Self-adaptive low-noise power supply circuit for optical module

Abstract

The invention provides a self-adaptive low-noise power supply circuit for an optical module in the technical field of optical modules. The self-adaptive low-noise power supply circuit comprises a primary voltage regulating module, a secondary voltage regulating module and a voltage feedback module, the first-stage voltage regulating module, the second-stage voltage regulating module, the voltage feedback module and the first-stage voltage regulating module are connected in sequence; the primary voltage regulating module comprises a voltage regulating chip U1, an inductor L1, a resistor R1 and a capacitor C1; the secondary voltage regulation module comprises a voltage regulation chip U2, a resistor R6, a resistor R7, a resistor R8, a capacitor C2, a capacitor C3, a capacitor C4 and a capacitor C5. The low-noise power supply circuit has the advantages that the power consumption and the cost of the low-noise power supply circuit are greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of optical modules, and in particular to an adaptive low-noise power supply circuit for an optical module. Background Art

[0002] The optical module is an optoelectronic device that performs photoelectric conversion and electro-optical conversion. According to the protocol and specifications of the optical module, the total power input of the optical module is generally 3.3V, and the 3.3V voltage needs to be converted into multiple power supply voltages of different levels inside the optical module to power different subsystems inside the optical module, such as 0.65V, 0.94V, 1.2V, 1.8V, 2.5V, 3.3V, 4V, 5V and other voltages.

[0003] In order to achieve voltage conversion of different levels, a variety of different power conversion chips are used inside the optical module, and some of the subsystems have high requirements for voltage stability and power noise (power ripple), such as DSP power supply circuit, clock source, reference level loop, etc. Especially as the optical module rate increases to 400G&800G&1.6T, the requirements for power noise are more stringent. Multiple subsystems require the power ripple to be controlled below 1mV, and conventional boost (BOOST) power chips or buck (DC-DC) power chips cannot meet the power ripple requirements. Therefore, it is necessary to use a low-noise power chip such as a primary LDO after the power conversion chip for voltage adjustment and ripple control to ensure that the power ripple meets the design requirements.

[0004] Traditionally, low-noise power supply circuits used in optical modules generally have two power supply voltage levels: Loop 1 is a power supply circuit with low noise requirements and greater than 3.3V, and Loop 2 is a power supply circuit with low noise requirements and less than 3.3V. Loop 1 consists of the first boost module (refer to Figure 3 ) and the first step-down module (refer to Figure 4 );Circuit 2 consists of the second step-down module (refer to Figure 5 ) and the third step-down module (refer to Figure 6 )composition.

[0005] The working principle of loop 1 from 3.3V to 4V is as follows: by adjusting the resistance values ​​of resistors R12 and R13, combined with power chip U11 (BOOST chip), the 3.3V power supply is boosted to 5V; by adjusting the resistance values ​​of resistors R15 and R16, combined with power chip U12 (LDO chip), the 5V power supply is reduced to 4V. VCC5V_EN and VCC4V_EN are used as host computer control signals to control the power chip U11 and the power chip U12 to enable work.

[0006] The working principle of loop 2 from 3.3V to 1.2V is as follows: by adjusting the resistance of resistors R18 and R19, combined with power chip U21 (DC-DC chip), the 3.3V power supply is reduced to 1.8V; by adjusting the resistance of resistors R21 and R2, combined with power chip U22 (LDO chip), the 1.8V power supply is reduced to 1.2V. VCC1V8_EN and VCC1V2_EN are used as host computer control signals to control the power chip U21 and the power chip U22 to enable work.

[0007] The traditional low-noise power supply circuit has the following disadvantages: 1. For the needs of boosting and bucking, different power supply chips need to be used for boosting or bucking first. The boosting and bucking circuits are not compatible, which increases the types of chip materials and thus increases the circuit cost; 2. The power supply chips of the primary power supply (first boost module, second buck module) and the secondary power supply (first buck module, third buck module) need to be controlled separately. In order to keep the circuit working stably, the output voltage of the first power supply will be kept with sufficient margin, which will cause the voltage difference of the LDO chip of the secondary power supply to increase; Since the working principle of the LDO chip is to keep the input and output currents the same, the goal of stable voltage drop and low noise is achieved by controlling the internal MOS tube to work, the energy loss caused by the voltage difference between the output and input ends of the LDO chip in the loop will all be used as the thermal power consumption of the LDO chip, resulting in greater heating of the LDO chip; 3. The power supply chips of the primary power supply and the secondary power supply need to be controlled independently, and the host computer IO output EN signal is required to control the power supply chip to enable the work, that is, a large amount of IO resources are occupied, which increases the circuit cost.

[0008] Therefore, how to provide an adaptive low-noise power supply circuit for an optical module to reduce the power consumption and cost of the low-noise power supply circuit has become a technical problem to be solved urgently. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide an adaptive low-noise power supply circuit for an optical module, so as to reduce the power consumption and cost of the low-noise power supply circuit.

[0010] The present invention is implemented as follows: an adaptive low-noise power supply circuit for an optical module comprises a primary voltage regulating module, a secondary voltage regulating module and a voltage feedback module; the primary voltage regulating module, the secondary voltage regulating module, the voltage feedback module and the primary voltage regulating module are connected in sequence;

[0011] The primary voltage regulating module includes a voltage regulating chip U1, an inductor L1, a resistor R1 and a capacitor C1; the secondary voltage regulating module includes a voltage regulating chip U2, a resistor R6, a resistor R7, a resistor R8, a capacitor C2, a capacitor C3, a capacitor C4 and a capacitor C5;

[0012] Pin 1 of the voltage regulating chip U1 is connected to capacitor C1, pin 2 is connected to resistor R1, pin 4 is connected to one end of inductor L1, pin 5 is connected to the other end of inductor L1, pins 6 and 9 are both grounded, pin 7 is connected to one end of capacitor C2, one end of capacitor C3, pins 6, 7, 8 of the voltage regulating chip U2 and the voltage feedback module, and pin 8 is connected to the voltage feedback module; the other end of capacitor C2 is connected to the other end of capacitor C3 and is grounded;

[0013] Pins 1 and 2 of the voltage regulating chip U2 are connected to one end of the resistor R6, the capacitor C5 and the voltage feedback module, pin 3 is connected to the other end of the resistor R6, one end of the resistor R7 and one end of the resistor R8, pin 4 is connected to the other end of the resistor R7 and grounded, and pin 5 is connected to the capacitor C20.

[0014] Furthermore, it also includes a host computer, which is connected to the pin 2 of the voltage regulating chip U1 and the other end of the resistor R8 respectively.

[0015] Further, the voltage feedback module includes a resistor R2, a resistor R3, a resistor R4 and a resistor R5;

[0016] One end of the resistor R2 is connected to pin 8 of the voltage regulating chip U1, and the other end is connected to one end of the resistor R3, one end of the resistor R4 and one end of the resistor R5; the other end of the resistor R3 is connected to pin 7 of the voltage regulating chip U1; the other end of the resistor R4 is grounded; the other end of the resistor R5 is connected to pins 1 and 2 of the voltage regulating chip U2.

[0017] The advantages of the present invention are:

[0018] A primary voltage regulating module, a secondary voltage regulating module and a voltage feedback module are provided, and the primary voltage regulating module, the secondary voltage regulating module, the voltage feedback module and the primary voltage regulating module are connected in sequence; the voltage regulating chip U1 of the primary voltage regulating module has the function of boosting and reducing voltage, and can be compatible with the requirements of boosting and reducing voltage on the basis of the voltage drop of the voltage regulating chip U2 of the secondary voltage regulating module, without the need to use different power chips for processing, thereby reducing the types of chip materials and the number of IO resources occupied by the host computer; the secondary output voltage of the secondary voltage regulating module is collected through the voltage feedback module and fed back to the primary voltage regulating module, so that the primary voltage regulating module can dynamically adjust the primary output voltage, without the need to keep the primary output voltage with sufficient margin as traditionally, effectively reducing the voltage difference of the voltage regulating chip U2 of the secondary voltage regulating module, so as to reduce the thermal power consumption of the voltage regulating chip U2, and finally greatly reducing the power consumption and cost of the low-noise power supply circuit, while also improving the overcurrent capacity of the voltage regulating chip U2, reducing the power consumption and cost of the entire low-noise power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0020] Figure 1 The invention discloses a circuit principle block diagram of an adaptive low-noise power supply circuit for an optical module.

[0021] Figure 2 The invention discloses a circuit diagram of an adaptive low-noise power supply circuit for an optical module.

[0022] Figure 3 It is a circuit diagram of the first boost module of the conventional circuit 1.

[0023] Figure 4 This is a circuit diagram of the first step-down module of the conventional circuit 1.

[0024] Figure 5 This is the circuit diagram of the second step-down module of traditional circuit two.

[0025] Figure 6 This is the circuit diagram of the third step-down module of the traditional circuit 2. DETAILED DESCRIPTION

[0026] The technical solution in the embodiment of the present application has the following general idea: the voltage regulating chip U1 of the first-level voltage regulating module is provided with the functions of boosting and reducing voltage, and can be compatible with the requirements of boosting and reducing voltage on the basis of the voltage drop of the voltage regulating chip U2 of the second-level voltage regulating module, thereby reducing the types of chip materials and the number of IO resources occupied by the host computer; the second-level output voltage of the second-level voltage regulating module is collected through the voltage feedback module and fed back to the first-level voltage regulating module, so that the first-level voltage regulating module can dynamically adjust the first-level output voltage without having to maintain a sufficient margin for the first-level output voltage as traditionally, thereby effectively reducing the voltage difference of the voltage regulating chip U2 of the second-level voltage regulating module, thereby reducing the thermal power consumption of the voltage regulating chip U2, and thereby reducing the power consumption and cost of the low-noise power supply circuit.

[0027] Please refer to Figures 1 to 6 As shown, a preferred embodiment of an adaptive low-noise power supply circuit for an optical module of the present invention comprises a primary voltage regulating module, a secondary voltage regulating module and a voltage feedback module; the primary voltage regulating module, the secondary voltage regulating module, the voltage feedback module and the primary voltage regulating module are connected in sequence; the secondary voltage regulating module is used to output a low-noise target power supply voltage;

[0028] The primary voltage regulating module includes a voltage regulating chip U1, an inductor L1, a resistor R1 and a capacitor C1; the secondary voltage regulating module includes a voltage regulating chip U2, a resistor R6, a resistor R7, a resistor R8, a capacitor C2, a capacitor C3, a capacitor C4 and a capacitor C5; the inductor L1 is used for energy storage, and can realize charging and discharging with the MOS tube inside the voltage regulating chip U1 to achieve the purpose of adjusting the output voltage; the resistor R1 is used as a pull-down resistor of VCCADJ_EN, which pulls down the level in the power-on stage, and can keep the voltage regulating chip U1 in an enabled state in the power-on stage, without voltage output, and VCC can be pulled up by the host computer The level of ADJ_EN starts the operation of the voltage regulating chip U1; the capacitor C1 and the capacitor C2 are used as filter capacitors to filter the voltage to reduce the power ripple; the resistor R6 and the resistor R7 are used to adjust the output voltage of the voltage regulating chip U2; the pins 7 and 8 of the voltage regulating chip U2 are connected to the pin 7 of the voltage regulating chip U1, and when the voltage regulating chip U1 enables the output, the operation of the voltage regulating chip U2 is started synchronously; the voltage regulating chip U1 is used for boosting and bucking, and the voltage regulating chip 2 is used to stabilize the voltage output and reduce the power ripple. In the specific implementation, it is sufficient to select a power chip that can realize this function from the prior art, and it is not limited to any model, such as SW6301V of I smartware Zhirong and IP2363 of Injo inic Yingjixin, and the control program is well known to those skilled in the art, which can be obtained by those skilled in the art without creative labor;

[0029] Pin 1 of the voltage regulating chip U1 is connected to capacitor C1, pin 2 is connected to resistor R1, pin 4 is connected to one end of inductor L1, pin 5 is connected to the other end of inductor L1, pins 6 and 9 are both grounded, pin 7 is connected to one end of capacitor C2, one end of capacitor C3, pins 6, 7, 8 of the voltage regulating chip U2 and the voltage feedback module, and pin 8 is connected to the voltage feedback module; the other end of capacitor C2 is connected to the other end of capacitor C3 and is grounded;

[0030] Pins 1 and 2 of the voltage regulating chip U2 are connected to one end of the resistor R6, the capacitor C5 and the voltage feedback module, pin 3 is connected to the other end of the resistor R6, one end of the resistor R7 and one end of the resistor R8, pin 4 is connected to the other end of the resistor R7 and grounded, and pin 5 is connected to the capacitor C20.

[0031] The device further comprises a host computer, which is connected to the pin 2 of the voltage regulating chip U1 and the other end of the resistor R8 respectively. The host computer can flexibly adjust the output voltage through the resistor R8.

[0032] The voltage feedback module includes a resistor R2, a resistor R3, a resistor R4 and a resistor R5; the resistors R2, R3, R4 and R5 are used to adjust the output voltage of the voltage regulator chip U1;

[0033] One end of the resistor R2 is connected to pin 8 of the voltage regulating chip U1, and the other end is connected to one end of the resistor R3, one end of the resistor R4 and one end of the resistor R5; the other end of the resistor R3 is connected to pin 7 of the voltage regulating chip U1; the other end of the resistor R4 is grounded; the other end of the resistor R5 is connected to pins 1 and 2 of the voltage regulating chip U2.

[0034] Working principle of the present invention:

[0035] The host computer sets an output target voltage value and sends it to the voltage regulating chip U1. The voltage regulating chip U1 is enabled through VCCADJ_EN. The voltage regulating chip U1 performs a voltage regulating operation on the input 3.3V voltage and outputs a first-level output voltage value to the voltage regulating chip U2. The voltage regulating chip U2 performs a voltage regulating operation on the input first-level output voltage value and outputs a second-level output voltage value.

[0036] The voltage feedback module collects the actual output voltage value of the voltage regulating chip U2 and feeds it back to the voltage regulating chip U1. The voltage regulating chip U1 compares the output target voltage value and the actual output voltage value to dynamically adjust the output primary output voltage value, and then dynamically adjust the output secondary output voltage value, so that the secondary output voltage value is infinitely close to the output target voltage value.

[0037] The host computer dynamically adjusts the actual output voltage value, the primary output voltage value and the secondary output voltage value by adjusting the voltage value of the resistor R8.

[0038] In summary, the advantages of the present invention are:

[0039] A primary voltage regulating module, a secondary voltage regulating module and a voltage feedback module are provided, and the primary voltage regulating module, the secondary voltage regulating module, the voltage feedback module and the primary voltage regulating module are connected in sequence; the voltage regulating chip U1 of the primary voltage regulating module has the function of boosting and reducing voltage, and can be compatible with the requirements of boosting and reducing voltage on the basis of the voltage drop of the voltage regulating chip U2 of the secondary voltage regulating module, without the need to use different power chips for processing, thereby reducing the types of chip materials and the number of IO resources occupied by the host computer; the secondary output voltage of the secondary voltage regulating module is collected through the voltage feedback module and fed back to the primary voltage regulating module, so that the primary voltage regulating module can dynamically adjust the primary output voltage, without the need to keep the primary output voltage with sufficient margin as traditionally, effectively reducing the voltage difference of the voltage regulating chip U2 of the secondary voltage regulating module, so as to reduce the thermal power consumption of the voltage regulating chip U2, and finally greatly reducing the power consumption and cost of the low-noise power supply circuit, while also improving the overcurrent capacity of the voltage regulating chip U2, reducing the power consumption and cost of the entire low-noise power supply circuit.

[0040] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. An adaptive low-noise power supply circuit for an optical module, characterized in that: It includes a primary voltage regulating module, a secondary voltage regulating module and a voltage feedback module; the primary voltage regulating module, the secondary voltage regulating module, the voltage feedback module and the primary voltage regulating module are connected in sequence; The primary voltage regulating module includes a voltage regulating chip U1, an inductor L1, a resistor R1 and a capacitor C1; the secondary voltage regulating module includes a voltage regulating chip U2, a resistor R6, a resistor R7, a resistor R8, a capacitor C2, a capacitor C3, a capacitor C4 and a capacitor C5; Pin 1 of the voltage regulating chip U1 is connected to capacitor C1, pin 2 is connected to resistor R1, pin 4 is connected to one end of inductor L1, pin 5 is connected to the other end of inductor L1, pins 6 and 9 are both grounded, pin 7 is connected to one end of capacitor C2, one end of capacitor C3, pins 6, 7, 8 of the voltage regulating chip U2 and the voltage feedback module, and pin 8 is connected to the voltage feedback module; the other end of capacitor C2 is connected to the other end of capacitor C3 and is grounded; Pins 1 and 2 of the voltage regulating chip U2 are connected to one end of the resistor R6, the capacitor C5 and the voltage feedback module, pin 3 is connected to the other end of the resistor R6, one end of the resistor R7 and one end of the resistor R8, pin 4 is connected to the other end of the resistor R7 and grounded, and pin 5 is connected to the capacitor C20.

2. The adaptive low-noise power supply circuit for an optical module according to claim 1, characterized in that: It also includes a host computer, which is connected to the pin 2 of the voltage regulating chip U1 and the other end of the resistor R8 respectively.

3. The adaptive low noise power supply circuit for an optical module according to claim 1, characterized in that: The voltage feedback module includes a resistor R2, a resistor R3, a resistor R4 and a resistor R5; One end of the resistor R2 is connected to pin 8 of the voltage regulating chip U1, and the other end is connected to one end of the resistor R3, one end of the resistor R4 and one end of the resistor R5; the other end of the resistor R3 is connected to pin 7 of the voltage regulating chip U1; the other end of the resistor R4 is grounded; the other end of the resistor R5 is connected to pins 1 and 2 of the voltage regulating chip U2.

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