TW202404237A - Constant-current switching power supply system and control circuit and control method thereof - Google Patents
Constant-current switching power supply system and control circuit and control method thereof Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M7/219—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/345—Current stabilisation; Maintaining constant current
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
Description
本發明涉及電路領域,更具體地涉及一種恒流開關電源系統及其控制電路和控制方法。 The present invention relates to the field of circuits, and more specifically to a constant current switching power supply system and its control circuit and control method.
開關電源又稱交換式電源、開關變換器,是電源供應器的一種。開關電源的功能是通過不同形式的架構(例如,返馳(fly-back)架構、降壓(BUCK)架構、或升壓(BOOST)架構等)將一個位准的電壓轉換為使用者端所需要的電壓或電流。 Switching power supply, also known as switching power supply and switching converter, is a type of power supply. The function of the switching power supply is to convert a level of voltage to the user's desired voltage through different architectures (for example, fly-back architecture, buck architecture, or boost architecture, etc.) required voltage or current.
根據本發明實施例的用於恒流開關電源系統的控制電路,其中,該恒流開關電源系統包括電感和功率開關,該控制電路被配置為:基於用於控制功率開關的導通與關斷的脈寬調變信號和表徵流過電感的電感電流的電流檢測信號,生成與電流檢測信號相關聯的電流採樣信號;以及基於電流採樣信號、表徵電感的退磁情況的退磁檢測信號、以及參考電壓,生成脈寬調變信號,其中,電流採樣信號在脈寬調變信號處於第一邏輯位準時為電流檢測信號本身,並且在脈寬調變信號處於第二邏輯位準時為對電流檢測信號進行採樣生成的採樣信號。 A control circuit for a constant current switching power supply system according to an embodiment of the present invention, wherein the constant current switching power supply system includes an inductor and a power switch, and the control circuit is configured to: based on the control circuit used to control the turn-on and turn-off of the power switch. The pulse width modulation signal and the current detection signal representing the inductor current flowing through the inductor generate a current sampling signal associated with the current detection signal; and based on the current sampling signal, the demagnetization detection signal representing the demagnetization of the inductor, and the reference voltage, Generating a pulse width modulation signal, wherein the current sampling signal is the current detection signal itself when the pulse width modulation signal is at a first logic level, and the current detection signal is sampled when the pulse width modulation signal is at a second logic level generated sampled signal.
根據本發明實施例的用於恒流開關電源系統的控制方法,其中,該恒流開關電源系統包括電感和功率開關,該控制方法包括:基於用於控制功率開關的導通與關斷的脈寬調變信號和表徵流過電感的電感電流的電流檢測信號,生成與電流檢測信號相關聯的電流採樣信號;以及基於電流採樣信號、表徵電感的退磁情況的退磁檢測信號、以及參考電壓,生成脈寬調變信號,其中,電流採樣信號在脈寬調變信號處於第一邏輯位準 時為電流檢測信號本身,並且在脈寬調變信號處於第二邏輯位準時為對電流檢測信號進行採樣生成的採樣信號。 A control method for a constant current switching power supply system according to an embodiment of the present invention, wherein the constant current switching power supply system includes an inductor and a power switch. The control method includes: based on a pulse width used to control the turn-on and turn-off of the power switch. The modulation signal and the current detection signal representing the inductor current flowing through the inductor generate a current sampling signal associated with the current detection signal; and based on the current sampling signal, the demagnetization detection signal representing the demagnetization of the inductor, and the reference voltage, generate a pulse wide modulation signal, wherein the current sampling signal is at the first logic level when the pulse width modulation signal is is the current detection signal itself, and is a sampling signal generated by sampling the current detection signal when the pulse width modulation signal is at the second logic level.
根據本發明實施例的恒流開關電源系統,包括上述控制電路。 A constant current switching power supply system according to an embodiment of the present invention includes the above control circuit.
100:恒流開關電源系統 100:Constant current switching power supply system
102:低壓降穩壓器模組 102:Low dropout voltage regulator module
1028:驅動器模組 1028:Driver module
104:退磁檢測模組 104: Demagnetization detection module
106:恒流控制模組 106:Constant current control module
108:驅動器模組 108:Driver module
BD1:整流器 BD1: Rectifier
C1:輸入電容 C1: input capacitor
C2:輸出負載電容 C2: Output load capacitance
C201,C202,C203,C303:電容 C201, C202, C203, C303: capacitor
CMP:誤差補償信號 CMP: error compensation signal
CS:電流檢測信號 CS: current detection signal
CS_peak:峰值電壓 CS_peak: peak voltage
CS_sample:電流採樣信號 CS_sample: current sampling signal
D1:二極體 D1: Diode
Dem:退磁檢測信號 Dem: demagnetization detection signal
Gate:閘極驅動信號 Gate: Gate drive signal
HV:引腳 HV:pin
IL,IL_Ton,IL_Toff:電感電流 IL,I L_Ton ,I L_Toff : inductor current
Iout:系統輸出電流 Iout: system output current
K201,K202,K203,K501:開關 K201, K202, K203, K501: switch
L:電感量 L: inductance
L1:電感 L1: Inductor
PWM:脈寬調變信號 PWM: pulse width modulation signal
PWM_off:關斷控制信號 PWM_off: turn off control signal
Q1:功率開關 Q1: Power switch
R1:電流偵測電阻 R1: current detection resistor
R502,R503:電阻 R502, R503: Resistor
Ramp:斜坡信號 Ramp: ramp signal
SW1:開關控制信號 SW1: switch control signal
Ton:持續時間 Ton: duration
U100:控制晶片 U100: Control chip
U200,U300:採樣控制單元 U200, U300: Sampling control unit
U201,U301:誤差放大器 U201, U301: error amplifier
U202,U302:斜坡產生單元 U202, U302: ramp generation unit
U203,U303:比較器 U203, U303: comparator
U204,U304:RS正反器 U204, U304: RS flip-flop
VIN:系統母線電壓 VIN: system bus voltage
Vout:系統輸出電壓 Vout: system output voltage
Vref:參考電壓 Vref: reference voltage
從下面結合圖式對本發明的具體實施方式的描述中可以更好地理解本發明,其中: The present invention can be better understood from the following description of specific embodiments of the invention in conjunction with the drawings, in which:
圖1示出了根據本發明實施例的用於發光二極體(Light Emitting Diode,LED)照明的恒流開關電源系統的示例電路圖。 FIG. 1 shows an example circuit diagram of a constant current switching power supply system for light emitting diode (LED) lighting according to an embodiment of the present invention.
圖2示出了圖1所示的恒流開關電源系統的多個信號的時序圖。 FIG. 2 shows a timing diagram of multiple signals of the constant current switching power supply system shown in FIG. 1 .
圖3示出了圖1所示的恒流控制單元的示例電路實現的電路圖。 FIG. 3 shows a circuit diagram of an example circuit implementation of the constant current control unit shown in FIG. 1 .
圖4示出了與圖3所示的採樣控制單元相關的多個信號的時序圖。 FIG. 4 shows a timing diagram of a plurality of signals related to the sampling control unit shown in FIG. 3 .
圖5示出了圖1所示的恒流控制單元的另一示例電路實現的電路圖。 FIG. 5 shows a circuit diagram of another example circuit implementation of the constant current control unit shown in FIG. 1 .
圖6示出了與圖5所示的採樣控制單元相關的多個信號的時序圖。 FIG. 6 shows a timing diagram of a plurality of signals related to the sampling control unit shown in FIG. 5 .
圖7示出了圖5所示的誤差放大器的示例電路實現的電路圖。 FIG. 7 shows a circuit diagram of an example circuit implementation of the error amplifier shown in FIG. 5 .
下面將詳細描述本發明的各個方面的特徵和示例性實施例。在下面的詳細描述中,提出了許多具體細節,以便提供對本發明的全面理解。但是,對於本領域技術人員來說很明顯的是,本發明可以在不需要這些具體細節中的一些細節的情況下實施。下面對實施例的描述僅僅是為了通過示出本發明的示例來提供對本發明的更好的理解。本發明決不限於下面所提出的任何具體配置和演算法,而是在不脫離本發明的精神的前提下覆蓋了元素、部件和演算法的任何修改、替換和改進。在圖式和下面的描述中,沒有示出公知的結構和技術,以便避免對本發明造成不必要的模糊。 Features and exemplary embodiments of various aspects of the invention are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The present invention is in no way limited to any specific configurations and algorithms set forth below, but covers any modifications, substitutions and improvements of elements, components and algorithms without departing from the spirit of the invention. In the drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessarily obscuring the present invention.
近年來,發光二極體(LED)由於相對於傳統白熾燈、鹵素燈、或螢光燈等照明產品具有壽命長、成本低、和體積小等優點,被廣泛應用在社會生產生活的各個方面,LED自身的亮度主要受流過LED的電流控制,因此高精度的恒流控制是設計用於LED照明的恒流開關電源系統的 關鍵。 In recent years, light-emitting diodes (LEDs) have been widely used in all aspects of social production and life due to their advantages such as long life, low cost, and small size compared to traditional incandescent lamps, halogen lamps, or fluorescent lamps and other lighting products. , the brightness of the LED itself is mainly controlled by the current flowing through the LED, so high-precision constant current control is designed for constant current switching power supply systems for LED lighting. key.
圖1示出了根據本發明實施例的用於LED照明的恒流開關電源系統100的示例電路圖。如圖1所示,恒流開關電源系統100採用BUCK架構,主要包括整流器BD1、輸入電容C1、二極體D1、電感L1、輸出負載電容C2、功率開關Q1、電流偵測電阻R1、以及控制晶片U100,其中:系統母線電壓VIN經由控制晶片U100的HV引腳為控制晶片U100供電;控制晶片U100基於表徵流過電感L1的電感電流IL(圖中未示出)的電流檢測信號(Current Sensor,CS),輸出用於驅動功率開關Q1的導通和關斷的閘極驅動信號Gate。
FIG. 1 shows an example circuit diagram of a constant current switching
如圖1所示,控制晶片U100包括低壓差穩壓器(Low Dropout Linear Regulator,LDO)模組102、退磁檢測模組104、恒流控制模組106、以及驅動器模組108,其中:低壓降穩壓器模組102基於系統母線電壓VIN為控制晶片U100的內部電路供電;退磁檢測模組104基於閘極驅動信號Gate,生成電感L1的退磁情況的退磁檢測信號Dem並將退磁檢測信號Dem輸出到恒流控制模組106(應該理解的是,退磁檢測模組104檢測電感L1的退磁情況的方式不限於此,退磁檢測模組104也可以基於經由晶片引腳從外部接收的退磁檢測相關信號來生成退磁檢測信號Dem);恒流控制模組106基於參考電壓Vref、退磁檢測信號Dem、以及電流檢測信號CS,生成用於控制功率開關Q1的導通與關斷的脈寬調變信號(Pulse Width Modulation,PWM)並將脈寬調變信號PWM輸出到驅動器模組108;驅動器模組108基於脈寬調變信號PWM,生成閘極驅動信號Gate並將閘極驅動信號Gate輸出到功率開關Q1的閘極。
As shown in Figure 1, the control chip U100 includes a low dropout linear regulator (LDO)
在圖1所示的恒流開關電源系統100中,功率開關Q1在脈寬調變信號PWM為邏輯高位準時處於導通狀態,並且在脈寬調變信號PWM為邏輯低位準時處於關斷狀態;參考電壓Vref用於控制恒流開關電源系統100的系統輸出電流Iout的大小;退磁檢測信號Dem用於系統恒流控制,同時用於控制恒流開關電源系統100工作在斷續導通模式
(Discontinuous Conduction Mode,DCM)或准諧振(Quasi-Resonant,QR)模式;電流檢測信號CS用於實現恒流開關電源系統100的閉環恒流控制。這裡,系統輸出電流Iout的設計值可以由以下等式1表示:
In the constant current switching
在圖1所示的恒流開關電源系統100中,主要利用流過電感L1的電感電流IL在功率開關Q1的一個開關週期中呈現近似三角形的波形特徵來實現恒流控制。但是,由於採用了共地的BUCK架構,電流偵測電阻R1在功率開關Q1處於關斷狀態期間無法檢測流過電感L1的電感電流IL,所以在傳統的恒流控制方案中,通過獲取電流檢測信號CS在功率開關Q1從導通狀態變為關斷狀態之前的峰值電壓CS_peak和電感L1的退磁時間並基於它們二者進行三角形面積運算來實現恒流控制。
In the constant current switching
圖2示出了圖1所示的恒流開關電源系統100中的多個信號的時序圖。如圖2所示,流過電感L1的電感電流IL在功率開關Q1的一個開關週期(即,閘極驅動信號Gate為邏輯高位準的持續時間Ton+閘極驅動信號Gate為邏輯低位準的持續時間Toff)中呈現近似三角形的波形特徵;並且在功率開關Q1處於關斷狀態期間(即,閘極驅動信號Gate為邏輯低位準的持續時間Toff內),電流檢測信號CS為0V。
FIG. 2 shows a timing diagram of multiple signals in the constant current switching
由於系統母線電壓VIN並非理想的直流電壓而是存在工頻波動,流過電感L1的電感電流IL在功率開關Q1處於導通狀態的持續時間Ton內並不是理想地線性增加。具體地,在功率開關Q1處於導通狀態時流過電感L1的電感電流IL可以由以下等式2表示: Since the system bus voltage VIN is not an ideal DC voltage but has power frequency fluctuations, the inductor current IL flowing through the inductor L1 does not increase linearly ideally during the duration Ton when the power switch Q1 is in the on state. Specifically, the inductor current IL flowing through the inductor L1 when the power switch Q1 is in the on state can be expressed by the following Equation 2:
IL_Ton=L×(Vin-Vout)×Ton <等式2>
I L_Ton = L ×( Vin - Vout )× Ton <
其中,IL_Ton表示在功率開關Q1處於導通狀態時流過電感L1的電感電流,Vin表示系統母線電壓VIN,Vout表示系統輸出電壓,L表示電感L1的電感量。從等式2可以看出,當系統母線電壓VIN較低且接
近系統輸出電壓時,電感電流IL相對線性變化畸變得更嚴重。
Among them, I L_Ton represents the inductor current flowing through the inductor L1 when the power switch Q1 is in the on state, Vin represents the system bus voltage VIN, Vout represents the system output voltage, and L represents the inductance of the inductor L1. It can be seen from
由於系統輸出電流Iout是功率開關Q1處於導通狀態時流過電感L1的電感電流IL_Ton和功率開關Q1處於關斷狀態時流過電感L1的電感電流IL_Toff的總和,所以在系統母線電壓VIN較低的情況下系統輸出電流Iout的實際值與設計值之間存在較大偏差,同時系統輸出電流Iout隨系統母線電壓VIN的變化而變化。特別地,在恒流開關電源系統100的功率因數較高的情況下,輸入母線電壓VIN呈M波形狀變化,即在一個工頻交流週期內系統母線電壓VIN在近似0V到1.4倍的交流線電壓的範圍內變化,交流線電壓的變化對系統輸出電流Iout的精度影響更大,即恒流開關電源系統100的線電壓調節能力較差。因此,提升恒流開關電源系統100的恒流控制精度,特別是線電壓調節能力是亟待解決的問題。
Since the system output current Iout is the sum of the inductor current I L_Ton flowing through the inductor L1 when the power switch Q1 is in the on state and the inductor current I L_Toff flowing through the inductor L1 when the power switch Q1 is in the off state, when the system bus voltage VIN is lower In this case, there is a large deviation between the actual value of the system output current Iout and the design value. At the same time, the system output current Iout changes with the change of the system bus voltage VIN. In particular, when the power factor of the constant current switching
鑒於以上所述的情況,提出了根據本發明實施例的恒流控制方案,其中,根據功率開關Q1的導通/關斷狀態和流過電感L1的電感電流IL的變化分階段進行恒流控制,以消除流過電感L1的電感電流IL的畸變引起的誤差,提高恒流控制精度。 In view of the above situation, a constant current control scheme according to an embodiment of the present invention is proposed, in which constant current control is performed in stages according to the on/off state of the power switch Q1 and the change of the inductor current IL flowing through the inductor L1, In order to eliminate the error caused by the distortion of the inductor current IL flowing through the inductor L1, and improve the constant current control accuracy.
結合圖2可以看出,流過電感L1的電感電流IL的畸變主要出現在功率開關Q1處於導通狀態的持續時間Ton內,而在功率開關Q1處於關斷狀態的持續時間Toff內流過電感L1的電感電流IL與電感L1的退磁時間之間基本上是線性關係,因此分階段進行恒流控制是一種優化的恒流控制方案,即在功率開關Q1處於導通狀態時內不對電流檢測信號CS進行採樣處理而直接基於電流檢測信號CS進行積分運算,並且在功率開關Q1處於關斷狀態時採用峰值採樣結合積分運算方式,使得在功率開關Q1的一個完整開關週期內電感電流IL的主要資訊被控制晶片U100完整檢測並參與到系統輸出電流Iout的運算中,從而使得系統輸出電流Iout更加符合理想的設計等式1,且幾乎不隨系統母線電壓VIN變化。
It can be seen from Figure 2 that the distortion of the inductor current IL flowing through the inductor L1 mainly occurs during the duration Ton when the power switch Q1 is in the on state, and flows through the inductor L1 during the duration Toff when the power switch Q1 is in the off state. There is basically a linear relationship between the inductor current IL and the demagnetization time of the inductor L1. Therefore, constant current control in stages is an optimized constant current control scheme, that is, the current detection signal CS is not performed when the power switch Q1 is in the on state. The sampling process directly performs the integral operation based on the current detection signal CS, and uses peak sampling combined with the integral operation method when the power switch Q1 is in the off state, so that the main information of the inductor current IL is controlled within a complete switching cycle of the power switch Q1. Chip U100 completely detects and participates in the calculation of system output current Iout, making the system output current Iout more consistent with the
根據本發明實施例的恒流控制方案主要由圖1所示的恒流控制模組106實現。具體地,恒流控制模組106可以被配置為:基於用於控
制功率開關Q1的導通與關斷的脈寬調變信號PWM和表徵流過電感L1的電感電流IL的電流檢測信號CS,生成與電流檢測信號CS相關聯的電流採樣信號CS_sample;以及基於電流檢測信號CS、電感L1的退磁情況的退磁檢測信號Dem、以及參考電壓Vref,生成脈寬調變信號PWM,其中,電流採樣信號CS_sample在脈寬調變信號PWM處於第一邏輯位準(例如,邏輯高位準)時為電流檢測信號CS本身,並且在脈寬調變信號PWM處於第二邏輯位準(例如,邏輯低位準)時為對電流檢測信號CS進行採樣生成的採樣信號。
The constant current control scheme according to the embodiment of the present invention is mainly implemented by the constant
在一些實施例中,恒流控制模組106可以進一步被配置為:基於電流採樣信號CS_sample和參考電壓Vref,生成用於控制功率開關Q1從導通狀態變為關斷狀態的關斷控制信號PWM_off。
In some embodiments, the constant
在一些實施例中,恒流控制模組106可以進一步被配置為:利用退磁檢測信號Dem作為用於控制功率開關Q1從關斷狀態變為導通狀態的導通控制信號。
In some embodiments, the constant
在一些實施例中,恒流控制模組106可以進一步被配置為:基於電流採樣信號CS_sample和參考電壓Vref,生成誤差補償信號CMP;基於脈寬調變信號PWM或電流檢測信號CS,生成斜坡信號Ramp;以及基於誤差補償信號CMP和斜坡信號Ramp,生成關斷控制信號PWM_off。
In some embodiments, the constant
圖3示出了圖1所示的恒流控制模組106的示例電路實現的電路圖。如圖3所示,恒流控制模組106包括採樣控制單元U200、誤差放大器U201、斜坡產生單元U202、比較器U203、RS正反器U204、以及電容C203,其中:採樣控制單元U200接收電流檢測信號CS,基於電流檢測信號CS生成電流採樣信號CS_sample,並將電流採樣信號CS_sample輸出到誤差放大器U201;誤差放大器U201的兩個輸入端分別接收參考電壓Vref和電流採樣信號CS_sample,通過將電流採樣信號CS_sample和參考電壓Vref之間的誤差進行放大生成誤差放大信號,並將誤差放大信號輸出到電容C203;電容C203通過對誤差放大信號進行積分運算生成誤差補償
信號CMP,並將誤差補償信號CMP輸出到比較器U203;斜坡產生單元U202接收脈寬調變信號PWM或電流檢測信號CS,基於脈寬調變信號PWM或電流檢測信號CS生成斜坡信號Ramp,並將斜坡信號Ram輸出到比較器U203;比較器U203的兩個輸入端分別接收誤差補償信號CMP和斜坡信號Ramp,基於誤差補償信號CMP和斜坡信號Ramp生成關斷控制信號PWM_off,並將關斷控制信號PWM_off輸出到RS正反器U204;RS正反器U204的兩個輸入端分別接收關斷控制信號PWM_off和退磁檢測信號Dem,基於關斷控制信號PWM_off和退磁檢測信號Dem生成脈寬調變信號PWM,並將脈寬調變信號PWM輸出到驅動器模組1028,其中,關斷控制信號PWM_off控制脈寬調變信號PWM從邏輯高位準變化到邏輯低位準,退磁檢測信號Dem控制脈寬調變信號PWM從邏輯低位準變化到邏輯高位準。
FIG. 3 shows a circuit diagram of an example circuit implementation of the constant
進一步地,如圖3所示,採樣控制單元U200包括開關K201、K202、K203以及電容C201、C202,其中,電容C201和C202的容值相同,開關K201和K203的導通與關斷由脈寬調變信號PWM控制,開關K202的導通與關斷由開關控制信號SW1控制。這裡,開關K201和K203在脈寬調變信號PWM為邏輯高位準時處於導通狀態,在脈寬調變信號PWM為邏輯低位準時處於關斷狀態;開關K202在開關控制信號SW1為邏輯高位準時處於導通狀態,在開關控制信號SW1為邏輯低位準時處於關斷狀態。 Further, as shown in Figure 3, the sampling control unit U200 includes switches K201, K202, K203 and capacitors C201 and C202. The capacitors C201 and C202 have the same capacitance. The on and off of the switches K201 and K203 are controlled by pulse width modulation. It is controlled by variable signal PWM, and the on and off of switch K202 is controlled by switch control signal SW1. Here, switches K201 and K203 are in a conducting state when the pulse width modulation signal PWM is a logic high level, and are in an off state when the pulse width modulation signal PWM is a logic low level; switch K202 is in a conducting state when the switch control signal SW1 is a logic high level. state, it is in the off state when the switch control signal SW1 is logic low.
圖4示出了與圖3所示的採樣控制單元U200相關的多個信號的時序圖。如圖4所示,開關控制信號SW1的上升沿(邏輯低位準變化到邏輯高位準的時刻)相比脈寬調變信號PWM的上升沿存在預設時間的延遲(圖示的t1~t2),開關控制信號SW1的下降沿(邏輯高位準變化到邏輯低位準的時刻)與脈寬調變信號PWM的下降沿一致;通過採樣控制電路U200,可以在脈寬調變信號PWM處於邏輯高位準時將完整的電流檢測信號CS作為電流採樣信號CS_sample輸入到誤差放大器U201,並在脈 寬調變信號PWM處於邏輯低位準時將電流檢測信號CS的峰值電壓CS_peak採樣並做“除以2”的運算得到的電流採樣信號CS_sample輸入到誤差放大器U201。 FIG. 4 shows a timing diagram of multiple signals related to the sampling control unit U200 shown in FIG. 3 . As shown in Figure 4, the rising edge of the switch control signal SW1 (the moment when the logic low level changes to the logic high level) is delayed by a preset time compared to the rising edge of the pulse width modulation signal PWM (t1~t2 in the figure) , the falling edge of the switch control signal SW1 (the moment when the logic high level changes to the logic low level) is consistent with the falling edge of the pulse width modulation signal PWM; through the sampling control circuit U200, the pulse width modulation signal PWM can be at the logic high level. Input the complete current detection signal CS as the current sampling signal CS_sample to the error amplifier U201, and When the wide modulation signal PWM is at a logic low level, the peak voltage CS_peak of the current detection signal CS is sampled and the current sampling signal CS_sample obtained by "dividing by 2" is input to the error amplifier U201.
具體地,如圖3和圖4所示,在脈寬調變信號PWM為邏輯高位準時(t0~t1),開關K201和K203處於導通狀態,開關K202處於關斷狀態,電流檢測信號CS直接輸入至電容C201和誤差放大器U201的輸入端,電容C202兩端的電壓Vc202=0V,電容C201兩端的電壓Vc201=Vcs_sample=Vcs;在脈寬調變信號PWM為邏輯低位準時的峰值採樣階段(t1~t2),開關K201、K202、和K203均處於關斷狀態,電流檢測信號CS的峰值電壓CS_peak被保存在電容C201和誤差放大器U201的輸入端,電容C202兩端的電壓Vc202=0V,電容C201兩端的電壓Vc201=Vcs_sample=Vcs_peak;在脈寬調變信號PWM為邏輯低位準時的峰值“除以2”運算階段(t2~t3),開關K201和K203處於關斷狀態,開關K202處於導通狀態,保存在電容C201上的峰值電壓CS_peak通過開關K202被電容C202調節,因為電容C201和C202的容值相等,且電容C202的初值電壓為0V,此時可以實現峰值電壓CS_peak的“除以2”的運算,即Vc201=Vc202=Vcs_sample=Vcs_peak/2。 Specifically, as shown in Figures 3 and 4, when the pulse width modulation signal PWM is at a logic high level (t0~t1), the switches K201 and K203 are in the on state, the switch K202 is in the off state, and the current detection signal CS is directly input To the input end of capacitor C201 and error amplifier U201, the voltage across capacitor C202 is Vc202=0V, and the voltage across capacitor C201 is Vc201=Vcs_sample=Vcs; in the peak sampling stage (t1~t2) when the pulse width modulation signal PWM is at a logic low level ), switches K201, K202, and K203 are all in the off state, the peak voltage CS_peak of the current detection signal CS is stored at the input end of the capacitor C201 and the error amplifier U201, the voltage across the capacitor C202 Vc202=0V, the voltage across the capacitor C201 Vc201=Vcs_sample=Vcs_peak; In the peak "divide by 2" operation stage (t2~t3) when the pulse width modulation signal PWM is at a logic low level, the switches K201 and K203 are in the off state, and the switch K202 is in the on state, which is stored in the capacitor The peak voltage CS_peak on C201 is adjusted by the capacitor C202 through the switch K202. Because the capacitance values of the capacitors C201 and C202 are equal, and the initial voltage of the capacitor C202 is 0V, the "division by 2" operation of the peak voltage CS_peak can be realized at this time. That is, Vc201=Vc202=Vcs_sample=Vcs_peak/2.
可以看出,在結合圖3和圖4描述的實施例中,恒流控制模組106可以進一步被配置為:在脈寬調變信號PWM處於邏輯低位準時,通過對電流檢測信號CS的峰值電壓CS_peak進行採樣並對採樣結果進行“除以2”的運算生成電流採樣信號CS_sample;通過對電流採樣信號CS_sample和參考電壓Vref進行誤差放大,生成誤差補償信號CMP;以及通過對誤差補償信號CMP和斜坡信號Ramp進行比較,生成關斷控制信號PWM_off。
It can be seen that in the embodiment described in conjunction with FIGS. 3 and 4 , the constant
圖5示出了圖1所示的恒流控制模組106的另一示例電路實現的電路圖。如圖5所示,恒流控制模組106包括採樣控制單元U300、誤差放大器U301、斜坡產生單元U302、比較器U303、RS正反器U304、以
及電容C303,其中,採樣控制單元U300在脈寬調變信號PWM為邏輯高位準時對電流檢測信號CS的處理與採樣控制單元U200相同,但是在脈寬調變信號PWM為邏輯低位準時僅對電流檢測信號CS的峰值電壓CS_peak進行採樣而不做“除以2”的運算,並且對於峰值電壓CS_peak的“除以2”的運算由誤差放大器U301實現。另外,斜坡產生單元U302、比較器U303、RS正反器U304、以及電容C303的處理與圖4所示的相應單元相同,因此不再贅述。圖6示出了與圖5所示的採樣控制單元U300相關的多個信號的時序圖。
FIG. 5 shows a circuit diagram of another example circuit implementation of the constant
圖7示出了圖6所示的誤差放大器U301的示例電路實現的電路圖。如圖7所示,誤差放大器U301通過阻值相等的兩個電阻R502和R503、開關K501、以及脈寬調變信號PWM來實現對電流採樣信號CS_sample的“除以2”的運算,並且對“除以2”的運算結果和參考電壓Vref進行誤差放大。 FIG. 7 shows a circuit diagram of an example circuit implementation of error amplifier U301 shown in FIG. 6 . As shown in Figure 7, the error amplifier U301 implements the "division by 2" operation on the current sampling signal CS_sample through two resistors R502 and R503 with equal resistance, the switch K501, and the pulse width modulation signal PWM, and " The operation result divided by 2" and the reference voltage Vref are used for error amplification.
可以看出,在結合圖5至圖7描述的實施例中,恒流控制模組106可以進一步被配置為:在脈寬調變信號PWM處於邏輯低位準時,通過對電流檢測信號CS的峰值電壓CS_peak進行採樣生成電流採樣信號CS_sample;通過對電流採樣信號CS_sample進行“除以2”的運算並對運算結果和參考電壓Vref進行誤差放大,生成誤差補償信號CMP;以及通過對誤差補償信號CMP和斜坡信號Ramp進行比較,生成關斷控制信號PWM_off。
It can be seen that in the embodiments described with reference to FIGS. 5 to 7 , the constant
如結合圖1至圖7所述,用於恒流開關電源系統100的控制方法包括:基於用於控制功率開關Q1的導通與關斷的脈寬調變信號PWM和表徵流過電感L1的電感電流IL的電流檢測信號CS,生成與電流檢測信號CS相關聯的電流採樣信號CS_sample;以及基於電流採樣信號CS_sample、電感L1的退磁情況的退磁檢測信號Dem、以及參考電壓Vref,生成脈寬調變信號PWM,其中,電流採樣信號CS_sample在脈寬調變信號PWM處於第一邏輯位準時為電流檢測信號CS本身,並且在脈寬調變信號
PWM處於第二邏輯位準時為對電流檢測信號CS進行採樣生成的採樣信號。
As described in conjunction with FIGS. 1 to 7 , the control method for the constant current switching
另外,根據本發明實施例的控制方法的具體細節與結合圖1至圖7所述的控制晶片U100的相應內容類別似,在此不再贅述。 In addition, the specific details of the control method according to the embodiment of the present invention are similar to the corresponding content categories of the control chip U100 described in conjunction with FIGS. 1 to 7 , and will not be described again here.
綜上所述,根據本發明實施例的用於恒流開關電源系統的控制電路和控制方法,根據功率開關Q1的導通/關斷狀態和流過電感L1的電感電流IL的變化分階段進行恒流控制,可以消除流過電感L1的電感電流IL的畸變引起的誤差,提高恒流控制精度。 To sum up, according to the control circuit and control method for a constant current switching power supply system according to the embodiment of the present invention, the constant current IL is performed in stages according to the on/off state of the power switch Q1 and the change of the inductor current IL flowing through the inductor L1. Current control can eliminate the error caused by the distortion of the inductor current IL flowing through the inductor L1 and improve the accuracy of constant current control.
本發明可以以其他的具體形式實現,而不脫離其精神和本質特徵。例如,特定實施例中所描述的演算法可以被修改,而系統體系結構並不脫離本發明的基本精神。因此,當前的實施例在所有方面都被看作是示例性的而非限定性的,本發明的範圍由所附請求項而非上述描述定義,並且,落入請求項的含義和等同物的範圍內的全部改變從而都被包括在本發明的範圍之中。 The present invention may be implemented in other specific forms without departing from its spirit and essential characteristics. For example, algorithms described in specific embodiments may be modified without departing from the basic spirit of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and the meanings and equivalents falling within the claims. All changes within the scope are therefore included in the scope of the invention.
106:恒流控制模組 106:Constant current control module
C201,C202,C203:電容 C201, C202, C203: capacitor
CMP:誤差補償信號 CMP: error compensation signal
CS:電流檢測信號 CS: current detection signal
CS_sample:電流採樣信號 CS_sample: current sampling signal
Dem:退磁檢測信號 Dem: demagnetization detection signal
EA:誤差放大器(Error Amplifier) EA: Error Amplifier
K201,K202,K203:開關 K201, K202, K203: switch
PWM:脈寬調變信號 PWM: pulse width modulation signal
PWM_off:關斷控制信號 PWM_off: turn off control signal
Q:RS觸發器輸出端 Q: RS flip-flop output terminal
Q1:功率開關 Q1: Power switch
R:RS觸發器Reset輸入端 R: RS trigger Reset input terminal
Ramp:斜坡信號 Ramp: ramp signal
S:RS觸發器Set輸入端 S: RS trigger Set input terminal
SW1:開關控制信號 SW1: switch control signal
U200:採樣控制單元 U200: Sampling control unit
U201:誤差放大器 U201: Error amplifier
U202:斜坡產生單元 U202: Ramp generation unit
U203:比較器 U203: Comparator
U204:RS觸發器 U204:RS trigger
Vref:參考電壓 Vref: reference voltage
Claims (19)
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CN202210778591.XA CN115021596A (en) | 2022-07-04 | 2022-07-04 | Constant-current switch power supply system and control circuit and control method thereof |
CN202210778591.X | 2022-07-04 |
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Publication Number | Publication Date |
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TW202404237A true TW202404237A (en) | 2024-01-16 |
TWI838862B TWI838862B (en) | 2024-04-11 |
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TW111134559A TWI838862B (en) | 2022-07-04 | 2022-09-13 | Constant current switching power supply system and control circuit and control method thereof |
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TW (1) | TWI838862B (en) |
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CN103296904B (en) * | 2012-02-29 | 2015-05-13 | 上海莱狮半导体科技有限公司 | Power-factor correction constant current controller and control method |
CN103066872B (en) * | 2013-01-17 | 2015-06-17 | 矽力杰半导体技术(杭州)有限公司 | Integration switch power supply controller and switch power supply using the same |
CN106208765B (en) * | 2016-09-12 | 2018-12-21 | 昂宝电子(上海)有限公司 | The control device and control method of Boost pfc converter for quasi-resonance operating mode |
CN109980945B (en) * | 2019-04-11 | 2020-08-14 | 电子科技大学 | Self-adaptive leading edge blanking control circuit based on current sampling |
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CN115021596A (en) | 2022-09-06 |
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