Addressable current reference array with 170dB dynamic range

Configurable high-performance bias current reference circuits are useful in complex mixed-signal chips. This paper presents the design of a configurable current reference array with ultra wide dynamic range (DR). A coarse-fine architecture using octal coarse current spacing and 8 bits of fine resolution increases the overall current DR with less area compared with the prior work. Compact current multipliers and dividers also save chip areas. Shifted-source current mirrors and an off-current suppression technique improve the accuracy of generated low currents. A buffer with dual-threshold source followers is used to generate the output biasing voltage with a wide DR input current. Biases are individually addressable and configurable. Measurement results of this design in UMC 0.18μm 1P6M CMOS process suggest that over 170dB DR is achieved at room temperature. Each additional bias occupies an incremental area of 360×22μm², which is smaller by a factor of 4 compared to the previous design.