Voltage detecting device

A device for detecting an interface voltage, comprising:

• a first control circuit receiving the interface voltage to generate a first control signal and drive a first voltage level indicator, comprising a first detecting circuit detecting the interface voltage to generate a first detect signal and a first driving circuit turning on the first voltage level indicator in response to the first detect signal if the interface voltage level is less than a first voltage level;
• a second control circuit receiving the interface voltage to generate a second control signal and drive a second voltage level indicator, comprising a second detecting circuit detecting the interface voltage to generate a second detect signal and a second driving circuit turning on the second voltage level indicator if the interface voltage level exceeds a second voltage level;
• and
• a third control circuit coupled to the first and second control circuits, receiving the first and second control signals to drive a third voltage level indicator if the interface voltage level is between the first and second voltage levels;
• wherein the third control circuit comprises:
• a first FET comprising a gate receiving the first control signal, a source coupled to ground, and a drain coupled to a cathode of the third voltage level indicator;
• and
• a second FET comprising a gate receiving the second control signal, a source coupled to ground, and a drain coupled to an anode of the third voltage level indicator;
• wherein the anode of the third voltage level indicator receives the interface voltage via a seventeenth resistor and a cathode thereof receives the interface voltage via an eighteenth resistor.

A detection device assembly comprising:

• an interface configured for receiving a signal from a peripheral electronic device of which an operating voltage range is between a first voltage level and a second voltage level;
• a detection device configured for detecting an interface voltage of the interface, the detection device comprising:
• a first control circuit comprising a first detecting circuit for receiving the interface voltage to generate a first detect signal, and a first driving circuit comprising a first voltage level indicator and receiving the first detect signal to generate a first control signal to control the first voltage level indicator;
• and
• a second control circuit comprising a second detecting circuit for receiving the interface voltage to generate a second detect signal, and a second driving circuit comprising a second voltage level indicator and receiving the second detect signal to generate a second control signal to control the second voltage level indicator, wherein
• when the interface voltage level is lower than the first voltage level, the first voltage level indicator turns on and when the interface voltage level is higher than the second voltage level, the second voltage level indicator turns on;
• wherein the second driving circuit comprises:
• a first transistor comprising a base receiving the second detect signal and the interface voltage via a first resistor, an emitter coupled to ground, and a collector receiving the interface voltage via a second resistor;
• a second transistor comprising a base coupled to the collector of the first transistor via a third resistor, an emitter coupled to ground, and a collector;
• a third transistor comprising an emitter receiving the interface voltage, a base coupled to the emitter of the third transistor via a fourth resistor and coupled to the collector of the second transistor, and a collector generating the second control signal and coupled to the base of the second transistor via a fifth resistor;
• and
• a diode comprising an anode coupled to the collector of the seventh transistor via a sixth resistor, and a cathode coupled to an anode of the second voltage level indicator;
• wherein the second voltage level indicator has a cathode coupled to ground,