TW201310908A - Under-voltage lockup circuit and high voltage device circuit having the same - Google Patents

Abstract

An under-voltage lockup circuit used in a high voltage device circuit is provided. The under-voltage lockup circuit comprises a load for receiving a first supply voltage, a reference high voltage transistor, a bias current source, a comparison current source and a comparison high voltage transistor. The reference high voltage transistor connected to the load has a gate for receiving a default reference voltage. The bias current source is connected between the drain of the reference high voltage transistor and a negative ground potential. An input gate of the comparison high voltage transistor is connected to the drain of the reference high voltage transistor. When the first supply voltage increases to a specific high level, the current-draining ability of the comparison high voltage transistor is greater than the current-supplying ability of the comparison current source connected to the output drain to make the output drain generate a power-activating signal.

Description

High voltage component circuit and its under voltage lockout circuit

The present disclosure relates to a circuit, and more particularly to a high voltage component circuit and its under voltage lockout circuit.

High-voltage components and circuit systems are used in a wide range of applications, such as power supply, automotive electronics, display drivers, motor control and lighting equipment, such as live electronic products. In recent years, due to environmental protection and energy issues, all countries are committed to the development of energy-saving products. If we can further expand the application of high-voltage components and circuit systems, it will greatly contribute to the development of energy-saving electronic products.

The under-voltage lockout circuit can control the power supply voltage of the circuit to initially send the power supply voltage to the functional circuit when the supply voltage reaches an appropriate level, and stop supplying the power supply voltage to the functional circuit when the supply voltage is too low. Achieve the benefits of circuit protection. However, in the environment of the high-voltage component circuit, some of the modules for constructing the under-voltage lockout circuit cannot be subjected to high voltage due to conventional components such as resistors, capacitors, etc., and it will be difficult to implement in the environment of the high-voltage component circuit.

Therefore, how to design a new voltage under-lock circuit for use in high-voltage component circuits is an urgent problem to be solved in the industry.

Therefore, one aspect of the present disclosure is to provide an under voltage lock-up circuit for use in a high voltage component circuit, the voltage under low lockout circuit includes: a load module, a reference potential high voltage transistor , bias current source module, comparison current source module and comparative high voltage transistor. The first end of the load module is configured to receive the first supply voltage. The reference potential high voltage transistor includes a gate that receives a reference preset potential and a source that is coupled to the second end of the load module. The bias current source module is connected between the drain of the reference potential high voltage transistor and the negative ground potential. The comparative high voltage transistor includes an input gate connected to the drain of the reference potential high voltage transistor and an output drain connected to the comparison current source module. When the first supply voltage is raised to a specific high level, the comparative high voltage transistor is turned on, and the current extraction capability is greater than the current supply capability of the comparison current source module, further causing the output drain to generate a power activation signal.

According to an embodiment of the present disclosure, the bias current source module includes a first current source that operates according to the first supply voltage, and the second current source operates according to the second supply voltage, wherein the second supply voltage is lower than the first A supply voltage.

In accordance with another embodiment of the present disclosure, the output dipole is coupled to an odd number of inverters to output a power enable signal by an odd number of inverters. The power start signal is output to the high voltage power start circuit or the normal voltage power start circuit, and the high voltage power supply circuit and the normal voltage power supply circuit for controlling the high voltage component circuit respectively provide a high voltage power supply and a normal voltage power supply.

According to still another embodiment of the present disclosure, the base of the reference potential high voltage transistor is connected to the source of the reference potential high voltage transistor.

According to still another embodiment of the present disclosure, the load module includes a plurality of diode-connected diode-connected high voltage transistors. The undervoltage lockout circuit further includes a delay switch connected to at least one of the high voltage transistors of the load module and configured to receive the power supply start signal, when the first supply voltage is lowered to the first specific low voltage level, The delayed open relationship shorts at least one of the high voltage transistors to cause the output drain to continue to output a power enable signal. When the first supply voltage drops to a second specific low voltage level lower than the first specific low voltage level, the high voltage cell system is turned off, and the output buck is stopped to output the power supply start signal. When the first supply voltage is raised to a certain high level, the first supply voltage is greater than the sum of the threshold voltage of the high voltage transistor of the load module and the threshold voltage of the comparative high voltage transistor.

According to an embodiment of the present disclosure, there is further provided a decoupling high voltage transistor connected to a source of a reference potential high voltage transistor.

Another aspect of the present disclosure is to provide a high voltage component circuit comprising: at least one high voltage functional module, a high voltage power supply circuit, and a low voltage lockout circuit. The high voltage function module includes at least one high voltage component. The high voltage power supply circuit is used to supply the high voltage power supply to the high voltage function module according to the power supply start signal. The under voltage lockout circuit comprises: a load module, a reference potential high voltage transistor, a bias current source module, a comparison current source module, and a comparative high voltage transistor. The first end of the load module is configured to receive the first supply voltage. The reference potential high voltage transistor includes a gate that receives a reference preset potential and a source that is coupled to the second end of the load module. The bias current source module is connected between the drain of the reference potential high voltage transistor and the negative ground potential. The comparative high voltage transistor includes an input gate connected to the drain of the reference potential high voltage transistor and an output drain connected to the comparison current source module. When the first supply voltage is raised to a specific high level, the comparative high voltage transistor is turned on, and the current extraction capability is greater than the current supply capability of the comparison current source module, further causing the output drain to generate a power activation signal.

According to an embodiment of the present disclosure, the bias current source module includes a first current source that operates according to the first supply voltage, and the second current source operates according to the second supply voltage, wherein the second supply voltage is lower than the first A supply voltage.

In accordance with another embodiment of the present disclosure, the output dipole is coupled to an odd number of inverters to output a power enable signal by an odd number of inverters.

According to still another embodiment of the present disclosure, the high voltage component circuit further includes a high voltage power supply starting circuit, and the power startup signal enables the high voltage power supply starting circuit to start the high voltage power supply circuit to supply the high voltage power supply to the high voltage function module.

According to still another embodiment of the present disclosure, the high voltage component circuit further includes a normal voltage power source starting circuit, at least one normal voltage function module, and a normal voltage power supply circuit, and the power source startup signal is further outputted to the normal voltage power source starting circuit. To supply a normal voltage power supply to the atmospheric pressure function module.

According to the present disclosure, there is an embodiment in which the base of the reference potential high voltage transistor is connected to the source of the reference potential high voltage transistor.

According to still another embodiment of the present disclosure, the load module includes a plurality of diode-connected diode-connected high voltage transistors. The undervoltage lockout circuit further includes a delay switch connected to at least one of the high voltage transistors of the load module and configured to receive the power supply start signal, when the first supply voltage is lowered to the first specific low voltage level, The delayed open relationship shorts at least one of the high voltage transistors to cause the output drain to continue to output a power enable signal. When the first supply voltage drops to a second specific low voltage level lower than the first specific low voltage level, the high voltage cell system is turned off, and the output buck is stopped to output the power supply start signal. When the first supply voltage is raised to a certain high level, the first supply voltage is greater than the sum of the threshold voltage of the high voltage transistor of the load module and the threshold voltage of the comparative high voltage transistor.

According to an embodiment of the present disclosure, the voltage under-lock circuit further includes a decoupling high voltage transistor connected to a source of the reference potential high voltage transistor.

The advantage of the application of the present disclosure is that the high-voltage component circuit environment in which the resistor cannot be used can also achieve the function of under-voltage locking by the setting of the load module and the comparative high-voltage transistor, and the above purpose can be easily achieved.

Please refer to Figure 1. 1 is a block diagram of a high voltage component circuit 1 according to an embodiment of the present disclosure. The high voltage component circuit 1 includes a voltage undervoltage lockout circuit 10, a high voltage power supply startup circuit 12, and a high voltage function module 14.

The voltage under-lock circuit 10 is configured to receive the first supply voltage 11 to generate the power-on signal 13 to the high-voltage power supply circuit 12 when the first supply voltage 11 reaches a certain high level. The high voltage power supply starting circuit 12 will thus drive the high voltage power supply circuit (not shown) in the high voltage function module 14 to start power supply, so that the high voltage function module 14 starts to operate. In an embodiment, the high voltage component circuit 1 can also include a normal voltage power source starting circuit 12' and a normal voltage function module 14'. The high voltage power source starting circuit 12 can further enable the normal voltage power source starting circuit 12' to drive the normal voltage function module. The normal voltage power supply circuit (not shown) in 14' starts to supply power, so that the atmospheric pressure function module 14' starts to operate.

In one embodiment, the high voltage functional module 14 includes at least one high voltage component, such as a high voltage P-type and N-type metal oxide semiconductor. In general, a high voltage component refers to an electronic component that can withstand at least 10 volts or more, while a normal voltage functional module 14' with respect to the high voltage functional module 14 contains only a small, low voltage, such as 5 volts or 3.3 volt P-type and N-type gold oxide semi-transistors. It should be noted that the above values are only examples, and are not intended to limit the voltage values that high voltage and atmospheric components are subjected to.

Please also refer to Figure 2. Fig. 2 is a more detailed circuit diagram of the voltage under-lock circuit 10 of Fig. 1 in an embodiment of the disclosure. The under voltage lockout circuit 10 includes a load module 20, a reference potential high voltage transistor 22, a bias current source module 24, a comparison current source module 26, and a comparative high voltage transistor 28.

The first end of the load module 20 is configured to receive the first supply voltage 11. In this embodiment, the load module 20 is formed by a plurality of high voltage transistors in the form of a diode connected in series. In one embodiment, the diode-connected high voltage transistors are P-type high voltage MOS semi-transistors in the form of a diode connection. In the present embodiment, the reference potential high voltage transistor 22 is a P-type high voltage MOS transistor connected to a source and a source for receiving a reference preset potential. In the present embodiment, the reference potential is a ground potential GND of about zero volts. The source of the reference potential high voltage transistor 22 is connected to the second end of the load module 20. Due to the setting of the reference potential high voltage transistor 22, it will be ensured that the value of the first supply voltage 11 is relative to the reference preset potential GND and not to the negative ground potential VGL.

The bias current source module 24 is connected between the drain of the reference potential high voltage transistor 22 (shown as point I in FIG. 2) and the negative ground potential VGL. In one embodiment, the bias current source module 24 includes a first current source 240 that operates in accordance with the first supply voltage 11 and a second current source 242 that operates in accordance with a second supply voltage (not shown), wherein The two supply voltages are lower than the first supply voltage 11. In an embodiment, the voltage level of the first supply voltage 11 can be supplied to the high voltage component, and the voltage level of the second supply voltage is supplied to the atmospheric component. By the arrangement of the first current source 240 and the second current source 242, the bias current source module 24 can not be made when the higher first supply voltage is not ready (if the circuit is just started but not up to the level) When the first current source 240 is in operation, the bias current can still be output by the second current source 242. The comparative high voltage transistor 28 is an N-type high voltage MOS transistor in this embodiment, the input gate of which is connected to the drain of the reference potential high voltage transistor 22 (ie, point I), and its output drain ( Connected to the comparison current source module 26 as shown in FIG. 2 as point O. In one embodiment, the comparison current source module 26 can also be a bias current source module 24, including two current sources that operate with different voltages.

Please also refer to Figure 3. FIG. 3 is a schematic diagram of the first supply voltage 11 as a function of time in an embodiment of the disclosure. In the initial situation, the level of the first supply voltage 11 is low, which is not enough to turn on the P-type MOS transistors in the load module 20, so the potential at the I point in FIG. 2 will be maintained. At low levels. The comparative high voltage transistor 28 is thus not turned on such that its output drain O point is maintained at a high level due to the presence of the comparator current source module 26. In the present embodiment, the output drain O point is further connected to the odd number of inverters 280 to output a low level signal, so that the high voltage power supply starting circuit 12 has not yet driven the power of the high voltage function module 14.

After the first supply voltage 11 is gradually increased, the potential at the I point is increased, and the comparative high voltage transistor 28 is turned on. In this embodiment, since the load module 20 has three P-type MOS transistors connected in series, and a comparative high-voltage transistor 28, the first supply voltage 11 needs to be greater than that of the load module 10. The sum of the threshold voltage Vthp of the high-voltage crystal and the threshold voltage Vthn of the comparative high-voltage transistor is a specific high level of 3Vthp+Vthn to turn on the comparative high-voltage transistor 28.

Therefore, after the first supply voltage 11 is raised to a certain high level, the comparative high voltage transistor 28 will be turned on. After comparing the high voltage transistor 28 to conduct, its current draw capability will be greater than the current supply capability of the comparator current source module 26, thus pulling down the potential of the output drain O point. After an odd number of inverters 280 have passed, a high potential power enable signal 13 will be generated.

Please refer to Figure 4. Fig. 4 is a detailed circuit diagram of the high voltage power source starting circuit 12 and the normal voltage source starting circuit 12' in the embodiment of the present disclosure. Upon receiving the power start signal 13, the high voltage power start circuit 12 generates a high voltage power drive signal VGH_OKH to start the high voltage function module 14. The high voltage power supply driving signal VGH_OKH can be further used as a signal for driving the normal voltage power supply starting circuit 12' to start the normal voltage function module 14', and enter the cycle of the power supply starting as shown in Fig. 3. It should be noted that, in an embodiment, the VGH and VGL connected to the high voltage power supply starting circuit 12 correspond to the first supply voltage 11 and the negative ground potential in FIG. 2, and the normal voltage power source starting circuit 12' is connected. VDD and VSS correspond to the second supply voltage and zero ground potential.

After the first supply voltage 11 is lowered, when the specific high level is lower than 3Vthp+Vthn, the comparative high-voltage transistor 28 can no longer be turned on, so the power-on signal 13 will be turned to the low level to make the high-voltage power supply. The starting circuit 12 and the normal voltage power starting circuit 12' stop starting the high voltage function module 14 and the normal pressure function module 14'.

Therefore, the voltage under-locking circuit of the present disclosure can achieve the function of under-voltage locking by using a load module and a comparative high-voltage transistor, so that the high-voltage component circuit environment in which the resistor cannot be used can achieve the function of circuit protection. . It should be noted that, in the above embodiments, the number of high-voltage transistors in the load module 20 and the configuration of the P-type and N-type MOS transistors can be adjusted according to actual needs, not the above description. limit.

Please also refer to Figure 5 and Figure 6. Fig. 5 is a circuit diagram of the voltage under-lock circuit 10 in Fig. 1 in another embodiment of the disclosure. FIG. 6 is a schematic diagram showing the first supply voltage 11 as a function of time in another embodiment of the disclosure. The voltage under-lock circuit 10 in this embodiment is similar to the one shown in FIG. The under-voltage lockout circuit 10 in FIG. 5 further includes a delay switch 50 connected to both ends of at least one of the high-voltage P-type transistors of the load module 20. In the present embodiment, the delay switch 50 is connected to both ends of a high voltage P-type transistor and receives the power start signal 13. In the present embodiment, the delay switch 50 is substantially a signal after receiving the output gate D point after passing through the two inverters, which is equivalent to the inversion of the power source start signal 13.

In the case where the power-on signal 13 is at a high level, the delay switch 50 will not be turned on, and thus the voltage under-lock circuit 10 will not be affected. However, when the power supply start signal 13 is lowered to a first specific low voltage level due to the first supply voltage 11 as shown in FIG. 6 and 3Vthp+Vthn as shown in FIG. 6, the delay switch 50 is switched from the high level to the low level. It will be turned on to short-circuit the high-voltage P-type transistor to which it is connected. Therefore, even if the first supply voltage 11 is lowered, the time for turning off the power-on signal 13 can be delayed, and the power-on signal 13 for continuously outputting the high level at the output drain O point can be delayed, and the power supply is turned off. Therefore, the first supply voltage needs to be reduced to a second specific low voltage level lower than the first specific low voltage level, as shown in FIG. 6 of 2Vthp+Vthn, so that the high voltage power supply starting circuit 12 is The voltage source startup circuit 12' turns off the power.

The voltage under-locking circuit 10 in this embodiment may further include a capacitor 52, which is implemented by decoupling a high voltage transistor, and is connected to the source of the reference potential high voltage transistor 22 to provide a voltage regulation function.

Therefore, the voltage under-locking circuit of the present disclosure can achieve the function of under-voltage locking by using a load module and a comparative high-voltage transistor, so that the high-voltage component circuit environment in which the resistor cannot be used can achieve the function of circuit protection. . Furthermore, by setting the delay switch, the effect of delaying the power-off can be achieved, making the design more flexible.

The present disclosure has been disclosed in the above embodiments, but it is not intended to limit the disclosure, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the disclosure. The scope of protection of the disclosure is subject to the definition of the scope of the patent application.

1. . . High voltage component circuit

10. . . Low voltage lockout circuit

11. . . First supply voltage

12. . . High voltage power supply starting circuit

12’. . . Atmospheric power supply starting circuit

13. . . Power start signal

14. . . High voltage function module

14’. . . Atmospheric pressure function module

20. . . Load module

twenty two. . . Reference potential high voltage transistor

twenty four. . . Bias current source module

240. . . First current source

242. . . Second current source

26. . . Comparison current source module

28. . . Comparing high voltage transistors

280. . . inverter

50. . . Delay switch

52. . . capacitance

The above and other objects, features, advantages and embodiments of the present disclosure will become more apparent and understood.

1 is a block diagram of a high voltage component circuit according to an embodiment of the present disclosure;

2 is a more detailed circuit diagram of the voltage under-lock circuit of FIG. 1 in an embodiment of the disclosure;

3 is a schematic diagram of a first supply voltage changing with time in an embodiment of the disclosure;

4 is a circuit diagram showing details of a high voltage power source starting circuit and a normal voltage power source starting circuit in an embodiment of the disclosure;

Figure 5 is a circuit diagram of the voltage under-lock circuit of Figure 1 in another embodiment of the present disclosure;

Figure 6 is a schematic diagram of the first supply voltage as a function of time in another embodiment of the disclosure.

10. . . Low voltage lockout circuit

11. . . First supply voltage

13. . . Power start signal

20. . . Load module

twenty two. . . Reference potential high voltage transistor

twenty four. . . Bias current source module

240. . . First current source

242. . . Second current source

26. . . Comparison current source module

28. . . Comparing high voltage transistors

280. . . inverter

Claims (21)

An under voltage lock-up circuit is applied to a high voltage component circuit, the voltage under low lock circuit includes: a load module, and the first end of the load module is configured to receive a first Supply voltage; a reference potential high voltage transistor, comprising a gate receiving a reference preset potential, and a source connected to a second end of the load module; a bias current source module connected to the reference a drain of the potential high voltage transistor and a negative ground potential; a comparison current source module; and a comparative high voltage transistor including one of the drain gates connected to the reference potential high voltage transistor and the connection And outputting a drain to one of the comparison current source modules; wherein when the first supply voltage is raised to a specific high level, the comparison high voltage transistor is turned on, and the current extraction capability is greater than the comparison current source mode The current supply capability of the group further causes the output buck to generate a power-on signal. The voltage under-locking circuit of claim 1, wherein the bias current source module comprises a first current source, operates according to the first supply voltage, and a second current source according to a second supply voltage Operating, wherein the second supply voltage is lower than the first supply voltage. The voltage under-locking circuit of claim 1, wherein the output drain is connected to an odd number of inverters to output the power-on signal by the odd-numbered inverters. The voltage under-locking circuit of claim 3, wherein the power-on signal is output to a high-voltage power-start circuit or a normal-voltage power-start circuit, and a high-voltage power supply circuit and a normal voltage of the high-voltage component circuit are controlled. The power supply circuit provides a high voltage power supply and a normal voltage power supply, respectively. The voltage under-locking circuit of claim 1, wherein a base of the reference potential high voltage transistor is connected to a source of the reference potential high voltage transistor. The voltage under-locking circuit of claim 1, wherein the load module comprises a plurality of diode-connected diode-connected high voltage transistors. The voltage under-locking circuit of claim 6, further comprising a delay switch connected to at least one of the high-voltage transistors of the load module, and configured to receive the power-on signal, A supply voltage is reduced to a first specific low voltage level that shorts at least one of the high voltage transistors such that the output drain continues to output the power enable signal. The voltage under-locking circuit of claim 7, wherein when the first supply voltage falls below a second specific low voltage level of the first specific low voltage level, the comparative high-voltage cell system is turned off. The output bungee stops outputting the power start signal. The voltage under-locking circuit of claim 6, wherein the first supply voltage is greater than a threshold voltage of the high-voltage transistors of the load module when the first supply voltage is raised to the specific high level And the sum of the threshold voltages of the comparative high voltage transistors The voltage under-locking circuit of claim 1 further includes a capacitor connected to the source of the reference potential high voltage transistor. A high voltage component circuit comprising: at least one high voltage function module comprising at least one high voltage component; a high voltage power supply circuit for supplying a high voltage power supply to the high voltage function module according to a power supply start signal; and a voltage under low lock The circuit includes: a load module, a first end of the load module is configured to receive a first supply voltage; a reference potential high voltage transistor includes a gate receiving a reference preset potential, and is coupled to the a source of the second end of the load module; a bias current source module connected between the drain of the reference potential high voltage transistor and a negative ground potential; a comparison current source module; and a relatively high a piezoelectric crystal comprising an input gate connected to one of the drains of the reference potential high voltage transistor and an output drain connected to the comparison current source module; wherein the first supply voltage is raised to a specific high level The position is such that the comparative high voltage transistor is turned on, and the current extraction capability thereof is greater than the current supply capability of the comparison current source module, further causing the output drain to generate a power activation signal. . The high voltage component circuit of claim 11, wherein the bias current source module comprises a first current source, operates according to the first supply voltage, and a second current source operates according to a second supply voltage. Wherein the second supply voltage is lower than the first supply voltage. The high voltage component circuit of claim 11, wherein the output drain is connected to an odd number of inverters to output the power enable signal by the odd number of inverters. The high voltage component circuit of claim 11 further comprising a high voltage power supply starting circuit, wherein the power supply starting signal causes the high voltage power starting circuit to activate the high voltage power supply circuit to supply the high voltage power supply to the high voltage function module. The high voltage component circuit of claim 11, further comprising a normal voltage power source starting circuit, at least one normal voltage function module, and a normal voltage power supply circuit, wherein the power source startup signal is further output to the normal voltage power source starting circuit, Supply a normal voltage power supply to the atmospheric pressure function module. The high voltage component circuit of claim 11, wherein a base of the reference potential high voltage transistor is coupled to a source of the reference potential high voltage transistor. The high voltage component circuit of claim 11, wherein the load module comprises a plurality of diode-connected diode-connected high voltage transistors. The high voltage component circuit of claim 17, wherein the voltage undervoltage locking circuit further comprises a delay switch connected to at least one of the high voltage transistors of the load module and configured to receive the power source The start signal, when the first supply voltage is lowered to a first specific low voltage level, the delayed open relationship shorts at least one of the high voltage transistors, so that the output drain continues to output the power start signal. The high voltage component circuit of claim 18, when the first supply voltage falls below a second specific low voltage level of the first specific low voltage level, the comparative high voltage die system is turned off, the output The bungee system stops outputting the power start signal. The high voltage component circuit of claim 17, wherein when the first supply voltage is raised to the specific high level, the first supply voltage is greater than a threshold voltage of the high voltage transistors of the load module and Compare the sum of the threshold voltages of the high voltage transistors. The high voltage component circuit of claim 11, wherein the voltage undervoltage locking circuit further comprises a capacitor connected to a source of the reference potential high voltage transistor.