LV8746V Bi-CMOS LSI PWM Current Control Stepping Motor Driver Application Note http://onsemi.com Overview LV8746V is 2-channel H-bridge driver IC that can switch a stepping motor driver, which is capable of micro-step drive and supports Full-step, Half-step (full torque), Half-step, and Quarter-step resolution, which can select the CLK-IN input and the parallel input. This is best suited for driving of the stepping motor for OA and amusement. Function PWM current control stepping motor driver BiCDMOS process IC On resistance (upper side: 0.84Ω, lower side: 0.7Ω, total of upper and lower: 1.54Ω; Ta=25˚C, IO=1A) Micro step mode can be set to full-step, half-step (full torque), half-step, and quarter-step mode CLK-IN input and parallel input selectable Motor current selectable in four steps Output short-circuit protection circuit incorporated Unusual condition warning output pins Built-in thermal shutdown circuit No control power supply required Typical Applications MFP (Multi Function Printer) PPC (Plain Paper Copier) LBP (Laser Beam Printer) Photo printer Scanner Industrial Cash Machine Amusement Textile Semiconductor Components Industries, LLC, 2013 December, 2013 1/37 LV8746V Application Note Package Dimensions unit : mm (typ) TOP VIEW SIDE VIEW BOTTOM VIEW 15.0 44 23 (3.5) 0.5 5.6 7.6 (4.7) 0.22 0.65 22 0.2 1.7MAX 1 (0.68) 0.1 (1.5) SIDE VIEW SANYO : SSOP44K(275mil) Caution: The package dimension is a reference value, which is not a guaranteed value. Recommended Soldering Footprint (Unit:mm) Reference symbol SSOP44K(275mil) eE 7.00 e 0.65 b3 0.32 l1 1.00 X (4.7) Y (3.5) 2/37 LV8746V Application Note Pin Assignment VG 1 44 NC VM 2 43 OUT1A CP2 3 42 PGND1 CP1 4 41 NC VREG5 5 40 NC ATT2 6 39 NC ATT1 7 38 VM1 EMO 8 37 NC CEM 9 36 RF1 NC 10 RCHOP 11 NC 12 35 NC LV8746V RST/PH1 13 34 OUT1B 33 OUT2A 32 NC STP/I01 14 31 RF2 FR/I11 15 30 NC MD2/PH2 16 29 VM2 MD1/I02 17 28 NC DM 18 27 NC OE/I12 19 26 NC ST 20 25 PGND2 VREF 21 24 OUT2B GND 22 23 NC Top view 3/37 LV8746V Application Note Block Diagram CP2 CP1 VG OUT1A RF1 OUT1B VM1 VM2 OUT2A OUT2B RF2 VREG5 Output preamplifier stage Output preamplifier stage Output preamplifier stage Charge pump PGND Output preamplifier stage VM EMO Output control logic Regulator CEM VREF Attenuator (4 levels selectable) Current selection (full/half-full/ half/quarter) Current selection (full/half-full/ half/quarter) Oscillation circuit TSD LVS RCHOP ST ATT1 ATT2 FR/ STP/ RST/ I11 I01 PH1 OE/ I12 MD1/ I02 MD2/ PH2 DM CPU Mi-com GND 4/37 LV8746V Application Note Specifications Absolute Maximum Ratings at Ta = 25C Parameter Symbol Conditions Ratings Unit Supply voltage VM max Output peak current IO peak Output current IO max Logic input voltage VIN -0.3 to +6 V EMO input voltage Vemo -0.3 to +6 V Allowable power dissipation Pd max 3.1 W Operating temperature Topr -20 to +85 C Storage temperature Tstg -55 to +150 C tw 10ms, duty 20% Ta 85C * 38 V 1.2 A 1 A 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. Recommended Operating Conditions at Ta 25C Parameter Symbol Conditions Ratings min typ Unit max Supply voltage range VM 9 35 V Logic input voltage VIN 0 5.5 V VREF input voltage range VREF 0 3 V Electrical Characteristics at Ta = 25°C, VM = 24V, VREF = 1.5V Parameter Symbol Conditions Standby mode current drain IMst ST = “L” Current drain IM ST = “H”, OE = “L”, with no load VREG5 output voltage Vreg5 IO = -1mA Thermal shutdown temperature TSD Design guarantee Thermal hysteresis width TSD Design guarantee Ratings min typ Unit max 190 300 A 3.3 5 mA 4.5 5 5.5 V 150 180 210 C C 40 Motor driver Output on resistance Ronu IO = 1A, Upper-side on resistance 0.84 1.1 Rond IO = 1A, Lower-side on resistance 0.7 0.9 Ω 50 A 1.3 V Output leakage current IOleak Diode forward voltage VD Logic pin input current(ST) IINL VIN = 0.8V IINH VIN = 5V Logic pin input current(other ST) IINL VIN = 0.8V IINH VIN = 5V Logic high-level input voltage VINH Logic low-level input voltage VINL Quarter-step Vtdac0_W drive Current setting comparator threshold Half-step drive ID = -1A 1.0 3 8 15 A 50 78 110 A 3 8 15 A 30 50 70 A 0.8 V 2.0 Step 0 (When initialized : channel 1 Ω V 0.29 0.3 0.31 V comparator level) Vtdac1_W Step 1 (Initial state+1) 0.29 0.3 0.31 V Vtdac2_W Step 2 (Initial state+2) 0.185 0.2 0.215 V Vtdac3_W Step 3 (Initial state+3) 0.09 0.1 0.11 V Vtdac0_M Step 0 (When initialized : channel 1 0.29 0.3 0.31 V Vtdac2_M Step 2 (Initial state+1) 0.185 0.2 0.215 V Vtdac0_H Step 0 (When initialized : channel 1 0.29 0.3 0.31 V Vtdac2_H Step 2 (Initial state+1) 0.29 0.3 0.31 V Vtdac2_F Step 2 0.29 0.3 0.31 V comparator level) voltage (CLK-IN input) Half-step (full torque) drive Full-step drive comparator level) Continued on next page. 5/37 LV8746V Application Note Continued from preceding page. Parameter Symbol Conditions Ratings min typ Unit max Current setting comparator Vtdac11 I01 = H , I11 = H 0.29 0.3 0.31 threshold voltage Vtdac01 I01 = L , I11 = H 0.185 0.2 0.215 V Vtdac10 I01 = H , I11 = L 0.09 0.1 0.11 V V (parallel input) V Current setting comparator Vtatt00 ATT1 = L, ATT2 = L 0.29 0.3 0.31 threshold voltage Vtatt01 ATT1 = H, ATT2 = L 0.185 0.2 0.215 V Vtatt10 ATT1 = L, ATT2 = H 0.135 0.15 0.165 V 0.09 0.1 0.11 45 62.5 75 (current attenuation rate switching) Vtatt11 ATT1 = H, ATT2 = H Chopping frequency Fchop Rchop = 20KΩ VREF pin input current Iref VREF = 1.5V V kHz A -0.5 Charge pump VG output voltage VG Rise time tONG VG = 0.1F 28 Oscillator frequency Fosc Rchop = 20KΩ EMO pin saturation voltage Vsatemo Iemo = 1mA CEM pin charge current Icem Vcem = 0V CEM pin threshold voltage Vthcem 28.75 30 V 0.5 mS 90 125 150 kHz 80 160 mV 7 10 13 A 0.8 1.0 1.2 V Output short-circuit protection 6/37 LV8746V Application Note 7/37 LV8746V Application Note 8/37 LV8746V Application Note Pin Functions Pin No. Pin Name Pin Function 6 ATT2 Motor holding current switching pin. 7 ATT1 Motor holding current switching pin. 13 RST/PH1 CLK-IN is input , RESET input pin / Equivalent Circuit Parallel is input , Channel 1 VREG5 forward/reverse rotation pin. 14 STP/I01 CLK-IN is input , STEP signal input pin / Parallel is input , Channel 1 output control input pin. 15 FR/I11 CLK-IN is input , forward/reverse signal input pin / Parallel is input , Channel 1 output control input pin. 16 MD2/PH2 CLK-IN is input , Excitation mode switching pin / Parallel is input , Channel 2 forward/reverse rotation pin. 17 MD1/I02 CLK-IN is input , Excitation mode switching pin / Parallel is input , Channel 2 output control input pin. 18 DM Drive mode switching pin. 19 OE/I12 CLK-IN is input , output enable signal GND input pin / Parallel is input , Channel 2 output control input pin. 20 ST Chip enable pin. VREG5 GND 24 OUT2B Channel 2 OUTB output pin. 25 PGND2 Power system ground pin2. 42 PGND1 Power system ground pin1. 29 VM2 Channel 2 motor power supply 31 RF2 33 OUT2A Channel 2 OUTA output pin. 34 OUT1B Channel 1 OUTB output pin. 36 RF1 Channel 1 current-sense resistor 38 VM1 Channel 1 motor power supply pin. 43 OUT1A Channel 1 OUTA output pin. 38 29 connection pin. Channel 2 current-sense resistor connection pin. 43 33 34 24 connection pin. 25 42 36 31 GND Continued on next page. 9/37 LV8746V Application Note 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 4 2 3 1 VREG5 100Ω GND 21 VREF Constant current control reference voltage input pin. VREG5 GND 5 VREG5 Internal power supply capacitor connection pin. VM GND 8 EMO Output short-circuit state warning output pin. VREG5 GND Continued on next page. 10/37 LV8746V Application Note 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 RCHOP Chopping frequency setting resistor connection pin. VREG5 GND 22 10,12 23,26 GND NC Ground. No Connection (No internal connection to the IC) 27,28 30,32 35,37 39,40 41,44 11/37 LV8746V Application Note Description of operation Input Pin Function The function to prevent including the turn from the input to the power supply is built into each input pin. Therefore, the current turns to the power supply even if power supply (VM) is turned off with the voltage impressed to the input pin and there is not crowding. (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 Charge pump Low or Open Standby mode Standby Standby High Operating mode Operating Operating (2) Input control method switching pin function The IC input control method is switched by setting the DM pin. The CLK-IN input control and the parallel input control can be selected by setting the DM pin. DM Input control method Low or Open CLK-IN input control High Parallel input control (3) 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. If VREF is open or the setting is out of the recommendation operating range, VREF is set around 5V. As a result, output current will increase and you cannot set constant current under normal condition. Hence, make sure that VREF is set in accordance with the specification. However, if current control is not performed (if the IC is used without saturation drive or current limit) make sure that the setting is as follows: VREF=5V or VREF=VREG5 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 66.7% Low High 50% High High 33.3% 12/37 LV8746V Application Note 50ms/div ATT1 5V/div VM=24V VREF=1V RF=0.47Ω ATT2 5V/div Motor Current Iout1 0.2A/div Iout2 0.2A/div 50% 100% 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 1.41V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of 0.47Ω, the output current is set as shown below. IOUT = 1.41V/5 × 100%/0.47Ω = 0.6A If, in this state, (ATT1, ATT2) is set to (H, H), IOUT will be as follows: IOUT = 0.6A × 33.3% = 0.2A In this way, the output current is attenuated when the motor holding current is supplied so that power can be conserved. (4) Setting the chopping frequency For constant-current control, chopping operation is made with the frequency determined by the external resistor (connected to the RCHOP pin). The chopping frequency to be set with the resistance connected to the RCHOP pin (pin 11) is as shown below. Chopping frequency settings (reference data) 100 Fchop – kHz 80 60 40 20 0 0 10 20 30 RCHOP – kΩ 40 50 60 PCA01883 (5) 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 this IC, the blanking time is fixed at 1/16 of one chopping cycle. 13/37 LV8746V Application Note (6) Current control operation specification (Sine wave increasing direction) (Sine wave decreasing direction) In each current mode, the operation sequence is as described below: At rise of chopping frequency, the CHARGE mode begins. (The section in which the CHARGE mode is forced regardless of the magnitude of the coil current (ICOIL) and set current (IREF) exists for 1/16 of one chopping cycle.) The coil current (ICOIL) and set current (IREF) are compared in this forced CHARGE section. When (ICOIL<IREF) state exists in the forced CHARGE section; CHARGE mode up to ICOIL IREF, then followed by changeover to the SLOW DECAY mode, and finally by the FAST DECAY mode for the 1/16 portion of one chopping cycle. When (ICOIL<IREF) state does not exist in the forced CHARGE section; 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. 14/37 LV8746V Application Note (7) Output Transistor Operation Mode Charge increases current. Switch from Charge to Slow Decay Current regeneration by Slow Decay 4. 5. FAST 6. VM VM VM OFF OFF U1 OFF U2 ON ON L2 RF U2 OUTB OUTA OFF L1 L2 OFF OFF L1 RF Switch from Slow Decay to Fast Decay OFF U1 OUTB OUTA OFF L1 OFF U2 U1 OUTB OUTA ON L2 RF Switch from Fast Decay to Charge Current regeneration by Fast Decay This IC controls constant current by performing chopping to output transistor. As shown above, by repeating the process from 1 to 6, setting current is maintained. Chopping consists of 3 modes: Charge/ Slow decay/ Fast decay. In this IC, for switching mode (No.2, 4, 6), there are between the transistors. This off period is set to be constant (≈ 0.5µs) which is controlled by the internal logic. The diagrams show parasitic diode generated due to structure of MOS transistor. When the transistor is off, output current is regenerated through this parasitic diode. Output Transistor Operation Function OUTA→OUTB (CHARGE) Output Tr U1 U2 L1 L2 OUTB→OUTA (CHARGE) Output Tr U1 U2 L1 L2 CHARGE ON OFF OFF ON SLOW OFF OFF ON ON FAST OFF ON ON OFF CHARGE OFF ON ON OFF SLOW OFF OFF ON ON FAST ON OFF OFF ON 15/37 LV8746V Application Note 10ms/div STEP 5V/div VM=24V VREF=1V RF=0.47Ω RCHOP=20kΩ Motor Current 0.2A/div 20µs/div 20µs/div STEP 5V/div Set Current STEP 5V/div Set Current Motor Current 0.2A/div Motor Current 0.5A/div OUTA 20V/div OUTA 20V/div OUTB 20V/div OUTB 20V/div Sine wave increasing direction Sine wave decreasing direction Current mode 5µs/div Motor Current 200mA/div OUTA 20V/div FAST CHARGE OUTB 20V/div SLOW When the motor current reaches to the setting current, it is switched to Slow Decay mode. Motor current switches from Slow Decay mode to Fast Decay mode for 1/16 of one chopping cycle. 16/37 LV8746V Application Note CLK-IN input control (DM = Low or Open) (1) STP pin function The excitation step progresses by inputting the step signal to the STP pin. Input Operating mode ST STP Low * Standby mode High Excitation step proceeds High Excitation step is kept STP input MIN pulse width (common in H/L): 500ns (MAX input frequency: 1MHz) However, constant current control is performed by PWM during chopping period, which is set by the resistor connected between RCHOP and GND. You need to perform chopping more than once per step. For this reason, for the actual STP frequency, you need to take chopping frequency and chopping count into consideration. For example, if chopping frequency is 62.5kHz (16µs) and chopping is performed twice per step, the maximum STP frequency is obtained as follows: f=1/(16µs×2) = 31kHz. (2) Input timing TstepH/TstepL : Clock H/L pulse width (min 500ns) Tds : Data set-up time (min 500ns) Tdh : Data hold time (min 500ns) (3) Reset function RST Operating mode Low Normal operation High Reset state When the RST pin is set to High, the excitation position of the output is forcibly set to the initial state. When RST is then set to Low, the excitation position is advanced by the next STP input. 17/37 LV8746V Application Note (4) Output enable function OE Operating mode High Output OFF Low Output ON 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 to the STP pin. Therefore, when OE is returned to Low, the output level conforms to the excitation position proceeded by the STEP input. (5) Forward/reverse switching function FR Operating mode Low Clockwise (CW) High Counter-clockwise (CCW) 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. 18/37 LV8746V Application Note (6) Output current vector locus (one step is normalized to 90 degrees) 100 θ2'(Full-step / Half-step full torque) θ1 θ0 Channel 1 phase current ratio (%) 80 θ2 60 40 θ3 20 θ4 0 0 20 40 60 Channel 2 phase current ratio (%) 80 100 Setting current ration in each excitation mode STEP Quarter Step (%) Channel 1 Half Step (%) Channel 2 Channel 1 0 100 0 1 100 33.3 2 66.7 66.7 3 33.3 100 4 0 100 Half Step (full torque) (%) Channel 2 Channel 1 Full Step (%) Channel 2 Channel 1 100 0 100 0 66.7 66.7 100 100 0 100 0 100 100 Channel 2 100 19/37 LV8746V Application Note (7) Excitation mode setting function The excitation mode of the stepping motor can be set as follows by setting the MD1 pin and the MD2 pin. MD1 MD2 Microstep Resolution Excitation mode Initial position Channel 1 Channel 2 Low Low Full Step 2 phase 100% -100% High Low Half Step (full torque) 1-2 phase (full torque) 100% 0% Low High Half Step 1-2 phase 100% 0% High High Quarter Step W1-2 phase 100% 0% This is the initial position of each excitation mode in the initial state after power-on and when the counter is reset. (8) Excitation mode switching operation When excitation mode is switched while the motor is rotating, each drive mode operates with the following sequence. Clockwise mode Before the Microstep Resolution changes Microstep Resolution Quarter Step Position Position after the Microstep Resolution is changed Quarter Step Half Step (full torque) Full Step θ0 θ2 θ2' θ2' θ1 θ2 θ2' θ2' θ2 θ4 θ4 θ2' θ3 θ2 θ2' θ2' -θ2 -θ2' -θ2' θ2' θ2' θ4 θ0 Half Step Half Step θ1 θ2 θ3 θ2' θ2' θ4 -θ3 -θ2' -θ2' θ0 θ1 θ2' θ2' Half Step (full torque) θ2' θ3 θ4 θ2' θ4 -θ3 -θ2 Full Step θ2' θ3 θ4 -θ2' θ4 *As for 0 to 4, please refer to the step position of current ratio setting. If you switch microstep mode while the motor is driving, the mode setting will be reflected from the next STEP and the motor advances to the closest excitation position at switching operation. 20/37 LV8746V Application Note (9) Typical current waveform in each excitation mode Full Step (CW mode) STP （％） I1 100 0 （％）－100 100 I2 0 －100 Half Step (full torque (CW mode)) STP (%) 100 I1 0 －100 (%) 100 I2 0 －100 21/37 LV8746V Application Note Half steprg (CW mode) STP (%) 100 I1 0 －100 (%) 100 I2 0 －100 Quarter Step (CW mode) STP (%) 100 I1 0 －100 (%) 100 I2 0 －100 22/37 LV8746V Application Note Parallel input Mode (DM-High) (1) Parallel input control logic I01(02) I11(12) Output current (IO) Low Low 0 High Low IO = ((VREF/5)/RF)×1/3 Low High IO = ((VREF/5)/RF)×2/3 High High IO = (VREF/5)/RF PH1(2) current direction Low OUTB → OUTA High OUTA → OUTB 23/37 LV8746V Application Note (2) Typical current waveform in each excitation mode when stepping motor parallel input control Full Step (CW mode) I01,I11 H PH1 I02,I12 H PH2 （％） 100 I1 0 （％）－100 100 I2 0 －100 Half Step (full torque (CW mode)) I01 I11 PH1 I02 I12 PH2 (%) 100 I1 0 －100 (%) 100 I2 0 －100 24/37 LV8746V Application Note Half Step (CW mode) I01 I11 PH1 I02 I12 PH2 (%) 100 I1 0 －100 (%) 100 I2 0 －100 Quarter Step (CW mode) I01 I11 PH1 I02 I12 PH2 (%) 100 I1 0 －100 (%) 100 I2 0 －100 25/37 LV8746V Application Note Output short-circuit protection function This output short protection circuit that makes the output a standby mode to prevent the thing that IC destroys when the output is short-circuited by a voltage short and the earth fault, etc. , and turns on the warning output to IC is built into. 1.High current flows if Tr1 and Tr4 are ON. 2.If RF voltage> setting voltage, then the mode switches to SLOW decay. 3.If the voltage between D and S of Tr4 exceeds the reference voltage for 4μs, short status is detected. VM short (left schematic) 1.High current flows if Tr1 and Tr4 are ON 2. If the voltage between D and S of Tr1 exceeds the reference voltage for 2μs, short status is detected. VM short VM Short-circuit Detection Short-circuit Detection Tr1 Tr3 ON OUTA M OFF OUTB Tr2 OFF VM Tr1 ON OUTA Tr4 Tr2 ON OFF Tr3 M OFF OUTB Tr4 ON RF RF Load short VM Tr1 ON OUTA Short-circuit Detection Tr3 M Tr2 OFF RF OFF OUTB VM Tr1 ON OUTA Tr4 Tr2 ON OFF Tr3 M OFF OUTB Tr4 ON RF (right schematic) 1.Without going through RF resistor, current control does not operate and current will continue to increase in CHARGE mode. 2. If the voltage between D and S of Tr1 exceeds the reference voltage for 4μs, short status is detected. 1.Without L load, high current flows. 2. If RF voltage> setting voltage, then the mode switches to SLOW decay. 3.During load short status in SLOW decay mode, current does not flow and overcurrent state is not detected. Then the mode is switched to FAST decay according to chopping cycle. 4. Since FAST state is short (≈1μs), switches to CHARGE mode before short is detected. 5.If voltage between D and S exceeds the reference voltage continuously during blanking time at the start of CHARGE mode (Tr1), CHARGE state is fixed (even if RF voltage exceeds the setting voltage, the mode is not switched to SLOW decay). After 4us or so, short is detected. 26/37 LV8746V Application Note (6) Detect current (1) Protection function operation (Latch type) In the latch mode, the output is turned off when the output current exceeds the detection current, and the state is maintained. The output short protection circuit starts operating so that IC may detect a short output. When short-circuit is the consecutive between internal timers (≈4s), the output where short-circuit is first detected is turned off. Even if the following time (Tcem) of the timer latch is exceeded, the output is turned ON again, and afterwards, when short-circuit is detected, all the outputs of correspondence ch side are still switched to the standby mode, and the state is maintained. This state is released by making it to ST ="L". Output ON H-bridge output status Output ON Output OFF Standby state Threshold voltage 4µs CEM Voltage Short-circuit Detection state ShortRelease circuit Short-circuit Internal counter 1st counter 1st counter 1st counter start stop start 1st counter end 2nd counter start 2nd counter end 27/37 LV8746V Application Note (2) Abnormal state warning output pin When IC operates the protection circuit detecting abnormality, the EMO pin has been installed as a terminal that outputs this abnormality to CPU side. This pin is an open drain output, and if abnormality is detected, the EMO output becomes (EMO="L") of ON. EMO pin enters on a state in the following. When a voltage short, the earth fault or the load is short-circuited and the output short-circuit protection circuit operates, the output pin When the junction temperature of IC rises, and the overheating protection circuit operates Unusual condition EMO Channel 1 Output Channel 2 Output Channel 1 short-circuit detected ON OFF - Channel 2 short-circuit detected ON - OFF Overheating condition detected ON OFF OFF (3) Timer latch time (Tcem) The time to output OFF when an output short-circuit occurs can be set by the capacitor connected between the CEM pin and GND. The capacitor (Ccem) value can be determined as follows : Tcem C × V/I [sec] V : Threshold voltage of comparator TYP 1V I : CEM charge current TYP 10µA Timer latch: Tcem Latch type 5µs/div OUT 10V/div OUT-GND short st 1 counter 4µs 1V nd 2 counter CEM charge CEM 0.5V/div EMO 5V/div Thermal shutdown function The thermal shutdown circuit is incorporated and the output is turned off when junction temperature Tj exceeds 180C and the abnormal state warning output is turned on. As the temperature falls by hysteresis, the output turned on again (automatic restoration). The thermal shutdown circuit does not guarantee the protection of the final product because it operates when the temperature exceed the junction temperature of Tjmax=150C. TSD = 180C (typ) TSD = 40C (typ) 28/37 LV8746V Application Note 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. I will recommend the drive of the motor to put the time of tONG or more after the ST pin is made "H", and to begin because I cannot control the output if there is no pressure voltage of the voltage of the VG pin enough. ST VG pin voltage VM+VREG5 VM+4V VM tONG VG Pin Voltage Schematic View tONG Startup time with different VG capacitor 50µs/div ST 5V/div VM+4V 500µs/div VG 5V/div Vout 10V/div tONG VM=24V CP1-CP2=0.1µF VG=0.1µF 0.1µF/220µs 0.22µF/500µs 1µF/2.4ms VM=24V CP1-CP2=0.1µF VG=0.1µF/0.22µF/1µF 29/37 LV8746V Application Note Application Circuit Example Clock input control mode application circuit (DM=Low) The setting conditions for the above circuit diagram example are as follows : Full-step drive (MD1/I02 = Low, MD2/PH2 = Low) Reset function fixed to normal operation (RST = Low) Chopping frequency : 62.5kHz (RCHOP = 20kΩ) ATT1 ATT2 Current setting reference voltage Low Low VREF/5×100% High Low VREF/5×67% Low High VREF/5×50% High High VREF/5×33% The set current value is as follows : IOUT = (VREF/5 Voltage setting ratio) / RF Example: When ATT=Low, ATT2=Low (VREF = 1.5V, RF=0.47Ω) IOUT = (1.5V / 5 1 ) / 0.47Ω = 0.64A 30/37 LV8746V Application Note Parallel input control mode application circuit (DM = High) 1 VG NC 44 2 VM OUT1A 43 3 CP2 PGND1 42 4 CP1 NC 41 5 VREG5 NC 40 6 ATT2 NC 39 7 ATT1 VM1 38 8 EMO NC 37 9 CEM RF1 36 0.1µF 0.1µF 10µF 0.1µF Logic input 47kΩ 0.47Ω 100pF 10 NC 11 RCHOP 20kΩ 12 NC LV8746V 13 RST/PH1 1ch control Logic input M OUT1B 34 OUT2A 33 NC 32 14 STP/I01 RF2 31 0.47Ω 15 FR/I11 NC 30 16 MD2/PH2 2ch control Logic input 1.5V NC 35 Logic input VM2 29 17 MD1/I02 NC 28 18 DM NC 27 19 OE/I12 NC 26 20 ST PGND2 25 21 VREF OUT2B 24 22 GND NC 23 The setting conditions for the above circuit diagram example are as follows : Chopping frequency : 62.5kHz (RCHOP = 20kΩ) I01(02) I11(12) Output current (IO) Low Low 0 High Low IO = ((VREF/5) / RF) × 1/3 Low High IO = ((VREF/5) / RF) × 2/3 High High IO = (VREF/5) / RF Example: When ATT=Low, ATT2=Low, I01(02)=High, I11(12)=High (VREF = 1.5V, RF=0.47Ω) IOUT = (1.5V / 5 1 ) / 0.47Ω = 0.64A PH1(2) Low High Electrical current direction OUTB → OUTA OUTA → OUTB 31/37 LV8746V Application Note Allowable power dissipation Substrate Specifications (Substrate recommended for operation of LV8746V) Size : 90mm × 90mm × 1.6mm 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. 32/37 LV8746V Application Note Evaluation board LV8746V (90.0mm90.0mm1.6mm, glass epoxy 2-layer board, with backside mounting) Bill of Materials for LV8746V Evaluation Board Designator Quantity C1 1 C2 1 C3 1 C4 1 C5 1 C6 1 R1 1 R2 1 R3 1 R4 1 IC1 SW1-SW10 TP1-TP23 1 10 23 Description Capacitor for Charge pump Capacitor for Charge pump 5VREG stabilization Capacitor Capacitor to set CEM timer VREF stabilization Capacitor VM Bypass Capasitor Pull-up Resistor for for terminal EMO Resistor to set chopping frequency Channel 1 output current detective Resistor Channel 2 output current detective Resistor Motor Driver Switch Test Point Value Tolerance 0.1µF, 100V Substitution Allowed Lead Free Manufacturer Manufacturer Part Number ±10% Murata GRM188R72A104KA35* Yes Yes 0.1µF, 100V ±10% Murata GRM188R72A104KA35* Yes Yes 0.1µF, 100V ±10% Murata GRM188R72A104KA35* Yes Yes 100pF, 50V ±5% Murata GRM1882C1H101JA01* Yes Yes ±10% GRM188R72A104KA35* Yes Yes ±20% Murata SUN Electronic Industries 50ME10HC Yes Yes 47kΩ, 1/10W ±5% KOA RK73B1JT**473J Yes Yes 20kΩ, 1/10W ±5% KOA RK73B1JT**203J Yes Yes 0.47Ω, 1W ±5% ROHM MCR100JZHJLR47 Yes Yes 0.47Ω, 1W ±5% ROHM SANYO ON Semiconductor semiconductors MIYAMA MAC8 MCR100JZHJLR47 Yes Yes LV8746V MS-621C-A01 ST-1-3 No Yes Yes Yes Yes Yes 0.1µF, 100V 10µF, 50V Footprint SSOP44K (275mil) 33/37 LV8746V Application Note Evaluation board circuit *VM Power supply input terminal 0.1µF 1 VG NC 44 2 VM OUT1A 43 3 CP2 PGND 42 4 CP1 NC 41 5 VREG5 NC 40 (3) 6 ATT2 NC 39 <4> 7 ATT1 VM1 38 C1 0.1µF C2 0.1µF C3 *VDD Power supply input terminal for Switch SW1 R1 47kΩ SW2 100pF 10µF Motor connection terminal C6 8 EMO NC 37 9 CEM RF1 36 C4 10 NC 0.47Ω R3 NC 35 20kΩ 11 RCHOP R2 12 NC <3> SW3 <1> (1) SW4 <2> SW5 SW6 SW7 SW8 *VREF Constant Current Control for Reference Voltage SW9 SW10 0.1µF LV8746V OUT1B 34 OUT2A 33 13 RST/PH1 NC 32 14 STP/I01 RF2 31 15 FR/I11 NC 30 16 MD2/PH2 VM2 29 17 MD1/I02 MC 28 18 DM NC 27 19 OE/I12 NC 26 20 ST 21 VREF 0.47Ω R4 (4) PGND 25 OUT2B 24 C5 22 GND NC 23 [Clock input control] VM=24V,VDD=3.3V,VREF=1.5V ST=H,DM=L EMM=L,RST/PH1=L,OE/I12=L ATT1=ATT2=L, FR/I11=L MD1/I02=MD2/PH2=H STP/I01=500Hz(Duty50%) 5ms/div (1) [Parallel input control(OUT1A-OUT1B)] VM=24V,VDD=3.3V,VREF=1.5V ST=H,DM=H EMM=L,ATT1=ATT2=L, STEP 5V/div 5ms/div <1> I01 5V/div <2> I11 5V/div <3> (3) Iout1 0.2A/div (4) PH1 5V/div Iout1 1A/div <4> Iout2 0.2A/div 34/37 LV8746V Application Note Evaluation Board Manual [Supply Voltage] VM (9 to 35V): Power Supply for LSI VREF (0 to 3V): Const. Current Control for Reference Voltage VDD (2 to 5V): Logic “High” voltage for toggle switch [Toggle Switch State] Upper Side: High (VDD) Middle: Open, enable to external logic input Lower Side: Low (GND) [Operation Guide] For clock input control 1. Initial Condition Setting: Set “Open” the toggle switch STP/I01, and “Open or Low” the other switches 2. Motor Connection: Connect the Motors between OUT1A and OUT1B, between OUT2A and OUT2B. 3. Power Supply: Supply DC voltage to VM, VREF and VDD. 4. Ready for Operation from Standby State: Turn “High” the ST terminal toggle switch. Channel 1 and 2 are into full-step initial position (100%, -100%). 5. Motor Operation: Input the clock signal into the terminal STP/I01. 6. Other Setting i. ATT1, ATT2: Motor current attenuation. ii. EMM: Short circuit protection mode change. iii. RST/PH1: Initial Mode. iv. FR/I11: Motor rotation direction (CW / CCW) setting. v. MD1/I02, MD2/PH2: Excitation mode. vi. OE/I12: Output Enable. For parallel input control 1. Initial Condition Setting: Set “Open” the toggle switch DM, and “Open or Low” the other switches 2. Motor Connection: Connect the Motors between OUT1A and OUT1B, between OUT2A and OUT2B. 3. Power Supply: Supply DC voltage to VM, VREF and VDD. 4. Ready for Operation from Standby State: Turn “High” the ST and DM terminal toggle switch. 5. Motor Operation: Set STP/I01, MD1/I02, RST/PH1, MD1/I02, OE/I12 and MD2/PH2 terminals according to the purpose 6. Other Setting i. ATT1, ATT2: Motor current attenuation. [Setting for External Component Value] 1. Constant Current (100%) At VREF=1.5V Iout =VREF [V] / 5 / RF [Ω] =1.5 [V] / 5 / 0.47 [Ω] =0.64 [A] 2. Chopping frequency setting. 62.5kHz (RCHOP=20kΩ) 3. Short Protection Latch Time Tscp =CEM [pF] x Vt[V] / Ichg [µA] =100 [pF] x 1 [V] / 10 [µA] =10 [µS] 35/37 LV8746V Application Note Warning: ●Power supply connection terminal [VM, VM1, VM2] Make sure to short-circuit VM, VM1 and VM2.For controller supply voltage, the internal regulator voltage of VREG5 (typ 5V) is used. Make sure that supply voltage does not exceed the absolute MAX ratings under no circumstance. Noncompliance can be the cause of IC destruction and degradation. Caution is required for supply voltage because this IC performs switching. The bypass capacitor of the power supply should be close to the IC as much as possible to stabilize voltage. Also if you intend to use high current or back EMF is high, please augment enough capacitance. ●GND terminal [GND, PGND1, PGND2, Exposed Die-Pad] Since GND is the reference of the IC internal operation, make sure to connect to stable and the lowest possible potential. Since high current flows into PGND, connect it to one-point GND. The exposed die-pad is connected to the board frame of the IC. Therefore, do not connect it other than GND. Independent layout is preferable. If such layout is not feasible, please connect it to signal GND. Or if the area of GND and PGND is larger, you may connect the exposed die pad to the GND. (The independent connection of exposed die pad to PGND is not recommended.) ●Internal power supply regulator terminal [VREG5] VREG5 is the power supply for logic (typ 5V). When VM supply is powered and ST is ”H”, VREG5 operates. Please connect capacitor for stabilize VREG5. The recommendation value is 0.1uF. Since the voltage of VREG5 fluctuates, do not use it as reference voltage that requires accuracy. ●Input terminal The logic input pin incorporates pull-down resistor (100kΩ). When you set input pin to low voltage, please short it to GND because the input pin is vulnerable to noise. The input is TTL level (H: 2V or higher, L: 0.8V or lower). VREF pin is high impedance. ●OUT terminal [OUT1A, OUT1B, OUT2A, OUT2B] During chopping operation, the output voltage becomes equivalent to VM voltage, which can be the cause of noise. Caution is required for the pattern layout of output pin. The layout should be low impedance because driving current of motor flows into the output pin. Output voltage may boost due to back EMF. Make sure that the voltage does not exceed the absolute MAX ratings under no circumstance. Noncompliance can be the cause of IC destruction and degradation. ●Current sense resistor connection terminal [RF1, RF2] To perform constant current control, please connect resistor to RF pin. To perform saturation drive (without constant current control), please connect RF pin to GND. If RF pin is open, then short protector circuit operates. Therefore, please connect it to resistor or GND. The motor current flows into RF – GND line. Therefore, please connect it to common GND line and low impedance line. ●NC terminal NC pin is not connected to the IC. If VM line and output line are wide enough in your layout, please use NC 36/37 LV8746V Application Note ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf. SCILLC reserves the right to make changes without further notice to any products herein. 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