Patent ID: 7486050

Claim:
A battery-voltage monitoring apparatus for monitoring a voltage of a specified number of serially-connected secondary batteries, the apparatus including plural integrated circuits, each of which comprising: a first voltage source terminal that is connected to a maximum voltage terminal of a corresponding part of the secondary batteries to be monitored, a first voltage being input to the first voltage source terminal; a second voltage source terminal that is connected to a minimum voltage terminal of the corresponding part of the secondary batteries to be monitored, a second voltage being input to the second voltage source terminal; a battery-voltage detecting unit that outputs a detection signal based on a result of a voltage monitoring of each of the secondary batteries; a first reference-voltage generating unit that receives the first voltage and the second voltage as operating voltages, and generates a first reference voltage; a first voltage converting unit that receives the detection signal, and converts the detection signal received into either the first reference voltage or the second voltage; and an output terminal that outputs the detection signal converted by the first voltage converting unit as an output detection signal, and wherein the output terminal that outputs the detection signal of a first integrated circuit is coupled via a resistor to a terminal coupled to the first reference voltage of a second integrated circuit, and an intermediate node of the resistor is coupled to the second integrated circuit to supply a control signal for the second integrated circuit.