A wideband calibration-free 1.5-GS/s 8-bit analog-to-digital converter with low latency

This article presents a wideband calibration-free 8-bit analog-to-digital converter (ADC) with low latency. The ADC employs a two-stage cascaded folding and interpolating architecture. A high-linearity and wideband track-and-hold amplifier combined with a low-parasitic-capacitance folding amplifier is employed to improve the performance. A binary-ROM with “keep-alive” current is proposed to guarantee no miscode when large bit-rate is input. When the sampling frequency is 1.5 GHz, the ADC achieves +0.29/?0.20 LSB DNL and 0.90 LSB INL. The ADC’s effective-number-of-bit and spur-free-dynamic-range are 7.0 bit and 51.8 dB respectively at 230 MHz input. The effective-resolution-bandwidth exceeds the second Nyquist zone up to 1.8 GHz. All of this makes this ADC suitable for wideband digital receiver system.