DE102009033280A1 - Low voltage supply circuit for operating integrated circuit of operating device, has integrated circuit supplied with electric current when voltage level at current supply connection of integrated circuit is lower than reference voltage - Google Patents

Abstract

The circuit has a current amplification circuit (10) for supplying an input voltage (1). The amplification circuit is subjected to a control input with a reference voltage that is produced by a zener diode based on the input voltage. An integrated circuit (8) is supplied with electric current, only when a voltage level at a current supply connection of the integrated circuit is lower than the reference voltage at the control input of the amplification circuit. Two parallel input resistances are switched between the amplification circuit and the integrated circuit. An independent claim is also included for a method for operating an integrated circuit in an operating device.

Description

The present invention relates to the field of so-called. Low-voltage supply, especially for control gear for lighting, such as electronic ballasts for gas discharge lamps as well as drivers for LED modules (LEDS, OLEDs).

The low-voltage supply is a circuit arrangement by means of which a DC voltage supply in a voltage range can be generated in the operating device, as is typical of the supply voltage of (active) electronic components (integrated circuits, microcontrollers, ASICs, etc.).

Typically, these DC supply voltages are in the range of less than 15 volts DC. In principle, it is known from the state of the art in the field of operating devices for lighting means that a start-up low-voltage supply is available for a starting phase of the operating device immediately after switching on the mains voltage supply. Typically, this low-voltage power supply for the start-up phase is a so-called start-up resistor, so an ohmic resistance, which is supplied with mains voltage. The resulting voltage at this starting voltage can be rectified and charge, for example, a capacitor whose charging voltage then supplies the necessary supply voltage for a control circuit of the operating device in an initial phase.

In a second phase, that is, when the control circuit is started up by means of the starting resistance, the control circuit controls the operation of the operating device. For this phase, ie when the control circuit is active, then usually the low-voltage supply is obtained from clocked circuit groups of the operating device. These clocked circuit groups can be, for example, a full bridge circuit or a half bridge circuit for supplying gas discharge lamps with HF voltage, an active PFC circuit in the form of a boost converter, a clocked heating circuit for filaments of gas discharge lamps etc. At these clocked component groups, for example, by a capacitive coupling for normal operation of the control unit necessary low-voltage supply can be obtained.

A disadvantage of this known two-stage design of the low-voltage power supply, it is natural that the starting resistance is also supplied with operational control circuit in normal operation and in standby mode continues to be supplied with mains voltage and thus at this starting resistance in normal operation and in standby mode of the operating device, a power loss drops.

An example for minimizing the standby power (representing a power dissipation) in a lighting device is from the EP 1 374 366 B1 also called in this case for the first phase, the low-voltage supply by an ohmic resistance (see 2 of the EP 1 374 366 B1 ) is won. In the EP 1 374 366 B1 is then a Zener diode D5 and a capacitor C12 as a low-voltage power supply for the integrated circuits, said capacitor / diode circuit is branched from the midpoint of a half-bridge circuit.

The invention has now taken on the task of designing the low-voltage power supply for integrated circuits in operating devices for lighting energy efficient.

This object is solved by the features of the independent claims. The dependent claims further form the central idea of the invention in a particularly advantageous manner.

In a first aspect, the invention relates to a low-voltage supply circuit for operating an integrated circuit of an operating device, in particular in the starting phase of the integrated circuit. In this case, the low-voltage supply circuit has a current amplification circuit supplied by a supply voltage, for example a mains voltage or battery voltage, which is acted on at a control input by a reference voltage generated by the supply voltage and only then supplies the integrated circuit with electrical current when the voltage level at a power supply terminal of the integrated circuit is lower than the reference voltage at the control input of the current amplification circuit.

The current amplification circuit can have one starting from the supply voltage transistor, at the control input of which the reference voltage can be present.

The level of the reference voltage at the control input of the transistor, for example about 13 V, is preferably at least as high as the voltage required by the integrated circuit.

The reference voltage can be generated by means of at least one zener diode or a plurality of series-connected zener diodes.

The entire Operating device or the integrated circuit can be operated in different operating modes. The entire operating device or the integrated circuit can be operated, for example, in normal operation with relatively high power consumption. The entire operating device or the integrated circuit can also be operated in a standby mode in which its power consumption is reduced. This can be done, for example, by switching off or deactivating certain functions or functional blocks of the integrated circuit or by reducing the clock of the integrated circuit. This may result in a lower current flow in standby mode. In comparison to the standby mode, more functions of the integrated circuit and also of the operating device (ie of the converter) can be activated in normal operation and in the startup phase.

Between the current amplifying circuit and the integrated circuit, two parallel switches are preferably connected. Anyone can also make an electrical connection between the integrated circuit and the low voltage supply circuit.

In another aspect, the invention relates to an integrated circuit for controlling an operating device. This has at least one input for supplying the integrated circuit with a low-voltage voltage. In this case, an input from a supply voltage (eg., Mains voltage) supplied power amplification circuit is connected downstream, which is acted upon at its control input with a reference voltage generated by the supply voltage and the input only then supplies the integrated circuit via the current amplification circuit with electric current, if the Voltage level at the input of the integrated circuit is lower than the reference voltage at the control input of the current amplification circuit.

The current amplification circuit may comprise a transistor. The reference voltage can be present at its control input.

The level of the reference voltage at the control input of the transistor, for example about 13 V, is preferably at least as high as the voltage required by the integrated circuit.

The reference voltage can be generated by means of at least one zener diode.

Furthermore, the invention provides an operating device for operating a load, in particular a light source such as one or more LEDs, OLEDs or gas discharge lamps. The operating device preferably has a low-voltage supply circuit, as described above, and can be based on an AC line voltage and / or a battery voltage be supplied.

In addition, the invention relates to an operating device for operating a load, in particular a luminous means such as one or more LEDs, OLEDs or gas discharge lamps, comprising an integrated circuit as described above.

The operating device may have a rectifier, which may be connected to a mains voltage.

The operating device also preferably has a power factor correction circuit (PFC) which is actively clocked by means of a switch controlled by a control unit (eg the integrated circuit) and which can be connected to the rectifier.

In addition, the operating device may include a clocked module (converter) connected to the power factor correction circuit. The clocked module preferably supplies the load and the integrated circuit with power as long as the clocked module is actively operated. The power consumption of the load (bulbs) can bpsw. Controlled or regulated via the clocking of the clocked module.

The control input of the current amplification circuit is in a preferred embodiment, via an AC / DC detection circuit, which may be connected to the mains input voltage, supplied with electric current.

The AC / DC detection circuit may consist of a measuring resistor and two different resistors connected in series between the two poles of the mains input voltage. Between these, the power supply for the control input of the current amplification circuit can be tapped. The voltage is preferably reduced by a voltage divider.

Finally, the invention also relates to a method for operating an integrated circuit in an operating device with a low-voltage supply voltage. It provides a clocked module as long as the integrated circuit with a low-voltage, as the clocked module is actively operated, d. H. the clocked module is in normal operation.

Otherwise, a separate low-voltage supply circuit, which has a power amplification circuit supplied from a supply voltage, supplies the integrated circuit with a low-voltage voltage.

The low-voltage supply circuit preferably supplies the integrated circuit with a low-voltage voltage in standby mode and in the start-up phase of the clocked module.

The electric current supplied to the integrated circuit through the low-voltage supply circuit may be controlled by the current-amplifying circuit.

The invention will be explained in more detail with reference to the accompanying drawings. Show it:

1 a schematic representation of the invention,

2 an embodiment of an operating device according to the invention,

3 a timing diagram of various voltages and currents during the transition of the operating device from standby mode to normal operation.

In 1 a schematic representation of the invention is shown. Here, an operating device for operating a load is sketched schematically.

An input voltage 1 of the operating device 11 is with an AC / DC converter 2 (Rectifier) connected. The input voltage is preferably a conventional AC mains source. However, it is also conceivable that a DC power source is used, in which case the AC / DC converter is not present.

The AC / DC converter is a converter 5 downstream. This has a current adjustment 3 For example, by means of a power factor correction circuit (PFC, Power Factor Correction) on. In addition, the converter has at least one clocked module 4 For example, an inverter such as a half or full bridge or a DC-DC converter such as a buck converter. At this is the burden 6 connected. At the converter 5 can also be on the power adjustment 3 be waived. Unless a power adjustment 3 is present, it can be a clocked assembly 4 be upstream.

The load is preferably one or more gas discharge lamps. However, it should be pointed out that the operating device can also be provided for any other load, for example for any light sources, such as LEDs, OLEDs, etc.

For controlling the control of the load by means of the converter 5 becomes an integrated circuit 8th used. It can be an ASIC. As an alternative to the ASIC, however, any other form of integrated circuit such as a microcontroller or a hybrid solution, or a conventional circuit can be used.

The integrated circuit is in normal operation of the clocked module 4 from this with electricity. For this, both are via a circuit 7 connected, which is designed for current / voltage adjustment. This is, for example, a down-converter.

In addition, the integrated circuit via a second, separate low-voltage supply circuit 9 . 10 powered. This draws its electrical supply current from the AC / DC converter 2 , For this purpose, the AC / DC converter via a current amplification circuit 10 connected to the integrated circuit.

The current amplification circuit is preferably a bipolar transistor. However, it is conceivable to use a field-effect transistor circuit. It is possible that the current amplification circuit is a component of the integrated circuit 8th represents. However, the current amplification circuit can also be designed as separate and / or discrete components.

Furthermore, at the control input of the current amplification circuit is a circuit 9 connected to current / voltage adjustment. This circuit 9 is preferably directly from the input voltage 1 fed. Through the circuit 9 the control input of the current amplification circuit is supplied with a constant low-voltage voltage. This is at least as high as the supply voltage required for the integrated circuit. Preferably, it is slightly higher.

The current amplifying circuit now supplies power to the integrated circuit only when the voltage applied to the terminal of the integrated circuit is lower than the voltage applied to the control input of the current amplifying circuit. This means that the current amplification circuit turns off when the integrated circuit is already supplied with power from the clocked module, which corresponds to the parameters provided for the integrated circuit. However, if the clocked module is inactive and thus does not power the integrated circuit, the power amplifier circuit provides a power supply. The current is adjusted as a function of the voltage level at the connection of the integrated circuit. The current increases with decreasing voltage level. This means that the integrated circuit is constantly connected to a low-voltage Supply voltage is operated, regardless of the state of the clocked module.

The current amplification circuit is thus used only when the clocked module is in standby mode, or in a start-up phase. The latter arises from the fact that the integrated circuit after activation of the operating device 11 For example, by a user via an input interface, about 100 μs earlier than the clocked module is active. In this phase, in which the integrated circuit requires a particularly large amount of power, accordingly, the low-voltage supply circuit must provide a power supply.

The embodiment of 2 corresponds to the schematic representation of the invention 1 , It is an equivalent circuit diagram showing the essential for the invention electrical components.

The operating device 11 is for operating one or more gas discharge lamps 6 designed. In the AC / DC converter 2 this is a bridge rectifier circuit in this embodiment. The power factor correction filter 3 and the clocked module 4 are shown here only as an equivalent circuit diagram. As a clocked module, a half-bridge is provided which generates a constant alternating current.

The power factor correction filter 3 may be, for example, an active clocked boost converter circuit. This power factor correction filter 3 is the clocked module 4 upstream, for reasons of clarity in the 2 these two components are shown separately and without connection.

The power factor correction filter 3 feeds the clocked module 4 which, in turn, the gas discharge lamps 6 provided.

The low voltage supply circuit 9 . 10 has a bipolar transistor 10 on, which represents the central part of the current amplification circuit. This supplied in the manner described above according to the invention, the integrated circuit 8th , in this case an ASIC, with power it receives from the rectifier 2 receives. For this purpose, the collector of the bipolar transistor is connected to the rectifier and the emitter to the power supply terminal, ie the ASIC supply pin, the integrated circuit.

The transistor circuit is thus designed such that a current flow starting from the rectified AC line voltage through the transistor takes place only when the voltage at the ASIC Versorgungspin is lower than the base voltage. However, as soon as the voltage at the ASIC pin reaches a region about the base voltage, no current flows through the transistor Q5. The ASIC is thus supplied exactly with the current value that it requires in its respective operating phase.

A diode D2 serves as a protection diode and prevents overvoltage between base and emitter.

To supply the base of the bipolar transistor with a constant voltage, this is via a circuit 9 for voltage adjustment with the input voltage 1 connected. The circuit 9 has an AC / DC detection circuit consisting of the resistors R16, R17, R18 and R19. Due to different resistances of R16 and R17, the positive and negative half-wave of the tapped input voltage are different. Thus it can be detected by measuring the resistor R19, whether it is the input voltage 1 is a DC or AC voltage.

To reduce the voltage, the circuit indicates 9 a voltage divider, consisting of the resistors R16 and the series circuit of R18 and R19, and the resistors R17 and the series circuit of R18 and R19. Another current or voltage limitation is effected by the resistor R21.

Two serially connected Zener diodes connected to resistor R21 and ground maintain a voltage of preferably 13 to 14 V, optimally 13.6 V constant. A slightly lower voltage of preferably 12.9 V is accordingly applied to the base of the bipolar transistor connected in parallel therewith.

The diode D3 is connected in series with the resistor R21. This prevents current flow from the ASIC supply pin via the protection diode D2 to the AC / DC detection circuit, which provides the current to the Zener diodes.

Parallel to the ASIC 8th is a capacitor C7 connected. This is charged by the supply current of the ASIC. Thus, it provides the necessary voltage for the ASIC and can smooth and buffer them.

The ASIC can be operated in different operating modes. It can be operated, for example, in normal operation with relatively high power consumption. It can also be operated in a standby mode in which its power consumption is reduced. This can be done, for example, by switching off or deactivating certain functions or function blocks or by reducing the Taken clock. These two possible operating modes are each exemplified by a switch S1 or S2 in series. The resistors R3 and R6 thereby represent the resulting load by the power consumption of the ASIC. As already mentioned, the operating device can 11 in three different operating modes. These are the standby mode, the startup phase and normal operation. The standby mode is symbolically represented by the closed switch S2 (with the switch S1 open). Thus, the ASIC has a symbolic resistance of 37 kOHM. In the start-up phase and in normal operation, however, it can be assumed that the ASIC has a load of a resistance of only 1 kOHM, which is symbolized by the closed switch S1 (switch S2 open).

It is now conceivable that in one to the in 2 shown alternative embodiment, at least part of the low-voltage supply circuit 9 . 10 as part of the integrated circuit 8th is trained. In particular, the diodes D2, D3, and the transistor circuit Q5 can be integrated. It is possible, the current amplification circuit 10 to realize by FET circuits (field-effect transistors) or CMOS circuits.

Thus, the integrated circuit has two inputs, ie preferably two PINs for low-voltage supply. At a PIN is accordingly the power supply of the clocked module 4 connected. At the other pin is the rectifier 2 connected. The two power supply PINs can be internally linked in the ASIC, but can also be linked externally and connected to a single power supply PIin.

The zener diodes D8 and D11 may also be integrated or formed as discrete components outside the integrated circuit.

In addition, a separate control output or a PIN designed for controlling the converter is provided on the integrated circuit 5 or the current amplification circuit 10 intended. The converter 5 may also include multiple active switching elements that are controlled by multiple control outputs of the integrated circuit.

The power supply pin can also be linked to the capacitor C7, which can stabilize the supply voltage of the ASIC as a buffer element.

The power supply of the control input of the transistor circuit Q5 can be done again in the manner described above. This means that this is connected to an AC / DC detection circuit 9 can be connected.

The main power supply of the transistor, which is connected to the collector when using a bipolar transistor, can be carried out in the manner explained above. This means that this again from a rectified mains voltage 1 can be supplied.

When the control input of the current amplification circuit to the AC / DC detection circuit 9 connected, this offers the advantage that the already existing AC / DC detection circuit 9 can be used for a further function and no further voltage paths are required to supply the control input of the current amplification circuit.

Because the control input of the current amplification circuit from a point in front of the rectifier 2 This offers the advantage that the active clocked power factor correction circuit PFC, 3 does not need to be put into operation to ensure sufficient energy supply for the current amplification circuit.

If the operating device is in normal operation, results for the converter 5 a high load.

This situation is represented by the symbolic resistance R5, which is symbolically switched on in this operating mode. In standby mode arises for the converter 5 a low load. This situation is represented by the symbolic resistance R13. In the standby mode, the connected lamp (gas discharge lamp 6 ) out of service and also modules of the converter 5 such as the power factor correction circuit PFC, 3 or the clocked module 4 (Inverter 4 ) can be inactive.

It should also be noted that the low-voltage power supply according to the invention can be used quite generally in any electronic device which has a control unit, preferably an integrated circuit, and can be in a standby mode.

3 illustrates a schematic timing diagram of various voltages and currents during the transition of the operating device from standby mode over the start-up phase to normal operation. The voltage U _HB at the clocked module 4 , which is preferably a half or full bridge, is zero during standby mode. In the start-up phase, which lasts about 100 μs, the clocked module goes into operation, which it then reached in the third section "normal operation".

The voltage U _V is provided to the ASIC by the low-voltage supply circuit. This is during the standby mode preferably 11 V. in the startup phase, this decreases to about 9 V. In normal operation, this invention 0 V, since from now on the ASIC of the clocked module 4 is supplied.

The current flow I _ASIC at the supply pin of the ASIC is minimal during standby, it is preferably not more than 300 μA. Especially in the start-up phase, the ASIC has a high power requirement. Here the current increases to preferably 10 mA. In the subsequent normal operation, the current can remain constant or fall again. The decisive advantage of the invention results from the fact that the ASIC is supplied in the start-up phase of the low-voltage supply circuit with the required high current, while in standby mode almost no leakage occurs.

As already mentioned, the ASIC and also the entire operating device can be operated in different operating modes. The ASIC can be operated, for example, in normal operation with relatively high power consumption. It can also be operated in a standby mode in which its power consumption is reduced. This can be done for example by switching off or disabling certain functions or function blocks or by reducing the clock. This may result in a lower current flow in standby mode. These two possible operating modes are each shown with a switch S1 or S2 in series beispielhaf. The resistors R3 and R6 thereby represent the resulting load by the power consumption of the ASIC. As already mentioned, the operating device can 11 in three different operating modes. These are the standby mode, the startup phase and normal operation.

The from the low voltage supply circuit 9 . 10 Provided voltage can also be used to power other existing in the operating device integrated circuits or other circuits (such as an interface).

LIST OF REFERENCE NUMBERS

1

Input voltage of the operating device

2

rectifier

3

Power Factor Correction Filter (PFC)

4

clocked module

5

converter

6

load

7

Circuit for voltage-current adjustment

8th

Integrated circuit

9

AC / DC detection circuit and voltage current adjustment circuit

10

Current amplification circuit

11

control gear

Q5

transistor

D8, D11

Zener diode

S1, S2

switch

D2, D3

diode

Rxx

resistance

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1374366 B1 [0006, 0006, 0006]

Claims (22)

Low-voltage supply circuit ( 9 . 10 ) for operating an integrated circuit ( 8th ) of an operating device ( 11 ), in particular in the starting phase of the integrated circuit, characterized in that the low-voltage supply circuit, starting from a supply circuit, in particular mains voltage ( 1 ) supplied power amplification circuit ( 10 ), which at a control input with a starting from the mains voltage ( 1 ) and only supplies the integrated circuit with electrical current when the voltage level at a power supply terminal of the integrated circuit is lower than the reference voltage at the control input of the current amplification circuit. Low-voltage supply circuit according to claim 1, characterized in that the current amplification circuit ( 10 ) has a transistor (Q5), at the control input of which the reference voltage is applied. Low-voltage supply circuit according to the preceding claim, characterized in that the height of the reference voltage at the control input of the transistor (Q5), preferably about 13 V, is at least as high as the voltage required by the integrated circuit. Low-voltage supply circuit according to one of the preceding claims, characterized in that the reference voltage is generated by means of at least one Zener diode (D8, D11). Low-voltage supply circuit according to one of the preceding claims, characterized in that between the current amplifying circuit and the integrated circuit, two parallel input resistors (R3, R6) are connected, each with a switch (S1, S2) arranged in series and each having an electrical connection between the integrated circuit ( 8th ) and the low-voltage supply circuit ( 9 . 10 ) produce. Integrated circuit ( 8th ) for controlling an operating device ( 11 ), comprising at least two inputs for supplying the integrated circuit ( 8th ) with a low-voltage voltage, characterized in that an input starting from a mains voltage ( 1 ) supplied power amplification circuit ( 10 ) is applied, which is acted upon at its control input with a reference voltage generated by the mains voltage and the input only the integrated circuit ( 8th ) via the current amplification circuit ( 10 ) is supplied with electrical current when the voltage level at the input of the integrated circuit is lower than the reference voltage at the control input of the current amplification circuit ( 10 ). Integrated circuit ( 8th ) according to claim 6, characterized in that the current amplification circuit ( 10 ) has a transistor (Q5), at the control input of which the reference voltage is applied. Integrated circuit ( 8th ) according to the preceding claim, characterized in that the height of the reference voltage at the control input of the transistor (Q5), preferably about 13 V, is at least as high as the voltage required by the integrated circuit. Integrated circuit ( 8th ) according to one of claims 6 to 8, characterized in that the reference voltage is generated by means of at least one Zener diode (D8, D11). Integrated circuit ( 8th ) according to one of claims 6 to 9, characterized in that the integrated circuit can assume different operating modes with different power consumption. Operating device for operating a load, in particular a light source ( 6 ), such as one or more LEDs, OLEDs or gas discharge lamps, comprising a low-voltage supply circuit ( 9 . 10 ) according to claims 1 to 5. Operating device for operating a load ( 6 ), in particular a luminous means such as one or more LEDs, OLEDs or gas discharge lamps, comprising an integrated circuit ( 8th ) according to claims 6 to 10. Operating device according to claims 11 or 12, characterized in that the operating device is a rectifier ( 2 ), which is connected to a mains voltage ( 1 ) connected. Operating device according to Claims 11 or 12, characterized in that the operating device has a power factor correction circuit (PFC, 3 ) which is connected to the rectifier ( 2 ) connected. Operating device according to Claims 11 or 12, characterized in that the operating device has a clocked module ( 4 ) connected to the power factor correction circuit ( 3 ) and the load ( 6 ) and the integrated circuit ( 8th ), as long as the clocked module is actively operated. Operating device according to claims 11 or 12, characterized in that the Control input of the current amplification circuit ( 10 ) via an AC / DC detection circuit ( 9 ) connected to the mains input voltage ( 1 ) is connected, is supplied with electric power. Operating device according to claims 11 or 12, characterized in that the AC / DC detection circuit ( 9 ) consists of a measuring resistor (R19) and two different resistors (R16, R17) connected in series between the two poles of the mains input voltage (R19). 1 ) and between which the power supply for the control input of the current amplification circuit ( 10 ) is tapped, wherein the voltage is reduced by a voltage divider (R16, R17, R18, R19). Method for operating an integrated circuit ( 8th ) in an operating device ( 11 ) with a low-voltage supply voltage, characterized in that - a clocked module ( 4 ) as long as the integrated circuit ( 8th ) is supplied with a low-voltage voltage, as the clocked module is actively operated, ie the clocked module is in normal operation, - otherwise a separate low-voltage supply circuit ( 9 . 10 ), one starting from a mains voltage ( 1 ) supplied power amplification circuit ( 10 ), which supplies the integrated circuit with a low-voltage voltage. Method for operating an integrated circuit with a low-voltage supply voltage according to claim 18, characterized in that the low-voltage supply circuit ( 9 . 10 ) in standby mode and in the startup phase of the clocked module ( 4 ) supplies the integrated circuit with a low voltage voltage. A method for operating an integrated circuit with a low-voltage supply voltage according to claims 18 and 19, characterized in that in normal operation and in the start-up phase more functions of the integrated circuit ( 8th ) are activated in comparison to standby mode. Method for operating an integrated circuit with a low-voltage supply voltage according to claims 18 to 20, characterized in that in standby mode certain parts of the integrated circuit ( 8th ) are disabled. Method for operating an integrated circuit with a low-voltage supply voltage according to claims 18 to 21, characterized in that the electrical current of the integrated circuit ( 8th ) by means of the low-voltage supply circuit ( 9 . 10 ) is supplied by the current amplification circuit ( 10 ) is controlled.

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