OVERCHARGE PREVENTING CIRCUIT AND SEMICONDUCTOR DEVICE

摘要

PURPOSE: An overcharge preventing circuit and a semiconductor device are provided to discharge current by using a clamp transistor and an overcharge protection switch in overcharging detection, and to clamping the voltage of a power generation unit with the voltage of a charge storage unit. CONSTITUTION: The negative terminal and the positive terminal of a solar cell(11) are connected to a low potential power source(VSS) and a power generation source(VSOL). The negative terminal and the positive terminal of a secondary battery(12) are connected to the low potential power and a battery power source(VBAT). An overcharging detection circuit(14) is operated between the battery power source and the low potential power source. The source terminal of an NMOS transistor(15) and a back gate terminal are connected to the low potential power source. The gate terminal of a PMOS transistor(16) is connected to the cathode terminal of a diode(13) and the battery power source. [Reference numerals] (14) Overcharging detection circuit;