Threshold judgment circuit of high-voltage clock power supply
By designing a high-voltage clock power supply threshold judgment circuit including resistors, transistors and transistors, the band gap reference design idea is used to solve the accuracy and temperature drift problems of the threshold judgment of high-voltage clock power supply in the existing technology, and the threshold judgment effect of high-precision and low-temperature drift is achieved.
Patent Information
- Application Number
- CN202420701681.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-07
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-04-07
AI Technical Summary
The prior art is difficult to monitor the threshold value of high-voltage clock power supply with high accuracy and low temperature drift, especially when the temperature characteristics and process batch performance are largely different.
A threshold value judgment circuit for high-voltage clock power supply is designed. Using the combination of resistors R1-R5, transistors B1-B2 and transistors N1-N4, the threshold value judgment of high-precision and low-temperature drift is achieved through the band gap reference design idea, avoiding the need for additional band gap reference circuits.
It realizes high-precision and low-temperature drifting threshold judgment of high-voltage clock power supply, overcomes the problems of temperature characteristics and process batch performance in traditional methods, and is suitable for threshold judgment of high-voltage jump power supply and other signals.
Smart Images
Figure CN222763868U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of power supply threshold judgment, and in particular relates to a threshold judgment circuit of a high-voltage clock power supply. Background Art
[0002] In chip design, some voltage signals are often monitored in real time. For example, taking a fixed single power supply voltage VCC as an example, the reference voltage is GND, and the VCC normal startup voltage threshold VCC_Vrising needs to be set.
[0003] When the chip is powered on, VCC will rise slowly. When VCC is higher than VCC_Vrising, other related circuits can start working. Otherwise, other circuits must wait for VCC to rise further to meet the minimum VCC operating voltage required for the normal operation of related circuits. Typical threshold circuits of this type often use a reference voltage and a divided voltage of VCC to determine whether VCC has reached the flip threshold through a voltage comparator, and the reference voltage achieves high precision and low temperature drift. When you need to monitor the high voltage voltage threshold, even when the positive and negative power supplies are clock power supplies, for example, VCC is a positive power supply signal, VSS is a negative power supply signal, and the difference between VCC and VSS is a fixed voltage signal. It is difficult to implement this type of high voltage power supply threshold monitoring by comparing with the reference voltage, because the on-chip reference circuits are generally low voltage circuits.
[0004] Generally, the most commonly used processing method is the simplest resistor voltage divider followed by a Schmidt inverter and other circuits, but the temperature characteristics of the detection threshold will be very obvious, and the process batch differences will be very large. Therefore, this type of threshold detection circuit is worth studying. Inspired by the design of low-voltage bandgap reference circuits, a flag signal for establishing a bandgap reference is often designed, and the bandgap reference circuit must have a minimum power supply voltage. If the minimum power supply voltage of the bandgap reference can be adjusted, the flag signal established by the bandgap reference voltage can be used as the flag signal for establishing the power supply voltage, except that the power domain of the circuit is changed to a high-voltage power domain, or even a high-voltage clock power domain.
[0005] Therefore, further improvements are made to the above problems. Utility Model Content
[0006] The main purpose of the utility model is to provide a threshold judgment circuit for a high-voltage clock power supply, which overcomes the complexity of circuit design and still meets the threshold judgment of the high-voltage clock power supply with high precision and low temperature drift requirements.
[0007] In order to achieve the above purpose, the utility model provides a threshold judgment circuit of a high-voltage clock power supply, including resistors R1-R5, transistors B1-B2 and transistors N1-N4, wherein:
[0008] The resistor R1 and the resistor R2 are connected between the positive power supply VCC and the negative power supply VSS, and the common terminal of the resistor R1 and the resistor R2 is provided with a connection point A, and the connection point A is electrically connected to the base of the transistor B1, the base of the transistor B2 and the gate of the transistor N3 respectively, the emitter of the transistor B1 is connected to the positive power supply VCC through the resistor R4 and the resistor R3, and the collector of the transistor B1 is electrically connected to the drain of the transistor N1, and the emitter of the transistor B2 is connected to the positive power supply VCC through the resistor R3, and the collector of the transistor B2 is electrically connected to the drain of the transistor N2;
[0009] The gate of transistor N1 is electrically connected to the gate of transistor N2, the source of transistor N1, the source of transistor N2 and the source of transistor N3 are all connected to the negative power supply VSS, the drain of transistor N3 is electrically connected to the source of transistor N4 and the gate of transistor N4 is electrically connected to the collector of transistor B2, the drain of transistor N4 is connected to the positive power supply VCC through resistor R5 and the drain of transistor N4 is also connected to the output terminal Y through Schmitt inverter SMIT1.
[0010] As a further preferred technical solution of the above technical solution, the ratio of the number of transistors B1 to that of transistors B2 is n:1, and a plurality of transistors B1 are connected in parallel.
[0011] As a further preferred technical solution of the above technical solution, the two ends of the resistor R2 are connected in parallel with the capacitor C1, and the two ends of the resistor R5 are connected in parallel with the capacitor C2.
[0012] As a further preferred technical solution of the above technical solution, the collector of the transistor B1 is provided with a connection point B, the collector of the transistor B2 is provided with a connection point C, and the drain of the transistor N4 is provided with a connection point D.
[0013] As a further preferred technical solution of the above technical solution, the gate and the drain of the transistor N1 are electrically connected. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 The utility model discloses a circuit diagram of a threshold value judgment circuit of a high-voltage clock power supply. DETAILED DESCRIPTION
[0015] The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the utility model.
[0016] The utility model discloses a threshold judgment circuit of a high-voltage clock power supply. The specific embodiments of the utility model are further described below in conjunction with preferred embodiments.
[0017] In the embodiments of the present invention, those skilled in the art note that the clock power supply and the like involved in the present invention may be regarded as prior art.
[0018] Preferred embodiments.
[0019] The utility model discloses a threshold judgment circuit of a high-voltage clock power supply, comprising resistors R1-R5, triodes B1-B2 and transistors N1-N4, wherein:
[0020] The resistor R1 and the resistor R2 are connected between the positive power supply VCC and the negative power supply VSS, and the common terminal of the resistor R1 and the resistor R2 is provided with a connection point A, and the connection point A is electrically connected to the base of the transistor B1, the base of the transistor B2 and the gate of the transistor N3 respectively, the emitter of the transistor B1 is connected to the positive power supply VCC through the resistor R4 and the resistor R3, and the collector of the transistor B1 is electrically connected to the drain of the transistor N1, and the emitter of the transistor B2 is connected to the positive power supply VCC through the resistor R3, and the collector of the transistor B2 is electrically connected to the drain of the transistor N2;
[0021] The gate of transistor N1 is electrically connected to the gate of transistor N2, the source of transistor N1, the source of transistor N2 and the source of transistor N3 are all connected to the negative power supply VSS, the drain of transistor N3 is electrically connected to the source of transistor N4 and the gate of transistor N4 is electrically connected to the collector of transistor B2, the drain of transistor N4 is connected to the positive power supply VCC through resistor R5 and the drain of transistor N4 is also connected to the output terminal Y through Schmitt inverter SMIT1.
[0022] Specifically, the number ratio of the transistors B1 to the transistors B2 is n:1, and a plurality of transistors B1 are connected in parallel.
[0023] More specifically, the two ends of the resistor R2 are connected in parallel with the capacitor C1 , and the two ends of the resistor R5 are connected in parallel with the capacitor C2 .
[0024] Furthermore, a connection point B is provided at the collector of the transistor B1 , a connection point C is provided at the collector of the transistor B2 , and a connection point D is provided at the drain of the transistor N4 .
[0025] Furthermore, the gate and the drain of the transistor N1 are electrically connected.
[0026] The principle of the utility model is:
[0027] The characteristic of this circuit is that it does not require an additional bandgap reference circuit to generate a reference voltage and a comparator, but it uses the idea of a bandgap reference design to achieve high precision and low temperature drift. It is used for threshold judgment of a high-voltage clock power supply. R1-R5 are resistors, B1 and B2 are PNP transistors with a quantity ratio of n:1, N1-N4 are NMOS, N1 and N2 are 1:1 proportional current mirrors, C1-C2 are filter capacitors, SMIT1 is a Schmitt inverter, VCC is a positive power supply, and the negative power supply is VSS. This circuit monitors the voltage difference ΔV between VCC and VSS. The output Y changes from a low level to a high level, indicating that ΔV exceeds the rising edge threshold.
[0028] Specific implementation process: Initially, since ΔV is very small, the voltage divider value VA (voltage at point A) between R1 and R2 is very small, the number of B1 is greater than B2, N1 and N2 are equal-proportional current mirrors, the voltage VB at point B will become higher first, N1 is working in the saturation region, and the voltage VC at point C will naturally be pulled down, so N2 actually enters the linear region, the current flowing through N1 is greater than the current flowing through N2, at this time N4 is cut off, the voltage at point D is high, and the output Y is low. When ΔV gradually increases, VA will increase accordingly. When the entire loop is established and stable, N1 and N2 will realize a 1:1 current mirror, N1 and N2 enter the saturation region, at this time VC will be pulled high, N4 will be turned on, so that VD will be pulled down, and the output Y will become high through the reverse of SMIT1. Therefore, the indicator that the output Y of this circuit changes from low to high is that after the loop is established stably, N1 and N2 reach a 1:1 current mirror.
[0029] The derivation process of the flip threshold is as follows:
[0030] The voltage in VA is calculated as follows:
[0031]
[0032]
[0033] When N1 and N2 realize 1:1 current mirror, assuming that the current is IPTAT, which is a positive temperature coefficient current, the emitter junction difference between B2 and B1 is ΔVbe=Vbe2-Vbe1, then IPTAT=ΔVbe / R4, the current flowing through R5 is 2*IPTAT=2*ΔVbe / R4, and the voltage drop on R5 is 2*IPTAT*R5. According to the basic principle of transistor, ΔVbe=VTln(n), VT is the voltage equivalent of temperature, at room temperature, VT=26mV, n is the ratio of B1 and B2, and thus according to the voltage relationship between VA passing through the emitter junction voltage of B2 and the voltage drop of R5, we know that VA+Vbe2+2*IPTAT*R5=VCC; further deduction is as follows:
[0034] VA+V be2+2*IPTAT*R5=VCC
[0035]
[0036]
[0037]
[0038] Obviously, ΔV itself is similar to a bandgap reference voltage. The first term Vbe2 in the numerator is a negative temperature coefficient, and the second term is a positive temperature coefficient. By adjusting the ratio of R4 and R5, the ratio of B1 and B2, and the weighted positive and negative temperature coefficients, a better zero temperature coefficient can be achieved. Adjusting the ratio of R1 and R2, the constant term 1-k in the denominator as a common factor does not affect the zero temperature coefficient, but can adjust the ΔV flip threshold, thus realizing an adjustable zero temperature threshold judgment. At the same time, if the ratio of the above parameters is increased by a certain amount of adjustment, a better zero temperature coefficient and accuracy can be achieved.
[0039] In summary, this circuit only has two signals, VCC and VSS, and only needs to judge their voltage difference. The design concept of the benchmark is used to realize the adjustable threshold judgment with high precision and low temperature drift. This circuit is also suitable for the threshold judgment of other signals besides the high-voltage jump power supply.
[0040] It is worth mentioning that the technical features such as the clock power supply involved in this utility model patent application should be regarded as the prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional methods in the field and should not be regarded as the invention point of this utility model patent. This utility model patent will not be further elaborated.
[0041] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.
Claims
1. A threshold judgment circuit for a high voltage clock power supply, characterized in that: It includes resistors R1-R5, transistors B1-B2 and transistors N1-N4, where: The resistor R1 and the resistor R2 are connected between the positive power supply VCC and the negative power supply VSS, and the common terminal of the resistor R1 and the resistor R2 is provided with a connection point A, and the connection point A is electrically connected to the base of the transistor B1, the base of the transistor B2 and the gate of the transistor N3 respectively, the emitter of the transistor B1 is connected to the positive power supply VCC through the resistor R4 and the resistor R3, and the collector of the transistor B1 is electrically connected to the drain of the transistor N1, and the emitter of the transistor B2 is connected to the positive power supply VCC through the resistor R3, and the collector of the transistor B2 is electrically connected to the drain of the transistor N2; The gate of transistor N1 is electrically connected to the gate of transistor N2, the source of transistor N1, the source of transistor N2 and the source of transistor N3 are all connected to the negative power supply VSS, the drain of transistor N3 is electrically connected to the source of transistor N4 and the gate of transistor N4 is electrically connected to the collector of transistor B2, the drain of transistor N4 is connected to the positive power supply VCC through resistor R5 and the drain of transistor N4 is also connected to the output terminal Y through Schmitt inverter SMIT1.
2. The threshold judgment circuit of a high-voltage clock power supply according to claim 1, characterized in that: The number ratio of the transistor B1 to the transistor B2 is n:1, and a plurality of transistors B1 are connected in parallel.
3. The threshold judgment circuit of a high-voltage clock power supply according to claim 2, characterized in that: The two ends of the resistor R2 are connected in parallel with the capacitor C1 , and the two ends of the resistor R5 are connected in parallel with the capacitor C2 .
4. The threshold judgment circuit of a high-voltage clock power supply according to claim 3, characterized in that: The collector of transistor B1 is provided with a connection point B, the collector of transistor B2 is provided with a connection point C, and the drain of transistor N4 is provided with a connection point D.
5. The threshold judgment circuit of a high-voltage clock power supply according to claim 4, characterized in that: The gate and drain of the transistor N1 are electrically connected.