XC7S15, XC7S6 Datasheet - Xilinx

Spartan-7 FPGAs Data Sheet: DC and AC Switching Characteristics DS189 (v1.9) March 13, 2019 Product Specification Introduction Spartan®-7 FPGAs are available in -2, -1, and -1L speed grades, with -2 having the highest performance.

The Spartan-7 FPGAs predominantly operate at a 1.0V core voltage.

The -1L devices are screened for lower maximum static power and can operate at lower core voltages for lower dynamic power than the -1 devices.

The -1L devices operate only at VCCINT = VCCBRAM = 0.95V