Pulse-Width DAC Circuit for Low-Power CIM Dot Products
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Convolutional neural networks (CNNs) using compute-in-memory (CIM) arrays face high power consumption due to the energy demands of digital-to-analog converters (DACs) and analog-to-digital converters (ADCs), which are necessary for generating dot products.
Innovation Solution
A circuit design incorporating a current source, switch, pulse signal generator, and multiplexor circuit within DACs to provide pulse signals with varying pulse widths, reducing power consumption by minimizing the number of wires and signals transmitted within the CIM array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional DACs and ADCs are used in CIM arrays, then dot product computations can be performed, but power consumption increases significantly
Solution Approach 1:
The patent replaces traditional digital-to-analog converters with a pulse-width modulation-based switching mechanism. Instead of using complex DAC circuitry to generate analog signals, the invention uses digital pulse signals with varying widths to directly control current switching, thereby performing dot product computations in the digital domain while minimizing analog conversion requirements and reducing power consumption
Solution Approach 2:
The invention changes the parameter used for data representation from amplitude-based analog voltages to time-based pulse widths. By encoding digital values as pulse durations rather than voltage levels, the system eliminates the need for high-power DACs while maintaining the ability to perform weighted computations through pulse width variation
2Quantity of substance
If multiple wires and signals are transmitted within CIM array, then data transmission is comprehensive, but power consumption and device complexity increase
Solution Approach 1:
The patent combines multiple data transmission functions into a single pulse signal line. By encoding both the data value and timing information in a unified pulse waveform, the system eliminates the need for separate digital and analog signal paths, reducing the number of wires and associated power consumption while maintaining full data transmission capability
Solution Approach 2:
The pulse signal serves multiple functions simultaneously: it carries digital data, provides timing synchronization, and directly controls current switching for computation. This multi-functional signal approach replaces what would traditionally require multiple dedicated signal lines, thereby reducing device complexity and power consumption
Data Source
AI summary
In one example, a circuit comprises: a current source having a current output; a switch coupled between the current output and a current terminal, the switch having a switch control input; a pulse signal generator having pulse signal outputs, the pulse signal generator configured to provide pulse signals having different pulse widths at the pulse signal outputs; and a multiplexor circuit having pulse signal inputs, a selection input and a selected pulse signal output, the selected pulse signal output coupled to the switch control input, and the pulse signal inputs coupled to the pulse signal outputs.