Voltage detecting device

1. A voltage detecting device comprising:

an analog converting circuit configured to level-convert voltages of a battery comprising plurality of battery cells into low voltages;

a digital converting circuit configured to convert the low voltages output by the analog converting circuit into digital values; and

a control circuit configured to be driven by a power supply provided separately to control the digital converting circuit;

wherein the analog converting circuit is driven by a first power generated from the plurality of battery cells, and

wherein the digital converting circuit is driven by a second power generated on a basis of a pulse signal generated by the control circuit.

2. The voltage detecting device according to claim 1 , further comprising

a smoothing circuit configured to generate the second power by smoothing the pulse signal generated by the control circuit.

3. The voltage detecting device according to claim 2 ,

wherein the pulse signal is a modulated signal including control information for the digital converting circuit.

4. The voltage detecting device according to claim 3 ,

wherein the modulated signal is a pulse width modulation signal indicating the control information as a duty ratio.

5. The voltage detecting device according to claim 2 ,

wherein the pulse signal is supplied from the control circuit to the smoothing circuit via a pulse transformer.