An 8 bit current steering DAC for offset compensation purposes in sensor arrays

Abstract

Abstract. An 8 bit segmented current steering DAC is presented for the compensation of mismatch of sensors with current output arranged in a large arrays. The DAC is implemented in a 1.8 V supply voltage 180 nm standard CMOS technology. Post layout simulations reveal that the design target concerning a sampling frequency of 2.6 MHz is exceeded, worst-case settling time equals 60.6 ns. The output current range is 0–10 μA, which translates into an LSB of 40 nA. Good linearity is achieved, INL < 0.5 LSB and DNL < 0.4 LSB, respectively. Static power consumption with the outputs operated at a voltage of 0.9 V is approximately 10 μW. Dynamic power, mainly consumed by switching activity of the digital circuit parts, amounts to 100 μW at 2.6 MHz operation frequency. Total area is 38.6 × 2933.0 μm2.

An 8 bit to 12 bit Resolution Programmable 5 MSample/s Current Steering Digital-to-Analog Converter in a 22 nm FD-SOI CMOS Technology

“…It is known from [6] that DACs in a sensor-actuator system do not need to have high-level performance in terms of speed, accuracy and linearity. Conversion speed of a few tens kilohertz and resolution of 6 to 8 bit are satisfactory in DACs for this application [6], [7]. DNL of less than 1 LSB (Least Significant Bit) is also good enough.…”

“…Performance comparison with recently published 8-bit [7], 10-bit [8] and 12-bit converters [9]- [11] is given in Table 3. The proposed CS-DAC has the maximum data rate of 5 MS/s, while the recently published 12-bit converters report the maximum data rates of a few hundred MSample/s.…”

“…The proposed CS-DAC has the maximum data rate of 5 MS/s, while the recently published 12-bit converters report the maximum data rates of a few hundred MSample/s. The CS-DAC targets for the sensor-actuator applications, where the speed requirement is much relaxed [6], [7]. Otherwise, the 12-bit converters mainly target for high speed applications in the communication systems, where the speed requirement is regarded as the highest priority.…”

“…There are many different types of DAC architectures available. Examples are delta-sigma DAC (DS-DAC) [2], switched capacitor DAC (SC-DAC) [3], current steering DACs (CS-DAC) [4][5][6][7][8][9][10][11], [13], [15][16], which have been successfully developed to meet various application requirements. The CS-DACs have become effective solutions for the communication system applications, since they are fast, cost effective and have higher linearity [5].…”