Integrated circuits in optical receivers
View Patent ↗A circuit may include a photodiode configured to receive an optical signal and convert the optical signal to a current signal. The circuit may also include a transimpedance amplifier coupled to the photodiode and configured to convert the current signal to a voltage signal. The circuit may also include an equalizer coupled to the transimpedance amplifier and configured to equalize the voltage signal to at least partially compensate for a loss of a high frequency component of the optical signal. The equalizer and the transimpedance amplifier may be housed within a single integrated circuit.
1. A circuit comprising:
a photodiode configured to receive an optical signal and convert the optical signal to a current signal;
a transimpedance amplifier configured to convert the current signal to a voltage signal;
an equalizer configured to equalize the voltage signal to at least partially compensate for a loss of a high frequency component of the optical signal; and
a driver coupled to the equalizer, the driver comprising a non-linear driver configured to drive the equalized voltage signal to a clock and data recovery circuit in a first integrated circuit separate from a second integrated circuit that includes the driver, the equalizer, and the transimpedance amplifier.
2. The circuit of claim 1 , wherein the equalizer comprises a linear equalizer.
3. The circuit of claim 1 , wherein the equalizer comprises a linear feedforward equalizer or a continuous time linear equalizer.
4. The circuit of claim 1 , wherein the equalizer comprises an analog equalizer.
5. The circuit of claim 1 , wherein the equalizer comprises a digital equalizer.
6. The circuit of claim 5 , wherein the digital equalizer is configured to allow for adjustment of equalization performed by the digital equalizer.
7. The circuit of claim 1 , wherein the voltage signal comprises a pair of differential voltage signals.
8. The circuit of claim 1 , wherein the equalizer includes:
a static portion configured to provide constant equalization of the voltage signal; and
an adjustable portion configured to provide adjustable equalization of the voltage signal.
9. A circuit comprising:
a photodiode configured to receive an optical signal and to convert the optical signal to a current signal;
a transimpedance amplifier coupled to the photodiode and configured to convert the current signal to a voltage signal; and
an equalizer coupled to the transimpedance amplifier, the equalizer comprising:
a static portion configured to provide constant equalization of the voltage signal; and
an adjustable portion configured to provide adjustable equalization of the voltage signal.
10. The circuit of claim 9 , wherein the equalizer is configured to equalize the voltage signal to at least partially compensate for a loss of a high frequency component of the optical signal.
11. The circuit of claim 9 , wherein the equalizer and the transimpedance amplifier are housed within a single integrated circuit.
12. The circuit of claim 9 , wherein the equalizer comprises a linear equalizer.
13. The circuit of claim 9 , wherein the equalizer comprises a linear feedforward equalizer or a continuous time linear equalizer.
14. The circuit of claim 9 , wherein the equalizer comprises an analog equalizer.
15. The circuit of claim 9 , wherein the equalizer comprises a digital equalizer.
16. The circuit of claim 9 , wherein the voltage signal comprises a pair of differential voltage signals.