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Features
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Operating voltage: 8 - 45 V
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7.0 A output peak current (3.0 A r.m.s.)
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Low R
power MOSFETS
DSon
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Programmable speed profile and positioning
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Programmable power MOS slew-rate
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Up to 1/128 microstepping
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Sensorless stall detection
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SPI interface
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Low quiescent and standby currents
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Programmable non dissipative overcurrent
protection on high and low-side
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Two levels overtemperature protection
Applications
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Bipolar stepper motor
Description
The L6470, realized in analog mixed signal
technology, is an advanced fully integrated
solution suitable for driving two phase bipolar
stepper motors with microstepping.
It integrates a dual low R
with all of the power switches equipped with an
Table 1.
Device summary
Order codes
L6470H
L6470HTR
November 2010
Fully integrated microstepping motor driver
DMOS full bridge
DSon
Doc ID 16737 Rev 2
with motion engine and SPI
accurate on chip current sensing circuitry suitable
for non dissipative current control and overcurrent
protections. Thanks to a unique control system a
true 1/128 steps resolution is achieved. The
digital control core can generate user defined
motion profiles with acceleration, deceleration,
speed or target position easily programmed
through a dedicated registers set. All commands
and data registers, including those used to set
analogue values (i.e. current control value,
current protection trip point, dead time, PWM
frequency etc.) are sent through a standard
5Mbit/s SPI.
A very rich set of protections (thermal, low bus
voltage, overcurrent, motor stall) allows designing
a fully protected application, as required by most
demanding motor control applications.
Package
HTSSOP28
HTSSOP28
L6470
HTSSOP28
Packing
Tube
Tape and reel
1/64
www.st.com
64
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Table of Contents
Related Manuals for ST L6470PD
Summary of Contents for ST L6470PD
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Page 1: Table 1. Device Summary
It integrates a dual low R DMOS full bridge DSon with all of the power switches equipped with an Table 1. Device summary Order codes Package Packing L6470H HTSSOP28 Tube L6470HTR HTSSOP28 Tape and reel November 2010 Doc ID 16737 Rev 2 1/64... -
Page 2: Table Of Contents
Contents L6470 Contents Block diagram ..........8 Electrical data . - Page 3 L6470 Contents 6.12 Reset and standby ......... . 26 6.13 External switch (SW pin) .
- Page 4 Contents L6470 9.1.15 K_THERM ..........42 9.1.16 ADC_OUT .
- Page 5 L6470 List of tables List of tables Table 1. Device summary ............1 Table 2.
- Page 6 List of tables L6470 Table 49. ResetPos command structure ..........59 Table 50.
- Page 7 L6470 List of figures List of figures Figure 1. Block diagram ............8 Figure 2.
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Page 8: Block Diagram
Block diagram L6470 Block diagram Figure 1. Block diagram OSCIN OSCOUT ADCIN VREG VBOOT Charge Ext. Osc. driver 16MHz pump & Oscillator Clock gen. Voltage Reg. STBY/RST boot boot FLAG OUT1A OUT2A Control PGND Logic boot boot OUT1B OUT2B Current DACs BUSY/SYNC Temperature &... -
Page 9: Electrical Data
L6470 Electrical data Electrical data Absolute maximum ratings Table 2. Absolute maximum ratings Symbol Parameter Test condition Value Unit Logic interface supply voltage Motor supply voltage Differential voltage between AGND, PGND ±0.3 GND, diff and DGND Bootstrap peak voltage boot Internal voltage regulator output pin and logic supply voltage Integrated ADC input voltage range... -
Page 10: Recommended Operating Conditions
Electrical data L6470 Recommended operating conditions Table 3. Recommended operating conditions Symbol Parameter Test condition Value Unit 3.3 V logic outputs Logic interface supply voltage 5 V logic outputs Motor supply voltage Differential voltage between , OUT1 , OUT2 , PGND out_diff and V , OUT1... -
Page 11: Electrical Characteristics
L6470 Electrical characteristics Electrical characteristics = 36 V; V = 3.3 V; internal 3 V regulator; T = 25°C, unless otherwise specified. Table 4. Electrical characteristics Symbol Parameter Test condition Max Unit General UVLO turn on threshold SthOn UVLO turn off threshold SthOff UVLO threshold hysteresis SthHyst... - Page 12 Electrical characteristics L6470 Table 4. Electrical characteristics (continued) Symbol Parameter Test condition Max Unit POW_SR = '00'; Iout = +1A POW_SR = '00'; Iout = -1A Fall time POW_SR = ‘11’, I = ±1A POW_SR = ‘10’, I = ±1A POW_SR = ‘01’, I = ±1A load...
- Page 13 L6470 Electrical characteristics Table 4. Electrical characteristics (continued) Symbol Parameter Test condition Max Unit Logic inputs and outputs Low level logic input voltage High level logic input voltage High level logic input current = 5 V µA Low level logic input current = 0 V µA = 3.3 V,...
- Page 14 Electrical characteristics L6470 Table 4. Electrical characteristics (continued) Symbol Parameter Test condition Max Unit SPI clock high and low time Chip select setup time setCS Chip select hold time holCS Deselect time disCS Data input setup time setSDI Data input hold time holSDI Data output enable time enSDO...
- Page 15 L6470 Electrical characteristics Table 4. Electrical characteristics (continued) Symbol Parameter Test condition Max Unit Power bridges disabled, μs Charge pump power-on and wake-up time = 10nF, cpwu = 220nF boot Internal voltage regulator Voltage regulator output voltage Voltage regulator output current Voltage regulator output voltage drop = 40mA REG, drop...
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Page 16: Pin Connection
Pin connection L6470 Pin connection Figure 2. Pin connection (top view) Pin list Table 5. Pin description Name Type Function Power Logic outputs supply voltage (pull-up reference) Internal 3 V voltage regulator output and 3.3 V external VREG Power logic supply Oscillator pin 1. - Page 17 L6470 Pin connection Table 5. Pin description (continued) Name Type Function Full bridge B power supply pin. must be connected to Power supply PGND Ground Power ground pin OUT1A Power output Full bridge A output 1 OUT2A Power output Full bridge A output 2 OUT1B Power output Full bridge B output 1...
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Page 18: Typical Applications
Typical applications L6470 Typical applications Table 6. Typical application values Name value 220 nF 100 µF VSPOL 100 nF 47 µF REGPOL 100 nF 10 µF DDPOL BAT46SW or 2x 1N4148 220 nF BOOT 10 nF 39 kΩ 100 Ω 10 nF 2.7 kΩ... -
Page 19: Functional Description
L6470 Functional description Functional description Device power-up At power-up end, the device state is the following: ● Registers are set to default, ● Internal logic is driven by internal oscillator and a 2MHz clock is provided by OSCOUT pin, ● Bridges are disabled (High Z), ●... -
Page 20: Microstepping
Functional description L6470 Figure 4. Charge pump circuitry Microstepping The driver is able to divide the single step into up to 128 microsteps. Stepping mode can be programmed by STEP_SEL parameter in STEP_MODE register (see Table 17). Step mode can be only changed when motor is stopped. Every time the step mode is changed the electrical position (i.e. -
Page 21: Absolute Position Counter
L6470 Functional description When motor speed is greater than a programmable full step speed threshold, the L6470 switches automatically to full-step mode; the driving mode returns to microstepping when motor speed decrease below the full step speed threshold. Full step speed threshold is set through the FS_SPD register (see Section 9.1.9). -
Page 22: Motor Control Commands
Functional description L6470 Motor control commands The L6470 can accept different types of commands: ● constant speed commands (Run, GoUntil, ReleaseSW), ● absolute positioning commands (GoTo, GoTo_DIR, GoHome, GoMark), ● motion commands (Move), ● stop commands (SoftStop, HardStop, SoftHiz, HardHiz). For detailed command descriptions refer to Section 9.2 on page 6.7.1... -
Page 23: Motion Commands
L6470 Functional description Figure 8. Positioning command examples 6.7.3 Motion commands Motion commands produce a motion in order to perform a user-defined number of microsteps in a user-defined direction that are sent to the device together with the command (see Figure Performed motor motion is compliant to programmed speed profile boundaries (acceleration, deceleration, minimum and maximum speed). -
Page 24: Step-Clock Mode
Functional description L6470 SoftHiZ command causes the motor to decelerate with programmed deceleration value until MIN_SPEED value is reached and then forces the bridges in high impedance state (no holding torque is present). HardHiZ command instantly forces the bridges in high impedance state (no holding torque is present). -
Page 25: Overcurrent Detection
L6470 Functional description Table 7. CL values according to external oscillator frequency Crystal/resonator freq. 8MHz 25pF (ESR = 80Ω) 16MHz 18pF (ESR = 50Ω) 24MHz 15pF (ESR = 40Ω) 32MHz 10pF (ESR = 40Ω) 1. First harmonic resonance frequency. 2. Lower ESR value allows driving greater load capacitors. If a direct clock source is used, it must be connected to OSCIN pin and OSCOUT pin supplies the inverted OSCIN signal (see Figure... -
Page 26: Undervoltage Lock-Out (Uvlo)
Functional description L6470 The overcurrent threshold can be programmed through the OCD_TH register in one of 16 available values ranging from 375 mA to 6 A with steps of 375 mA (see Table 8, paragraph 9.1.17). It is possible to set if an overcurrent event causes or not the MOSFETs turn-off (bridges in high impedance status)acting on OC_SD bit in the CONFIG register (see paragraph 9.1.21). -
Page 27: External Switch (Sw Pin)
L6470 Functional description On exit from standby mode the bridges are disabled (HiZ flag high) and whichever motion command makes the device exiting from High Z state (HardStop and SoftStop included). Caution: It is not recommended to reset device when outputs are active. The device should be switched to high impedance state before being reset. -
Page 28: Programmable Dmos Slew-Rate, Dead-Time And Blanking-Time
Functional description L6470 6.14 Programmable DMOS slew-rate, dead-time and blanking-time Using the POW_SR parameter in the CONFIG register, it is possible to set the commutation speed of the power bridges output (see Table 25, paragraph 9.1.21). 6.15 Integrated analog to digital converter The L6470 integrates a NADC bit ramp-compare analog to digital converter with a reference voltage equal to VREG. -
Page 29: Busy\Sync Pin
L6470 Functional description 6.17 BUSY\SYNC pin This pin is an open drain output which can be used as busy or synchronization signal according to SYNC_EN bit value (STEP_MODE register). 6.17.1 BUSY operation mode The pin works as busy signal when SYNC_EN bit is set low (default condition). In this mode the output is forced low while a constant speed, absolute positioning or motion command is under execution. -
Page 30: Phase Current Control
Phase current control L6470 Phase current control The L6470 controls the phase current applying a sinusoidal voltage to motor windings. Phase current amplitude is not directly controlled but depends on phase voltage amplitude, load torque, motor electrical characteristics and rotation speed. Sinewave amplitude is proportional to the motor supply voltage multiplied by a coefficient (K ). -
Page 31: Sensorless Stall Detection
L6470 Phase current control Sensorless stall detection Depending on motor speed and load angle characteristics, L6470 offers a motor stall condition detection using a programmable current comparator. When a stall event occurs, the respective flag (STEP_LOSS_A or STEP_LOSS_B) is forced low until a GetStaus command or a system reset occurs (see paragraph 9.2.20 Low speed optimization... -
Page 32: Bemf Compensation
Phase current control L6470 BEMF compensation Using the speed information, a compensation curve is added to the amplitude of the voltage waveform applied to the motor winding in order to compensate the BEMF variations during acceleration and deceleration (see Figure 14 Compensation curve is approximated by a stacked line with a starting slope (ST_SLP) when speed is lower than a programmable threshold speed (INT_SPEED) and a fine slope (FN_SLP_ACC and FN_SLP_DEC) when speed is greater than the threshold speed (see... -
Page 33: Winding Resistance Thermal Drift Compensation
L6470 Phase current control Figure 15. Motor supply voltage compensation circuit Motor supply voltage compensation can be enabled setting high the EN_VSCOMP bit of the CONFIG register (see Table 21 , paragraph 9.1.21 ). If EN_VSCOMP bit is low the compensation is disabled and the internal analog to digital converter is at user disposal;... -
Page 34: Serial Interface
Serial interface L6470 Serial interface The integrated 8bit serial peripheral interface (SPI) is used for a synchronous serial communication between the host microprocessor (always master) and the L6470 (always slave). The SPI uses chip select (CS), serial clock (CK), serial data input (SDI) and serial data output (SDO) pins. -
Page 35: Figure 17. Daisy-Chain Configuration
L6470 Serial interface Figure 17. Daisy-chain configuration Doc ID 16737 Rev 2 35/64... -
Page 36: Programming Manual
Programming manual L6470 Programming manual Registers and flags description Following a map of the user registers available (detailed description in respective paragraphs): Table 8. Registers map Address Reset Reset Len. Remarks Register name Register function [bit] [Hex] Value ABS_POS Current position 000000 0 R, WS EL_POS... -
Page 37: Abs_Pos
L6470 Programming manual Table 8. Registers map (continued) Address Reset Reset Len. Remarks Register name Register function [bit] [Hex] Value Internal oscillator, 2MHz OSCOUT clock, supply voltage compensation CONFIG IC configuration 2E88 disabled, R, WH overcurrent shutdown enabled, slew-rate = 290 V/µs PWM frequency = 15.6kHz. -
Page 38: Mark
Programming manual L6470 9.1.3 MARK The MARK register contains an absolute position called MARK in according to the selected step mode; the stored value unit is equal to the selected step mode (full, half, quarter, etc.). It is in two's complement format and it ranges from -2 to +2 9.1.4 SPEED... -
Page 39: Dec
L6470 Programming manual 9.1.6 The DEC register contains the speed profile deceleration expressed in step/tick (format unsigned fixed point 0.40). In order to convert DEC value in step/s the following formula can be used: Equation 6 − ⋅ step tick where DEC is the integer number stored into the register and tick is 250 ns. -
Page 40: Fs_Spd
Programming manual L6470 where MIN_SPEED is the integer number stored into the register and tick is the ramp 250 The available range is from 0 to 976.3 step/s with a resolution of 0.238 step/s. When LSPD_OPT bit is set high, low speed optimization feature is enabled and MIN_SPEED value indicates the speed threshold below which the compensation works. -
Page 41: Int_Speed
L6470 Programming manual Table 11. Voltage amplitude regulation registers KVAL_X [7..0] Output voltage x (1/256) x (254/256) x (255/256) 9.1.11 INT_SPEED The INT_SPEED register contains the speed value at which the BEMF compensation curve changes slope (see paragraph for details). Its value is expressed in step/tick and to convert it in [step/s] the following formula can be used: Equation 9 −... -
Page 42: Fn_Slp_Dec
Programming manual L6470 9.1.14 FN_SLP_DEC The FN_SLP_DEC register contains the BEMF compensation curve slope that is used when the speed is greater than the intersect speed during deceleration (see paragraph details). Its value is expressed in s/step and the available range is from 0 to 0.004 with a resolution of 0.000015. -
Page 43: Ocd_Th
L6470 Programming manual 9.1.17 OCD_TH The OCD_TH register contains the overcurrent threshold value (see paragraph details). The available range is from 375 mA to 6 A, steps of 375 mA as shown in Table 14 Table 14. Overcurrent detection threshold OCD_TH [3..0] Overcurrent detection threshold 375 mA... -
Page 44: Table 17. Step Mode Selection
Programming manual L6470 Table 17. Step mode selection STEP_SEL[2..0] Step mode Full step Half step 1/4 microstep 1/8 microstep 1/16 microstep 1/32 microstep 1/64 microstep 1/128 microstep Every time the step mode is changed the electrical position (i.e. the point of microstepping sinewave that is generated) is reset to the first microstep. -
Page 45: Alarm_En
L6470 Programming manual the synchronization signal is obtained starting from electrical position information (EL_POS register) according to following Table 9 Table 19. SYNC signal source SYNC_SEL[2..0] Source EL_POS[7] EL_POS[6] EL_POS[5] EL_POS[4] EL_POS[3] EL_POS[2] EL_POS[1] EL_POS[0] 9.1.20 ALARM_EN The ALARM_EN register allows selecting which alarm signals are used to generate the FLAG output. -
Page 46: Table 22. Oscillator Management
Programming manual L6470 The OSC_SEL and EXT_CLK bits set the system clock source: Table 22. Oscillator management EXT_CLK OSC_SEL[2..0] Clock source OSCIN OSCOUT Internal Oscillator: 16MHz Unused Unused Supplies a 2MHz Internal Oscillator: 16MHz Unused clock Supplies a 4MHz Internal Oscillator: 16MHz Unused clock Supplies a 8MHz... -
Page 47: Table 24. Overcurrent Event
L6470 Programming manual The OC_SD bit sets if an overcurrent event causes or not the bridges to turn-off; the OCD flag in status register is forced low anyway: Table 24. Overcurrent event OC_SD Overcurrent event Bridges shut down Bridges do not shut down The POW_SR bits set the slew rate value of power bridge output: Table 25. -
Page 48: Table 28. Pwm Frequency: Multiplication Factor
Programming manual L6470 The F_PWM_DEC bits set the multiplication factor of PWM frequency generation. Table 28. PWM frequency: multiplication factor F_PWM_DEC [2..0] Multiplication factor 0.625 0.75 0.875 1.25 1.75 In the following tables all available PWM frequencies are listed according to oscillator frequency, F_PWM_INT and F_PWM_DEC values (CONFIG register OSC_SEL parameter has to be correctly programmed). -
Page 49: Table 30. Available Pwm Frequencies [Khz]: 16 Mhz Oscillator Frequency
L6470 Programming manual Table 30. Available PWM frequencies [kHz]: 16 MHz oscillator frequency F_PWM_DEC F_PWM_INT 19.5 23.4 27.3 31.3 39.1 46.9 54.7 62.5 11.7 13.7 15.6 19.5 23.4 27.3 31.3 10.4 13.0 15.6 18.2 20.8 11.7 13.7 15.6 10.9 12.5 10.4 Table 31. -
Page 50: Status
Programming manual L6470 Table 32. Available PWM frequencies [kHz]: 32 MHz oscillator frequency F_PWM_DEC F_PWM_ 39.1 46.9 54.7 62.5 78.1 93.8 109.4 125.0 19.5 23.4 27.3 31.3 39.1 46.9 54.7 62.5 13.0 15.6 18.2 20.8 26.0 31.3 36.5 41.7 11.7 13.7 15.6 19.5... -
Page 51: Table 34. Status Register Dir Bit
L6470 Programming manual The UVLO, TH_WRN, TH_SD, OCD, STEP_LOSS_A, STEP_LOSS_B, NOTPERF_CMD, WRONG_CMD and SW_EVN flags are latched: when the respective conditions make them active (low or high) they remain in that state until a GetStatus command is sent to the IC. The BUSY bit reflects the BUSY pin status. -
Page 52: Application Commands
Programming manual L6470 Application commands The commands summary is given in the Table 36 Table 36. Application commands Command Mnemonic Command binary code Action [7..5] [4] [2..1] [0] Nothing SetParam(PARAM,VALUE) 000 [PARAM] Writes VALUE in PARAM register GetParam(PARAM) [PARAM] Returns the stored value in PARAM register Run(DIR,SPD) DIR Sets the target speed and the motor direction Put the device in step clock mode and impose DIR... -
Page 53: Command Management
L6470 Programming manual 9.2.1 Command management The host microcontroller can control motor motion and configure the L6470 through a complete set of commands. All commands are composed by a single byte. After the command byte, some bytes of arguments should be needed (see Figure 18 ). -
Page 54: Setparam (Param, Value)
Programming manual L6470 9.2.3 SetParam (PARAM, VALUE) Table 38. SetParam command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PARAM Byte 2 (if needed) From host Byte 1 (if needed) Byte 0 The SetParam command sets the PARAM register value equal to VALUE;... -
Page 55: Run (Dir, Spd)
L6470 Programming manual 9.2.5 Run (DIR, SPD) Table 40. Run command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 from host SPD (Byte 2) from host SPD (Byte 1) from host SPD (Byte 0) from host The Run command produces a motion at SPD speed;... -
Page 56: Move (Dir, N_Step)
Programming manual L6470 9.2.7 Move (DIR, N_STEP) Table 42. Move command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 from host N_STEP (Byte 2) from host N_STEP (Byte 1) from host N_STEP (Byte 0) from host The move command produces a motion of N_STEP microsteps;... -
Page 57: Goto_Dir (Dir, Abs_Pos)
L6470 Programming manual 9.2.9 GoTo_DIR (DIR, ABS_POS) Table 44. GoTo_DIR command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 from host ABS_POS (Byte 2) from host ABS_POS (Byte 1) from host ABS_POS (Byte 0) from host The GoTo_DIR command produces a motion to ABS_POS absolute position imposing a... -
Page 58: Releasesw (Act, Dir)
Programming manual L6470 9.2.11 ReleaseSW (ACT, DIR) Table 46. ReleaseSW command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 from host The ReleaseSW command produces a motion at minimum speed imposing a forward (DIR = '1') or reverse (DIR = '0') rotation. -
Page 59: Resetpos
L6470 Programming manual Any attempt to perform a GoMark command when a previous command is under execution (BUSY low) causes the command to be ignored and the NOTPERF_CMD flag to rise (see paragraph 9.1.22 9.2.14 ResetPos Table 49. ResetPos command structure Bit 7 Bit 6 Bit 5... -
Page 60: Softhiz
Programming manual L6470 When the motor is in high-impedance state, a HardStop command forces the bridges to exit from high impedance state; no motion is performed. 9.2.18 SoftHiZ Table 53. SoftHiZ command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1... -
Page 61: Package Mechanical Data
L6470 Package mechanical data Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. -
Page 62: Figure 21. Htssop28 Mechanical Data
Package mechanical data L6470 Figure 21. HTSSOP28 mechanical data 62/64 Doc ID 16737 Rev 2... -
Page 63: Revision History
L6470 Revision history Revision history Table 57. Document revision history Date Revision Changes 06-Nov-2009 Initial release. 05-Nov-2010 Document status promoted from preliminary data to datasheet. Doc ID 16737 Rev 2 63/64... - Page 64 No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein.
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