Charging control circuit, charging chip and charging equipment

Abstract

The invention provides a charge control circuit, including a voltage conversion module, a voltage detection module, a timer, a comparison trigger module and a controller. The voltage conversion module is used to generate a preset DC voltage and output it through the output interface, and charge the capacitive element connected to the output interface. The voltage detection module detects the voltage output by the output interface to obtain a detection voltage. The comparison trigger module generates first and second trigger signals respectively when the detected voltage is greater than the first threshold voltage and less than the second preset voltage value. The voltage converting module is turned off and turned on respectively when receiving the first and second trigger signals. The timer responds to the first and second trigger signals to count and stop timing respectively. The capacitive element is discharged when the voltage conversion module is turned off. The controller calculates the current output by the output interface according to the timing duration, the capacitance value of the capacitive element, and the first and second threshold voltages. The invention also provides a charging chip and a charging device. The invention can realize small current charging and current detection.

Description

technical field [0001] The invention relates to a charging circuit, in particular to a charging control circuit for controlling the charging process, a charging chip with the charging control circuit and a charging device with the charging control circuit. Background technique [0002] At present, with the rapid development of electronic products, there are more and more types of smart wearable devices with small-capacity batteries, such as smart watches, smart bracelets, and wireless earphones, and their use is becoming more and more extensive. Correspondingly, there is an increasing demand to ensure good charging of smart wearable products with small-capacity batteries. Generally speaking, since smart wearable devices use small-capacity batteries, the battery capacity is small, and the charging current used also needs to be small. For example, a general smart wearable device needs to be charged with a current of 5-10mA (milliampere), but for a general charging device, the...

AI Technical Summary

Problems solved by technology

However, in the existing 10-bit ADC, the general detection accuracy is 1-2mv. If it is necessary to detect a small current of 1-10mA, the resistance value of the sampling resistor needs to be 0.5 ohm-1 ohm. When the charging device is in a large current output, the loss is large , and need to add 10bit ADC, the cost is high

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