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2022-09-16 16:00:09
DRV8805 single -step motor driver integrated circuit
Features
4 channel protection low -side drive
- NMOS FET
- Integrated inductor clamping diode [123 ]
Single -pole step motor index/converter
- Simple step/direction interface
- 1-2 phase half step, 1 phase wave driver)
dw package: 1.5-a (single channel opening)/800 mAh (four channel opening) maximum driver current of each channel) (25 ° C)
PWP package: 2-a (single channel opening)/1-a (four-channel opening) maximum driving current (25 ° C, appropriate ones appropriate PCB heat dissipation)
8.2-V to 60-V working power supply voltage range
thermal enhancement surface installation component
ApplicationGame console
General single -pole stepping motor drive
Instructions
DRV8805
provided the driver order Integration solutions of the motor. It includes four low -side drives and over -current protection, and provides built -in diode to cut off the turning transients generated by the motor winding. The indexer logic control single -pole step motor is also integrated using a simple step/direction interface. Support three step mode: 2 phases (full steps), 1-2 phase (half-step) and 1 phase (wave drive).
In SOIC (DW) packaging, the DRV8805 can provide continuous output currents of up to 1.5-a (one channel opening) or 800 mA under 25 ° C at 25 ° C. In HTSSOP (PWP) packaging, it can provide continuous output currents of up to 2-a (one channel open) or 1-a (four channels) at a temperature of 25 ° C at a temperature of 25 ° C. Essence
Provide an internal shutdown function of over -current protection, short -circuit protection, low -voltage locking and overheating, and the fault is indicated by the fault output pin.
DRV8805 has 20 -pin thermal enhanced SOIC packaging and 16 -pin HTSSOP packaging (environmentally friendly: ROHS AMP; No SB/BR).
Equipment information
(1), please refer to the appointment appendix at the end of the data table.
Simplified schematic diagram
Typical features 
Detailed instructions 
DRV8805 is an integrated 4 -channel single -pole stepping motor driver with a step/direction interface, which can control low -end drive output And allow simple control solutions. The output of the four low -side drives includes four N -channel MOSFETs, and its typical RDS (ON) is 500 m A separate motor power input VM is used as a device power supply and is adjusted internally to power the low -voltage side grille drive. By making Nenbl pins high, device output can be disabled. This device has several security functions, including integrated over -current protection, limiting the motor current to a fixed maximum value, and the device that exceeds the value will be closed. The heat shutdown protection allows the device to automatically shut down when the mold temperature exceeds the TTSD limit, and restarts after the mold reaches the safety temperature. If the VM is lower than the underwriting threshold, the UVLO protection will disable all circuits in the device.
Figure Figure
Feature description 
DRV8805 contains four protected low -end drives. Each output has an integrated clamp diode, which is connected to a public pin VCLAMP.
VCLAMP can be connected to the main power voltage VM. It can also be connected to Qina or TVS diode to VM, allowing the switching voltage to exceed the main power voltage VM. When the driver requires a fast current attenuation load, this connection is beneficial, such as a single step into the motor.
In all cases, the output voltage must not exceed the maximum output voltage specification.
Index operation
DRV8805 integrates an indexer that allows motor control through simple steps and direction interfaces. Logically, the indexer is shown in Figure 6.
Starting and reset operation 
When driving high electricity, the internal logic of resetting the pin is used. The index is reset to the main state. When reset activation, all inputs are ignored. Note that RESET has an internal drop -down menu. It also provides internal power and reset, so it is not necessary to drive reset when power is powered.
Protective circuit
DRV8805 has sufficient protection to prevent pressure, over current and overheating events.
Overcurrent protection (OCP)
The analog current limit circuit on each FET is limited to the current by removing the grid driver. If the simulation current limit continuesOccasionally exceed the TOCP mud removal time (about 3.5 μs), the driver will be disabled, and the NFAULT pin will be driven to a low level. The driver will keep a disabled state within the review time (about 1.2 milliseconds), and then the fault will be automatically cleared. If the resetting pin is activated or the VM is removed, and the fault will be cleared immediately.
Hot shutdown (TSD)
If the mold temperature exceeds the safety limit, all output FET will be disabled, and the NFAULT pin will be driven low. The step input will be ignored. Once the mold temperature drops to the safe level, the operation will automatically restore.
IOU locking (UVLO)
If the voltage on the VM pins is lower than the voltage of the underwriting lock at any time, all circuits in the device will be disabled, the internal logic will be heavy, and the internal logic will be heavy. Set. When VM is higher than the UVLO threshold, the operation will be restored.
Equipment function mode
Step mode
SM0 and SM1 pin selection of the step mode of the converter, as shown in Table 1.
Under all mode, under the conditions of failure, the order input will be ignored. For details, see. The output order of the protection circuit is shown in Table 2, Table 3, and Table 4. 
Application and Implement Its accuracy or integrity. TI's customers are responsible for determining the applicability of the component. Customers should verify and test their design implementation to confirm the system function. 
DRV8805 can be used to drive the single -step motor.
Typical application
Design requirements
Table 5 lists the design parameters of the design example.
Detailed design program
motor voltage
The motor voltage used depends on the rated value of the selected motor and the required torque required torque required Essence The higher voltage shortens the current rising time in the step motor coil, allowing the motor to generate a larger average torque. Using higher voltage can also make the motor run at a faster voltage and faster speed. 
The current path starts with the power VM, through the sensing winding load, and the low -side sink NMOS power FET. The power loss of the power field of the single groove NMOS power field is shown in the following formula.
On the standard FR-4 PCB, the DRV8805 has been measured at 1.5-A single channel or 800 mAh four-channel (DW packaging) and 2-a singlesChannel or 1-A four-channel (PWP package). The maximum square -rooted current will change according to the PCB design and environmental temperature.
Application curve
Body capacitance
A suitable local volume capacitance is the design of the motor drive system design An important factor. Generally speaking, more volume capacitors are beneficial, but the disadvantage is increased cost and physical dimensions.
The required local power capacity depends on multiple factors, including:
the highest current required for the motor system
capacitance of the power supply The ability to provide current
Positive inductance between the power supply and the motor system
acceptable voltage ripples
#8226 The type of motor used (there are brushing DC, brushless DC, step motor)
electrical mechanism method
The inductance between the power supply and the motor drive system will limit the power supply to the power supply. The rate of current. If the local large -capacity capacitance is too small, the system will respond to excessive current requirements, or uninstall from the motor as the voltage changes. When using sufficient large -capacity capacitors, the motor voltage remains stable and can quickly provide large current.
The data table usually provides a recommended value, but it is necessary to perform system -level tests to determine large -capacity capacitors with appropriate size.
The rated voltage of a large -capacity capacitor should be higher than the operating voltage, so that it can provide a lot of time when the motor transmits energy to the power supply.
Layout
Layout Guide
The placement of large -capacity capacitors should be reduced as much as possible to drive the distance from the large current path of the motor -driven device. The width of the metal trace line should be as wide as possible, and multiple excess perforated should be used when connecting the PCB layer. These methods minimize the inductance and allow large capacitor to transport high current.
small value capacitors should be ceramics and placed near the device pins.
High current equipment output shall use wide metal trace lines.
The equipment hot pad should be welded on the floor floor floor of the PCB. Multiple pores should be used to connect to large bottom ground planes. Use large metal planes and multiple holes to help the I2 × RDS (ON) heat generated in the dissipation device.
layout example
Heat Precautions
DRV8805 has the heat shutdown (TSD) described in the heat shutdown (TSD). If the mold temperature exceeds about 150 ° C, the device will be disabled until the temperature drops to the safe level.
Equipment advanceAny trend to enter TSD indicates that power consumption is too large, insufficient heat dissipation, or high ambient temperature.
Power consumption
The power consumption of DRV8805 is mainly consumed by the output field effect tube resistance (ON). When running a static load, the average power consumption of each field effect tube can be roughly estimated with equations 2.
where:
P is the power consumption of a fet
RDS (on) is every The resistance of a fET
IOUT is equal to the average current consumed by the load
Note that under the condition of starting and failure, the current is much higher than the normal operating current; Peak current and its duration. When multiple loads are driven at the same time, all effective output levels must be added.
The maximum power consumed in the device depends on the ambient temperature and heat dissipation.
Note that RDS (on) increases as the temperature increases, so when the device is heated, the power consumption will increase. When determining the size of the heat sink, this must be considered.
Heating
DRV8805DW packaging uses a standard SOIC shape, but the center pins are melted on the chip pad to remove the calories in the device more effectively. The two central leads on each side should be connected together to eliminate the calories of the equipment as much as possible. If the copper zone is on the other side of the PCB, the thermal hole is used to convey the heat between the top and the bottom layer.
Generally speaking, the more copper area provided, the greater the consumption power.
DRV8805ppp package uses a HTSSOP package and exposed PowerPad #8482 ;. Power board #8482; packaging uses an exposed mat to remove the calories of the device. In order to correctly operate, the pad must be connected to the copper heat on the PCB to dissipate heat. On the multi -layer PCB with the floor, this can be achieved by adding multiple holes to connect the hot pad to the horizon. On PCB without internal planes, you can add copper area to any side of the PCB to dissipate heat. If the copper zone is on the other side of the PCB, the thermal hole is used to convey the heat between the top and the bottom layer.