Digital　sensor　arrays　based　on　ring　oscillators　are　used　to　monitor　the　temperature　of　Field　Programmable　Gate　Array　(FPGA)　chips,　but　traditional　sensor　structures　using　binary　frequency　counters　consume　excessive　hardware　logic　resources.　This　paper　proposed　a　compact　temperature　sensor　array　that　used　low-decoding-complexity　linear　feedback　shift　registers　(LFSR)　as　a　frequency　counter　to　efficiently　count　the　ring　oscillator　frequency.　We　implemented　an　experimental　system　on　a　Spartan-6　FPGA,　and　the　logic　resource　consumption　of　the　entire　system　was　927　Look-Up-Tables　(LUTs)　with　an　overhead　of　only　10%.　The　single　sampling　time　was　approximately　40　μs.　The　proposed　temperature　sensor　array　has　good　temperature　sensing　capabilities,　and　the　measured　error　is　±0.9°C(3σ).　©　2021　Elsevier　Ltd