&lt;b&gt;Design of a low-power flash analog-to-digital converter chip for temperature sensors in 0.18 µm CMOS process

Al Al,Mohd Alauddin Mohd Ali,Mamun Bin Ibne Reaz,Jubayer Jalil

doi:10.4025/actascitechnol.v37i1.20870

<b>Design of a low-power flash analog-to-digital converter chip for temperature sensors in 0.18 µm CMOS process

Al Al, Mohd Alauddin Mohd Ali + Show 2 more

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https://doi.org/10.4025/actascitechnol.v37i1.20870

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Abstract

Current paper proposes a simple design of a 6-bit flash analog-to-digital converter (ADC) by process in 0.18 μm CMOS. ADC is expected to be used within a temperature sensor which provides analog data output having a range of 360 mV to 560 mV. The complete system consisting of three main blocks, which are the threshold inverter quantization (TIQ)-comparator, the encoder and the parallel input serial output (PISO) register. The TIQ-comparator functions as quantization of the analog data to the thermometer code. The encoder converts this thermometer code to 6-bit binary code and the PISO register transforms the parallel data into a data series. The design aims to get a flash ADC on low power dissipation, small size and compatible with the temperature sensors. The method is proposed to set each of the transistor channel length to find out the threshold voltage difference of the inverter on the TIQ comparator. A portion design encoder and PISO registers circuit selected a simple circuit with the best performance from previous studies and adjusted to this system. The design has an input range of 285 to 600 mV and 6-bit resolution output. The chip area of the designed ADC is 844.48 x 764.77 µm 2 and the power dissipation is 0.162 µW with 1.6 V supply voltage.

Highlights

Technological developments and use of wirelesssystem applications with low power consumption have become one of the main attractions in circuit design
Explosive growth of embedded sensor into radio frequency identification (RFID) tag is nowadays used with low voltage supply
The threshold inverter quantization (TIQ)-Comparator is functioning as data quantization of the analog data to thermometer code (TC), and is important for linearity and accuracy of the data transfer

Summary

Introduction

Technological developments and use of wirelesssystem applications with low power consumption have become one of the main attractions in circuit design. Explosive growth of embedded sensor into radio frequency identification (RFID) tag is nowadays used with low voltage supply. Sensor data, integrated into the RFID systems, require ADC circuits. The ADC design presented in this paper is a converter suitable for a temperature sensor. The temperature sensor is implanted on the RFID-Tag chip, which is integrated. Technology into the RFID or wireless system. The design is expected to have lower power dissipation and operating voltage, small area size and easy to integrate with the other circuits. The Flash-ADC has many advantages, such as high speed, high linearity, low voltage and reduced power dissipation (YOO et al, 2003). Previous researches have undertaken a variety of methods to get the best performance of ADC, as Table 1 shows

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