Four‐channel self‐compensating single‐slope ADC for space environments

Abstract

A multichannel high-resolution single-slope analogue-to-digital converter (SS ADC) is presented that automatically compensates for process, voltage and temperature variations, as well as for radiation effects, in order to be used in extreme environmental conditions. The design combines an efficient implementation by using a feedback loop that ensures an inherently monotonic and very accurate ramp generation, with high levels of configurability in terms of resolution and conversion rate, as well as input voltage range. The SS ADC was designed in a standard 0.35 µm CMOS technology. Experimental measurements of the performance and stability against radiation and temperature are presented to verify the proposed approach.Introduction: Single-slope analogue-to-digital converters (SS ADCs) are widely used in many multichannel data acquisition applications by implementing parallel readout architectures. The ramp generator is a key element in this conversion scheme, given the direct relationship between its performance and the ADC transfer characteristic. When medium to high resolutions are the aim, process, voltage and temperature (PVT) and ageing variations can limit the accuracy of the SS ADC. Moreover, in space environments, circuits are required to operate in an extended temperature range and also to deal with the total ionising dose (TID) radiation effects that degrade the DC and AC performance characteristics with a gradual change with time [1]. All of these effects can produce variations in the slope of the ramp, which critically affects the performance of the overall SS ADC. This is illustrated in Fig. 1.

CMOS Rad-Hard Front-End Electronics for Precise Sensors Measurements

“…The input voltage range can also be configured with many ranges between 0 and 2.8 V. High impedance paths can be connected at the input of each channel when required. The implementation consists of parallel readout architecture with a ramp generator and four self-biased comparators [22], as shown in Fig. 13.…”

A Front-End ASIC for a 3-D Magnetometer for Space Applications by Using Anisotropic Magnetoresistors

“…An integrator driven by an nMOS transistor, acting as a voltage-controlled current source, implements the ramp generator. The generation of the ramp is controlled by a feedback loop comprised by a capacitor (C F ) and two pairs of switches [12]. The feedback loop locks the end value of the ramp, to the reference voltage (V REF LAST ), by regulating the input voltage of the current source.…”

Pulse train‐controlled CCM boost converter with suppression of low‐frequency oscillation

“…Boost converters have been popularly used in switching power supply, DC motor feedback system, high step-up ratio DC-DC converter and power factor correction [1,2] due to their advantages of simple topology, continuous input current and excellent steadystate performance. The researches of switching converter control technology started in the 1960s and have made significant contributions to the development of power electronics industry [3][4][5][6][7][8][9][10][11][12][13][14][15]. The traditional classic pulse width modulation (PWM) technology can realise the output voltage regulation by adjusting the conduction time of the switch in a switching period.…”

“…Deisch reported in 1978 that the peak current control could improve the response speed to the input voltage change and the precision of the output voltage but not deal with the immediate load change [11]. The introduction of compensation slope can ensure the stale operation of the switching converter, but it reduces the dynamic performance of the whole system [12]. The valley-current control technology was first introduced in 1985, and its practical application was pointed out in 2001 [13], which explained that this technology has the superior transient response characteristics.…”