CN210864029U

CN210864029U - Push-pull type pulse amplifier modulation circuit

Info

Publication number: CN210864029U
Application number: CN201921613106.3U
Authority: CN
Inventors: 璁告旦; 许浩
Original assignee: Aerospace Science And Technology Microsystem Technology Co ltd
Current assignee: Aerospace Science And Technology Microsystem Technology Co ltd
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2020-06-26
Anticipated expiration: 2029-09-26

Abstract

The utility model discloses a push-pull pulse amplifier modulation circuit, which comprises a push-pull MOSFET amplifier; a MOSFET driver for driving the push-pull MOSFET amplifier; and a switch tube control circuit connected between the push-pull MOSFET amplifier and the MOSFET driver to prevent two power switch tubes in the push-pull MOSFET amplifier from being opened at the same time. The fast discharging circuit can provide a fast discharging path for the filter capacitor in the power-off process of the pulse amplifier, reduces the power-off time of the pulse amplifier, controls the rising edge and the falling edge within 50ns, and obviously reduces the blind distance of the pulse system radar.

Description

Push-pull type pulse amplifier modulation circuit

Technical Field

The utility model relates to an amplifier pulse modulation circuit field, more specifically the utility model relates to a push-pull type pulse amplifier modulation circuit that says so.

Background

There are generally two basic types of radar: continuous wave radar and pulse radar. The pulse radar intermittently transmits pulse periodic signals and receives reflected echo signals at a transmitting interval, namely, at a transmitting and receiving interval. The power supply of the drain electrode of a pulse amplifier in the pulse system radar is quite critical, and after the pulse amplifier works for a period of time, a large amount of charges are accumulated on a filter capacitor on a power supply line of the drain electrode. The existing pulse amplifier adopts a pulse modulation circuit of a single MOSFET, and has the following defects: the filter capacitor cannot be rapidly discharged, so that the power-off time of the pulse amplifier is very long, the rising edge and the falling edge of the pulse amplifier are generally about 100ns, and the blind distance of the pulse radar is increased.

SUMMERY OF THE UTILITY MODEL

The utility model provides a solve above-mentioned technical problem and provide a push-pull pulse amplifier modulation circuit.

The utility model discloses a following technical scheme realizes:

a push-pull pulse amplifier modulation circuit comprising:

the push-pull MOSFET comprises a PMOS tube and an NMOS tube;

a MOSFET driver for driving the push-pull MOSFET;

and the switch tube control circuit is connected between the push-pull MOSFET and the MOSFET driver to prevent the PMOS tube and the NMOS tube in the push-pull MOSFET from being simultaneously opened.

The amplifier pulse modulation circuit of this scheme adopts push-pull structure, and adopts switch tube control circuit control push-pull MOSFET in the state of two switch tubes, avoids two power switch tubes to open simultaneously, causes the direct ground of external input power. By adopting the push-pull type pulse amplifier modulation circuit, a rapid discharge path can be provided for the filter capacitor in the power-off process of the pulse amplifier, the power-off time of the pulse amplifier is reduced, the rising edge and the falling edge are both controlled within 50ns, and the blind distance of the pulse system radar is obviously reduced.

Preferably, the switching tube control circuit comprises a first control branch connected between the output end of the MOSFET driver and the gate of the NMOS tube in the push-pull MOSFET, and a second control branch connected between the output end of the MOSFET driver and the gate of the NMOS tube in the push-pull MOSFET, wherein the first control branch and the second control branch comprise a diode and a resistor which are connected in parallel, and the conduction directions of the diodes of the first control branch and the second control branch are different. The on-off control of the MOSFET is realized by adopting the technology of parallel connection of the resistor and the diode, the conduction directions of the diodes of the first control branch and the second control branch are different, two power switch tubes, namely the MOSFET, can be prevented from being simultaneously opened according to an external TTL signal, and an external input power supply is prevented from being directly grounded.

Preferably, the source of the PMOS transistor of the push-pull MOSFET is connected to an input power supply terminal, the gate of the PMOS transistor of the push-pull MOSFET is connected to a second resistor, the input power supply terminal is connected to a ground capacitor, and the sources of the NMOS transistors are all grounded.

Furthermore, in order to reduce the circuit volume, the PMOS tube and the NMOS tube adopt a chip Si 5504. The push-pull structure is realized by adopting the chip Si5504, the circuit structure is simple, and the occupied area of the circuit is reduced.

Compared with the prior art, the utility model, following advantage and beneficial effect have:

1. the utility model discloses a push-pull pulse amplifier modulation circuit can provide the fast discharge route for filter capacitor at pulse amplifier's the power-off in-process, has reduced pulse amplifier's the power-off time, will rise along, fall along all controlling within 50ns, has obviously reduced the blind distance of pulse system radar.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention.

Fig. 1 is a schematic diagram of the present solution.

Fig. 2 is a schematic circuit diagram of the MOSFET driving circuit and the switching tube control circuit according to this embodiment.

Fig. 3 is a schematic circuit diagram of a push-pull MOSFET.

Fig. 4 is a schematic diagram of an implementation of the push-pull type pulse amplifier modulation circuit according to the present embodiment.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the following examples and drawings, and the exemplary embodiments and descriptions thereof of the present invention are only used for explaining the present invention, and are not intended as limitations of the present invention.

Example 1

A push-pull pulse amplifier modulation circuit as shown in fig. 1, comprising:

the push-pull MOSFET comprises a PMOS tube and an NMOS tube;

a MOSFET driver for driving the push-pull MOSFET;

Example 2

Based on the principle of the above embodiments, the present embodiment discloses a specific implementation manner.

The MOSFET driver uses the circuit shown in fig. 2, and U2 uses the chip LM 5110.

As also shown in fig. 2, the switching tube control circuit includes a first control branch connected between the output terminal of the MOSFET driver and the gate of the NMOS tube in the push-pull MOSFET, and a second control branch connected between the output terminal of the MOSFET driver and the gate of the NMOS tube in the push-pull MOSFET, where the first control branch and the second control branch include a diode and a resistor connected in parallel, and the diode conduction directions of the first control branch and the second control branch are different. Namely, D1 and R1 form a first control branch, and D2 and R3 form a second control branch.

As shown in fig. 3, the push-pull MOSFET includes a PMOS transistor and an NMOS transistor, a source of the PMOS transistor is connected to an input power supply terminal, a gate of the PMOS transistor is connected to a second resistor, the input power supply terminal is connected to a ground capacitor, and sources of the NMOS transistors are all grounded. Specifically, the PMOS transistor and the NMOS transistor adopt a chip Si5504, namely U1 in the figure.

As shown IN fig. 4, the drains of the PMOS transistor and the NMOS transistor of the push-pull type pulse amplifier modulation circuit IN this embodiment are connected to an external power amplifier PA as output terminals, the IN _ a pin, i.e., the T _ ON terminal, of U2 is connected to an external TTL signal source, and the +5V power supply is an external power supply. The MOSFET driver provides a synchronous pulse modulation signal for the push-pull MOSFET according to the input pulse modulation signal and enhances the current driving capability of the pulse modulation signal. The push-pull MOSFET comprises two MOSFETs with high current, small resistance and low junction capacitance, namely a PMOS tube and an NMOS tube, wherein the source electrode of the PMOS tube is connected with an external power supply, and the drain electrode is connected with the drain electrode of the power amplifier as an output end and is used as an upper power channel; the source electrode of the NMOS tube is grounded, and the drain electrode is used as an output end and connected with the drain electrode of the power amplifier to be used as a power-off channel. When the MOSFET driver outputs a low level, the PMOS tube is quickly opened, the NMOS tube is closed, and an external power supply is output to a load; when the MOSFET driver outputs a high level, the PMOS tube is closed, the NMOS tube is opened, the external power supply cannot output the high level, and meanwhile, the charges originally stored in the load circuit are quickly released through the opened NMOS tube, so that a faster falling edge is ensured.

A parallel circuit of a resistor and a diode is added between the MOSFET driver and the G pole of the push-pull MOSFET to prevent the NMOS tube and the PMOS tube from being simultaneously opened to cause the direct connection of an external input power supply to the ground. When the output of the MOSFET driver is changed from low level to high level, D1 is switched on, D2 is switched off, the G-level voltage of the PMOS tube rises through a diode D1, the G-level voltage of the NMOS tube rises through a resistor R2, and the switching-off speed of the P tube is faster than the switching-on speed of the NMOS tube because the on-resistance of the diode is very small; similarly, the closing speed of the NMOS tube is faster than the opening speed of the P tube.

The circuit adopts a push-pull structure of two MOSFETs, a +5V power supply is externally input, the push-pull pulse amplifier modulation circuit enables the +5V power supply to be output to a drain electrode of an amplifier or to be closed according to the change rule of a pulse modulation signal under the control of the pulse modulation signal, the final rising edge and the final falling edge can be within 50ns, and the rapid switching on and off of a drain electrode of the pulse amplifier is realized, so that the power-off time of the pulse amplifier is reduced, and the blind distance of a pulse system radar is obviously reduced.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above description is only the embodiments of the present invention, and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A push-pull pulse amplifier modulation circuit, comprising:

the push-pull MOSFET comprises a PMOS tube and an NMOS tube;

a MOSFET driver for driving the push-pull MOSFET amplifier;

2. The push-pull pulse amplifier modulation circuit according to claim 1, wherein the switching tube control circuit comprises a first control branch connected between the output terminal of the MOSFET driver and the gate of the NMOS tube in the push-pull MOSFET, and a second control branch connected between the output terminal of the MOSFET driver and the gate of the PMOS tube in the push-pull MOSFET, the first and second control branches comprising a diode and a resistor connected in parallel, and the diode conduction directions of the first and second control branches are different.

3. The modulation circuit according to claim 1, wherein the source of the PMOS transistor of the push-pull MOSFET is connected to an input power supply terminal, the gate of the PMOS transistor of the push-pull MOSFET is connected to a second resistor, the input power supply terminal is connected to a ground capacitor, and the sources of the NMOS transistors are grounded.

4. The push-pull pulse amplifier modulation circuit according to claim 3, wherein the PMOS transistor and the NMOS transistor are chip Si 5504.