Features

Double #189; -H Bridge motor driver

-A winding or other load of driving DC motor or step motor

-Low MOSFET Direction resistance: HS+LS 280 MΩ

1.8-A maximum driving current

separate motor and logic power supply foot: motor work voltage -0-11 v

-1.8-V to 7-V logic power supply voltage

single #189; -h bridge control input interface

#8226; Low-power sleep mode, the maximum combination of power current is 120 mAh

2.00-mm × 3.00-mm 12-pin WSON component

] battery power supply:

- SLR lens

- Consumer product

- Toys

- Medical Devices

Instructions

DRV8839

provides a universal power supply for cameras, consumer goods, toys and other low -voltage or battery power supply applications Driver solution. The device has two independent #189; -H bridge drivers, which can drive a winding or step motor winding, and other devices, such as snail pipes. The output level is configured to #189; -H bridge N-channel power MOSFET. The internal charge pump generates the required grid drive voltage.

DRV8839 provides an output current of up to 1.8-a. Its working voltage is 0-11V motor power supply voltage and 1.8V-7V equipment power supply voltage.

DRV8839 is an independent input and enable pin per #189; -H bridge, allowing independent control of each output.

Provide internal shutdown functions of overcurrent protection, short -circuit protection, low -voltage locking and ultra -temperature.

DRV8839 is packaged in 12 strips, 2.00-mm × 3.00-mm WSON packaging (environmentally friendly: ROHS and NO SB/br).

Equipment information

(1), please refer to the appointment appendix at the end of the data table.

Simplified schematic diagram

Detailed description

Overview

DRV8839 is an integrated motor drive solution for carbon brush motor control. The device integrates two independent #189; H bridges, which can drive one motor or one -way drive two motors in both directions. The output drive block of each #189; H bridge consists of N -channel power MOSFET. The internal charge pump generates a gate driver voltage. The protection function includes overcurrent protection, short -circuit protection, low -pressure atresia and overheating protection.

If necessary, DRV8839 allows motor voltage and logical voltage to separate. If VM and VCC are less than 7 V, two voltages can be connected.

The control interface between DRV8839 uses INX and ENX to control each #189; respectively.

Function box diagram

Feature description

Protective circuit

DRV8839 has sufficient protection to prevent under pressure, which can prevent pressure. Excessive 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 duration of the simulated current limit exceeds OCP time, all FETs in the H bridge will be disabled. About 1 milliseconds, the bridge will automatically enable.

Over -current conditions on high -voltage and low -voltage side devices; short circuit, short -circuit of power supply, or short circuit between motor winding in the motor will lead to over -current suspension.

Hot shutdown (TSD)

If the mold temperature exceeds the safety limit, all FETs in the H bridge will fail. Once the mold temperature drops to the safe level, the operation will automatically restore.

IOU locking (UVLO)

If the voltage on the VCC pin is lower than the voltage lock threshold voltage at any time, all circuits in the device will be disabled and the internal logic is reset. When VCC is higher than the UVLO threshold, the operation recovers.

Equipment function mode

When the NSLEEP pin is set to logic high, DRV8839 is activated. In the dormant mode, #189; H bridge FET is disabled (high Z).

Bridge control

DRV8839 controls and input pins alone through each #189; -H bridge.

The logic of DRV8839 shows below:

Sleep mode

Low -power dormant mode. In this state, all unnecessary internal circuits will be powered off.

电机连接

如果单个直流电机连接到DRV8839，则它连接在OUT1和OUT2引脚之间，如图7所示：

[123 ]

Motor operation control is shown in Table 4.

(1), the status depends on EN2 and IN2, but does not affect the operation of the motor because OUT1 is three state.

(2), the status depends on EN1 and IN1, but does not affect the operation of the motor, because OUT2 is a three -state.

Two DC motors can be connected to DRV8839. In this mode, it is impossible to reverse the direction of the motor; they only rotate in one direction. The connection is shown in Figure 8:

The operation control of the motor is shown in Table 5.

Application and implementation

Note

The information in the following application chapters is not part of the TI component specification. TI does not guarantee 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.

Application information

DRV8839 is used for a control application.

Typical application

The following design is a common application of DRV8839.

Design requirements

The design requirements are shown in Table 6.

Detailed design program

The design process below can be used to configure DRV8839 in the application of a brush motor.

Motor voltage

Appropriate motor voltage depends on the rated value of the selected motor and the required speed. The higher voltage makes the rotation speed of the brushing motor faster, and the same pulse width modulation duty cycle is applied to the power field effect transistor. The higher voltage will also increase the current changes in the current through the inductive motor winding.

Low -power operation

When entering the sleep mode, TI recommends setting all inputs as low logic and minimizing system power.

Application curve

The following is a typical start and operation range. Channel 1 is VM, channel 2 is IN1, channel 3 is IN2, and channel 4 is motor current. The motor used is NMB technology, PPN7PA12C1.

Power suggestion

Whether there are VCC and VM power supply, the input pin can be driven under its recommended working conditions. There is no leakage current path. There is a weaker on each input pinPull resistance (about 100 kΩ) ground.

VCC and VM can be applied and deleted in any order. When the VCC is removed, the device enters a low power consumption state, and the current from the virtual machine is very small. If the power supply voltage is between 1.8 V and 7 V, VCC and VM can be connected together.

VM voltage power supply does not have any underwriting lock protection (UVLO), so as long as VCC GT; 1.8 V, the internal device logic is maintained. This means that the VM pin voltage may fall to 0V. However, under the low VM voltage, the load may not be fully driven.

Body capacitance

It is an important factor in the design of the motor drive system. 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 -by -step motor)

Electrometer braking method

Layout

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Layout Guide

The low ESR ceramic side electric container should be used to use the VCC pins to GND. The recommended value is 0.1-μF VCC rated value. The capacitor should be placed near the VCC pin as much as possible, leaving thicker traces.

The VM pin should be bypass to the GND with low ESR ceramic beam capacitors, and the recommended value is 0.1 μF VM rated value. The capacitor should be placed near the VM tube as possible, leaving thicker traces. The VM pin must be bypass using the appropriate large -capacity capacitor. This part can be an electrolyte, which should be located near the DRV8839 device.

layout example

Heat Precautions

DRV8839 has the heat shutdown (TSD) as described above. If the mold temperature exceeds about 150 ° C, the device will be disabled until the temperature drops to the safe level.

Any trend of the device's entry into the heat stack indicates that the power consumption is too large, insufficient heat dissipation, or the environmental temperature is too high.

Power consumption

The power consumption of DRV8839 is the function of the RMS motor current and the FET resistance (RDS (on)) of each output. ]

In this example, VVM u003d 1.8 V, VVCC u003d 1.8 V, the ambient temperature is 35 ° C, and the knot temperature reaches 65 ° C.At 65 ° C, the total of RDS (on) is about 1 #8486;.If the current of the motor is 0.8 A, the dispersing power in the form of heat will be 0.8 A2 × 1 #8486; u003d 0.64 W.

The temperature reached by DRV8839 depends on the heat resistance to air and PCB.It is important to welded the equipment hot pads to the PCB floor, and connects the hole on the top and bottom plates in order to distribute the heat to the PCB and reduce the equipment temperature.In the example used here, the effective thermal resistance of DRV8839 is 47 ° C/W.