Product Folder Sample & Buy Technical Documents Support & Community Tools & Software Reference Design DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 DRV8832-Q1 Low-Voltage Motor Driver IC 1 Features 3 Description • • The DRV8832-Q1 device provides an integrated motor driver solution for battery-powered toys, printers, and other low-voltage or battery-powered motion control applications. The device has one Hbridge driver, and can drive one DC motor or one winding of a stepper motor, as well as other loads like solenoids. The output driver block consists of Nchannel and P-channel power MOSFETs configured as an H-bridge to drive the motor winding. 1 • • • • • • • • Qualified for Automotive Applications AEC-Q100 Qualified With the Following Results: – Device Temperature Grade 1: –40°C to 125°C Ambient Operating Temperature Range – Device HBM ESD Classification Level H2 – Device CDM ESD Classification Level C4B H-Bridge Voltage-Controlled Motor Driver – Drives DC Motor, One Winding of a Stepper Motor, or Other Actuators/Loads – Efficient PWM Voltage Control for Constant Motor Speed With Varying Supply Voltages – Low MOSFET ON-Resistance: HS + LS 450 mΩ 1-A Maximum DC/RMS or Peak Drive Current 2.75-V to 6.8-V Operating Supply Voltage Range 300-nA (Typical) Sleep Mode Current Reference Voltage Output Current Limit Circuit Fault Output Thermally Enhanced Surface Mount Packages 2 Applications • • Battery-Powered: – Printers – Toys – Robotics – Cameras – Phones Small Actuators, Pumps, and so forth Provided with sufficient PCB heatsinking, the DRV8832-Q1 can supply up to 1-A of DC/RMS or peak output current. It operates on power supply voltages from 2.75 V to 6.8 V. To maintain constant motor speed over varying battery voltages while maintaining long battery life, a PWM voltage regulation method is provided. An input pin allows programming of the regulated voltage. A built-in voltage reference output is also provided. Internal protection functions are provided for over current protection, short-circuit protection, undervoltage lockout, and overtemperature protection. The DRV8832-Q1 also provides a current limit function to regulate the motor current during conditions like motor startup or stall, as well as a fault output pin to signal a host processor of a fault condition. The DRV8832-Q1 is available in tiny 3-mm x 3-mm 10-pin MSOP package with PowerPAD™ (Ecofriendly: RoHS & no Sb/Br). Device Information(1) PART NUMBER DRV8832-Q1 PACKAGE BODY SIZE (NOM) MSOP-PowerPAD (10) 3.00 mm × 3.00 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Simplified Schematic 2.75V to 6.8V DRV8832-Q1 IN1 IN2 Controller Controller Brushed DC Motor Driver 1.3A peak BDC Protection 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 6.1 6.2 6.3 6.4 6.5 6.6 4 4 4 4 5 6 Absolute Maximum Ratings ...................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics........................................... Typical Characteristics .............................................. Detailed Description .............................................. 7 7.1 7.2 7.3 7.4 Overview ................................................................... 7 Functional Block Diagram ......................................... 7 Feature Description................................................... 8 Device Functional Modes........................................ 11 8 Application and Implementation ........................ 12 8.1 Application Information............................................ 12 8.2 Typical Application ................................................. 12 9 Power Supply Recommendations...................... 16 9.1 Power Supervisor.................................................... 16 9.2 Bulk Capacitance .................................................... 16 10 Layout................................................................... 17 10.1 Layout Guidelines ................................................. 17 10.2 Layout Example .................................................... 17 10.3 Thermal Considerations ........................................ 17 11 Device and Documentation Support ................. 19 11.1 11.2 11.3 11.4 11.5 Documentation Support ........................................ Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 19 19 19 19 19 12 Mechanical, Packaging, and Orderable Information ........................................................... 19 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision B (January 2014) to Revision C • Page Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section ................................................................................................. 4 Changes from Revision A (August 2013) to Revision B Page • Changed Bridge Control section............................................................................................................................................. 8 • Changed Current Limit section ............................................................................................................................................. 10 • Changed Thermal Shutdown (TSD) section......................................................................................................................... 10 • Added Power Supervisor section ......................................................................................................................................... 16 2 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 5 Pin Configuration and Functions DGQ Package 10-Pin MSOP Top View OUT2 ISENSE OUT1 VCC GND 1 10 2 9 GND (PPAD) 3 4 5 8 7 6 IN2 IN1 VREF VSET FAULTn Pin Functions PIN NAME NO. I/O (1) EXTERNAL COMPONENTS OR CONNECTIONS DESCRIPTION GND 5 — Device ground FAULTn 6 OD Fault output Open-drain output driven low if fault condition present IN1 9 I Bridge A input 1 Logic high sets OUT1 high IN2 10 I Bridge A input 2 Logic high sets OUT2 high ISENSE 2 IO Current sense resistor Connect current sense resistor to GND. Resistor value sets current limit level. OUT1 3 O Bridge output 1 Connect to motor winding OUT2 1 O Bridge output 2 Connect to motor winding VCC 4 — Device and motor supply Bypass to GND with a 0.1-μF (minimum) ceramic capacitor. VREF 8 O Reference voltage output Reference voltage output VSET 7 I Voltage set input Input voltage sets output regulation voltage (1) Directions: I = input, O = output, OZ = tri-state output, OD = open-drain output, IO = input/output Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 3 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) VCC (1) (2) MIN MAX UNIT Power supply voltage –0.3 7 V Input pin voltage –0.5 7 V Internally limited A Peak motor drive output current (3) Continuous motor drive output current (3) –1 Continuous total power dissipation 1 A See Themral Information TJ Operating virtual junction temperature –40 150 °C Tstg Storage temperature –60 150 °C (1) (2) (3) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltage values are with respect to network ground terminal. Power dissipation and thermal limits must be observed. 6.2 ESD Ratings VALUE Electrostatic discharge V(ESD) (1) (2) Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) ±4000 Charged-device model (CDM), per JEDEC specification JESD22-C101 (2) UNIT V ±1500 JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 6.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) MIN VCC Motor power supply voltage IOUT (1) Continuous or peak H-bridge output current (1) NOM MAX UNIT 2.75 6.8 V 0 1 A Power dissipation and thermal limits must be observed. 6.4 Thermal Information DRV8832-Q1 THERMAL METRIC (1) DGQ (MSOP) UNIT 10 PINS RθJA Junction-to-ambient thermal resistance 69.3 °C/W RθJC(top) Junction-to-case (top) thermal resistance 63.5 °C/W RθJB Junction-to-board thermal resistance 51.6 °C/W ψJT Junction-to-top characterization parameter 1.5 °C/W ψJB Junction-to-board characterization parameter 23.2 °C/W RθJC(bot) Junction-to-case (bottom) thermal resistance 9.5 °C/W (1) 4 For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 6.5 Electrical Characteristics VCC = 2.75 V to 6.8 V, TA = -40°C to 125°C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT POWER SUPPLIES IVCC VCC operating supply current VCC = 5 V 1.4 2 mA IVCCQ VCC sleep mode supply current VCC = 5 V, TA = 25°C 0.3 1 μA VCC undervoltage lockout voltage VCC rising 2.575 2.75 VCC falling 2.47 VUVLO V LOGIC-LEVEL INPUTS VIL Input low voltage 0.25 x VCC VIH Input high voltage VHYS Input hysteresis IIL Input low current VIN = 0 IIH Input high current VIN = 3.3 V 0.5 x VCC V V 0.08 × VCC -10 10 μA 50 μA LOGIC-LEVEL OUTPUTS (FAULTn) VOL Output low voltage VCC = 5 V, IOL = 4 mA (1) 0.5 VCC = 5 V, IO = 0.8 A, TJ = 125°C 340 VCC = 5 V, IO = 0.8 A, TJ = 25°C 250 VCC = 5 V, IO = 0.8 A, TJ = 125°C 270 VCC = 5 V, IO = 0.8 A, TJ = 25°C 200 V H-BRIDGE FETS RDS(ON) HS FET on resistance RDS(ON) LS FET on resistance IOFF Off-state leakage current 450 360 mΩ mΩ –20 20 μA ns MOTOR DRIVER tR Rise time VCC = 3 V, load = 4 Ω 50 300 tF Fall time VCC = 3 V, load = 4 Ω 50 300 fSW Internal PWM frequency 44.5 ns kHz PROTECTION CIRCUITS IOCP Overcurrent protection trip level tOCP OCP deglitch time TTSD Thermal shutdown temperature 1.3 3 Die temperature (1) A μs 2 150 160 180 °C 1.235 1.285 1.335 V VOLTAGE CONTROL VREF Reference output voltage ΔVLINE Line regulation VCC = 3.3 V to 6 V, VOUT = 3 V (1) IOUT = 500 mA ΔVLOAD Load regulation VCC = 5 V, VOUT = 3 V IOUT = 200 mA to 800 mA (1) ±1% ±1% CURRENT LIMIT VILIM Current limit sense voltage tILIM Current limit fault deglitch time RISEN Current limit set resistance (external resistor value) (1) 160 200 240 275 0 mV ms 1 Ω Not production tested. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 5 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com 100% 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 0.2 90% 80% 70% EFFICENCY EFFICIENCY 6.6 Typical Characteristics 60% 50% 40% 30% 0.4 0.6 0.8 LOAD - A Linear Regulator 20% DRV8832-Q1 10% 0% 0.5 1.5 2.5 3.5 4.5 5.5 VOUT - V Figure 2. Efficiency vs Output Voltage (VIN = 5 V, IOUT = 500 mA) Figure 1. Efficiency vs Load Current (VIN = 5 V, VOUT = 3 V) 2000 5500 5000 –40°C 25°C 125°C 1800 –40°C 25°C 125°C 4500 4000 IVCCQ (nA) I VCC (µA) 1600 1400 3500 3000 2500 2000 1200 1500 1000 1000 500 800 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 0 2.5 6.5 VVCC (V) 3.0 3.5 Figure 3. IVCC vs VVCC 1000 –40°C 25°C 125°C 900 5.0 5.5 6.0 6.5 C002 2.9 V 5V 6V 900 RDS(ON) HS + LS) (mΩ) C003 RDS(ON) (HS + LS) (mΩ) 4.5 Figure 4. IVCCQ vs VVCC 1000 800 700 600 500 800 700 600 500 400 400 300 3.0 3.5 4.0 4.5 5.0 5.5 VVCC (V) 6.0 300 –40 25 Temperature (°C) C003 Figure 5. RDS(on) HS + LS vs VVCC 6 4.0 VVCC (V) C001 125 C004 Figure 6. RDS(on) HS + LS vs Temperature Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 7 Detailed Description 7.1 Overview The DRV8832-Q1 is an integrated motor driver solution used for brushed motor control. The device integrates one H-bridge, current regulation circuitry, and a PWM voltage regulation method. Using the PWM voltage regulation allows the motor to maintain the desired speed as VCC changes. Battery operation is an example of using this feature. When the battery is new or fully charged VCC will be higher than when the battery is old or partially discharged. The speed of the motor will vary based on the voltage of the battery. By setting the desired voltage across the motor at a lower voltage, a fully charged battery will use less power and spin the motor at the same speed as a battery that has been partially discharged. 7.2 Functional Block Diagram Battery VCC VCC VCC OCP Integ. Comp VREF Ref Gate Drive + OUT1 VSET DCM VCC Logic IN1 OCP IN2 Gate Drive OverTemp FAULTn OUT2 Osc Current Sense ISENSE GND Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 7 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com 7.3 Feature Description 7.3.1 PWM Motor Driver The DRV8832-Q1 contains an H-bridge motor driver with PWM voltage-control circuitry with current limit circuitry. See Figure 7 for a block diagram of the motor control circuitry. VCC VCC OCP IN1 OUT 1 IN2 Predrive PWM DCM OUT2 VSET + COMP - OCP /4 Integrator DIFF + - ITRIP ISENSE COMP REF Figure 7. Motor Control Circuitry 7.3.2 Bridge Control The IN1 and IN2 control pins enable the H-bridge outputs. The following table shows the logic: Table 1. H-Bridge Logic IN1 IN2 OUT1 OUT2 Function 0 0 Z Z Sleep/coast 0 1 L H Reverse 1 0 H L Forward 1 1 H H Brake When both bits are zero, the output drivers are disabled and the device is placed into a low-power sleep state. The current limit fault condition (if present) is also cleared. Note that when transitioning from either brake or sleep mode to forward or reverse, the voltage control PWM starts at zero duty cycle. The duty cycle slowly ramps up to the commanded voltage. This can take up to 12 ms to go from sleep to 100% duty cycle. Because of this, highspeed PWM signals cannot be applied to the IN1 and IN2 pins. To control motor speed, use the VSET pin as described in the following paragraph. Because of the sleep mode functionality described previously, when applying an external PWM to the DRV8832Q1, hold one input logic high while applying a PWM signal to the other. If the logic input is held low instead, then the device will cycle in and out of sleep mode, causing the FAULTn pin to pulse low on every sleep mode exit. 8 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 7.3.3 Voltage Regulation The DRV8832-Q1 provides the ability to regulate the voltage applied to the motor winding. This feature allows constant motor speed to be maintained even when operating from a varying supply voltage such as a discharging battery. The DRV8832-Q1 uses a pulse-width modulation (PWM) technique instead of a linear circuit to minimize current consumption and maximize battery life. The circuit monitors the voltage difference between the output pins and integrates it, to get an average DC voltage value. This voltage is divided by 4 and compared to the VSET pin voltage. If the averaged output voltage (divided by 4) is lower than VSET, the duty cycle of the PWM output is increased; if the averaged output voltage (divided by 4) is higher than VSET, the duty cycle is decreased. During PWM regulation, the H-bridge is enabled to drive current through the motor winding during the PWM on time. This is shown in Figure 8 as case 1. The current flow direction shown indicates the state when IN1 is high and IN2 is low. Note that if the programmed output voltage is greater than the supply voltage, the device will operate at 100% duty cycle and the voltage regulation feature will be disabled. In this mode the device behaves as a conventional H-bridge driver. During the PWM off time, winding current is re-circulated by enabling both of the high-side FETs in the bridge. This is shown as case 2 in Figure 8. VCC 2 1 OUT1 Shown with OUT2 IN1=1, IN2=0 1 PWM on 2 PWM off Figure 8. Voltage Regulation 7.3.4 Reference Output The DRV8832-Q1 includes a reference voltage output that can be used to set the motor voltage. Typically for a constant-speed application, VSET is driven from VREF through a resistor divider to provide a voltage equal to 1/4 the desired motor drive voltage. For example, if VREF is connected directly to VSET, the voltage will be regulated at 5.14 V. If the desired motor voltage is 3 V, VREF should be 0.75 V. This can be obtained with a voltage divider using 53 kΩ from VREF to VSET, and 75 kΩ from VSET to GND. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 9 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com 7.3.5 Current Limit A current limit circuit is provided to protect the system in the event of an overcurrent condition, such as what would be encountered if driving a DC motor at start-up or with an abnormal mechanical load (stall condition). The motor current is sensed by monitoring the voltage across an external sense resistor. When the voltage exceeds a reference voltage of 200 mV for more than approximately 3 µs, the PWM duty cycle is reduced to limit the current through the motor to this value. This current limit allows for starting the motor while controlling the current. If the current limit condition persists for some time, it is likely that a fault condition has been encountered, such as the motor being run into a stop or a stalled condition. An overcurrent event must persist for approximately 275 ms before the fault is registered. After approximately 275 ms, a fault signaled to the host by driving the FAULTn signal low. Operation of the motor driver will continue. The current limit fault condition is self-clearing and will be released when the abnormal load (stall condition) is removed. The resistor used to set the current limit must be less than 1 Ω. Its value may be calculated as follows: 200 mV RISENSE = ¾ ILIMIT where • • RISENSE is the current sense resistor value ILIMIT is the desired current limit (in mA) (1) If the current limit feature is not needed, the ISENSE pin may be directly connected to ground. 7.3.6 Protection Circuits The DRV8832-Q1 is fully protected against undervoltage, overcurrent and overtemperature events. 7.3.6.1 Overcurrent Protection (OCP) An analog current limit circuit on each FET limits the current through the FET by removing the gate drive. If this analog current limit persists for longer than the OCP time, all FETs in the H-bridge will be disabled, and the FAULTn signal will be driven low. The device will remain disabled until VCC is removed and re-applied. Overcurrent conditions are sensed independently on both high and low side devices. A short to ground, supply, or across the motor winding will all result in an overcurrent shutdown. Note that OCP is independent of the current limit function, which is typically set to engage at a lower current level; the OCP function is intended to prevent damage to the device under abnormal (for example, short circuit) conditions. 7.3.6.2 Thermal Shutdown (TSD) If the die temperature exceeds safe limits, all FETs in the H-bridge will be disabled and the FAULTn signal will be driven low. Once the die temperature has fallen to a safe level operation will automatically resume. 7.3.6.3 Undervoltage Lockout (UVLO) If at any time the voltage on the VCC pins falls below the undervoltage lockout threshold voltage, all circuitry in the device will be disabled, the FAULTn signal will be driven low, and internal logic will be reset. Operation will resume when VCC rises above the UVLO threshold. Table 2. Device Protection FAULT CONDITION ERROR REPORT H-BRIDGE INTERNAL CIRCUITS RECOVERY VCC undervoltage (UVLO) VCC < VUVLO FAULTn Disabled Disabled VCC > VUVLO Overcurrent (OCP) IOUT > IOCP FAULT n Disabled Operating Power cycle VCC Thermal shutdown (TSD) TJ > TTSD FAULTn Disabled Operating TJ > TTSD – THYS 10 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 7.4 Device Functional Modes The DRV8832-Q1 is active when either IN1 or IN2 are set to a logic high. Sleep mode is entered when both IN1 and IN2 are set to a logic low. When in sleep mode, the H-bridge FETs are disabled (Hi-Z). Table 3. Modes of Operation FAULT CONDITION H-BRIDGE INTERNAL CIRCUITS Operating IN1 or IN2 high Operating Operating Sleep mode IN1 or IN2 low Disabled Diabled Fault encountered Any fault condition met Disabled See Table 2 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 11 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information The DRV8832-Q1 is used in brushed DC applications to provide a constant motor speed over varying voltages. The following design procedure can be used to configure the DRV8832 for a system with a VCC variance of 4V to 6V. 8.2 Typical Application Figure 9 is a common application of the DRV8832-Q1. VCC VCC OUT1 10 µF BDC IN1 IN2 Controller OUT2 VREF 2.87k ISENSE VSET 0.4 10k FAULTn GND PPAD Figure 9. Motor Control Circuitry 12 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 Typical Application (continued) 8.2.1 Design Requirements Table 4 lists the design parameters of the DRV8832-Q1. Table 4. Design Parameters DESIGN PARAMETER REFERENCE EXAMPLE VALUE Motor voltage VCC 5V Motor RMS current IRMS 0.3 A Motor start-up ISTART 1.3 A Motor current trip point ILIMIT 0.9 A 8.2.2 Detailed Design Procedure 8.2.2.1 Motor Voltage The motor voltage to use will depend on the ratings of the motor selected and the desired RPM. A higher voltage spins a brushed DC motor faster with the same PWM duty cycle applied to the power FETs. A higher voltage also increases the rate of current change through the inductive motor windings. For the DRV8832-Q1, TI recommends to set a motor voltage at the lowest system VCC. This will maintain a constant RPM across varying VCC conditions. For example if the VCC voltage can vary from 4.5V to 5.5V, setting the VSET voltage to 1.125 V will compensate for power supply variation. The DRV8832-Q1 will set the motor voltage at 4.5 V, even if VCC is 5.5 V. 8.2.2.2 Motor Current Trip Point When the voltage on pin ISENSE exceeds VILIM (0.2 V), overcurrent is detected. The RSENSE resistor should be sized to set the desired ILIMIT level. RISENSE = 0.2 V / ILIMIT (2) To set IILIMIT to 0.5 A, RISENSE = 0.2 V / 0.9 A = 0.22 Ω. To prevent false trips, ILIMIT must be higher than regular operating current. Motor current during start-up is typically much higher than steady-state spinning, because the initial load torque is higher, and the absence of back-EMF causes a higher voltage and extra current across the motor windings. It can be beneficial to limit start-up current by using series inductors on the DRV8832-Q1 output, as that allows ILIMIT to be lower, and it may decrease the system’s required bulk capacitance. Start-up current can also be limited by ramping the forward drive duty cycle. 8.2.2.3 Sense Resistor Selection For optimal performance, it is important for the sense resistor to be: • Surface-mount • Low inductance • Rated for high enough power • Placed closely to the motor driver The power dissipated by the sense resistor equals IRMS² x R. For example, if peak motor current is 1 A, RMS motor current is 0.7 A, and a 0.4-Ω sense resistor is used, the resistor will dissipate 0.7 A² x 0.4 Ω = 0.2 W. The power quickly increases with higher current levels. Resistors typically have a rated power within some ambient temperature range, along with a de-rated power curve for high ambient temperatures. When a PCB is shared with other components generating heat, margin should be added. It is always best to measure the actual sense resistor temperature in a final system, along with the power MOSFETs, as those are often the hottest components. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 13 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com Because power resistors are larger and more expensive than standard resistors, it is common practice to use multiple standard resistors in parallel, between the sense node and ground. This distributes the current and heat dissipation. 8.2.2.4 Low Power Operation Under normal operation, using sleep mode to minimize supply current should be sufficient. If desired, power can be removed to the DRV8832-Q1 to further decrease supply current. TI recommends to remove power to the FAULTn pullup resistor when removing power to the DRV8832-Q1. Removing power from the FAULTn pullup resistor will eliminate a current path from the FAULTn pin through an ESD protection diode to VCC. TI recommends to set both IN1 and IN2 as a logic low when power is removed. 8.2.3 Application Curves The following scope captures show how the output duty cycle changes to as VCC increases. This allows the motor to spin at a constant speed as VCC changes. At VCC = 3.9 V, the output duty cycle is 100% on. As the VCC voltage increases to greater than 4 V, the output duty cycle begins to decrease. The output duty cycle is shown at VCC = 4.5 V, VCC = 5 V and VCC = 5.5 V. • Channel 1 – OUT1: IN1 – Logic Low • Channel 2 – OUT2: IN2 – Logic High • Channel 4 – Motor current: VSET – 1 V • Motor used: NMB Technologies Corporation, PPN7PA12C1 14 Figure 10. Output Pulse Width Modulating at VCC = 3.9 V Figure 11. Output Pulse Width Modulating at VCC = 4 V Figure 12. Output Pulse Width Modulating at VCC = 4.5 V Figure 13. Output Pulse Width Modulating at VCC = 5 V Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 Figure 14. Output Pulse Width Modulating at VCC = 5.5 V Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 15 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com 9 Power Supply Recommendations 9.1 Power Supervisor The DRV8832-Q1 is capable of entering a low-power sleep mode by bringing both of the INx control inputs logic low. The outputs will be disabled Hi-Z. To exit the sleep mode, bring either or both of the INx inputs logic high. This will enable the H-bridges. When exiting the sleep mode, the FAULTn pin will pulse low. 9.2 Bulk Capacitance Having appropriate local bulk capacitance is an important factor in motor drive system design. It is generally beneficial to have more bulk capacitance, while the disadvantages are increased cost and physical size. The amount of local capacitance needed depends on a variety of factors, including: • The highest current required by the motor system. • The power supply’s capacitance and ability to source current. • The amount of parasitic inductance between the power supply and motor system. • The acceptable voltage ripple. • The type of motor used (Brushed DC, Brushless DC, Stepper). • The motor braking method. The inductance between the power supply and motor drive system will limit the rate current can change from the power supply. If the local bulk capacitance is too small, the system will respond to excessive current demands or dumps from the motor with a change in voltage. When adequate bulk capacitance is used, the motor voltage remains stable and high current can be quickly supplied. The data sheet generally provides a recommended value, but system-level testing is required to determine the appropriate sized bulk capacitor. Parasitic Wire Inductance Motor Drive System Power Supply VCC ++ ±± + Motor Driver GND Local Bulk Capacitor IC Bypass Capacitor Figure 15. Example Setup of Motor Drive System with External Power Supply The voltage rating for bulk capacitors should be higher than the operating voltage, to provide margin for cases when the motor transfers energy to the supply. 16 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 10 Layout 10.1 Layout Guidelines The VCC pin should be bypassed to GND using low-ESR ceramic bypass capacitors with a recommended value of 0.1-μF rated for VCC. This capacitor should be placed as close to the VCC pin as possible with a thick trace or ground plane connection to the device GND pin. The VCC pin must be bypassed to ground using an appropriate bulk capacitor. This component may be an electrolytic and should be placed close to the DRV8832-Q1. 10.2 Layout Example 10 µF OUT2 IN2 ISENSE IN1 OUT1 VREF VCC VSET GND FAULTn Figure 16. Layout Recommendations 10.3 Thermal Considerations The DRV8832-Q1 has thermal shutdown (TSD) as described in Thermal Shutdown (TSD). If the die temperature exceeds approximately 160°C, the device will be disabled until the temperature drops to a safe level. Any tendency of the device to enter TSD is an indication of either excessive power dissipation, insufficient heatsinking, or too high an ambient temperature. 10.3.1 Power Dissipation Power dissipation in the DRV8832-Q1 is dominated by the power dissipated in the output FET resistance, or RDS(ON). Average power dissipation when running a stepper motor can be roughly estimated by Equation 3. PTOT = 2 · RDS(ON) · (IOUT(RMS)) 2 (3) where PTOT is the total power dissipation, RDS(ON) is the resistance of each FET, and IOUT(RMS) is the RMS output current being applied to each winding. IOUT(RMS) is equal to the approximately 0.7x the full-scale output current setting. The factor of 2 comes from the fact that at any instant two FETs are conducting winding current for each winding (one high-side and one low-side). The maximum amount of power that can be dissipated in the device is dependent on ambient temperature and heatsinking. Note that RDS(ON) increases with temperature, so as the device heats, the power dissipation increases. This must be taken into consideration when sizing the heatsink. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 17 DRV8832-Q1 SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 www.ti.com Thermal Considerations (continued) 10.3.2 Heatsinking The PowerPAD™ package uses an exposed pad to remove heat from the device. For proper operation, this pad must be thermally connected to copper on the PCB to dissipate heat. On a multi-layer PCB with a ground plane, this can be accomplished by adding a number of vias to connect the thermal pad to the ground plane. On PCBs without internal planes, copper area can be added on either side of the PCB to dissipate heat. If the copper area is on the opposite side of the PCB from the device, thermal vias are used to transfer the heat between top and bottom layers. For details about how to design the PCB, see TI application report, PowerPAD™ Thermally Enhanced Package (SLMA002), and TI application brief, PowerPAD™ Made Easy (SLMA004), available at www.ti.com. In general, the more copper area that can be provided, the more power can be dissipated. 18 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 DRV8832-Q1 www.ti.com SLVSBW9C – APRIL 2013 – REVISED DECEMBER 2015 11 Device and Documentation Support 11.1 Documentation Support 11.1.1 Related Documentation For related documentation see the following: • PowerPAD™ Thermally Enhanced Package Application Report, SLMA002 • PowerPAD™ Made Easy, SLMA004 11.2 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 11.3 Trademarks PowerPAD, E2E are trademarks of Texas Instruments. All other trademarks are the property of their respective owners. 11.4 Electrostatic Discharge Caution These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 11.5 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 12 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: DRV8832-Q1 19 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily performed. TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use of any TI components in safety-critical applications. In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and requirements. Nonetheless, such components are subject to these terms. No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties have executed a special agreement specifically governing such use. Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of non-designated products, TI will not be responsible for any failure to meet ISO/TS16949. Products Applications Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps DSP dsp.ti.com Energy and Lighting www.ti.com/energy Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial Interface interface.ti.com Medical www.ti.com/medical Logic logic.ti.com Security www.ti.com/security Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com OMAP Applications Processors www.ti.com/omap TI E2E Community e2e.ti.com Wireless Connectivity www.ti.com/wirelessconnectivity Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2015, Texas Instruments Incorporated