dc‑dc converter with linear overtemperature protection circuit

Abstract

The invention relates to a DC-DC converter with a linear over-temperature protection circuit. The DC-DC converter includes: a temperature triode, which generates a junction voltage signal on the basis of the collected temperature of the DC-DC converter; a linear over-temperature protection circuit, which forms an error amplification signal on the basis of the junction voltage signal and a first voltage reference signal; a clamp circuit, which limits the maximum value and the minimum value of the error amplification signal to enable the error amplification signal to keep within a fixed voltage range, and also forms a temperature adjusting signal; a PWM signal generation circuit, which forms a PWM pulse signal on the basis of the temperature adjusting signal and a slope signal; and a drive circuit, which generates, on the basis of the PWM pulse signal, a drive signal to control the output power of a DC-DC boost circuit. According to the embodiment, the output power of the DC-DC converter can be linearly adjusted so that the inner temperature keeps constant, thereby preventing an overly high temperature from affecting the converter and an internal chip. Moreover, noise caused by frequent turning on and turning off of the chip in the prior art is avoided, and thus the DC-DC converter can function steadily.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a DC-DC converter with a linear over-temperature protection circuit. Background technique [0002] figure 1 It shows a synchronous step-up DC-DC (Direct Current, DC power supply) converter structure, the input signal VIN is connected to the SW terminal through the inductor L, and the low-side NMOS transistor is connected between the SW terminal and the common terminal GND; when the When the low-side NMOS transistor is turned on, the inductor L is charged. The high-end PMOS transistor is connected between the SW terminal and the output terminal VOUT; when the high-end PMOS transistor is turned on, the inductor L is discharged. By controlling the switching action of the low-end NMOS transistor and the high-end PMOS transistor, the inductor L is charged and discharged, thereby outputting a stable DC voltage signal. When abnormal conditions such as high ambient tempera...

AI Technical Summary

Problems solved by technology

[0004] One of the objectives of the present invention is to provide a DC-DC converter with a linear over-temperature protection circuit to solve the problem of abnormal operation of the DC-DC converter caused by the shutdown of devices by the existing over-temperature protection circuit or the influence of noise on DC -Technical issues with DC converter work

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