Circuit for expanding working range of input voltage by using iW3677 chip

Abstract

A circuit for expanding an input voltage working range by using an iW3677 chip comprises an iW3677 driving chip, a resistor R5 and a capacitor C4, and the iW3677 driving chip comprises a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin and a 15kohm internal resistor. The first pin, the third pin, the fourth pin, the fifth pin, the sixth pin and the seventh pin are connected with the outside of the iW3677 driving chip, and the second pin on the iW3677 driving chip is connected with the resistor R5 and the capacitor C4. Compared with the prior art, on the basis of calculation, the input voltage range of a plurality of types of machines using iW3677 chips can be expanded from 90-305v to 108-382v by the value obtained by the circuit, so that the input range of the products can cover the global market.

Description

Technical Field

[0001] The utility model relates to a circuit, in particular to a circuit which uses an iW3677 chip to expand an input voltage working range. Background Art

[0002] According to the requirements, the input voltage range needs to be expanded based on the existing iW3677 chip as the driver product, and the input voltage range needs to be expanded from AC108~305v to AC108v~382v. There are two problems involved here. First, the input high-end voltage rises, and the design parameters need to be changed accordingly. This patent does not include this part. Second, based on the calculation, the existing 108~305v products were tested. When the input voltage rises to less than 320v, the driver is protected, and the original product manual of the LED driver chip 3677 also states that the product is applicable to the AC input voltage range: 90VAC~305VAC.

[0003] To solve the above problems, we made a series of improvements. Utility Model Content

[0004] The purpose of the utility model is to provide a circuit for expanding the input voltage working range by using the iW3677 chip, so as to overcome the above-mentioned shortcomings and deficiencies existing in the prior art.

[0005] A circuit for extending an input voltage working range by using an iW3677 chip comprises: an iW3677 driver chip, an R5 resistor and a C4 capacitor, wherein the iW3677 driver chip comprises: a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin and a 15kohm internal resistor, the first pin, the third pin, the fourth pin, the fifth pin, the sixth pin and the seventh pin are externally connected to the iW3677 driver chip, the second pin on the iW3677 driver chip is connected to the R5 resistor and the C4 capacitor, the other end of the R5 resistor is connected to a DC power supply after the input AC voltage is rectified, the other end of the C4 capacitor is connected to a grounding point, the 15kohm internal resistor is arranged inside the iW3677 driver chip, one end of the second pin is internally connected to the 15kohm internal resistor, the other end of the second pin is externally connected to the R5 resistor and the C4 capacitor, and the 15kohm internal resistor is connected to the grounding point.

[0006] Beneficial effects of the utility model:

[0007] Compared with the traditional technology, the utility model is verified on the basis of calculation on multiple models using the iW3677 chip, and the value obtained by using the circuit can expand the input voltage range of these models from 90-305V to 108-382V, so that the input range of these products can cover the global market. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural schematic diagram of the utility model.

[0009] Reference numerals:

[0010] iW3677 driver chip 100 , first pin 110 , second pin 120 , third pin 130 , fourth pin 140 , fifth pin 150 , sixth pin 160 , seventh pin 170 , 15kohm internal resistor 180 , R5 resistor 200 and C4 capacitor 300 . DETAILED DESCRIPTION

[0011] The following is a further description of the present invention in conjunction with specific embodiments. It should be understood that the following embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0012] Example 1

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] like Figure 1 As shown, a circuit using an iW3677 chip to expand an input voltage operating range includes: an iW3677 driver chip 100, an R5 resistor 200, and a C4 capacitor 300, wherein the iW3677 driver chip 100 includes: a first pin 110, a second pin 120, a third pin 130, a fourth pin 140, a fifth pin 150, a sixth pin 160, a seventh pin 170, and a 15kohm internal resistor 180, and the first pin 110, the third pin 130, the fourth pin 140, the fifth pin 150, the sixth pin 160, and the seventh pin 170 are connected to the iW3677 driver chip The iW3677 driver chip 100 is externally connected, the second pin 120 on the iW3677 driver chip 100 is connected to the R5 resistor 200 and the C4 capacitor 300, the other end of the R5 resistor 200 is connected to the DC power supply 400 after the input AC voltage is rectified, the other end of the C4 capacitor 300 is connected to the ground point, and a 15kohm internal resistor 180 is arranged inside the iW3677 driver chip 100, one end of the second pin 120 is internally connected to the 15kohm internal resistor 180, and the other end of the second pin 120 is externally connected to the R5 resistor 200 and the C4 capacitor 300, and the 15kohm internal resistor 180 is connected to the ground point.

[0015] The principle of the utility model is: through the voltage division sampling of the 15kohm internal resistor 180 and the R5 resistor 200, the iW3677 driver chip 100 senses the rectified DC voltage value through the second pin 120 of the iW3677 driver chip 100, and also senses the input AC voltage value. The C4 capacitor 300 plays a filtering role in stabilizing the adopted signal.

[0016] The level of the second pin 120 = the rectified DC voltage value * 15kohm internal resistor 180 / (15kohm internal resistor 180+R5 resistor 200). As long as the level of the second pin 120 is greater than 0.41v and less than 1.5v, from the perspective of AC (input) voltage detection, the iW3677 driver chip 100 enters the working state.

[0017] The 15kohm internal resistor 180 is connected between the second pin 120 of the iW3677 driver chip 100 and the ground GND. The recommended value of the external voltage divider R5 resistor 200 is 4MΩ (90-265VAC) with a voltage divider ratio of 0.00373. The voltage level of the second pin 120 is from 0.4754 to 1.3999V, which verifies that it is indeed within the range of 0.41 to 1.5V.

[0018] The recommended value of the external voltage divider R5 resistor 200 is 4.4MΩ (90~305VAC). The voltage divider ratio is equal to 0.00339. The level of the second pin 120 is from 0.4324~1.4652V, which is indeed within the range of 0.41~1.5V.

[0019] The voltage divider ratio is calculated as 15kohm internal resistor 180 / (15kohm internal resistor 180+R5 resistor 200), and the rectified DC voltage value = input AC power supply * 1.414. In order to make the level of the second pin 120 not exceed 1.5v at a higher input voltage, we try to make the level of the second pin 120 as low as possible at the lowest input voltage 108V, taking 0.415V, slightly higher than the lower limit 4.1V that the iW3677 driver chip 100 can turn on, through: the level of the second pin = voltage divider ratio * rectified DC voltage; rectified DC voltage = input AC voltage * 1.414; calculate the voltage divider ratio, voltage divider ratio = 15kohm internal resistor 180 / (15kohm internal resistor 180+R5 resistor 200), calculate R5 resistor 200. The utility model has been verified on the basis of calculations on multiple models using the iW3677 chip, and the values ​​obtained by using the circuit can expand the input voltage range of these models from 90-305V to 108-382V, so that the input range of these products can cover the global market.

[0020] The specific implementation modes of the present invention are described above, but the present invention is not limited thereto. The present invention can also have various changes without departing from the purpose of the present invention.

Claims

1. A circuit for extending the input voltage operating range using the iW3677 chip, comprising: An iW3677 driver chip (100), an R5 resistor (200) and a C4 capacitor (300), wherein the iW3677 driver chip (100) comprises: a first pin (110), a second pin (120), a third pin (130), a fourth pin (140), a fifth pin (150), a sixth pin (160), a seventh pin (170) and a 15 kohm internal resistor (180), wherein the first pin (110), the third pin (130), the fourth pin (140), the fifth pin (150), the sixth pin (160) and the seventh pin (170) are externally connected to the iW3677 driver chip (100), and wherein: the iW3677 driver chip (100) comprises: a first pin (110), a second pin (120), a third pin (130), a fourth pin (140), a fifth pin (150), a sixth pin (160) and a seventh pin (170) The second pin (120) on the W3677 driver chip (100) is connected to the R5 resistor (200) and the C4 capacitor (300), the other end of the R5 resistor (200) is connected to a DC power supply after the input AC voltage is rectified, the other end of the C4 capacitor (300) is connected to a ground point, the 15kohm internal resistor (180) is arranged inside the iW3677 driver chip (100), one end of the second pin (120) is internally connected to the 15kohm internal resistor (180), the other end of the second pin (120) is externally connected to the R5 resistor (200) and the C4 capacitor (300), and the 15kohm internal resistor (180) is connected to a ground point.

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