| 摘要 |
A light to frequency converter includes a temperature coefficient generator, a programmable gain amplifier, and a current controlled oscillator having at least one photodiode configured to receive incident light, the at least one photodiode configured for generating a photodiode control current. The temperature coefficient generator outputs a bandgap reference voltage with temperature coefficient compensation (VBG_TC) in response to a bandgap reference voltage (VBG). The programmable gain amplifier is responsive to the bandgap reference voltage with temperature coefficient compensation (VBG_TC) for outputting an oscillator reference voltage (VREF). Lastly, the current controlled oscillator further includes a switching capacitor configured to provide a feedback current, the current controlled oscillator responsive to the oscillator reference voltage (VREF), the photodiode control current, and the feedback current for producing an output signal having a frequency proportional to an intensity of the incident light, wherein the bandgap reference voltage with temperature coefficient compensation modifies a temperature coefficient of the switched capacitor feedback current to match a temperature coefficient of the photodiode control current. According to another embodiment, the light to frequency converter operates with the use of a bandgap voltage generator, the bandgap generator not including temperature coefficient compensation.
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