阅读说明：本技术 一种带隙基准电压高速上电防过冲电路 (High-speed electrification overshoot-prevention circuit for band-gap reference voltage ) 是由 王述前 龙冬庆 于 2019-03-06 设计创作，主要内容包括：本发明公开了一种带隙基准电压高速上电防过冲电路,包括：主电路、启动模块、输出模块、滤波延时控制模块。本发明通过滤波延时控制模块滤除在启动阶段产生的过冲电流,并将其转换为延时后的电压信号,然后利用单级放大器检测该电压信号,最终控制输出模块,进而减弱或消除输出电压的过冲,使其保持稳定。此外,在滤波延时控制模块中采用单级放大器来做阈值检测电路,相比于采用反相器,单级放大器具有放大倍数高,检测精度高,动态功耗小等优点。另外由于第十一开关管为电流源连接,其栅极电压恒定,由工艺偏差引起的阈值电压的变化对其检测精度影响可以忽略不计。(The invention discloses a high-speed electrification overshoot-prevention circuit for band-gap reference voltage, which comprises: the device comprises a main circuit, a starting module, an output module and a filtering delay control module. The invention filters the overshoot current generated in the starting stage through the filtering delay control module, converts the overshoot current into the delayed voltage signal, then detects the voltage signal by using the single-stage amplifier, and finally controls the output module, thereby weakening or eliminating the overshoot of the output voltage and keeping the overshoot stable. In addition, a single-stage amplifier is adopted in the filtering delay control module to serve as a threshold detection circuit, and compared with a phase inverter, the single-stage amplifier has the advantages of being high in amplification factor, high in detection precision, small in dynamic power consumption and the like. In addition, because the eleventh switching tube is connected with a current source, the grid voltage of the eleventh switching tube is constant, and the influence of the change of the threshold voltage caused by process deviation on the detection precision of the eleventh switching tube can be ignored.)

1. An anti-overshoot circuit for high speed power-on of a bandgap reference voltage, comprising:

a main circuit (10) connected to a power supply (VCC) and configured to output a reference current;

the starting module (20) is connected with the main circuit (10) and is used for starting the main circuit (10);

the output module (30) is connected with the main circuit (10) and used for outputting band gap reference voltage with required specification according to the reference current provided by the main circuit (10);

and the filtering delay control module (40) is respectively connected with the main circuit (10) and the output module (30) and is used for acquiring an overshoot signal generated by the main circuit (10) in a starting stage and delaying the output module (30) to sample the main circuit (10) according to the acquired overshoot signal so as to avoid sampling the overshoot signal generated by the main circuit (10).

2. The high-speed power-on overshoot-prevention circuit for a bandgap reference voltage according to claim 1, wherein the main circuit (10) comprises: a first switch tube (Q1), a second switch tube (Q2), a first resistor (R1), a third switch tube (PM1), a fourth switch tube (PM2), an operational amplifier (P),

the source electrode and the grid electrode of the first switch tube (Q1) are grounded, the drain electrode of the first switch tube (Q1) is connected with one end of a first resistor (R1), the other end of the first resistor (R1) is respectively connected with the non-inverting input end of the operational amplifier (P) and the drain electrode of a third switch tube (PM1), the grid electrode of the third switch tube (PM1) is respectively connected with the output end of the operational amplifier (P) and the grid electrode of a fourth switch tube (PM2), the source electrode of the third switch tube (PM1) is connected with a power supply (VCC),

the source electrode and the grid electrode of the second switch tube (Q2) are grounded, the drain electrode of the second switch tube (Q2) is respectively connected with the inverting input end of the operational amplifier (P) and the drain electrode of the fourth switch tube (PM2), the source electrode of the fourth switch tube (PM2) is connected with a power supply (VCC),

the output end of the operational amplifier (P) is also respectively connected with the starting module (20), the output module (30) and the filtering delay control module (40).

3. The high-speed power-on overshoot protection circuit for bandgap reference voltages according to claim 2, wherein the start-up module (20) comprises: a fifth switch tube (NM1), a sixth switch tube (NM2), a second resistor (R3),

the drain electrode of the fifth switching tube (NM1) is connected with the output end of the operational amplifier (P), the source electrode of the fifth switching tube (NM1) is grounded, the grid electrode of the fifth switching tube (NM1) is respectively connected with one end of the second resistor (R3) and the drain electrode of the sixth switching tube (NM2), the other end of the second resistor (R3) is connected with the power supply (VCC), the source electrode of the sixth switching tube (NM2) is grounded, and the grid electrode of the sixth switching tube (NM2) is connected with the output module (30).

4. The high-speed power-on overshoot protection circuit for bandgap reference voltages according to claim 3, wherein the output module (30) comprises: a seventh switch tube (Q3), a third resistor (R2), an eighth switch tube (PM6b) and a ninth switch tube (PM3),

the source and the gate of the seventh switching tube (Q3) are grounded, the drain of the seventh switching tube (Q3) is connected with one end of a third resistor (R2), the other end of the third resistor (R2) is respectively connected with the drain of the eighth switching tube (PM6b) and the gate of the sixth switching tube (NM2), the gate of the eighth switching tube (PM6b) is connected with the filtering delay control module (40), the source of the eighth switching tube (PM6b) is connected with the drain of the ninth switching tube (PM3), the gate of the ninth switching tube (PM3) is connected with the output end of the operational amplifier (P), the source of the ninth switching tube (PM3) is connected with a power supply (VCC), and an output port for load connection is arranged between the other end of the third resistor (R2) and the drain of the eighth switching tube (PM6 b).

5. The high-speed power-on overshoot protection circuit for bandgap reference voltages according to claim 4, wherein the filtering delay control module (40) comprises: a tenth switching tube (NM3b), an eleventh switching tube (PM5b), a twelfth switching tube (PM4b) and a capacitor (C1b),

the source of the tenth switching tube (NM3b) is grounded, the gate of the tenth switching tube (NM3b) is connected to the drain of the twelfth switching tube (PM4b) and the upper plate of the capacitor (C1b), respectively, the lower plate of the capacitor (C1b) is grounded, the drain of the tenth switching tube (NM3b) is connected to the drain of the eleventh switching tube (PM5b) and the gate of the eighth switching tube (PM6b), respectively, the gate of the eleventh switching tube (PM5b) is connected to the output terminal of the operational amplifier (P), the source of the eleventh switching tube (PM5b) is connected to the power supply (VCC), the gate of the twelfth switching tube (PM4b) is connected to the output terminal of the operational amplifier (P), and the source of the twelfth switching tube (PM4b) is connected to the power supply (VCC).

6. The high-speed power-on overshoot protection circuit of the bandgap reference voltage according to claim 5, wherein the eighth switch transistor (PM6b) is an N-type MOS transistor or a P-type MOS transistor.

7. The high-speed power-on overshoot protection circuit for bandgap reference voltage according to claim 5, wherein the capacitor (C1b) is MIM capacitor or MOS capacitor.

Technical Field

The invention relates to the technical field of integrated circuits, in particular to an overshoot prevention circuit for high-speed electrification of band-gap reference voltage.

Background

The bandgap reference voltage circuit is a very important part of all electronic systems, and provides accurate and stable reference voltage for other circuits in the electronic systems. Therefore, the precision, speed and stability of the bandgap reference voltage circuit are important. However, when the power is powered on at a high speed, the output voltage of the bandgap reference voltage circuit has a large overshoot due to the time limit of the feedback loop setup of the bandgap reference voltage circuit, and the devices in the high-voltage part of the circuit have a breakdown risk when the reference source is provided for the boost circuit. In the traditional solution, the current is increased to accelerate the setup time of the system loop, so as to improve the overshoot phenomenon of the output voltage during the fast start. However, this poses additional problems, excessive power consumption and loop stability risks, and it is difficult to completely eliminate the overshoot voltage.

Disclosure of Invention

In order to solve the problems in the prior art, the embodiment of the invention provides an anti-overshoot circuit for high-speed electrification of a band gap reference voltage. The technical scheme is as follows:

in one aspect, an embodiment of the present invention provides an anti-overshoot circuit for high-speed power-on of a bandgap reference voltage, including: the main circuit is connected with a power supply and is used for outputting band-gap reference voltage according to power supply voltage provided by the power supply;

the main circuit is connected with a power supply and is used for outputting reference current;

the starting module is connected with the main circuit and used for starting the main circuit;

the output module is connected with the main circuit and used for outputting band gap reference voltage with required specification according to the reference current provided by the main circuit;

and the filtering delay control module is respectively connected with the main circuit and the output module and is used for acquiring the overshoot signal generated by the main circuit in the starting stage and delaying the output module to sample the main circuit according to the acquired overshoot signal so as to avoid sampling the overshoot signal generated by the main circuit.

In the above-mentioned high-speed power-on overshoot-prevention circuit of a bandgap reference voltage according to an embodiment of the present invention, the main circuit includes: a first switch tube, a second switch tube, a first resistor, a third switch tube, a fourth switch tube, and an operational amplifier,

the source electrode and the grid electrode of the first switch tube are grounded, the drain electrode of the first switch tube is connected with one end of a first resistor, the other end of the first resistor is respectively connected with the non-inverting input end of the operational amplifier and the drain electrode of a third switch tube, the grid electrode of the third switch tube is respectively connected with the output end of the operational amplifier and the grid electrode of a fourth switch tube, the source electrode of the third switch tube is connected with a power supply,

the source electrode and the grid electrode of the second switch tube are grounded, the drain electrode of the second switch tube is respectively connected with the inverting input end of the operational amplifier and the drain electrode of the fourth switch tube, the source electrode of the fourth switch tube is connected with the power supply,

the output end of the operational amplifier is also connected with the starting module, the output module and the filtering delay control module respectively.

In the above anti-overshoot circuit for high-speed power-on of bandgap reference voltage according to the embodiment of the present invention, the starting module includes: a fifth switch tube, a sixth switch tube, a second resistor,

the drain electrode of the fifth switching tube is connected with the output end of the operational amplifier, the source electrode of the fifth switching tube is grounded, the grid electrode of the fifth switching tube is respectively connected with one end of the second resistor and the drain electrode of the sixth switching tube, the other end of the second resistor is connected with the power supply, the source electrode of the sixth switching tube is grounded, and the grid electrode of the sixth switching tube is connected with the output module.

In the above anti-overshoot circuit for high-speed power-on of bandgap reference voltage according to the embodiment of the present invention, the output module includes: a seventh switch tube, a third resistor, an eighth switch tube, a ninth switch tube,

the source electrode and the grid electrode of the seventh switch tube are grounded, the drain electrode of the seventh switch tube is connected with one end of the third resistor, the other end of the third resistor is respectively connected with the drain electrode of the eighth switch tube and the grid electrode of the sixth switch tube, the grid electrode of the eighth switch tube is connected with the filtering delay control module, the source electrode of the eighth switch tube is connected with the drain electrode of the ninth switch tube, the grid electrode of the ninth switch tube is connected with the output end of the operational amplifier, the source electrode of the ninth switch tube is connected with the power supply, and an output port for connecting a load is arranged between the other end of the third resistor and the drain electrode of the eighth switch tube.

In the above high-speed power-on overshoot prevention circuit for a bandgap reference voltage according to the embodiment of the present invention, the filtering delay control module includes: a tenth switch tube, an eleventh switch tube, a twelfth switch tube and a capacitor,

the source electrode of the tenth switching tube is grounded, the grid electrode of the tenth switching tube is respectively connected with the drain electrode of the twelfth switching tube and the upper polar plate of the capacitor, the lower polar plate of the capacitor is grounded, the drain electrode of the tenth switching tube is respectively connected with the drain electrode of the eleventh switching tube and the grid electrode of the eighth switching tube, the grid electrode of the eleventh switching tube is connected with the output end of the operational amplifier, the source electrode of the eleventh switching tube is connected with the power supply, the grid electrode of the twelfth switching tube is connected with the output end of the operational amplifier, and the source electrode of the twelfth switching tube is connected with the power supply.

In the high-speed power-on overshoot prevention circuit of the bandgap reference voltage according to the embodiment of the present invention, the eighth switch transistor is an N-type MOS transistor or a P-type MOS transistor.

In the anti-overshoot circuit for high-speed electrification of the bandgap reference voltage according to the embodiment of the invention, the capacitor is an MIM capacitor or an MOS capacitor.

The technical scheme provided by the embodiment of the invention has the following beneficial effects:

when the overshoot signal generated by the main circuit in the starting stage is sampled by the delay control module, the delay output module is controlled to delay the sampling of the main circuit, the delay time is controllable, and the output module can be controlled to sample after the overshoot signal passes, so that the overshoot of the output voltage can be weakened or eliminated, and the voltage output of the output module is stable. In addition, a single-stage amplifier is adopted in the filtering delay control module to serve as a threshold detection circuit, and compared with a phase inverter, the single-stage amplifier has the advantages of being high in amplification factor, high in detection precision, small in dynamic power consumption and the like. In addition, because the eleventh switching tube is connected with a current source, the grid voltage of the eleventh switching tube is constant, and the influence of the change of the threshold voltage caused by process deviation on the detection precision of the eleventh switching tube can be ignored.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a circuit diagram of an anti-overshoot circuit for high-speed power-on of a bandgap reference voltage according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a gate control voltage Vfb of an eighth switching transistor according to an embodiment of the present invention;

fig. 3 is a schematic diagram of the output voltage VBG _ OUT of the input terminal of the anti-overshoot circuit for high-speed power-up of the bandgap reference voltage according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.