With the development of electron micro technology, motor control, electrical transmission forms a "motion control" technology intersection with multiple subjects. The motion control system enables accurate position control, speed control, acceleration control, torque or force control, and integrated control of these controlled machines. The H-bridge driving circuit can form a complete motion control system with the main processor, motor or the like, which can be applied to the motion control of stepper motor, AC motor and DC motor. 1 Motor Motion Control and Its Drive Circuit In motion control of the motor, the most common is that the two-way rotation and speed regulation of the motor is controlled by the current size and direction of the motor windings. Figure 1, Figure 2 is a H-bridge composed of four N-channel MOS tubes (M1 to M4) and one motor (M). In FIG. 1, when M1 and M4 are turned on, the current passes through the motor from the left to right of M1 from the left to the right, and then returns to the power supply negative by M4, the motor is rotated along the time. In FIG. 2, when M3 and M2 are turned on, the current flows from the right to left through the motor, and the motor rotates in counterclockwise. Therefore, by adjusting the turning and cutoff timing of the MOS tube, the steering of the motor can be controlled by adjusting the size of the motor current to control the speed of the motor. Here is a HiP4081-based thick film H-bridge motor drive circuit for an arm. The CMOS control circuit is integrated and an H bridge consisting of MOS tube, which provides a continuous current of 5 A for the load. The circuit can work safely within 60 V power supply range, and users only need to provide a PWM signal compatible with the TTL level to control the magnitude and direction of 4 quadrant mode, and the interface with the digital controller is very simple. Its internal circuitry provides an appropriate dead time interval to protect the four N-channel field effect tubes of the H-bridge, with efficiency of 97%. Offering a TTL compatible enable pin to turn off 4 field effectors. 2 HIP4081 Internal Structure and Technical Features HIP4081 is a high-frequency full bridge drive chip specifically used to control the H-bridge in INTERSIL. The latch anti-interference CMOS manufacturing process has independent low-end and high-end input channels, separately drives four N-channel MOS tubes independently; the output peak current is 2 A; the interior of the chip has charge pump and dead time setting; suspension power supply With the bootstrap circuit, its high-end operating voltage can reach 95 V, the logic power supply voltage range 6 ~ 15 V, high operating frequency, can reach 1 MHz; there is a prohibition of all inputs, convenient to the external element to form a protection circuit. . Figure 3 shows the pin arrangement definition of HIP4081, and Fig. 4 shows the internal function block diagram of 1 / 2HIP4081 (A side). The main components are: logical input, enable, charge pump, level translation, and dead time settings. 3 HIP4081 Pin is arranged in Figure 4, Au, AHL is a low edge input and high side input of A side; ALO, AHO is the low side output and high side output of A side, DIS is enabled; In the internal function diagram of half (B), BLI, BHL are the low edge input and high side inputs of B, and BL0, BH0 is the low side output and high side output of the B side, respectively. The logical relationship between them is shown in Table 1. 3 Circuit Implementation Basic Principle Circuit Principles As shown in Figure 5. In Fig. 5, the VCC is the low voltage power supply of the internal logic circuit and the MOS tube and the lower arm driver; Vs is the H-bridge power supply, the MOS tube obtains the output current from this power supply, the foot voltage ranges from VCC ~ + 80 V; V01, for the half-bridge output foot 1, when the PWM input ALI is high, the BLi is low, the foot output is VS; VO2 is the output foot 2 of the half bridge, when the PWM input ALI is low, the BL is high, The foot output is VS; SENSE is a common coupling point of 2 half bridges, which can be connected to a detection resistor to VS to detect current, which can be directly connected to the VS. GND is an input logic and VCC; the PWM lump is a PWM signal used to input to TTL, and the duty ratio is between o% to 100%; DIS is used to shut down 4 MOS tubes, the foot is 1 To turn off, it is enabled. 3.1 Circuit Working Logic Timing and Motor Motion Status Analysis In Figure 5, when the power D1S is at a high level "1", whether Ali, BLI is "1" or "O", Alo, BLO, AH0, BH0 is "0", the circuit is inhibited, and the motor is parked. When the enabled DIS is at a low "O", all and BLI can simultaneously receive the high level "1" and low level "0" of the PWM signal at the same time by inverter. When ALL is 1, BLi is 0, at this time, AlO is 1, Aho is 0, and BLO is O, BHO is 1, the MOS tube M1 and M4 in the H bridge are turned on, and the H bridge is in Figure 1, the motor is smooth Time-rotating. When Ali is O, BLI is 1, at this time, Al0 is 0, Aho is 1, BLO is 1, BHO is O, the MOS tube M3 and M2 in the H bridge are turned on, the H bridge is in Figure 2, the motor is reverse Time-rotating. When Ali, BLI is O, Alo, BLO is O, AH0, BHO is 1, and there is no current in the motor, and in a brake state. When Ali, BLi is 1, Al0, BLO is 1, AHO, BHO is O, and there is no current flow in the motor, the same is in the brake state. Its logical relationship is shown in Table 2.
3.2 Dead time Consideration In Figure 5, it is important to ensure that the MOS tube (M1 and M2, M3 and M4) on the H bridge is not very important. If MOS tubes M1 and M2 (or M3, or M4) are turned on, the current is directly returned to the negative electrode from the power Vs positive to 2 MOS tubes. At this point, there is no other load outside the MOS tube in the circuit, so the current on the circuit may reach the maximum (this current is limited only by power supply performance), and even burn the MOS tube. Based on the above reasons, in the actual drive circuit, M1 and M2 or M3 and M4 have a delay in the on-time, and the dead time is also referred to. HIP4081 has two ports of HDEL and LDEL (see Figure 4), and users can customize dead time according to the actual circuit operation through an external resistor. The relationship between dead time and HDEL / LDEL resistor is shown in Figure 6. 3.3 Treatment Consideration In Figure 5, the main rate of the driving circuit is determined by the following three factors: the static power consumption of the H1P4081; the dynamic power consumption of the VCC power supply; the I2R loss of the MOS tube. Since HIP4081 is a CMOS device, subsection (1) is small, negligible, although the item (2) loss is large, but far less than (3) (especially when the full load is output). The I2R of the MOS tube is determined by its conduction resistance, so selecting a suitable M0S tube constitutes an H-bridge circuit, which can reduce (3) item loss. This circuit uses N-channel HexFetPower MOSFET IRFPP250N, which is O. 075 Ω reduces conduction loss and improves efficiency. 3.4 Consideration of Product Structure (1) The product structure is designed with a thick film mixed integrated technology. As shown in FIG. 7, a thick film substrate is fabricated by a thick film bike process on an Aln ceramic substrate having a high thermal conductivity. The substrate metallization and welding technique, welding the AlN substrate with the metal housing, greatly improves the heat transfer capacity and power density of the circuit. (2) In Fig. 7, all active devices inside the product use a naked chip, and assembles components, Aln thick film ceramic substrates, and metal housing together by mixing the secondary integrated process technology of the integrated circuit. A double-column-in-line thick film mixed integrated product having a full sealing metal casing is formed, which greatly reduces the volume, reducing the internal level and solder joints in the product, and improves reliability. The thick film H-bridge motor drive circuit has shown that the circuit is not only safe and reliably realizing the two-way rotation and speed regulation of the motor, which improves the reliability of the drive circuit and the system, but the product is small, the thermal conductivity is good, the efficiency is high. Can work safely in harsh use environments, suitable for military and civilian use. , Reading the full text, the technology area
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