Digital to analog converter based on pulse-width adding

• Author(s): Viegas, Vítor ; Pereira, José Miguel Costa Dias
• Date: 2024
• Persistent ID: http://hdl.handle.net/10400.26/57371
• Origin: Instituto Politécnico de Setúbal
• Subject(s): Digital-to-analog converter; DAC; Pulse width; PWM
• Document Type: Journal article
• Language: English
• Contributor(s): Repositório Comum

Description

This paper presents a digital-to-analog converter (DAC) based on the pulse width created naturally by the binary counting sequence. The concept involves combining the counting impulses of the bits to form a pulse-width modulated signal, where the mean voltage is proportional to the input digital code. We propose a circuit capable of achieving this using general-purpose components. Although our design targets 8 bits, it is scalable for any number of nibbles. The paper details simulations conducted to verify the proper functioning of the circuit and to evaluate its performance. Tests were performed to determine the static characteristics of the converter, measure its differential nonlinearity (DNL), and observe its step response. In static terms, the converter exhibited negligible gain and offset errors, with a DNL below 1 LSB (least significant bit). The converter operated correctly without any missing codes. In dynamic terms, the converter demonstrated a bandwidth of 10 kHz and behaved like a second-order low-pass filter with critical damping.