LV8741V Bi-CMOS LSI PWM Current Control Stepper Motor Driver Application Note http://onsemi.com Overview The LV8741V is a 2-channel H-bridge driver IC that can switch a stepper motor driver, which is capable of micro-step drive and supports Full-step, Half-step (full torque), Half-step, and Quarter-step resolution, and two channels of a brushed motor driver, which supports forward, reverse, brake, and standby of a motor. Function Single-channel PWM current control stepping motor driver (selectable with DC motor driver channel 2) incorporated. BiCDMOS process IC On resistance (upper side: 0.5 ; lower side: 0.5 ; total of upper and lower: 1.0 ; Ta = 25C, IO = 1.5A) Micro step mode can be set to full-step, half-step (full torque), half-step, and quarter-step mode Excitation step proceeds only by step signal input Motor holding current selectable in four steps IO max = 1.5A Output-stage push-pull structure enabling high-speed operation Output short-circuit protection circuit (selectable from latch-type or auto reset-type) incorporated Thermal shutdown circuit and power supply monitor circuit incorporated Supports control power supply VCC = 3.3V 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 1/44 LV8741V Application Note Package Dimensions unit: mm (typ) 3333 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) 2/44 LV8741V Application Note Pin Assignment CP2 1 44 VM CP1 2 43 VG VCC 3 42 PGND VREG5 4 41 NC ATT2 5 40 GND ATT1 6 39 NC NC 7 38 NC EMO 8 37 OUT1A CEM 9 36 VM1 EMM 10 35 RF1 RCHOP 11 MONI 12 LV8741V 34 OUT1B 33 OUT2A RST 13 32 VM2 STP/DC22 14 31 RF2 FR/DC21 15 30 OUT2B MD2/DC12 16 29 NC NC 17 28 NC MD1/DC11 18 27 GND DM 19 26 NC OE 20 25 NC ST 21 24 NC VREF 22 23 SGND Top view 3/44 LV8741V Application Note Block Diagram OUT1B Output preamplifier stage Charge pump VM OUT1A RF1 PGND VM1 VM2 OUT2A OUT2B RF2 Output preamplifier stage VG Output preamplifier stage CP1 Output preamplifier stage CP2 ＥＭO MONI VREG5 Output control logic Regulator CＥＭ Attenuator (4 levels selectable) VREF Current selection (full/half-full/ half/quarter) Current selection (full/half-full/ half/quarter) VCC Oscilation circuit TSD SGND LVS RCHOP ST ATT1 ATT2 RST DM FR/ MD1/ OE EMM DC11 DC21 MD2/ STP/ DC12 DC22 4/44 LV8741V Application Note Specifications Absolute Maximum Ratings at Ta = 25C Parameter Symbol Conditions Ratings Unit Supply voltage 1 VM max 38 Supply voltage 2 VCC max 6 V 1.75 A Output peak current IO peak Output current IO max tw 10ms, duty 20% V 1.5 A Logic input voltage VIN -0.3 to VCC+0.3 V EMO input voltage VEMO -0.3 to VCC+0.3 V 0.55 W Allowable power dissipation 1 Pd max1 Independent IC Allowable power dissipation 2 Pd max2 * Our recommended two-layer substrate *1, *2 2.9 W Operating temperature Topr -20 to +85 C Storage temperature Tstg -55 to +150 C *1 Specified circuit board : 90901.7mm3 : glass epoxy printed circuit board *2 For mounting to the backside by soldering, refer the precautions. 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 1 VM 9.5 35 V Supply voltage range 2 VCC 2.7 5.5 V VREF input voltage range VREF 0 VCC-1.8 V Electrical Characteristics at Ta = 25°C, VM = 24V, VCC = 5V, VREF = 1.5V Parameter Standby mode current drain 1 Current drain 1 Standby mode current drain 2 Current drain 2 Symbol IMstn IM ICCstn ICC Conditions Ratings min typ Unit max ST = ”L” 150 200 A ST = ”H”, OE = ”H”, no load 0.75 1 mA ST = ”L” 110 160 A mA 2.5 3 VCC low-voltage cutoff voltage VthVCC ST = ”H”, OE = ”H”, no load 2.2 2.35 2.5 V Low-voltage hysteresis voltage VthHIS 100 150 200 mV TSD Design guarantee 180 C Thermal hysteresis width TSD Design guarantee 40 C Output on-resistance Ronu IO = 1.5A, Upper-side on resistance 0.5 0.7 Rond IO = 1.5A, Lower-side on resistance 0.5 0.6 Output leakage current IOleak 50 A Diode forward voltage 1 VD1 1 1.3 V Diode forward voltage 2 VD2 ID = -1.5A Logic pin input current IINL VIN = 0.8V IINH VIN = 5V Thermal shutdown temperature Logic high-level input voltage VINH Logic low-level input voltage VINL ID = -1.0A 1.1 1.5 V 3 8 15 A 30 50 70 A 0.8 V 2.0 V Continued on next page. 5/44 LV8741V Application Note Continued from preceding page. Current Quarter-step selection drive Vtdac0_W Step 0(When initialized : channel 1 0.485 0.5 0.515 V comparator level) comparator Vtdac1_W Step 1 (Initial state+1) 0.485 0.5 0.515 V threshold Vtdac2_W Step 2 (Initial state+2) 0.323 0.333 0.343 V Vtdac3_W Step 3 (Initial state+3) 0.155 0.167 0.179 V Step 0 (When initialized: channel 1 0.485 0.5 0.515 V Step 2 (Initial state+1) 0.323 0.333 0.343 V Step 0 (Initial state, channel 1 comparator 0.485 0.5 0.515 V voltage (Current step switch) Half-step drive Vtdac0_H comparator level) Vtdac2_H Half-step (full Vtdac0_HF torque) drive level) Vtdac2_HF Full-step drive Vtdac2_F Step 2 (Initial state+1) 0.485 0.5 0.515 V Step 2 0.485 0.5 0.515 V Chopping frequency Fchop RCHOP = 20k 45 62.5 75 Current setting reference voltage VRF00 ATT1 = L, ATT2 = L 0.485 0.5 0.515 V VRF01 ATT1 = H, ATT2 = L 0.323 0.333 0.343 V VRF10 ATT1 = L, ATT2 = H 0.237 0.25 0.263 V VRF11 ATT1 = H, ATT2 = H 0.155 0.167 0.179 VREF pin input current Iref VREF = 1.5V kHz V A -0.5 Charge pump VREG5 output voltage VG output voltage Vreg5 IO = -1mA VG Rise time tONG VG = 0.1F Oscillator frequency Fosc RCHOP = 20k 4.5 5 5.5 V 28 28.7 29.8 V 0.5 ms 90 125 150 kHz 50 100 mV Output short-circuit protection EMO pin saturation voltage Vsatemo Iemo = 1mA 6/44 LV8741V Application Note 7/44 LV8741V Application Note 8/44 LV8741V Application Note Pin Functions Pin No. Pin name Pin Function 5 ATT2 Motor holding current switching pin. 6 ATT1 Motor holding current switching pin. 10 EMM Output short-circuit protection mode 13 RST RESET signal input pin 14 STP/DC22 STEP signal input pin (STM) / Channel 15 FR/DC21 Equivalent Circuit VCC switching pin. 2 output control input pin 2 (DCM). CW / CCW signal input pin (STM) / Channel 2 output control input pin 1 5kΩ (DCM). 16 MD2/DC12 Excitation mode switching pin 2 (STM) / Channel 1 output control input pin 2 (DCM). 18 MD1/DC11 100kΩ Excitation mode switching pin 1 (STM) / Channel 1 output control input pin 1 (DCM). 19 DM Drive mode (STM/DCM) switching pin. 20 OE Output enable signal input pin. 21 ST Chip enable pin. 30 OUT2B Channel 2 OUTB output pin. 31 RF2 Channel 2 current-sense resistor 36 connection pin. 32 32 VM2 33 OUT2A Channel 2 OUTA output pin. 34 OUT1B Channel 1 OUTB output pin. 35 RF1 Channel 1 current-sense resistor 36 VM1 Channel 1 motor power supply pin. 37 OUT1A Channel 1 OUTA output pin. 42 PGND Power system ground. GND Channel 2 motor power supply connection pin. VCC connection pin. 37 33 34 30 35 GND 42 1 CP2 Charge pump capacitor connection pin. 2 CP1 Charge pump capacitor connection pin. 43 VG Charge pump capacitor connection pin. 44 VM Motor power supply connection pin. 2 VREG5 31 44 1 43 100Ω GND Continued on next page. 9/44 LV8741V Application Note Continued from preceding page. Pin No. 22 Pin Name VREF Pin Function Equivalent Circuit Constant current control reference voltage input pin. VCC 500Ω GND 4 VREG5 Internal power supply capacitor connection pin. VM 2kΩ 78kΩ 26kΩ GND 12 MONI Position detection monitor pin. VCC 500Ω GND Continued on next page. 10/44 LV8741V Application Note Continued from preceding page. Pin No. 8 Pin Name EMO Pin Function Equivalent Circuit Output short-circuit state warning output VCC pin. GND 9 CEM Pin to connect the output short-circuit state detection time setting capacitor. VCC 500Ω GND 11 RCHOP Chopping frequency setting capacitor connection pin. VCC GND 1kΩ 27, 40 GND Ground. 7, 17 NC No Connection (No internal connection to the IC) 24, 25 26, 28 29, 38 39, 41 11/44 LV8741V Application Note Description of operation Input Pin Function (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) Drive mode switching pin function The IC drive mode is switched by setting the DM pin. In STM mode, stepping motor channel 1 can be controlled by the CLK-IN input. In DCM mode, DC motor channel 2 or stepping motor channel 1 can be controlled by parallel input. Stepping motor control using parallel input is full-step or half-step full torque. DM Drive mode Application Low or Open STM mode Stepping motor channel 1 (CLK-IN) High DCM mode DC motor channel 2 or stepping motor channel 1 (parallel) STM mode (DM = Low or Open) (1) STP pin function 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) 12/44 LV8741V Application Note (3) Positional detection monitor function MONI pin is a Positional detection monitor output pin. When the excitation position is an initial position, the MONI output becomes Low, the other position, the MONI output becomes High. Please refer to (example of current wave type in each excitation mode). (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/3)/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% 50ms/div ATT1 5V/div ATT2 5V/div Motor Current VCC=5V VM=24V VREF=0.53V RF=0.22Ω Iout1 0.5A/div Iout2 0.5A/div 100% 50% The formula used to calculate the output current when using the function for attenuating the VREF input voltage is given below. IOUT = (VREF/3) × (attenuation ratio)/RF resistance Example: At VREF of 0.66V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of 0.22, the output current is set as shown below. IOUT = 0.66V/3 × 100%/0.22 = 1.0A If, in this state, (ATT1, ATT2) is set to (H, H), IOUT will be as follows: IOUT = 1.0A × 33.3% = 0.33A In this way, the output current is attenuated when the motor holding current is supplied so that power can be conserved. 13/44 LV8741V Application Note (5) Reset function RST Operating mode High Normal operation Low Reset state When the RST pin is set Low, the output excitation position is forced to the initial state, and the MONI output also goes Low. When RST is set High after that, the excitation position proceeds to the next STP input. (6) Output enable function OE Operating mode Low Output OFF High Output ON When the OE pin is set Low, 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 High, the output level conforms to the excitation position proceeded by the STEP input. 14/44 LV8741V Application Note (7) 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. (8) 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 15/44 LV8741V Application Note (9) 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. (10)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 0 Half step (%) Channel 2 100 Channel 1 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 16/44 LV8741V Application Note (11)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. (12)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. 17/44 LV8741V Application Note (13)Typical current waveform in each excitation mode Full Step (CW mode) STP MONI （％） I1 100 0 （％）－100 100 I2 0 －100 Half Step (full torque) (CW mode) STP MONI (%) 100 I1 0 －100 (%) 100 I2 0 －100 18/44 LV8741V Application Note Half step (CW mode) STP MONI (%) 100 I1 0 －100 (%) 100 I2 0 －100 Quarter Step (CW mode) STP MONI (%) 100 I1 0 －100 (%) 100 I2 0 －100 19/44 LV8741V Application Note (14)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. 20/44 LV8741V Application Note (15)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 21/44 LV8741V Application Note 10ms/div STEP 5V/div VCC=5V VM=24V VREF=0.53V RF=0.22Ω RCHOP=43kΩ Motor Current 0.5A/div 20µs/div 20µs/div STEP 5V/div Set Current Set Current STEP 5V/div Motor Current 0.5A/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 10µs/div Motor Current 200mA/div OUTA 20V/div OUTB 20V/div FAST CHARGE 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. 22/44 LV8741V Application Note DCM Mode (DM-High) (1) DCM mode output control logic Parallel input Output Mode DC11 (21) DC12 (22) OUT1 (2) A OUT1 (2) B Low Low OFF OFF Standby High Low High Low CW (Forward) Low High Low High CCW (Reverse) High High Low Low Brake When the control input switched from CW mode or CCW mode to standby mode, the current is pulled out with FAST DECAY. Afterwards, when the current becomes 0, the output is forcibly turned off. This forced OFF is released on the following condition. 1) Switched to CW mode or CCW mode. 2) Setting ST to low. Therefore, forced OFF might not be released, If the input signal is followed in order by CW(CCW) mode, standby mode, and brake mode. When the standby mode enters the above-mentioned timing, set the input time of the standby mode less than 0.5µs. (2) Reset function RST Operating mode MONI High or Low Reset operation not performed High output The reset function does not operate in DCM mode. In addition, the MONI output is High, regardless of the RST pin state. (3) Output enable function OE Operating mode Low Output OFF High Output ON When the OE pin is set Low, the output is forced OFF and goes to high impedance. When the OE pin is set High, output conforms to the control logic. 23/44 LV8741V Application Note (4) PWM control You can perform H-Bridge direct PWM control to DC11, DC12, DC21, and DC22 by inputting PWM signal. The maximum frequency of PWM signal is 200kHz. However, dead zone is generated when On-Duty is around 0%. Make sure to select optimum PWM frequency according to the target control range. Input-Output Characteristics of H-Bridge(Reference data) VM=24V,VREF=1.5V Forward/Reverse↔Brake RCHOP=20kΩ 24/44 LV8741V Application Note Forward⇔Brake No load VM=24V, DC12=10kHz (DC11=H) 20µs/div High High Low High DC11 5V/div DC12 5V/div OUTA 10V/div OUTB 10V/div Forward Brake Forward⇔Standby No load VM=24V, DC11=10kHz (DC12=L) 20µs/div High Low Low Low DC11 5V/div DC12 5V/div OUTA 10V/div OUTB 10V/div Forward Standby Motor load VM=24V, DC11=10kHz (DC12=L) 0.5µs/div 20µs/div Forward w/out load (no current), even if the counterpart transistor is on, output turns off at a MIN time (≈0.5us) Standby Current=0A DC11 5V/div Motor Current 200mA/div OUTA 10V/div OUTB 10V/div Counterpart transistor ON Counterpart transistor ON Standby mode turns on the counterpart transistor (synchronous rectification) . After motor current fades off, output turns off. Synchronous rectification reduces heat generation compared to diode regeneration. 25/44 LV8741V Application Note (5) 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 500µs/div VM=24V VREF=0.53V RF=0.22Ω ATT1=ATT2=L High DC11 5V/div Low DC12 5V/div Brush noise Current limit Motor Current 0.5A/div Forward Brake 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/3) /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 66.7% Low High 50% High High 33.3% The formula used to calculate the output current when using the function for attenuating the VREF input voltage is given below. Ilimit = (VREF/3) × (attenuation ratio) /RF resistance Example: At VREF of 0.66V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of 0.22, the output current is set as shown below. Ilimit = 0.66V/3 × 100%/0.22 = 1.0A If, in this state, (ATT1, ATT2) has been set to (H, H), Ilimit will be as follows: Ilimit = 1.5A × 33.3% = 0.33A 26/44 LV8741V Application Note (6) Blanking period In this IC, the blanking time is fixed at 1/16 of one chopping cycle. 5µs/div Iout 100mA/div 16µs 1µs VOUT 10V/div 27/44 LV8741V Application Note (7) Typical current waveform in each excitation mode when stepping 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 I1 0 －100 (%) 100 I2 0 －100 28/44 LV8741V Application Note Output short-circuit protection circuit To protect the IC from damage due to short-circuit of the output caused by lightening or ground fault, the output short-circuit protection circuit to put the output in standby mode and turn on the alarm output is incorporated. The protection is detected when the potential difference between D-S of upside output Tr abnormally grows or when becoming the voltage twice or more a reference voltage for setting current in the voltage of RF. Therefore, when the RF pin is short-circuited to GND, this output short-circuit protection is not effective against shorting to power. (1) Detect current The formula used to calculate the lower over-current when using the function for attenuating the VREF input voltage is given below. IOCPL = (VREF/3) × (attenuation ratio)/RF resistance × 2 Example: At VREF of 0.66V, a reference voltage setting of 100% [(ATT1, ATT2) = (L, L)] and an RF resistance of 0.22, the output current is set as shown below. IOUT = 0.66V/3 × 100%/0.22 = 1.0A IOCPL = (0.66V/3) × 100%/0.22 = 2.0A Detect current of the upper over-current is as shown in the figure below. 29/44 LV8741V Application Note (2) Output short-circuit detection operation Resistance exists between RF and GND. VM short 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 RF voltage exceeds the reference voltage for Tscp, short status is detected. GND 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 Tscp, short status is detected. VM Short-circuit Detection Tr1 Tr1 Tr3 ON OUTA VM Short-circuit Detection ON OUTA OFF OUTB M Tr2 OFF Tr3 Tr4 Tr2 ON OFF M OFF OUTB Tr4 ON RF RF Load short (short status is not detected) VM Short-circuit Detection Tr1 ON OUTA Tr3 M VM Tr1 OFF OUTB Tr2 OFF Tr3 OFF OUTA Tr4 Tr2 ON ON M Tr4 ON RF RF VM Tr1 OFF OUTA OFF OUTB (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 Tscp, 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 state in SLOW decay mode, current does not flow and overcurrent status 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. Because 2-4 is repeated, short status is not detected. Tr3 M Tr2 ON OUTB Tr4 ON OFF RF 30/44 LV8741V Application Note Resistance doesn't exist between RF and GND. 1.High current flows if Tr1 and Tr4 are ON. 2.Because RF voltage is GND level, short status is not detected. VM short (short status is not detected) (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 Tscp, short status is detected. GND short Short-circuit Detection VM Short-circuit Detection Tr1 ON OUTA Tr3 M VM OFF OUTB Tr1 Tr3 ON OUTA Tr2 Tr4 Tr2 OFF ON OFF M Tr4 ON RF RF VM Tr1 ON OUTA (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 Tscp, short status is detected. 1.Without L load, high current flows. 2. If the voltage between D and S of Tr1 exceeds the reference voltage for Tscp, short status is detected. Load short (short is not detected) Short-circuit Detection OFF OUTB Tr3 M Tr2 OFF OUTB Tr4 OFF ON RF 31/44 LV8741V Application Note (3) Output short-circuit protection operation changeover function Changeover to the output short-circuit protection of IC is made by the setting of OCPM pin. EMM State Low or Open Auto reset method High Latch method (4) Auto reset method When the output current is below the output short-circuit protection current, the output is controlled by the input signal. When the output current exceeds the detection current, the switching waveform as shown below appears instead. (When a 20kΩ resistor is inserted between RCHOP and GND) Exceeding the over-current detection current ON OFF ON OFF ON Output current 1V OCP voltage Tscp 1 to 2μs 256μs (TYP) When output short-circuit state is detected, the short-circuit detection circuit is activated. When the short-circuit detection circuit operation exceeds the timer latch time described later, the output is changed over to the standby mode and reset to the ON mode again in 256µs (TYP). In this event, if the over-current mode still continues, the above switching mode is repeated till the overcurrent mode is canceled. (5) Latch method Similar to the case of automatic reset method, the short-circuit detection circuit is activated when it detects the output short-circuit state. When the short-circuit detection circuit operation exceeds the timer latch time described later, the output is changed over to the standby mode. In this method, latch is released by setting PS = “L” (6) Output short-circuit condition warning output pin EMO, warning output pin of the output short-circuit protection circuit, is an open-drain output. EMO outputs ON when output short-circuit is detected. 32/44 LV8741V Application Note (7) Timer latch time (Tscp) 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 (C) value can be determined as follows: Tscp Td+C V/I [sec] Td : Internal delay time TYP 4µs V : Threshold voltage of comparator TYP 1V I : CEM charge current TYP 2.5µA Timer latch: Tscp The Tscp time must be set so as not to exceed 80% of the chopping period. The CEN pin must be connected to (S) GND when the output short protection function is not to be used. Unusual condition EMO Channel 1 Output Channel 2 Output Channel 1 short-circuit detected ON OFF OFF Channel 2 short-circuit detected ON OFF OFF Overheating condition detected - OFF OFF Latch type Auto reset type 1ms/div 5µs/div OUT 10V/div OUT-GND short 1V 2µs CEM 0.5V/div 2ms TSCP EMO 5V/div Thermal shutdown function The thermal shutdown circuit is incorporated and the output is turned off when junction temperature Tj exceeds 180C. 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) 33/44 LV8741V 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. If the VG pin voltage is not boosted sufficiently, the output cannot be controlled, so be sure to provide a wait time of tONG or more after setting the ST pin High before starting to drive the motor. ST VG pin voltage VM+VREG5 VM+4V VM tONG OE (STM mode) High after the tONG wait time has elapsed DC11, DC12, DC21 and DC22 (DCM mode) VG Pin Voltage Schematic View When controlling the stepping motor driver with the CLK-IN input, set the ST pin High, wait for the tONG time duration or longer, and then set the OE pin High. In addition, when controlling the stepping motor and DC motor driver with parallel input, set the ST pin High, wait for the tONG time duration or longer, and then start the control for each channel. tONG with different VG capacitor 500µs/div ST 5V/div VG 5V/div VM+4V tONG: 0.1µF /230µs 0.22µF /460µs 1µF /2ms VM=24V CP1-CP2=0.1µF VG=0.1µF/0.22µF/1µF 34/44 LV8741V Application Note Recommended Power-on Sequence Provide a wait time of 10µs or more after the VCC power supply rises before supplying the motor power supply. Provide a wait time of 10µs or more after the motor power supply rises before setting the ST pin High. VCC VM 10μs or longer 10μs or longer ST The above power-on sequence is only a recommendation, and there is no risk of damage to the IC even if this sequence is not followed. 35/44 LV8741V Application Note Application Circuits Stepping motor driver application circuit example 24V 0.1µF 1 CP2 VM 44 2 CP1 VG 43 3 VCC PGND 42 4 VREG5 5 ATT2 GND 40 6 ATT1 NC 39 7 NC NC 38 8 EMO OUT1A 37 9 CEM VM1 36 10 EMM RF1 35 5V 10µF 0.1µF NC 41 0.1µF 47kΩ Short-circuit state detection monitor 43kΩ 11 RCHOP LV8741V 12 MONI Position detection monitor 0.22Ω OUT1B 34 OUT2A 33 13 RST VM2 32 14 STP/DC22 RF2 31 M 0.22Ω Clock input 15 FR/DC21 Logic input OUT2B 30 16 MD2/DC12 NC 29 17 NC NC 28 18 MD1/DC11 GND 27 19 DM NC 26 20 OE NC 25 21 ST NC 24 0.66V 22 VREF GND 23 Each constant setting type in the example of the above-mentioned circuit is as follows. When setting current ratio = 100%, VREF = 0.66V, the following output current flows: IOUT = VREF/3/RF resistance = 0.66V/3× 100%/0.22Ω=1.0A Chopping frequency setting. 37kHz (RCHOP=43kΩ) Latch-type output short-circuit protection function (EMM = High) Reset function fixed to normal operation (RST = High) 36/44 LV8741V Application Note DC motor driver application circuit example 24V 0.1µF 1 CP2 VM 44 2 CP1 VG 43 3 VCC PGND 42 4 VREG5 5 ATT2 GND 40 6 ATT1 NC 39 7 NC NC 38 8 EMO OUT1A 37 9 CEM VM1 36 10 EMM RF1 35 5V 10µF 0.1µF NC 41 0.1µF 47kΩ Short-circuit state detection monitor 20kΩ 11 RCHOP LV8741V 12 MONI Position detection monitor Logic input 0.22Ω M OUT2A 33 VM2 32 14 STP/DC22 RF2 31 OUT2B 30 16 MD2/DC12 NC 29 17 NC NC 28 18 MD1/DC11 M OUT1B 34 13 RST 15 FR/DC21 0.22Ω GND 27 19 DM NC 26 20 OE NC 25 21 ST NC 24 0.66V 22 VREF GND 23 Each constant setting type in the example of the above-mentioned circuit is as follows. When setting current LIMIT = 100%, VREF = 0.66V, the following output current flows: Ilimit = VREF/5/RF resistance = 0.66V/3×100%/0.22Ω=1.0A Chopping frequency setting. 62.5kHz (RCHOP=20kΩ) Latch-type output short-circuit protection function (EMM = High) 37/44 LV8741V Application Note DC motor driver parallel connection application circuit example By connecting OUT1A and OUT2A as well as OUT2A and OUT2B, you can double the current capability. However, you cannot use current limit function. (RF=GND) 24V 0.1µF 1 CP2 VM 44 2 CP1 VG 43 3 VCC PGND 42 4 VREG5 5 ATT2 GND 40 6 ATT1 NC 39 7 NC NC 38 8 EMO OUT1A 37 9 CEM VM1 36 10 EMM RF1 35 5V 10µF 0.1µF NC 41 0.1µF Short-circuit state detection monitor 47kΩ 20kΩ 11 RCHOP LV8741V 12 MONI Position detection monitor OUT2A 33 13 RST VM2 32 14 STP/DC22 RF2 31 15 FR/DC21 Logic input OUT1B 34 OUT2B 30 16 MD2/DC12 NC 29 17 NC NC 28 18 MD1/DC11 GND 27 19 DM NC 26 20 OE NC 25 21 ST NC 24 22 VREF M GND 23 Each constant setting type in the example of the above-mentioned circuit is as follows. Chopping frequency setting. 62.5kHz (RCHOP=20kΩ) Latch-type output short-circuit protection function (EMM = High) Current Ability (Iomax) OUT1 1.5A OUT2 1.5A OUT1/2(Parallel Connect) 3A 38/44 LV8741V Application Note Pd max – Ta Allowable power dissipation, Pd max – W 4.0 3.0 *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 2.90 Two-layer circuit board 2 *2 2.0 2.05 1.51 1.07 1.0 0 – 20 0 20 40 60 80 100 Ambient temperature, Ta – °C Substrate Specifications (Substrate recommended for operation of LV8741V) Size : 90mm × 90mm × 1.7mm (two-layer substrate [2S0P]) Material : Glass epoxy Copper wiring density : L1 = 90% / L2 = 95% 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 95% 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. 39/44 LV8741V Application Note Evaluation board LV8741V (90.0mm90.0mm1.7mm, glass epoxy 2-layer board, with backside mounting) M C6 “VM” Power Supply R3 R2 C1 IC1 C2 “VCC” Power Supply C3 C4 R1 C5 SW1 SW2 SW3 SW4 SW5 SW6 SW7 SW8 SW9 SW10 SW11 1 Input Top view Bottom view Bill of Materials for LV8741V Evaluation Board Designator Quantity C1 1 C2 1 C3 1 C4 1 C5 1 C6 1 R1 1 R2 1 R3 1 IC1 SW1-SW11 TP1-TP25 1 11 25 Description Value Tolerance Capacitor for Charge 0.1µF, pump 100V ±10% Capacitor for Charge 0.1µF, pump 100V ±10% VCC Bypass 0.1µF, Capacitor 100V ±10% VREG5 stabilization 0.1µF, Capacitor 100V ±10% VREF stabilization 0.1µF, Capacitor 100V ±10% VM Bypass Capasitor 10µF, 50V ±20% Resistor to set chopping 43kΩ, frequency 1/10W ±5% Channel 1 output current detective 0.22Ω, Resistor 1W ±5% Channel 2 output current detective 0.22Ω, Resistor 1W ±5% Motor Driver Switch Test Point Footprint SSOP44K (275mil) Substitution Allowed Lead Free Manufacturer Manufacturer Part Number TDK-EPC FK28X7R1H104K Yes Yes TDK-EPC FK28X7R1H104K Yes Yes TDK-EPC FK28X7R1H104K Yes Yes TDK-EPC FK28X7R1H104K Yes Yes TDK-EPC SUN Electronic Industries FK28X7R1H104K Yes Yes 50ME10HC Yes Yes akane ohm RD16S433J Yes Yes JAPAN RESISTOR MFG KNP2WR22J/R0 Yes Yes KNP2WR22J/R0 Yes Yes LV8741V MS-621C-A01 ST-1-3 No Yes Yes Yes Yes Yes JAPAN RESISTOR MFG SANYO ON Semiconductor semiconductors MIYAMA MAC8 40/44 LV8741V Application Note Evaluation board circuit *VM Power supply input terminal 0.1µF *VCC Power supply input terminal 1 CP2 VM 44 2 CP1 VG 43 3 VCC PGND 42 4 VREG5 5 ATT2 GND 40 6 ATT1 NC 39 7 NC NC 38 C2 C1 0.1µF 0.1µF 0.1µF C3 C4 SW1 SW2 SW3 43kΩ 8 EMO OUT1A 37 9 CEM VM1 36 10 EMM RF1 35 11 RCHOP R1 (2) (1) SW5 SW6 <1> SW7 SW8 SW9 SW10 SW11 0.1µF LV8741V 12 MONI SW4 *VREF Constant Current Control for Reference Voltage NC 41 OUT1B 34 <2> Motor connection terminal 10uF 0.22Ω C6 <3> R2 OUT2A 33 13 RST VM2 32 14 STP/DC22 RF2 31 15 FR/DC21 (3) <4> 0.22Ω R3 OUT2B 30 16 MD2/DC12 NC 29 17 NC NC 28 18 MD1/DC11 (4) GND 27 19 DM NC 26 20 OE NC 25 21 ST NC 24 22 VREF GND 23 C5 【DC Motor(OUT1A-OUT1B)】 VCC=5V, VM=24V, VREF=0.9V ST=H,DM=H ATT1=ATT2=L, FR/DC21=STP/DC22=L MD1/DC11=H MD2/DC12=100kHz(Duty50%) 【Stepping Motor】 VCC=5V, VM=24V, VREF=0.53V ST=H,DM=L ATT1=ATT2=L, FR/DC21=L MD1/DC11=MD2/DC12=H STP/DC22=500Hz(Duty50%) 5ms/div (1) STP 5V/div (2) MONI 5V/div (3) (4) Iout1 0.5A/div Iout2 0.5A/div 2µs/div <1> DC12 5V/div <2> OUT1A 10V/div <3> OUT1B 10V/div <4> Iout1 1A/div 41/44 LV8741V Application Note Evaluation Board Manual [Supply Voltage] VCC (2.7 to 5.5V): Logic Supply for LSI VM (9 to 35V): Power Supply for LSI VREF (0 to 3V): Const. Current Control for Reference Voltage [Toggle Switch State] Upper Side: High (VCC) Middle: Open, enable to external logic input Lower Side: Low (GND) [Operation Guide] For stepping motor control 1. Initial Condition Setting: Set “Open” the toggle switch STP/D22, 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 VCC, VM, and VREF. 4. Ready for Operation from Standby State: Turn “High” the ST terminal toggle switch. After the tONG time passes, turn “High” the OE terminal toggle switch. Channel 1 and 2 are into full-step initial position (100%, -100%). 5. Motor Operation: Turn “High” the RST terminal toggle switch. Input the clock signal into the terminal STP/DC22. 6. Other Setting i. ATT1, ATT2: Motor current attenuation. ii. EMM: Short circuit protection mode change. iii. RST: Initial Mode. iv. FR/DC21: Motor rotation direction (CW / CCW) setting. v. MD1/DC11, MD2/DC12: Excitation mode. vi. OE: Output Enable. For DC motor control 1. Initial Condition Setting: Set “Open” the toggle switch DM, and “Open or Low” the other switches 2. Motor Connection: Connect the Motor(s) between OUT1A and OUT1B, between OUT2A and OUT2B. 3. Power Supply: Supply DC voltage to VCC, VM, and VREF. 4. Ready for Operation from Standby State: Turn “High” the ST and DM terminal toggle switch. 5. Motor Operation: After the tONG time passes since turn “High” the ST, Set MD1/DC11, MD2/DC12 and STP/DC22 terminals according to the purpose. 6. Other Setting i. ATT1, ATT2: Motor current attenuation. ii. EMM: Short circuit protection mode change. iii. RST: Not performed iv. OE: Output enable. [Setting for External Component Value] 1. Constant Current (100%) At VREF=0.66V Iout =VREF [V] / 3 / RF [Ω] =0.66 [V] / 3 / 0.22 [Ω] =1 [A] 2. Chopping frequency setting. 37kHz (RCHOP=43kΩ) 42/44 LV8741V Application Note Notes in design: ●Power supply connection terminal [VCC, VM, VM1, VM2] VCC is the power supply connection terminal for logic. VM, VM1, and VM2 are the power supply connection terminal for motor power. Make sure to short-circuit VM, VM1 and VM2. 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, PGND, 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 output Tr and charge pomp circuit (typ 5V). When VCC and VM supply are 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. Set input pin to high after VCC supply is powered, because the diode is connected between the logic terminal and VCC power supply. ●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. 43/44 LV8741V 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. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. 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