Sub-microwatt analog VLSI trainable pattern classifier
Sub-microwatt analog VLSI trainable pattern classifier
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DOI:
10.1109/jssc.2007.894803
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发表时间:
2007-05-01
影响因子:
5.4
通讯作者:
Cauwenberghs, Gert
中科院分区:
文献类型:
--
作者:
Chakrabartty, Shantanu;Cauwenberghs, Gert
The design and implementation of an analog system-on-chip template-based pattern classifier for biometric signature verification at sub-microwatt power is presented. A programmable array of floating-gate subthreshold MOS translinear circuits matches input features with stored templates and combines the scores into category outputs. Subtractive normalization of the outputs by current-mode feedback produces confidence scores which are integrated for category selection. The classifier implements a support vector machine to select programming values from training samples. A two-step calibration procedure during programming alleviates offset and gain errors in the analog array. A 24-class, 14-input, 720-template classifier trained for speaker identification and fabricated on a 3 mm x 3 mm chip in 0.5 mu m CMOS delivers real-time recognition accuracy on par with floating-point emulation in software. At 40 classifications per second and 840 nW power, the processor attains a computational efficiency of 1.3 x 10(12) multiply-accumulates per second per Watt of power.