System main board with optical module soft-start function and control device for soft-start optical module

Abstract

A system motherboard with optical module protection function is suitable for connecting a plurality of optical modules. It includes a plurality of port interface devices and a plurality of control devices respectively disposed therein. Each control device includes a switching unit and a control circuit. The switching unit determines the switching between an on and off state between a power conversion circuit and the optical module. The control circuit is electrically connected to the optical module and the switching unit and receives an access signal indicating whether the optical module is connected. When the access signal indicates that the optical module is connected, the control device controls the switching unit to switch to the on state after a delay time. By delaying the drive current when the optical module is connected, the control circuit reduces the large inrush current generated at the moment of optical module connection, avoiding damage to the power conversion circuit or reducing its service life.

Claims

1. A control device capable of soft-starting an optical module, suitable for electrically connecting a power conversion circuit and the optical module to provide a drive current output by the power conversion circuit to the optical module, the control device comprising: a switching unit for being electrically connected between the power conversion circuit and the optical module, and switchable between an on state and a non-conducting state; and a control circuit having a first terminal for being electrically connected to the optical module and a control terminal for being electrically connected to the switching unit, the control circuit being configured to receive an access signal indicating whether the optical module is accessed via the first terminal, and, upon the access signal indicating that the optical module is accessed, controlling the switching unit via the control terminal with a drive signal after a delay time, causing the switching unit to switch from the non-conducting state to the on state, thereby transmitting the drive current to the optical module and activating the optical module; and a detection circuit electrically connected to the switching unit; wherein... The control circuit also has a second terminal electrically connected to the detection circuit; wherein the detection circuit is used to receive a first reference voltage related to the power level of the optical module and a second reference voltage indicating the magnitude of the drive current currently transmitted to the optical module. The detection circuit is configured to generate a comparison signal based on the first reference voltage and the second reference voltage, and send the comparison signal to the second terminal of the control circuit. The comparison signal indicates whether the drive current transmitted to the optical module is abnormal. When the comparison signal indicates that the drive current is abnormal, the control circuit is configured to control the switching unit based on the comparison signal, so that the switching unit switches to the non-conducting state.

2. The control device as claimed in claim 1, wherein the switching unit is a metal-oxide-semiconductor field-effect transistor (MOSFET) having a gate electrically connected to the control circuit to receive the drive signal, a source electrically connected to the power conversion circuit, and a drain electrically connected to the optical module.

3. The control device as claimed in claim 2, wherein the control circuit comprises: A first transistor having a base electrically connected to the first terminal, a collector, and a grounded emitter; A second transistor has a base electrically connected to the collector of the first transistor, a collector electrically connected to the gate of the switching unit, and a grounded emitter. When the optical module is connected, the connection signal is at a low level, the first transistor is not turned on and the second transistor is turned on, so that the switching unit switches to the on state.

4. The control device as claimed in claim 1, wherein the detection circuit includes a current detector electrically connected between the switching unit and the optical module for detecting the drive current, and the detection circuit is configured to generate the second reference voltage based on the detection result of the current detector.

5. The control device as claimed in claim 4, wherein the current detector is a resistor having two terminals electrically connected to the switching unit and the optical module respectively, and the detection circuit further includes: A first comparator having two input terminals respectively connected to the two ends of the current detector and an output terminal, the first comparator being configured to generate the second reference voltage based on the voltage drop between the two ends of the current detector; and a second comparator having a first input terminal electrically connected to the output terminal of the first comparator to receive the second reference voltage, a second input terminal for receiving the first reference voltage, and an output terminal electrically connected to the control circuit, the second comparator being configured to output a comparison signal to the control circuit through the output terminal based on the first reference voltage and the second reference voltage.

6. A system motherboard with an optical module soft-start function, suitable for connecting at least one optical module, and comprising: a power conversion circuit for providing a plurality of drive currents; a plurality of port interface devices for respectively connecting the optical module; and a plurality of control devices respectively disposed in the port interface devices, each of the control devices comprising: A switching unit is electrically connected between the power conversion circuit and the optical module, and can switch between an on state and a off state; a control circuit has a first terminal electrically connected to the optical module and a control terminal electrically connected to the switching unit. The control circuit is configured to receive an access signal indicating whether the optical module is accessed via the first terminal, and when the access signal indicates that the optical module is accessed, control the switching unit via a drive signal through the control terminal after a delay time, so that the switching unit switches from the off state to the on state, so as to transmit the drive current to the optical module and thereby start the corresponding optical module; wherein, each of the control devices further includes a detection circuit electrically connected to the switching unit, and the control circuit also has a second terminal electrically connected to the detection circuit. The detection circuit is used to receive a first reference voltage related to the power level of the optical module and a second reference voltage indicating the magnitude of the drive current currently transmitted to the optical module. The detection circuit is configured to generate a comparison signal based on the first reference voltage and the second reference voltage, and send the comparison signal to the second terminal of the control circuit. The comparison signal indicates whether the drive current transmitted to the optical module is abnormal. When the comparison signal indicates that the drive current is abnormal, the control circuit is configured to control the switching unit based on the comparison signal, so that the switching unit switches to the non-conducting state.

7. The system motherboard as described in claim 6, wherein, For each of these control devices, the detection circuit further includes a current detector electrically connected between the switching unit and the optical module for detecting the drive current, the detection circuit being configured to generate the second reference voltage based on the detection result of the current detector.

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