针对非制冷红外探测器系统,提出了一种恒流偏置的红外读出电路( ROIC),该电路具有衬底温度补偿功能,且可实现片上偏移非均匀性补偿.基于微测辐射热计等效电阻受目标温度、衬底温度等影响的等效模型,每个读出通道采用两个盲电阻以消除衬底温度的影响,同时使用 DAC逐点调节参考电压,以完成片上偏移非均匀性补偿.该 ROIC应用到阵列大小为 320×240的非制冷微测辐射热计焦平面上,已在 CSMC 05MIXDDST02的 0.5 .m CMOS标准工艺下成功流试验片.电路测试结果表明:对于常温目标,当衬底温度变化 60 K时,输出电压变化小于 500 mV;经偏移非均匀性补偿后,阵列的固定图像噪声为 11.8 mV.该 ROIC适用于应用于复杂温度环境的高均匀性非制冷红外探测器.

This paper describes a constant current-biased readout circuit with substrate temperature compensation and non-uniformity compensation for the uncooled micro-bolometer detector.The influence of temperature for the equivalent resistance of micro-bolometer is evaluated.Then an effective way for substrate temperature compensation is proposed,which utilizes two blind micro-bolometers in each readout circuit channel.On the other hand,the non-uniformity compensation is also achieved by a 5 bits on-chip DAC.A 320×240 uncooled micro-bolometer focal plane array(FPA)based on the proposed circuit was implemented on silicon by 0.5 .m CMOS technology.The measurement data show that the maximum difference of a normal temperature object over 60 K substrate of which temperature change is only 500 mV and the fixed pattern noise(FPN)is less than 11.8 mV.Thus it is ideally suited for high performance production applications.