High-power flyback power supply chip and controller

Abstract

The utility model discloses a high-power flyback power supply chip and a controller. The high-power flyback power supply chip comprises a packaging shell, and a flyback control chip, wherein the flyback control chip is packaged in the packaging shell. The power switch tube and the diode are packaged in the packaging shell, a grid electrode of the power switch tube is connected to the flyback control chip, and a source electrode of the power switch tube is connected to the flyback control chip and a power switch tube current detection pin of the packaging shell; the positive electrode of the diode is connected to the drain electrode of the power switch tube and the drain electrode pin of the packaging shell, and the negative electrode of the diode is connected to the RCD pin and used for protecting the power switch tube. According to the utility model, the flyback power supply device can be highly integrated, the packaging volume of the flyback power supply chip is reduced, the heat dissipation effect can be improved, the number of discrete devices can be reduced, and the production cost and the failure rate can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of switching power supply, especially relates to a high -power flyback power supply chip and controller. BACKGROUND

[0002] Flyback switching power supply has the advantages of simple topology structure, easy to realize etc, is widely used in various electronic products, equipment, for example, notebook adapter, mobile phone charger, LCD display, electric tool, electric bicycle charger and television standby power supply etc.

[0003] At present, the product without built-in MOS of 100W above flyback switching power supply chip, carries out device connection through the mode of external MOS, and the flyback switching power supply chip without leakage inductance absorption diode within 100W.

[0004] Therefore, the flyback switching power supply chip of different power has more discrete devices, not only increases the failure rate of product, but also greatly improves production cost and material cost, simultaneously, if these chips are installed in a package, the heat dissipation problem cannot be solved, the service life of product is shortened. UTILITY MODEL CONTENT

[0005] The utility model aims at the deficiency of prior art and provides a high -power flyback power supply chip and controller technical scheme, can not only make flyback power supply device highly integrated, reduce the volume of flyback power supply chip package, but also can improve the heat dissipation effect, can reduce the quantity of discrete device simultaneously, reduce production cost and failure rate.

[0006] In order to solve the above technical problem, the utility model adopts the following technical scheme:

[0007] A kind of high -power flyback power supply chip, including

[0008] Packaging shell;

[0009] And flyback control chip, flyback control chip is packaged in packaging shell;

[0010] Its characterized in that;

[0011] It further includes power switch tube and diode packaged in packaging shell, the gate of power switch tube is connected to flyback control chip, the source of power switch tube is connected to flyback control chip and the power switch tube current detection pin of packaging shell;

[0012] The anode of diode is connected to the drain of power switch tube and the drain pin of packaging shell, the cathode of diode is connected to RCD pin, for protecting power switch tube.

[0013] The above-described structure design not only enables highly integrated flyback power supply devices and reduces the size of flyback power supply chip packages, but also improves heat dissipation, reduces the number of discrete components, and lowers production costs and failure rates.

[0014] Furthermore, the flyback control chip is connected to the power supply voltage input pin of the package housing.

[0015] Furthermore, the flyback control chip is connected to the output voltage feedback pin of the package housing.

[0016] Furthermore, the flyback control chip is connected to the function selection pin of the package housing to select the output mode.

[0017] Furthermore, the flyback control chip is connected to the ground pin of the package housing.

[0018] A controller is characterized in that it includes a high-power flyback power supply chip as described above, a resistor R1 and a capacitor C2, wherein the diode of the high-power flyback power supply chip, the resistor R1 and the capacitor C2 form an RCD snubber circuit.

[0019] Furthermore, the current detection pin of the power switch of the high-power flyback power supply chip is connected to resistor R2 and capacitor C1.

[0020] Furthermore, the drain pin of the high-power flyback power supply chip is connected to a transformer.

[0021] This utility model, by adopting the above-mentioned technical solution, has the following beneficial effects:

[0022] This invention not only enables highly integrated flyback power supply devices and reduces the size of flyback power supply chip packages, but also improves heat dissipation, reduces the number of discrete components, and lowers production costs and failure rates. Attached image description:

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] Figure 1 This is a circuit diagram of the flyback power supply chip in the high-power flyback power supply chip and controller of this utility model.

[0025] Figure 2 This is the circuit diagram of the controller in this utility model.

[0026] In the diagram: 1-Flyback control chip; 2-Power switch; 3-Diode; 4-Package housing. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0030] like Figure 1 As shown, this utility model discloses a high-power flyback power supply chip, which includes a package shell 4 and a flyback control chip 1, with the flyback control chip 1 packaged inside the package shell 4.

[0031] It also includes a power switch 2 and a diode 3 encapsulated in the package housing 4. The gate of the power switch 2 is connected to the flyback control chip 1, and the source of the power switch 2 is connected to the flyback control chip 1 and the power switch 2 current detection pin CS of the package housing 4.

[0032] The positive terminal of diode 3 is connected to the drain of power switch 2 and the drain pin D of package 4, and the negative terminal of diode 3 is connected to the RCD pin to protect power switch 2.

[0033] The flyback control chip 1 is connected to the power supply voltage input pin VCC of the package housing 4.

[0034] The flyback control chip 1 is connected to the output voltage feedback pin FB of the package housing 4.

[0035] The flyback control chip 1 is connected to the function selection pin DEM of the package housing 4 to select the output mode. Grounding is the constant voltage output mode, and connecting it is the capacitor-type constant voltage and constant current output mode.

[0036] The flyback control chip 1 is connected to the ground pin GND of the package housing 4.

[0037] The package in this application can be a GBU-7 package, and the pin order can be selected according to the actual application requirements.

[0038] The above-described structure design not only enables highly integrated flyback power supply devices and reduces the size of flyback power supply chip packages, but also improves heat dissipation, reduces the number of discrete components, and lowers production costs and failure rates.

[0039] like Figure 2 As shown, this utility model provides a controller that includes a high-power flyback power supply chip, a resistor R1, and a capacitor C2, as described above. The diode 3 of the high-power flyback power supply chip, along with the resistor R1 and capacitor C2, forms an RCD absorption circuit.

[0040] The current sensing pin CS of the power switch 2 of the high-power flyback power supply chip is connected to resistor R2 and capacitor C1.

[0041] The drain pin D of the high-power flyback power supply chip is connected to the transformer.

[0042] In actual operation, the flyback control chip 1 controls the power switch 2 to turn on. At this time, current flows in from the drain pin D of the package 4 and out from the current detection pin CS of the power switch 2. The external resistor R2 connected to the current detection pin CS samples the current flowing through the power switch 2. When the flyback control chip 1 detects that the current flowing through the power switch 2 reaches a threshold, it turns off the power switch 2. At this time, due to the resonance between the transformer leakage inductance and the equivalent capacitance at this point, the drain pin D generates a spike voltage greater than the withstand voltage of the power switch 2. The spike voltage at the drain pin D is absorbed by the RCD absorption circuit composed of diode 3, external resistor R1, and capacitor C2, thus protecting the power switch 2. After the flyback control chip 1 waits for a certain period of time to allow the transformer to demagnetize and output energy, it controls the power switch 2 to turn on again, and the above steps are repeated.

[0043] The above are merely specific embodiments of this utility model, but the technical features of this utility model are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on this utility model to achieve essentially the same technical effect are all covered within the protection scope of this utility model.

Claims

1. A high-power flyback power supply chip, comprising: Encapsulation shell; and a flyback control chip, wherein the flyback control chip is packaged within the package housing; Its features ； It also includes a power switch and a diode packaged in the package housing, wherein the gate of the power switch is connected to the flyback control chip, and the source of the power switch is connected to the flyback control chip and the power switch current detection pin of the package housing; The positive terminal of the diode is connected to the drain of the power switch and the drain pin of the package, and the negative terminal of the diode is connected to the RCD pin to protect the power switch.

2. The high-power flyback power supply chip according to claim 1, characterized in that: The flyback control chip is connected to the power supply voltage input pin of the package housing.

3. A high-power flyback power supply chip according to claim 1, characterized in that: The flyback control chip is connected to the output voltage feedback pin of the package housing.

4. A high-power flyback power supply chip according to claim 1, characterized in that: The flyback control chip is connected to the function selection pin of the package housing and is used to select the output mode.

5. A high-power flyback power supply chip according to claim 1, characterized in that: The flyback control chip is connected to the ground pin of the package housing.

6. A controller, characterized in that: It includes a high-power flyback power supply chip as described in any one of claims 1 to 5, a resistor R1 and a capacitor C2, wherein the diode of the high-power flyback power supply chip, the resistor R1 and the capacitor C2 form an RCD snubber circuit.

7. A controller according to claim 6, characterized in that: The current detection pin of the power switch of the high-power flyback power supply chip is connected to resistor R2 and capacitor C1.

8. A controller according to claim 6, characterized in that: The drain pin of the high-power flyback power supply chip is connected to a transformer.

Images