Ordering number : ENA1482B LV8731V Monolithic Linear IC PWM Constant-Current Control Stepper Motor Driver http://onsemi.com Overview The LV8731V is a 2-channel H-bridge driver IC that can switch a stepper motor driver, which supports micro-step drive with 1/16-step resolution, and two channels of a brushed motor driver, which supports forward, reverse, brake, and standby of a motor. It is ideally suited for driving brushed DC motors and stepper motors used in office equipment and amusement applications. Function • Single-channel PWM current control stepper motor driver (selectable with DC motor driver channel 2) incorporated. • BiCDMOS process IC • Low on resistance (upper side : 0.3Ω ; lower side : 0.25Ω ; total of upper and lower : 0.55Ω ; Ta = 25°C, IO = 2A) • Micro-step mode can be set to Full-step, Half-step, Quarter-step , or 1/16-step • Excitation step proceeds only by step signal input • Motor current selectable in four steps • Output short-circuit protection circuit (selectable from latch-type or auto-reset-type) incorporated • Unusual condition warning output pins • No control power supply required Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Symbol Conditions Ratings Unit Supply voltage VM max VM , VM1 , VM2 36 V Output peak current IO peak Tw ≤ 10ms , duty 20% , Per 1ch 2.5 A Output current IO max Per 1ch 2 A Logic input voltage VIN ATT1 , ATT2 , EMM , RST/BLK , -0.3 to +6 V STEP/DC22 ,FR/DC21,MD2/DC12, MD1/DC11,DM,OE,ST MONI/EMO input voltage Vmoni/Vemo Allowable power dissipation Pd max -0.3 to +6 V 3.25 W Operating temperature Storage temperature Topr -20 to +85 °C Tstg -55 to +150 °C * * Specified circuit board : 90.0mm×90.0mm×1.6mm, glass epoxy 2-layer board, with backside mounting. Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time. Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current, high voltage, or drastic temperature change, the reliability of the IC may be degraded. Please contact us for the further details. Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. Allowable Operating Ratings at Ta = 25°C Parameter Symbol Conditions Ratings Unit Supply voltage range VM VM , VM1 , VM2 9 to 32 V Logic input voltage VIN ATT1 , ATT2 , EMM , RST/BLK , STEP/DC22 , 0 to 5.5 V 0 to 3 V FR/DC21 , MD2/DC12 , MD1/DC11 , DM , OE , ST VREF input voltage range VREF ORDERING INFORMATION See detailed ordering and shipping information on page 26 of this data sheet. Semiconductor Components Industries, LLC, 2013 June, 2013 61213NK 20121220-S00001 / D0909 SY / 82609 MS PC 20090512-S00006 No.A1482-1/26 LV8731V Electrical Characteristics at Ta = 25°C, VM = 24V, VREF = 1.5V Parameter Symbol Conditions Ratings min typ Unit max Standby mode current drain IMst ST = “L” , I(VM)+I(VM1)+I(VM2) 100 400 μA Current drain IM ST = “H”, OE = “L”, with no load 3.2 5 mA VREG5 output voltage Vreg5 IO = -1mA 4.5 5 5.5 V Thermal shutdown temperature TSD Design guarantee 150 180 200 °C Thermal hysteresis width ΔTSD Design guarantee 40 Ronu IO = 2A, Upper-side on resistance 0.3 0.4 Rond IO = 2A, Lower-side on resistance 0.25 0.33 Ω 50 μA 1.2 1.4 V 4 8 12 μA 50 I(VM)+I(VM1)+I(VM2) °C Motor driver Output on resistance Output leakage current IOleak Diode forward voltage VD ID = -2A Logic pin input current IINL ATT1 , ATT2 , EMM , RST/BLK , Ω STEP/DC22 , FR/DC21 , MD2/DC12 , MD1/DC11 , DM , OE , ST , VIN = 0.8V Logic input voltage High Low Current setting 1/16 step comparator resolution IINH VIN = 5V 30 70 μA VINh ATT1 , ATT2 , EMM , RST/BLK , 2.0 5.5 V VINl STEP/DC22 , FR/DC21 , MD2/DC12 , 0 0.8 V Vtdac0_4W Step 0 (When initialized : channel 1 MD1/DC11 , DM , OE , ST 0.291 0.3 0.309 V comparator level) threshold voltage Vtdac1_4W Step 1 (Initial state+1) 0.291 0.3 0.309 V (current step Vtdac2_4W Step 2 (Initial state+2) 0.285 0.294 0.303 V Vtdac3_4W Step 3 (Initial state+3) 0.279 0.288 0.297 V Vtdac4_4W Step 4 (Initial state+4) 0.267 0.276 0.285 V Vtdac5_4W Step 5 (Initial state+5) 0.255 0.264 0.273 V Vtdac6_4W Step 6 (Initial state+6) 0.240 0.249 0.258 V Vtdac7_4W Step 7 (Initial state+7) 0.222 0.231 0.240 V Vtdac8_4W Step 8 (Initial state+8) 0.201 0.21 0.219 V Vtdac9_4W Step 9 (Initial state+9) 0.180 0.189 0.198 V Vtdac10_4W Step 10 (Initial state+10) 0.157 0.165 0.173 V Vtdac11_4W Step 11 (Initial state+11) 0.134 0.141 0.148 V Vtdac12_4W Step 12 (Initial state+12) 0.107 0.114 0.121 V Vtdac13_4W Step 13 (Initial state+13) 0.080 0.087 0.094 V Vtdac14_4W Step 14 (Initial state+14) 0.053 0.06 0.067 V switching) Quarter step Vtdac15_4W Step 15 (Initial state+15) 0.023 0.03 0.037 V Vtdac0_W Step 0 (When initialized : channel 1 0.291 0.3 0.309 V V resolution Half step comparator level) Vtdac4_W Step 4 (Initial state+1) 0.267 0.276 0.285 Vtdac8_W Step 8 (Initial state+2) 0.201 0.21 0.219 V Vtdac12_W Step 12 (Initial state+3) 0.107 0.114 0.121 V Vtdac0_H Step 0 (When initialized : channel 1 0.291 0.3 0.309 V resolution Full step comparator level) Vtdac8_H Step 8 (Initial state+1) 0.201 0.21 0.219 V Vtdac8_F Step 8' (When initialized : channel 1 0.291 0.3 0.309 V 0.291 0.3 0.309 V resolution comparator level) Current setting comparator Vtatt00 ATT1 = L, ATT2 = L threshold voltage Vtatt01 ATT1 = H, ATT2 = L 0.232 0.24 0.248 V Vtatt10 ATT1 = L, ATT2 = H 0.143 0.15 0.157 V Vtatt11 ATT1 = H, ATT2 = H 0.053 0.06 0.067 Fchop Cchop = 200pF 40 50 60 kHz (current attenuation rate switching) Chopping frequency V CHOP pin charge/discharge current Ichop 7 10 13 μA Chopping oscillation circuit Vtup 0.8 1 1.2 V threshold voltage Vtdown 0.4 0.5 0.6 V Continued on next page No.A1482-2/26 LV8731V Continued from preceding page. Parameter Symbol Conditions VREF pin input current Iref VREF = 1.5V MONI pin saturation voltage Vsatmon Imoni = 1mA min typ max Unit μA -0.5 400 mV Charge pump VG output voltage VG Rise time tONG 28 VG = 0.1μF , Between CP1-CP2 0.1uF 28.7 29.8 V 200 500 μS 125 150 kHz 400 mV ST=”H” →VG=VM+4V Oscillator frequency Fosc 90 Output short-circuit protection EMO pin saturation voltage Vsatemo Iemo = 1mA CEM pin charge current Icem Vcem = 0V CEM pin threshold voltage Vtcem 7 10 13 μA 0.8 1 1.2 V Package Dimensions unit : mm (typ) 3333A TOP VIEW SIDE VIEW BOTTOM VIEW 15.0 44 23 (3.5) 0.5 5.6 7.6 (4.7) 22 0.22 0.2 1.7 MAX 0.65 0.05 (1.5) SIDE VIEW 3.25 SSOP44K(275mil) Pd max – Ta 4.0 Allowable power dissipation, Pd max – W 1 (0.68) *1 With components mounted on the exposed die-pad board *2 With no components mounted on the exposed die-pad board Two-layer circuit board 1 *1 3.0 2.20 2.0 Two-layer circuit board 2 *2 1.69 1.14 1.0 0 – 20 0 20 40 60 80 100 Ambient temperature, Ta – °C No.A1482-3/26 LV8731V Substrate Specifications (Substrate recommended for operation of LV8731V) Size : 90mm × 90mm × 1.6mm (two-layer substrate [2S0P]) Material : Glass epoxy Copper wiring density : L1 = 85% / L2 = 90% L1 : Copper wiring pattern diagram L2 : Copper wiring pattern diagram Cautions 1) The data for the case with the Exposed Die-Pad substrate mounted shows the values when 90% or more of the Exposed Die-Pad is wet. 2) For the set design, employ the derating design with sufficient margin. Stresses to be derated include the voltage, current, junction temperature, power loss, and mechanical stresses such as vibration, impact, and tension. Accordingly, the design must ensure these stresses to be as low or small as possible. The guideline for ordinary derating is shown below : (1)Maximum value 80% or less for the voltage rating (2)Maximum value 80% or less for the current rating (3)Maximum value 80% or less for the temperature rating 3) After the set design, be sure to verify the design with the actual product. Confirm the solder joint state and verify also the reliability of solder joint for the Exposed Die-Pad, etc. Any void or deterioration, if observed in the solder joint of these parts, causes deteriorated thermal conduction, possibly resulting in thermal destruction of IC. No.A1482-4/26 LV8731V Pin Assignment VG 1 44 OUT1A VM 2 43 OUT1A CP2 3 42 PGND CP1 4 41 NC VREG5 5 40 NC ATT2 6 39 VM1 ATT1 7 38 VM1 EMO 8 37 RF1 CEM 9 36 RF1 EMM 10 35 OUT1B CHOP 11 MONI 12 34 OUT1B LV8731V RST/BLK 13 33 OUT2A 32 OUT2A STEP/DC22 14 31 RF2 FR/DC21 15 30 RF2 MD2/DC12 16 29 VM2 MD1/DC11 17 28 VM2 DM 18 27 NC OE 19 26 NC ST 20 25 PGND VREF 21 24 OUT2B GND 22 23 OUT2B Top view No.A1482-5/26 MONI PGND VM GND VREF VREG5 + - LVS TSD + - CHOP Oscillation circuit Regulator ATT2 Attenuator (4 levels selectable) ST ATT1 Charge pump Output preamplifier stage RF OUT B VM VM2 OUT2A RF2 DM EMM Current selection (4W1-2/ W1-2/1-2/2) Current selection (4W1-2/ W1-2/1-2/2) MD1/ MD2/ FR/ STEP/ RST/ OE DC11 DC12 DC21 DC22 BLK + Output control logic OUT2B + OUT A Output preamplifier stage VG Output preamplifier stage CF Output preamplifier stage CP2 CEM EMO LV8731V Block Diagram No.A1482-6/26 LV8731V Pin Functions Pin No. Pin Name Pin Function 6 ATT2 Motor holding current switching pin. 7 ATT1 Motor holding current switching pin. 10 EMM Output short-circuit protection mode Equivalent Circuit VREG5 switching pin. 13 RST/BLK 14 STEP/DC22 15 FR/DC21 RESET input pin (STM) / Blanking time switching pin (DCM). STEP signal input pin (STM) / Channel 2 output control input pin 2 (DCM). CW / CCW signal input pin (STM) / 10kΩ Channel 2 output control input pin 1 (DCM). 16 MD2/DC12 Excitation mode switching pin 2 (STM) / 100kΩ Channel 1 output control input pin 2 (DCM). 17 MD1/DC11 Excitation mode switching pin 1 (STM) / Channel 1 output control input pin 1 GND (DCM). 18 DM Drive mode (STM/DCM) switching pin. 19 OE Output enable signal input pin. 20 ST Chip enable pin. VREG5 20kΩ 10kΩ 80kΩ GND 23, 24 OUT2B Channel 2 OUTB output pin. 25, 42 PGND Power system ground. 28, 29 VM2 Channel 2 motor power supply 30, 31 RF2 32, 33 OUT2A Channel 2 OUTA output pin. 34, 35 OUT1B Channel 1 OUTB output pin. 36, 37 RF1 Channel 1 current-sense resistor 38, 39 VM1 Channel 1 motor power supply pin. 43, 44 OUT1A Channel 1 OUTA output pin. 38 39 28 29 connection pin. Channel 2 current-sense resistor connection pin. 34 35 23 24 43 44 32 33 connection pin. 10kΩ 500Ω 25 42 500Ω 36 37 30 31 GND Continued on next page. No.A1482-7/26 LV8731V Continued from preceding page. Pin No. Pin Name Pin Function 1 VG Charge pump capacitor connection pin. 2 VM Motor power supply connection pin. 3 CP2 Charge pump capacitor connection pin. 4 CP1 Charge pump capacitor connection pin. Equivalent Circuit 2 4 3 1 VREG5 100Ω GND 21 VREF Constant current control reference voltage input pin. VREG5 500Ω GND 5 VREG5 Internal power supply capacitor connection pin. VM 2kΩ 78kΩ 26kΩ GND 8 EMO Output short-circuit state warning output pin. 12 MONI VREG5 Position detection monitor pin. GND Continued on next page. No.A1482-8/26 LV8731V Continued from preceding page. Pin No. 9 Pin Name CEM Pin Function Pin to connect the output short-circuit state detection time setting capacitor. Equivalent Circuit VREG5 GND 11 CHOP Chopping frequency setting capacitor connection pin. VREG5 500Ω 500Ω GND 22 26, 27 40, 41 GND NC Ground. No Connection (No internal connection to the IC) No.A1482-9/26 LV8731V Description of operation 1. Input Pin Function 1-1) Chip enable function This IC is switched between standby and operating mode by setting the ST pin. In standby mode, the IC is set to power-save mode and all logic is reset. In addition, the internal regulator circuit and charge pump circuit do not operate in standby mode. ST Mode Internal regulator Low or Open Standby mode Standby Charge pump Standby High Operating mode Operating Operating 1-2) Drive mode switching pin function The IC drive mode is switched by setting the DM pin. In STM mode, stepper motor channel 1 can be controlled by the CLK-IN input. In DCM mode, DC motor channel 2 or stepper motor channel 1 can be controlled by parallel input. Stepper motor control using parallel input is Full-step or Half-step full torque. DM Drive mode Application Low or Open STM mode Stepper motor channel 1 (CLK-IN) High DCM mode DC motor channel 2 or stepper motor channel 1 (parallel) 2. STM mode (DM = Low or Open) 2-1) STEP pin function Input Operating mode ST STP Low * Standby mode High Excitation step proceeds High Excitation step is kept 2-2) Excitation mode setting function MD1 MD2 Micro-step resolution (Excitation mode) Initial position Channel 1 Channel 2 Low Low Full step(2 phase excitation) 100% -100% High Low Half step(1-2 phase excitation) 100% 0% Low High Quarter step 100% 0% 100% 0% (W1-2 phase excitation) High High 1/16 step(4W1-2 phase excitation) This is the initial position of each excitation mode in the initial state after power-on and when the counter is reset. 2-3) Position detection monitoring function The MONI position detection monitoring pin is of an open drain type. When the excitation position is in the initial position, the MONI output is placed in the ON state. (Refer to "2-12.Examples of current waveforms in each micro-step mode.") No.A1482-10/26 LV8731V 2-4) Setting constant-current control reference current This IC is designed to automatically exercise PWM constant-current chopping control for the motor current by setting the output current. Based on the voltage input to the VREF pin and the resistance connected between RF and GND, the output current that is subject to the constant-current control is set using the calculation formula below : IOUT = (VREF/5)/RF resistance * The above setting is the output current at 100% of each excitation mode. The voltage input to the VREF pin can be switched to four-step settings depending on the statuses of the two inputs, ATT1 and ATT2. This is effective for reducing power consumption when motor holding current is supplied. Attenuation function for VREF input voltage ATT1 ATT2 Current setting reference voltage attenuation ratio Low Low 100% High Low 80% Low High 50% High High 20% The formula used to calculate the output current when using the function for attenuating the VREF input voltage is given below. IOUT = (VREF/5) × (attenuation ratio)/RF resistance Example : At VREF of 1.5V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of 0.3Ω, the output current is set as shown below. IOUT = 1.5V/5 × 100%/0.3Ω = 1.0A If, in this state, (ATT1, ATT2) is set to (H, H), IOUT will be as follows : IOUT = 1.0A × 20% = 200mA In this way, the output current is attenuated when the motor holding current is supplied so that power can be conserved. 2-5) Input Timing TstepH TstepL STEP Tdh Tds (md1 step) (step md1) MD1 Tdh Tds (md2 step) (step md2) MD2 Tdh Tds (fr step) (step fr) FR TstepH/TstepL : Clock H/L pulse width (min 500ns) Tds : Data set-up time (min 500ns) Tdh : Data hold time (min 500ns) 2-6) Blanking period If, when exercising PWM constant-current chopping control over the motor current, the mode is switched from decay to charge, the recovery current of the parasitic diode may flow to the current sensing resistance, causing noise to be carried on the current sensing resistance pin, and this may result in erroneous detection. To prevent this erroneous detection, a blanking period is provided to prevent the noise occurring during mode switching from being received. During this period, the mode is not switched from charge to decay even if noise is carried on the current sensing resistance pin. In the stepper motor driver mode (DM = Low or Open) of this IC, the blanking time is fixed at approximately 1μs. In the DC motor driver mode (DM = High), the blanking time can be switched to one of two levels using the RST/BLK pin. (Refer to "Blanking time switching function.") No.A1482-11/26 LV8731V 2-7) Reset function RST Operating mode Low Normal operation High Reset state RST RESET STEP MONI 1ch output 0% 2ch output Initial state When the RST pin is set to High, the excitation position of the output is forcibly set to the initial state, and the MONI output is placed in the ON state. When RST is then set to Low, the excitation position is advanced by the next STEP input. 2-8) Output enable function OE Operating mode Low Output ON High Output OFF OE Power save mode STEP MONI 1ch output 0% 2ch output Output is high-impedance When the OE pin is set High, the output is forced OFF and goes to high impedance. However, the internal logic circuits are operating, so the excitation position proceeds when the STEP signal is input. Therefore, when OE is returned to Low, the output level conforms to the excitation position proceeded by the STEP input. No.A1482-12/26 LV8731V 2-9) Forward/reverse switching function FR Operating mode Low Clockwise (CW) High Counter-clockwise (CCW) FR CW mode CCW mode CW mode STEP Excitation position (1) (2) (3) (4) (5) (6) (5) (4) (3) (4) (5) 1ch output 2ch output The internal D/A converter proceeds by one bit at the rising edge of the input STEP pulse. In addition, CW and CCW mode are switched by setting the FR pin. In CW mode, the channel 2 current phase is delayed by 90° relative to the channel 1 current. In CCW mode, the channel 2 current phase is advanced by 90° relative to the channel 1 current. 2-10) Chopping frequency setting For constant-current control, this IC performs chopping operations at the frequency determined by the capacitor (Cchop) connected between the CHOP pin and GND. The chopping frequency is set as shown below by the capacitor (Cchop) connected between the CHOP pin and GND. Fchop = Ichop/ (Cchop × Vtchop × 2) (Hz) Ichop : Capacitor charge/discharge current, typ 10μA Vtchop : Charge/discharge hysteresis voltage (Vtup-Vtdown), typ 0.5V For instance, when Cchop is 200pF, the chopping frequency will be as follows : Fchop = 10μA/ (200pF × 0.5V × 2) = 50kHz No.A1482-13/26 LV8731V 2-11) Output current vector locus (one step is normalized to 90 degrees) 100.0 θ0 θ1 θ2 θ8' (2-phase) θ3 θ4 θ5 θ6 Channel 1 phase current ratio (%) θ7 θ8 66.7 θ9 θ 10 θ 11 θ 12 33.3 θ 13 θ 14 θ 15 θ 16 0.0 0.0 33.3 66.7 100.0 Channel 2 current ratio (%) Setting current ration in each micro-step mode STEP 1/16 step (%) Channel 1 Quarter step (%) Channel 2 Channel 1 θ0 100 0 θ1 100 10 θ2 98 20 θ3 96 29 θ4 92 38 θ5 88 47 θ6 83 55 θ7 77 63 θ8 70 70 θ9 63 77 θ10 55 83 θ11 47 88 θ12 38 92 θ13 29 96 θ14 20 98 θ15 10 100 θ16 0 100 Half step (%) Channel 2 Channel 1 100 0 92 38 70 70 38 92 0 100 Full step (%) Channel 2 Channel 1 100 0 70 70 0 100 100 Channel 2 100 No.A1482-14/26 LV8731V 2-12) Examples of current waveforms in each micro-step mode Full step (CW mode) STEP MONI (%) 100 l1 0 -100 (%) 100 I2 0 -100 Half step (CW mode) STEP MONI (%) 100 I1 0 -100 (%) 100 I2 0 -100 No.A1482-15/26 LV8731V Quarter step (CW mode) STEP MONI (%) 100 I1 0 -100 (%) 100 I2 0 -100 1/16 step (CW mode) STEP MONI (%) 100 50 I1 0 -50 -100 (%) 100 50 I2 0 -50 -100 No.A1482-16/26 LV8731V 2-13) Current control operation specification (Sine wave increasing direction) STEP Set current Set current Coil current Forced CHARGE section fchop Current mode CHARGE SLOW FAST CHARGE SLOW FAST (Sine wave decreasing direction) STEP Set current Coil current Forced CHARGE section Set current fchop Current mode CHARGE SLOW FAST Forced CHARGE section FAST CHARGE SLOW In each current mode, the operation sequence is as described below : • At rise of chopping frequency, the CHARGE mode begins. (In the time defined as the “blanking time,” the CHARGE mode is forced regardless of the magnitude of the coil current (ICOIL) and set current (IREF).) • The coil current (ICOIL) and set current (IREF) are compared in this blanking time. When (ICOIL < IREF) state exists ; The CHARGE mode up to ICOIL ≥ IREF, then followed by changeover to the SLOW DECAY mode, and finally by the FAST DECAY mode for approximately 1μs. When (ICOIL < IREF) state does not exist ; The FAST DECAY mode begins. The coil current is attenuated in the FAST DECAY mode till one cycle of chopping is over. Above operations are repeated. Normally, the SLOW (+FAST) DECAY mode continues in the sine wave increasing direction, then entering the FAST DECAY mode till the current is attenuated to the set level and followed by the SLOW DECAY mode. No.A1482-17/26 LV8731V 3. DCM Mode (DM=High) 3-1) DCM mode output control logic Parallel input Output DC11 (21) DC12 (22) Low High Mode OUT1 (2) A OUT1 (2) B Low OFF OFF Standby Low High Low CW (Forward) Low High Low High CCW (Reverse) High High Low Low Brake 3-2) Blanking time switching function BLK Blanking time Low 2μs High 3μs 3-3) Output enable function OE Operating mode Low Output ON High Output OFF When the OE pin is set High, the output is forced OFF and goes to high impedance. When the OE pin is set Low, output conforms to the control logic. No.A1482-18/26 LV8731V 3-4) Current limit reference voltage setting function By setting a current limit, this IC automatically exercises short braking control to ensure that when the motor current has reached this limit, the current will not exceed it. (Current limit control time chart) Set current Current mode Coil current Forced CHARGE section fchop Current mode CHARGE SLOW The limit current is set as calculated on the basis of the voltage input to the VREF pin and the resistance between the RF pin and GND using the formula given below. Ilimit = (VREF/5) /RF resistance The voltage applied to the VREF pin can be switched to any of the four setting levels depending on the statuses of the two inputs, ATT1 and ATT2. Function for attenuating VREF input voltage ATT1 ATT2 Current setting reference voltage attenuation ratio Low Low 100% High Low 80% Low High 50% High High 20% The formula used to calculate the output current when using the function for attenuating the VREF input voltage is given below. Ilimit = (VREF/5) × (attenuation ratio) /RF resistance Example : At VREF of 1.5V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of 0.3Ω, the output current is set as shown below. Ilimit = 1.5V/5 × 100%/0.3Ω = 1.0A If, in this state, (ATT1, ATT2) has been set to (H, H), Ilimit will be as follows : Ilimit = 1.0A × 20% = 200mA No.A1482-19/26 LV8731V 3-5) Examples of current waveform in each micro-step mode when stepper motor parallel input control Full step (CW mode) DC11 DC12 DC21 DC22 (%) 100 I1 0 -100 (%) 100 I2 0 -100 Half step full torque (CW mode) DC11 DC12 DC21 DC22 (%) 100 l1 0 -100 (%) 100 l2 0 -100 No.A1482-20/26 LV8731V 4. Output short-circuit protection function This IC incorporates an output short-circuit protection circuit that, when the output has been shorted by an event such as shorting to power or shorting to ground, sets the output to the standby mode and turns on the warning output in order to prevent the IC from being damaged. In the stepping motor driver (STM) mode (DM = Low), this function sets the output to the standby mode for both channels by detecting the short-circuiting in one of the channels. In the DC motor driver mode (DM = High), channels 1 and 2 operate independently. (Even if the output of channel 1 has been short-circuited, channel 2 will operate normally.) 4-1) Output short-circuit protection mode switching function Output short-circuit protection mode of IC can be switched by the setting of EMM pin. EMM State Low or Open Latch method High Auto reset method 4-2) Latch type In the latch mode, when the output current exceeds the detection current level, the output is turned OFF, and this state is held. The detection of the output short-circuited state by the IC causes the output short-circuit protection circuit to be activated. When the short-circuited state continues for the period of time set using the internal timer (approximately 2μs), the output in which the short-circuiting has been detected is first set to OFF. After this, the output is set to ON again as soon as the timer latch time (Tcem) described later has been exceeded, and if the short-circuited state is still detected, all the outputs of the channel concerned are switched to the standby mode, and this state is held. This state is released by setting ST to low. Output ON H-bridge output state Output ON Output OFF Standby state Threshold voltage 2μs CEM voltage Short-circuit detection state Short- Release circuit Short-circuit Internal counter 1st counter start 1st counter 1st counter stop start 1st counter end 2nd counter start 2nd counter end No.A1482-21/26 LV8731V 4-3) Auto reset type In the automatic reset mode, when the output current exceeds the detection current level, the output waveform changes to the switching waveform. As with the latch system, when the output short-circuited state is detected, the short-circuit protection circuit is activated. When the operation of the short-circuit detection circuit exceeds the timer latch time (Tcem) described later, the output is changed over to the standby mode and is reset to the ON mode again in 2ms (typ). In this event, if the over current mode still continues, the switching mode described above is repeated until the over current mode is canceled. 4-4) Unusual condition warning output pins (EMO, MONI) The LV8731V is provided with the EMO pin which notifies the CPU of an unusual condition if the protection circuit operates by detecting an unusual condition of the IC. This pin is of the open-drain output type and when an unusual condition is detected, the EMO output is placed in the ON (EMO = Low) state. In the DC motor driver mode (DM = High), the MONI pin also functions as a warning output pin. The functions of the EMO pin and MONI pin change as shown below depending on the state of the DM pin. When the DM is low (STM mode) : EMO : Unusual condition warning output pin MONI : Excitation initial position detection monitoring When the DM is high (DCM) mode) : EMO : Channel 1 warning output pin MONI : Channel 2 warning output pin Furthermore, the EMO (MONI) pin is placed in the ON state when one of the following conditions occurs. 1. Shorting-to-power, shorting-to-ground, or shorting-to-load occurs at the output pin and the output short-circuit protection circuit is activated. 2. The IC junction temperature rises and the thermal protection circuit is activated. Unusual condition DM = L (STM mode) DM = H (DCM mode) EMO MONI EMO MONI Channel 1 short-circuit detected ON - ON - Channel 2 short-circuit detected ON - - ON Overheating condition detected ON - ON ON 4-5) Timer latch time (Tcem) The time taken for the output to be set to OFF when the output has been short-circuited can be set using capacitor Ccem, connected between the CEM pin and GND. The value of capacitor Ccem is determined by the formula given below. Timer latch : Tcem 5. Tcem ≈ Ccem × Vtcem/Icem [sec] Vtcem : Comparator threshold voltage, typ 1V Icem : CEM pin charge current, typ 10μA Thermal shutdown function The thermal shutdown circuit is included, and the output is turned off when junction temperature Tj exceeds 180°C and the abnormal state warning output is turned on at the same time. When the temperature falls hysteresis level, output is driven again (automatic restoration) The thermal shutdown circuit doesn’t guarantee protection of the set and the destruction prevention of IC, because it works at the temperature that is higher than rating (Tjmax=150°C) of the junction temperature TTSD = 180°C (typ) ∆TSD = 40°C (typ) No.A1482-22/26 LV8731V 6. Charge Pump Circuit When the ST pin is set High, the charge pump circuit operates and the VG pin voltage is boosted from the VM voltage to the VM + VREG5 voltage. If the VG pin voltage is not boosted to VM+4V or more, the output pin cannot be turned on. Therefore it is recommended that the drive of motor is started after the time has passed tONG or more. ST VG pin voltage VM+VREG5 VM+4V VM tONG VG Pin Voltage Schematic View No.A1482-23/26 LV8731V Application Circuit Example • Stepper motor driver circuit (DM = Low) 0.1μF 0.1μF 0.1μF 47kΩ Short-circuit state detection monitor 100pF Position detection monitor Clock input Logic input - + 1.5V OUT1A 44 2 VM OUT1A 43 3 CP2 PGND 42 4 CP1 NC 41 5 VREG5 NC 40 6 ATT2 VM1 39 7 ATT1 VM1 38 8 EMO RF1 37 9 CEM RF1 36 10 EMM OUT1B 35 11 CHOP 12 MONI 13 RST/BLK LV8731V 200pF 47kΩ 1 VG 24V + 10μF 0.22Ω OUT1B 34 OUT2A 33 M OUT2A 32 14 STEP/DC22 RF2 31 15 FR/DC21 RF2 30 16 MD2/DC12 VM2 29 17 MD1/DC11 VM2 28 18 DM NC 27 19 OE NC 26 20 ST PGND 25 21 VREF OUT2B 24 22 GND OUT2B 23 0.22Ω The formulae for setting the constants in the examples of the application circuits above are as follows : Constant current (100%) setting When VREF = 1.5V IOUT = VREF/5/RF resistance = 1.5V/5/0.22Ω = 1.36A Chopping frequency setting Fchop = Ichop/ (Cchop × Vtchop × 2) = 10μA/ (200pF × 0.5V × 2) = 50kHz Timer latch time when the output is short-circuited Tcem = Ccem × Vtcem/Icem = 100pF × 1V/10μA = 10μs No.A1482-24/26 LV8731V • DC motor driver circuit (DM = High, and the current limit function is in use.) 0.1μF 0.1μF 0.1μF 47kΩ Channel 1 short-circuit state detection monitor 100pF Channel 2 position detection monitor Logic input - + 1.5V OUT1A 44 2 VM OUT1A 43 3 CP2 PGND 42 4 CP1 NC 41 5 VREG5 NC 40 6 ATT2 VM1 39 7 ATT1 VM1 38 8 EMO RF1 37 9 CEM RF1 36 10 EMM OUT1B 35 11 CHOP 12 MONI 13 RST/BLK LV8731V 200pF 47kΩ 1 VG 24V + - M 10μF 0.22Ω OUT1B 34 OUT2A 33 OUT2A 32 14 STEP/DC22 RF2 31 15 FR/DC21 RF2 30 16 MD2/DC12 VM2 29 17 MD1/DC11 VM2 28 18 DM NC 27 19 OE NC 26 20 ST PGND 25 21 VREF OUT2B 24 22 GND OUT2B 23 0.22Ω M The formulae for setting the constants in the examples of the application circuits above are as follows : Constant current limit (100%) setting When VREF = 1.5V Ilimit = VREF/5/RF resistance = 1.5V/5/0.22Ω = 1.36A Chopping frequency setting Fchop = Ichop/ (Cchop × Vtchop × 2) = 10μA/ (200pF × 0.5V × 2) = 50kHz Timer latch time when the output is short-circuited Tcem = Ccem × Vtcem/Icem = 100pF × 1V/10μA = 10μs No.A1482-25/26 LV8731V ORDERING INFORMATION LV8731V-TLM-H Device Package SSOP44K (275mil) (Pb-Free / Halogen Free) LV8731V-MPB-H SSOP44K (275mil) (Pb-Free / Halogen Free) Shipping (Qty / Packing) 2000 / Tape & Reel 30 / Fan-Fold ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). 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