC FPGA 312 I/O 456FBGA
APA300-BG456IPM98
IC FPGA 290 I/O 456BGA