Transmission network having an optical receiver that utilizes dual power pins and a single status pin to lower power consumption, lower manufacturing cost, and increase transmission efficiency
View Patent ↗A communication network is provided for interconnecting a network of digital systems, such as multimedia devices. Each node of the communication network may include a receiver and a transmitter. The receiver and transmitter of each node can be an optical receiver and transmitter. The optical receiver is preferably powered by two power supply pins, each providing different supply amounts. An activity detector within the receiver can be powered from a first supply amount, and the signal path of the optical receiver can be supplied from a second supply amount greater than the first supply amount. The first supply amount is provided at all times, and the second supply amount is only provided if activity is detected. A voltage regulator which provides the first supply amount can be beneficially embodied on the same integrated circuit as a network interface to reduce the manufacturing cost of the network. By powering the activity detector separate from the signal path, power down and power up (normal) operating states are envisioned for reducing power consumption and increasing longevity of the optical receiver and transmitter.
1. A transmitter circuit, comprising:
a transmitter comprising a light emitting diode (LED); and
an input pin coupled to the LED and configured to receive a digitally programmed output from a driver and/or an output from the driver that depends on a control signal sent from a receiver that is coupled to the driver;
wherein the control signal is sent from a downstream receiver coupled to receive an optical signal sent from the transmitter upstream from the downstream receiver; and
wherein a comparator within the downstream receiver compares an incoming signal corresponding to the optical signal to a predetermined value, a downstream network interface computes if the comparison results yields a power up or a power down value, a downstream transmitter coupled to the downstream network interface sends the power up or power down value optically to the receiver as the control signal, and the receiver forwards the control signal to the driver.
2. The transmitter circuit as recited in claim 1 , wherein the receiver is coupled via an upstream network interface to the LED for increasing the driver output or decreasing the driver output depending on whether the downstream network interface computes a power up or a power down value, respectively.
3. The transmitter circuit as recited in claim 1 , wherein the predetermined amount is stored in memory.
4. The transmitter circuit as recited in claim 1 , further comprising a diagnostic tool coupled between the LED and the receiver to calibrate output from the LED depending on a signal strength measured by the tool and placed upon the receiver.