LV8762T Bi-CMOS LSI Forward/Reverse H-bridge Driver Application Note http://onsemi.com Overview The LV8762T is a 1-channel H-bridge motor driver that can control four operation modes (forward, reverse, brake, and standby) of a motor. The IC is optimal for use in driving brushed DC motors for office equipment. Function Forward/reverse H-bridge motor driver: 1 channel Built-in current limiter Built-in thermal protection circuit Single power supply Built-in short-circuit protection function (selectable from latch-type or auto reset-type). IOmax = 1A Current limit mask function Alert signal output Typical Applications Multi Function Printer Plain Paper Copier Laser Beam Printer Photo Printer Page Scanner Industrial Cash Dispenser Entertainment Pin Assignment Package Dimensions unit: mm(typ) EMM 1 24 EMO PGND 2 23 CMK OUTB 3 22 SCP OUTB 4 21 CHOP RNF 5 20 VREF 6.5 0.5 18 IN1 OUTA 10 15 CP2 NC 11 14 VG ST 12 13 GND Semiconductor Components Industries, LLC, 2013 December, 2013 12 1 0.5 0.15 0.22 (0.5) 1.2max 16 CP1 (1.0) OUTA 9 TSSOP24 (225mil) 6.4 4.4 19 IN2 17 REG5 VM 8 13 0.08 VM 7 LV8762T RNF 6 24 SANYO : TSSOP24(225mil) Top view 1/16 LV8762T Application Note Recommended Soldering Footprint Reference TSSOP24(225mil) Symbol eE 5.80 e 0.50 b3 0.32 l1 1.00 Specifications Absolute Maximum Ratings at Ta = 25C Parameter Symbol Supply voltage VM max Output peak current IO peak Conditions tw 10ms, duty 20% Ratings Unit 36 V 1.5 A Output continuous current IO max 1.0 A Logic input voltage VIN max -0.3 to +6 V EMO pin input voltage VEMO -0.3 to +6 V Allowable power dissipation Pd max 1.4 W Operating temperature Topr -20 to +85 C Storage temperature Tstg -55 to +150 C Mounted on a specified board. * * Specified circuit board : 57mm57mm1.6mm, glass epoxy both-type board. 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. 2/16 LV8762T Application Note Recommended Operating Conditions at Ta 25C Ratings Parameter Symbol Conditions Unit min Supply voltage range typ max VM 9 32 V VREF input voltage VREF 0 3 V Logic input voltage VIN 0 5.5 V Electrical Characteristics at Ta = 25°C, VM = 24V, VREF = 1.5V Ratings Parameter Symbol Conditions Unit min typ max General Standby mode current drain Operating mode current drain IMst 100 A mA 3 5 4.5 5 5.5 V TSD Design guarantee * 150 180 200 C TSD Design guarantee * Output on resistance RonU IO = 1A, upper side ON resistance 0.75 0.97 RonD IO = -1A, under side ON resistance 0.5 0.65 Output leakage current IOleak VO = 32V 50 A Diode forward voltage VD 1.4 V Thermal shutdown temperature Thermal hysteresis width VREG ST = “H”, IN1 = “H”, IN2 = “L”, with no load 400 IO = -1mA REG5 output voltage IM ST = “L” C 40 Output block ID = -1A 1.2 Rising time tr 10% to 90% 100 200 ns Falling time tf 90% to 10% 100 200 ns Input output delay time tpLH IN1 to OUTA, IN2 to OUTB (L H) 550 750 ns tpHL IN1 to OUTA, IN2 to OUTB (H L) 550 750 ns 0.8 V A Control system input block Logic pin input H-level voltage VINH Logic pin input L-level voltage VINL Logic pin input current 1 2.0 V IINL VIN = 0.8V IINH VIN = 5V 4 8 12 30 50 70 VREF input current IREF VREF = 1.5V -0.5 Current limit comparator Vtlim VREF = 1.5V 0.291 0.3 0.309 V -6.5 -5 -3.5 A A A threshold voltage CHOP pin charge current CHOP pin threshold voltage CMK pin charge current CMK pin threshold voltage ICHOP VtCHOP ICMK VtCMK 0.8 1 1.2 V -32.5 -25 -17.5 A 1.2 1.5 1.8 V 27.7 28.7 29.7 V 250 550 s 125 155 kHz 0.4 V Charge pump block Step-up voltage VGH VM = 24V Rising time tONG VG = 0.1F Oscillation frequency Fcp 90 Short-circuit protection block EMO output saturation voltage SCP pin charge current Comparator threshold voltage VEMO ISCP IEMO = 1mA SCP = 0V VtSCP -6.5 -5 -3.5 A 0.8 1 1.2 V * Design guarantee value and no measurement were made. 3/16 LV8762T Application Note Block Diagram Ｍ CP1 CP2 VM VG OUTA OUTB RNF ＰGND Charge pump Reference voltage circuit ST REG5 EMO Oscillator Output control logic VREF TSD Brake time control circuit LVS GND Current limiter circuit Short-circuit Protection circuit Current limit mask SCP CHOP EMM IN1 IN2 CMK 4/16 LV8762T Application Note VCC=5V, Temp=25 ﾟ C VCC=5V, VM=24V 5/16 LV8762T Application Note 6/16 LV8762T Application Note Pd-Ta Chart Pd max - Ta Allowable power dissipation, Pd max - W 2.0 1.5 1.40 1.0 0.73 0.5 0 —20 0 20 40 60 80 Ambient temperature, Ta - 100 C PCB Specifications (PCB recommended for operation of LV8762T) Size: 57mm × 57mm × 1.6mm (two-layer substrate) Material: Glass epoxy-type board L1 : Copper wiring pattern diagram L2 : Copper wiring pattern diagram Cautions 1) 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 2) 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. 7/16 LV8762T Application Note Pin Functions Pin No. Pin Name Pin Functtion 18 IN1 Output control signal input pin 1. 19 IN2 Output control signal input pin 2. 1 EMM Short protection mode setting. Equivalent Circuit VREG5 19 18 1 GND 12 ST Standby mode setting VREG5 12 GND 9, 10 OUTA OUTA output pin. 3, 4 OUTB OUTB output pin. 7, 8 VM Motor power-supply connection pin. 5, 6 RNF Current sense resistor connection pin. PGND Power ground. 2 7 8 9 10 3 4 2 5 6 GND 14 VG Charge pump capacitor connection pin. 8 VM Motor power-supply connection pin. 16 CP1 Charge pump capacitor connection pin. 15 CP2 Charge pump capacitor connection pin. VREG5 16 8 15 14 GND Continued on next page. 8/16 LV8762T Application Note Continued from preceding page. Pin No. 20 Pin Name VREF Pin Functtion Reference voltage input pin for output current limit setting. Equivalent Circuit VREG5 20 GND 17 REG5 Internal reference voltage output pin. VM 17 GND 24 EMO Alert signal output VREG5 24 GND 21 CHOP Capacitor connection for current limit VREG5 break time setting 22 SCP Capacitor connection for short detection time setting GND 21 22 23 CMK Capacitor connection for current limit mask setting VREG5 23 GND 9/16 LV8762T Application Note Application Information Introduction The LV8762T is a simple 1-channel brushed DC MOTOR driver for printers, cash dispenser, amusement, and so on. This device has 4 mode operations as FORWARD, REVERSE, SHORT-BREAK, and OFF. It has some protection functions and it has 5V-regulator for single power supply operation. So it is easy and safe to use. Low standby current consumption: Almost circuit blocks are shutdown during standby-mode as ST pin is LOW. Mid-range output current: The LV8762 has H-Bridge with 1A-range. If looking for the other output current range devices, please contact our sales. Built-in charge-pump Built-in 5V regulator Current limiter by current chopping Current limiter masking Short circuit protector Over current protector Over heat protector ALERT signal. Regulator block The LV8762T has a 5V regulator for Single Power Supply Operation. This regulator has a capability of about 5mA for the internal blocks. For external usages, it can be used for pull-up, and as reference voltage. The load regulation is shown in Figure. 1. This regulator is disabled by the ST pin when set to LOW or OPEN. Figure. 1 VM=24V CREG5=0.1uF Charge-pump block The LV8762T has a charge-pump. It generates voltage about VM+4V to the VG pin for drive gate of H-bridge. This charge pump block needs two capacitors between CP1 to CP2, and VG to GND. In the standby mode, charge pump block is disabled for low power consumption as ST pin is LOW. This is up converted voltage as VG pin for use only internal blocks. It should not use the VG power for other purposes. The load regulation chart is shown in Figure. 2 VM=24V CP1-CP2=0.1uF CVG=0.1uF. The charge pump is started by setting ST pin to HIGH. It needs about 250us to work the H-bridge. So it should wait more than 250us once ST pin is set to HIGH for correct operation. The figure of transition VG pin during start up is shown in Figure. 3. Figure. 2 VM=24V CP1-CP2=0.1uF CVG=0.1uF Figure. 3 VM=24V CVG=0.1uF Thresh=VM+4V Output H-Bridge block This LSI is a 1- channel H-Bridge driver. The upper side ON resistance is 0.75 ohm and the lower side ON resistance is 0.5 ohm TYP; it can use 1A continuously, and the peak current is 1.5A. This LSI gets heat by the current as W=Iout2*(RON-upper + .RON-under). When designing a PCB, the LV8762T have to use under PdMAX value on Absolute Maximum Ratings. If power is over the PdMAX, it will be destroyed by overheating so it is necessary to have heat sink or larger PCB pattern. The Pdmax-Ta chart is shown above. The line to VM, OUTA, OUTB, and RNF throw high current so this line needs thicker one. The reference PCB pattern is shown above. Current sensing block The RNF resistor serves as the current sensor. There is a voltage produced by the current flowing from the output of the motor driver circuit to GND through the RNF resistor. This voltage is compared with the VREF. The RNF resistor is decided by the current limit value, see the topic of ‘Current Limit block’. Current Limiter block The LV8762T has a current limit function. Output current starts to chop when the current is over the value of VREF over RNF (see Figure. 4.) The value of current limit is decided by the equation below. When the output current exceeds that value, the output transistor becomes OFF. And next, that is 10/16 LV8762T Application Note become ON by CHOP timer like PWM. The current limiter utilizes PWM control in order to acquire very efficient current limiter. Limit[A] = VREF[V] / 5 / RNF[ohm] LIMIT current Output current OUTA Tchop OUTB CHARGE SLOW Figure. 4 Waveform of CHOP sequence Current Limit Mask block The current becomes high when round up the dc-motor because the motor generates no EMF. So when rounding up the motor, it needs current as shown in the equation below. The EMF stands for Electromotive Force. The EMF is generated by rotating the motor. The EMF is proportional to the rounding speed of the motor. I[A] = VM[V] / (Motor Resistance + RON+RNF)[ohm] The current limiter has many functions too. It causes a slow start up to the motor. If it should round up the motor too fast, it should use the Current Limit Mask function. The current limit is stopped by Current Limit Mask during masking time that is set by CMK capacitor. The masking time is calculated by the equation below. TCMK[sec] = CCMK[uF] x 1.5[V] / 25[uA] This situation is shown in Figure. 5. VREF input block The VREF pin is used for setting the motor current limit value. The voltage range is limited from 0V to around 3V by internal circuit. When voltage is over 3V, the current limit circuit will not function. Pull-up the VREF pin to REG5 pin when not using the current limit. Short Circuit Protection block The short circuit detector watches the OUTA and OUTB. It can detect the short line that are between OUTA to OUTB, OUTA to VM, OUTA to GND, OUTB to VM, OUTB to GND. The Short Circuit Protection circuit disabled the Output circuit when it senses 2A; it ignores when shorted time is under 2useconds. The short circuit detector checks the current two times to prevent the false detection. The first check is started immediately. A timing of second time check is decided by the SCP capacitor. These timing charts are shown in Figure. 6 Waveform of SCP (Latch Mode). The first period in figure shows the case of no short circuit occurrence because the time of short circuit is under 2uS. The second period shows the short circuit protection sequence. After a moment that is decided by the SCP capacitor, the output is switched ON, and current is checked again. If the circuit is still shorted, the output is switched OFF again. The detection time is calculated by the equation below. TSCP[sec] = CSCP[uF] x 1.0[V] / 5[uA] The short circuit detector has twice sequence. One is the Latch Mode and the other is the Auto Retry Mode. Both modes are decided by the state of EMM pin. The truth table is shown in Table 1. The Latch Mode is to OFF the output permanently until there are changes in the ST pin. The Auto Retry Mode is to OFF the output and check continuously for flowing current. The checking interval is about 2ms. The checking process is same as the Latch Mode. The Auto Retry Mode sequence is shown in Figure. 7 Waveform of SCP sequence (Auto Retry Mode). Output ON Tscp H-bridge output state Output ON Output OFF Standby state Threshold voltage 2us SCP voltage Short-circuit detection state ShortRelease circuit Shortcircuit Figure. 5 Waveform of CMK sequence Internal counter The current is less than round up current at almost case during rounding the motor because the BEMF is generated by the rounding motor. I[A] = (VM[V] – BEMF[V]) / (Res as above [ohm]) 1st counter start 1st counter start 1st counter stop 1st counter end 2nd counter start 2nd counter end Figure. 6 Waveform of SCP (Latch Mode) If this function is not used, CMK pin is set OPEN or pull-up to the REG5 pin. 11/16 LV8762T Application Note EMM L Open H Short Circuit Mode Latch Mode AutoRetry Mode Table 1 Truth Table of EMM Alert signal block The EMO pin outputs the ALERT signal. The alert signal is asserted when shorted outputs and overheating are detected. This pin is Open-drain type, so it should be pulled up when using this pin. Let this pin open if not in use. The EMO pin has RON that is 400[ohm]@1mA. Decide the resistance of pull-up res below threshold value of MCU. Thermal shutdown block The LV8762 has over heat protector. When junction temperature is higher than about 180°C the output is turned OFF by this block. The output is set to OFF continuously during the junction temperature is higher about 180°C. When the junction temperature is less than about 180-40°C, the output restarts and will work normally. When this block detects overheating, it asserts signal to the EMO pin. This signal assertion continues until ST pin sets to negative. Control Input block The LV8762T has three pins for operation: ST pin, IN1 pin and IN2 pin. The ST pin switches standby-mode and operating-mode. IN1 and IN2 pins are responsible for the direction of the motor. The truth table is shown in Table 2. The LV8762T will be in standby mode when ST pin is set to LOW, despite the state of IN1 pin and IN2 pin. In this condition OUTA and OUTB become OFF state. Set ST pin to HIGH to operate the OUT pin. The BREAK state means short break. It makes the OUTA and OUTB to be shorted to the RNF pin. It is possible to stop the motor early because the current that generated EMF is used to stop the motor. There are no limitations to change the state to another state. However, it is necessary to take care of rush current of the motor over the current of maximum rating when changing the state- both stopping to moving, and rounding forward to reverse. Rush current becomes too high when rounding changes forward to reverse and the opposite because the high current is generated by EMF and VM. The equation is shown below. IRUSH-MAX[A] = (VM[V]+EMF[V]) / Ra[ohm] Ra = Resistance of the winding of the motor. ST L open H H H H Input IN1 - IN2 - OUTA Output OUTB OFF OFF L H L H L L H H OFF ON OFF BREAK OFF OFF ON BREAK Table 2 Truth Table of Control 12/16 LV8762T Application Note Figure. 7 Waveform of SCP sequence (Auto Retry Mode) Figure. 8 Waveform of CMK sequence Figure. 8 Waveform of CMK sequence shows the sequence when the motor is turned on. When the IN get changing state, the CMK pin start charging to the CMK capacitor. In this period, the current limiter does not work. When the CMK voltage is higher than CMK threshold value, the current limiter starts. Figure. 9 Waveform of CHOP sequence Figure. 9 shows the sequence of current limiter. When the CMK voltage is over the CMK threshold voltage, the current limiter starts. The output becomes temporary off when the current is higher than threshold that is decided by VREF pin. And the CHOP capacitor is charged. When CHOP capacitor over the thresh voltage, the OUTPUT become ON again. And repeat the detection of current. 13/16 LV8762T Application Note Figure. 10 PCB Design of Component side Figure. 11 PCB Design of Solder side. BILL OF materials FOR THE EVALUATION BOARD (LV8762TEVB) Design ator CVM 1 CVG CCP CREG5 CCHOP CSCP CCMK REMO 1 1 1 1 1 1 1 RNF 1 ST, IN1, IN2, EMM ST, VM, VG, VCC, GND, REG5, IN1, IN2, VREF, CHOP, SCP, EMO, CMK, EMM, OUTA, OUTB LV8762 TEVB Board 4 VG cap CP cap 5Vreg cap CHOP cap SCP cap CMK cap EMO pull-up res Current Sense res SWITCH 16 TEST PIN Qty 1 Descripti on VM cap Value Tol 10uF/50V ±20% Footprint 1608 0.1uF/100V 0.1uF/100V 0.1uF/100V 47pF/50V 47pF/50V 0.1uF/100V 47k ohm ±10% ±10% ±10% ±5% ±5% ±10% ±5% 0.47 ohm ±5% Manufacture Manufacture partnumber 50ME10HC Substitution Alowed yes PbFree yes 1608 1608 1608 1608 1608 1608 1608 SUN Electronic Industries MURATA MURATA MURATA MURATA MURATA MURATA KOA GRM188R72A104KA35D GRM188R72A104KA35D GRM188R72A104KA35D GRM1882C1H470J GRM1882C1H470J GRM188R72A104KA35D RK73B1JT473J yes yes yes yes yes yes yes yes yes yes yes yes yes yes 6432 ROHM MCR100JZHJLR47 yes yes MIYATA ELECTRIC MS-621C-A01 yes yes MAC8 ST-1-3 yes yse no 14/16 LV8762T Application Note Figure. 12 Completed PCB with Devices 1 B Power Supply Pin Input Pin Pin Output Pin Pin Monitor Pin D E OUTB Pin C OUTA A 1 RNF 0.47 VCC VCC VCC SW-ST SCP CP2 CHOP CCHOP 47pF CCSP CCMK 47pF 0.1uF VCC 3 RVREFH (optional) (optional) 0.1uF VCC VREF CVM 10uF IN2 REG5 SW-IN2 IN1 SW-IN1 SCP 21 VM VM CMK RVREFL VCC EMO 23 CREG5 VCC VCC EMM 22 GND PGND CHOP 17 CP1 47k REMO 6 5 RNF RNF CMK LV8762T 2 1 24 13 2 16 0.1uF IC VG VREF 0.1uF EMO IN2 CCP EMM VM VM 20 15 CVG ST 19 14 VG OUTB OUTB OUTA OUTA 7 8 IN1 VM REG5 12 ST 18 2 3 4 3 10 9 SW-EMM GND LV8762T Evaluation Board Schematic 4 4 5/12/2011 A B C D E Figure. 13 Design Example Schematic 15/16 LV8762T Application Note ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). 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