Hot-Swap Testing Results for the A5977 and A5979 Microstepping DMOS Drivers

Hot-Swap Testing Results for the A5977 and A5979 Microstepping DMOS Drivers

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Introduction

Hot-swapping, disconnecting, or connecting power supply inputs and/or power outputs of an IC while in operation is
不推荐，但在某些应用中是正常的做法。雷竞技最新网址其中一个应用是在纺织机器中雷竞技最新网址，其中电动机和电源引线可以连接和断开，同时电流供应到两个电动机绕组。在本申请中，IC电机输出和
电源连接到电机驱动电脑board (6 pins) via a switching relay arrangement.

This report outlines hot-swap test results forA5977.和A5979.stepper motor drivers. To duplicate the hot-swap conditions, we have selected an IC motor supply voltage (VBB) of 24 V and motor current of 1.5 A per winding for our tests. Testing was performed with different microstepping resolutions and with the following hot-swap methods:

• 两套电机和电源之间的热插拔
• Hot-swapping a single motor from on-line to off-line
• 两套电机与电机驱动器的热插拔总是供电
• 热插拔单个电机，带电机驱动器始终供电
• Faulty conditions during single phasing of stepper motor
• Switching the power supply on-off with stepper motor terminals always connected

Objective

To evaluate the hot-swapping performance of the A5977 and A5979 microstepping DMOS driver ICs.

Experimental Setup

Figure 1 shows the test connections for hot-swapping the stepper motor driver (A5977/A5979). The experimental test prototype of the same has been developed in lab as shown in Figure 2. In this setup, a 6-pole, double-throw switch is used for hot-swapping between the motors and the power supply. Two power supplies of 100 W each and two stepper motors are connected on six poles of the switch as depicted in Figure 1. The evaluation board used is a standard A5977/79 socket board.

Figure 3 shows the front and rear view images of the 6-pole, double-throw switch used for development of the hot-swap testing setup.

测量参数

Figure 4 shows the typical setup for the measurement of various parameters during hot-swap testing. VDD and IDD represents the logic supply voltage and current, respectively.

Hot-Swap Test Results for the A5977/A5979 Microstepping Motor Driver ICs

The following section presents the evaluation of the A5977/A5979 stepper motor driver power ICs during various hot-swapping conditions. The various conditions of hot-swap testing are summarized as follows:

1. 两套电机和电源之间的热插拔.
2. Hot-swapping a single motor from on-line to off-line.
3. 两套电机与电机驱动器的热插拔总是供电.
4. 热插拔单个电机，带电机驱动器始终供电.
5. Faulty conditions during single phasing of stepper motor.
6. Switching the power supply on-off with stepper motor terminals always connected.

The stepper motor driver has been tested multiple times for the above mentioned conditions. Following are the results observed at these conditions.

HOT-SWAPPING BETWEEN TWO SETS OF MOTORS AND POWER SUPPLIES

This case is the most basic case of hot-swapping in which the stepper motor driver is hot-swapped between the two sets of a motor and power supply combination. A 6-pole, double-throw switch is used for hot-swapping the motor driver between the two stepper motors and power supply sets. Figure 5 (a) through (d) shows the results observed during the full-, half-, quarter-, and eighth-step (A5977) modes, respectively. This test has been carried out on 20 ICs with a minimum of 100 hot-swaps. The driver operated normally with no change in performance after each hot-swap.

HOT-SWAPPING A SINGLE MOTOR FROM ON-LINE TO OFF-LINE

In this case, a single stepper motor and power supply set is connected to the motor driver; therefore, all the six lines, including VBB, GND, OUT1A, OUT1B, OUT2A, and OUT2B are connected and disconnected during hot-swapping. Figure 6 (a) through (d) shows the results observed during the full-, half-, quarter-, and eighth-step (A5977) modes, respectively. This test has been carried out on 20 ICs with a minimum of 100 hot-swaps. The driver operated normally with no change in performance after each hot-swap.

HOT-SWAPPING BETWEEN TWO SETS OF MOTORS WITH MOTOR DRIVER ALWAYS POWERED UP

In this case, two stepper motors are hot-swapped while the power supply is always connected to the motor driver. Therefore, only four lines, including OUT1A, OUT1B, OUT2A, and OUT2B, are connected and disconnected during hot-swapping. Figure 7 (a) through (d) shows the results observed during the full-, half-,
quarter-, and eighth-step (A5977) modes, respectively. This test has been carried out on 20 ICs with a minimum of 100 hot-swaps. The driver operated normally with no change in performance after each hot-swap.

热插拔单个电机，带电机驱动器始终供电

In this case, a single stepper motor is hot-swapped while the power supply is always connected to the motor driver. Therefore, only four lines, including OUT1A, OUT1B, OUT2A, and OUT2B, are connected and disconnected during hot-swapping. Figure 8 (a) through (d) show the results observed during the full, half, quarter, and eighth step (A5977) modes, respectively. This test has been carried out on 20 ICs with a minimum of 100 hotswaps. The driver operated normally with no change in performance after each hot-swap.

步进电机单相位阶段的故障条件

在这种情况下，步进电机的一个相连接并断开电源，电源总是连接到电动机驱动器。因此，在这种情况下，在热交换期间连接和断开来自四条线中的任何一个的单线，即OUT1A，OUT1B，OUT2A和OUT2B。图9（a）至（d）显示了在全部，半，四分之一和第八步（A5977）模式期间观察到的结果。该测试已在20个ICS上进行，最少100个热插拔。驾驶员通常在每次热插拔后的性能没有变化。

步进电机单相位阶段的故障条件

在这种情况下，步进电机的一个相连接并断开电源，电源总是连接到电动机驱动器。因此，在这种情况下，在热交换期间连接和断开来自四条线中的任何一个的单线，即OUT1A，OUT1B，OUT2A和OUT2B。Figure 10 (a) through (d) shows the results observed during the full-, half-, quarter-, and eighth-step (A5977) modes, respectively. This test has been carried out on 20 ICs with a minimum of 100 hot-swaps. The driver operated normally with no change in performance after each hot-swap.

CONCLUSION

本报告中已进行A5977和A5979步进电机驱动程序的严格热插拔测试。所有6个提到的热插拔条件（6条件×20 IC×100次）每个6个都测试了至少20个IC，每个IC都是100次测试的100次=每次=总数12000个事件）。

This hot-swap testing has also been performed on a single device for four different stepping modes, i.e. full-step, half-step, quarter-step, and eighth-step (A5977) modes. The driver operated normally with no change in performance after each hot-swap.

We can conclude that the A5977 and A5979 have robust hot-swap performance under the conditions presented in this report.