Resistance value measuring circuit and method, temperature monitoring device, battery pack and management system

The invention provides a resistance value measuring circuit and a method, a temperature monitoring device, a battery pack and a management system. The resistance value measuring method comprises the following steps of: obtaining a ratio K X VAL of a to-be-tested temperature-sensitive impedance unit voltage to a reference source voltage according to the characteristics of the analog-to-digital converter by setting a measuring auxiliary circuit that is in parallel with the thermistor measuring circuit and providing the reference source voltage of the analog-to-digital converter; and characterizing the current ratio in a form of combining K X VAL with resistance ratio according to the relationship between the current ratio and the total resistance ratio of the measuring auxiliary circuit andthe thermistor measuring circuit , and calculating the impedance value RX of the to-be-tested temperature-sensitive impedance unit. The voltage of the reference power supply and the reference source voltage of the analog-to-d