High speed digital-analog conversion circuit and operating method thereof

Abstract

The invention relates to a high speed digital-analog conversion circuit and an operating method thereof. The high speed digital-analog conversion circuit is characterized by consisting of two or more D / A subsystems. Segmented current steering structures are adopted between the subsystems; and each subsystem consists of a digital-analog conversion (DAC) module, a latch unit, a decoder circuit, a switch array circuit, a unit current source array circuit, a binary weighted current source circuit and two resistance ROUTs. The high speed digital-analog conversion circuit has the advantages of: 1, improving the reliability of the circuit; 2, improving the DAC speed and reducing errors; 3, effectively eliminating the noise and the detuning error; 4, realizing the high speed high precision digital-analog conversion function; and 5, ensuring a clear circuit structure, operation convenience and high practicability.

Description

(1) Technical field: [0001] The invention relates to a digital-to-analog conversion circuit, in particular to a high-speed digital-to-analog conversion circuit and its working method. (two) background technology: [0002] In traditional technologies, digital-to-analog conversion chips are mostly implemented with a charge-scaling or current-scaling structure. The normal operation of the charge-scaling digital-to-analog converter requires non-overlapping two-phase clocks, and the charging and discharging of the capacitor is controlled by the clock to realize the analog-to-digital conversion function. This structure has high precision, but has a large area, is sensitive to parasitic capacitance, and requires a two-phase clock, making the circuit complex. The current scaling digital-to-analog converter uses transistors to divide the reference current source into several groups with different weights, and the input digital signal controls different switches to select different o...

AI Technical Summary

Problems solved by technology

The current scaling digital-to-analog converter has two main disadvantages: First, it is not suitable for low-voltage applications, because the transistor is superimposed on the reference current source, which may cause the reference current source to enter when the output voltage is particularly low. linear region, so that the correct output signal cannot be obtained

Second, a relatively large reference current is required. When the resolution is high, too large a reference current will cause a sharp increase in power consumption

In the DAC design, the binary decoding circuit is simple and small in size, which is conducive to improving the working speed, but its matching is poor, there are glitches, and it is easy to introduce large DNL errors, especially at high positions; the structure of the thermometer decoding circuit has a good Excellent matching performance, small burrs, but its structure is complex, and its area and power consumption are relatively large

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