FAN8727

www.fairchildsemi.com FAN8727 Spindle + 4-CH Motor Drive IC Features • • • • • • • • • • • • Built-in Power Save Circuit Built-in Current Limit Circuit Built-in Thermal Shutdown Circuit (TSD) Built-in Hall Bias Built-in FG Signal Output Circuit Built-in Rotational Direction Detecting Circuit Built-in Protection Circuit For Reverse Rotation Built-in Short Brake Circuit Built-in Normal OP-AMP Built-in 4-CH Balanced Transformerless (BTL) Driver Built-in BTL MUTE Circuit (CH1-2, CH3 and CH4) Corresponds to 3.3V DSP Description The FAN8727 is a monolithic integrated circuit suitable for a 4-CH motor driver which drives the tracking actuator, focus actuator, sled motor, loading motor and 3-phase BLDC spindle motor of the MDP/CAR-MD/CAR-NAVIGATION system. 48-QFPH-1414 Typical Applications • • • • Mini Disk Player Digital Video Disk Player Car Mini Disk Player Car Navigation System Ordering Information Device FAN8727 FAN8727_NL Notes: note1 Package 48-QFPH-1414 48-QFPH-1414 Operating Temperature -35°C ~ +85°C -35°C ~ +85°C 1. NL: Lead-free type Rev. 1.0.3 ©2004 Fairchild Semiconductor Corporation FAN8727 Pin Assignments BTLSNGD MUTE12 MUTE3 38 48 VH FG ECR EC 1 2 3 4 5 6 47 46 45 44 43 42 41 40 39 MUTE4 37 36 35 34 33 32 31 DO4 + DO4 − AVM3 DO3 + DO3 − BTLPGND2 30 29 28 27 26 25 VCC2 PC1 FAN8727 SIGGND VM CS1 SS DIR SB 7 8 9 10 11 12 13 PWRGND 14 A3 15 A2 16 A1 17 OPIN+ 18 OPIN− 19 OPOUT 20 VCC1 21 AVM12 22 DI4 23 DI3 24 DI2 AVM4 BIAS H3 + H2 + H1 + H3 − H2 − H1 − BTLPGND1 DO2 + DO2 − DO1 + DO1 − DI1 2 FAN8727 Pin Definitions Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Pin Name VH FG ECR EC VCC2 PC1 SIGGND VM CS1 S/S DIR SB PWRGND A3 A2 A1 OPIN+ OPINOPOUT VCC1 AVM12 DI4 DI3 DI2 DI1 DO1DO1+ DO2DO2+ BTLPGND1 BTLPGND2 DO3DO3+ I/O I O I I I I O I O O O I I O I I I I O O O O O O Hall Bias FG Signal Output Torque Control Reference Torque Control Signal Supply Voltage Phase Compensation Capacitor Signal Ground Motor Supply Voltage Current Sensor Start/stop 3-Phase Rotational Direction Output Short Brake Power Ground 3-Phase Output 3 3-Phase Output 2 3-Phase Output 1 OP-AMP Input (+) OP-AMP Input (-) OP-AMP Output Supply Voltage BTL Ch-1, 2 Motor Supply Voltage BTL Drive Input 4 BTL Drive Input 3 BTL Drive Input 2 BTL Drive Input 1 BTL Drive 1 Output (-) BTL Drive 1 Output (+) BTL Drive 2 Output (-) BTL Drive 2 Output (+) BTL Power Ground 1 BTL Power Ground 2 BTL Drive 3 Output (-) BTL Drive 3 Output (+) Pin Function Description 3 FAN8727 Pin Definitions (Continued) Pin Number 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Pin Name AVM3 DO4DO4+ MUTE4 MUTE3 MUTE12 AVM4 BIAS BTLSGND H1H1+ H2H2+ H3H3+ I/O O O I I I I I I I I I Pin Function Description BTL CH3 Motor Supply Voltage BTL Drive 4 Output (-) BTL Drive 4 Output (+) BTL Drive Mute CH 4 BTL Drive Mute CH 3 BTL Drive Mute CH 1, 2 BTL CH 4 Motor Supply Voltage BTL Bias Voltage BTL Drive Signal Ground Hall1(-) Input Hall1(+) Input Hall2(-) Input Hall2(+) Input Hall3(-) Input Hall3(+) Input 4 FAN8727 Internal Block Diagram BTLSGND MUTE3 38 48 47 46 45 44 43 42 41 40 MUTE12 39 VH FG ECR EC VCC2 PC1 1 MUTE3 MUTE4 2 MUTE12 Hall Bias FG Generator MUTE4 37 AVM4 BIAS H3+ H3- H2+ H2- H1+ H1- 36 DO4+ DO4AVM3 DO3+ DO3BTLPGND2 35 3 Hall Amp TSD Detection AVM4 34 4 33 5 32 Logic 6 AVM3 31 Absolute Values VM CS1 Current Sense Amp Reverse Rotation AVM12 Output Current Limit SIGGND VM CS1 SS DIR SB 7 30 BTLPGND1 DO2+ DO2DO1+ DO1DI1 8 29 9 Short Brake AVM12 Distributor 28 10 27 11 26 12 25 13 14 15 16 17 18 19 20 21 22 23 24 PWRGND OPOUT AVM12 OPIN+ OPIN- VCC1 A3 DI4 DI3 DI2 A2 A1 5 FAN8727 Equivalent Circuits Hall Bias FG Signal Output 10K Ω 1 25Ω 2 100KΩ Torque Control Reference & Signal Phase Compensation Capacitor 3 4 25Ω 1KΩ 6 25Ω 1KΩ Current Detector Start/Stop 100KΩ 9 5KΩ 10 25Ω 50KΩ 30KΩ 6 FAN8727 Equivalent Circuits (Continued) 3-Phase Rotational Direction Output Short Brake 10KΩ 11 25Ω 12 1kΩ 20kΩ 25Ω 3-Phase Output OP-AMP Input 15KΩ 2KΩ 2KΩ 14 15 16 17 25Ω 1KΩ 1KΩ 25Ω 18 2KΩ 2KΩ OP-AMP Ouput BTL Drive Input 22 18 23 24 25 25Ω 50Ω 7 FAN8727 Equivalent Circuits (Continued) BTL Drive Output BTL Drive Mute 26 27 20KΩ 37 38 39 25Ω 50KΩ 30KΩ 28 29 32 33 35 36 30KΩ BTL Bias Voltage Hall Input 43 44 46 25Ω 1KΩ 1KΩ 25Ω 41 25Ω 0.5KΩ 45 47 48 8 FAN8727 Absolute Maximum Ratings ( Ta=25°C) Parameter Supply Voltage (BTL Signal) Supply Voltage (Spindle Signal) Supply Voltage (Motor) Supply Voltage (BTL Motor) Power Dissipation Operating Temperature Range Storge Temperature Range Maximum Output Current (Spindle Part) Maximum Output Current (BTL Part) Symbol VCC1max VCC2max VMmax VMBTLmax Pd Topr Tstg IOMAXS IOMAXB Value 15 7 15 15 3.0note -35 ~ +85 -55 ~ +150 1.3 1 Unit V V V V W °C °C A A Note: 1. When mounted on 70mm × 70 mm × 1.6mm PCB (Phenolic resin material) 2. Power dissipation is reduced 24 mW/°C for using above Ta=25°C 3. Do not exceed Pd and SOA. Pd [mW] 3,000 2,000 1,000 0 0 25 50 75 100 125 150 175 Ambient Temperature, Ta [°C] Recommended Operating Conditions ( Ta=25°C) Parameter Operating Supply Voltage (BTL Signal) Operating Supply Voltage (Spindle Signal) Operating Supply Voltage ( Spindle Motor) Operating Supply Voltage (BTL Motor) Note: The VM should be turn on before the VCC2. Symbol VCC1 VCC2 VM note Min. 4.5 4.5 4.5 4.5 Typ. - Max. 13.2 5.5 13.2 VCC1 Unit V V V V VMBTL 9 FAN8727 Electrical Characteristics (Ta=25°C, VCC2=5V, VM=12V) Parameter Circuit Current 1 Circuit Current 2 START/STOP On Voltage Range Off Voltage Range HALL BIAS Hall Bias Voltage HALL AMP Hall Bias Current In-Phase in Voltage Range Minimum in Level In Voltage Range Offset Voltage (-) In Current In/output Gain FG FG Output Voltage (H) FG Output Voltage (L) Input Voltage Range OUTPUT BLOCK Saturation Voltage (Upper TR) Saturation Voltage (Lower TR) Torque Limit Current DIRECTION DETECTOR Dir Output Voltage (H) Dir Output Voltage (L) SHORT BRAKE On Voltage Range Off Voltage Range VSBON VSBOFF 2.5 0 VCC 1.0 V V VDIRH VDIRL IFG= -10uA IFG= 10uA 3.0 VCC 0.5 V V VOH VOL ITL IO= -300mA IO= 300mA RCS= 0.5Ω 560 0.9 0.2 700 1.6 0.6 840 V V mA note note note Symbol ICC 1 ICC2 VPSON VPSOFF VHB IHA VHAR VINH EC ECOFFECOFF+ ECIN GEC VFGH VFHL VFGR Condition Power Save=0V Power Save=5V L-H Circuit On H-L Circuit Off IHB= 20mA ECR= 2.5V ECR= 2.5V EC= ECR= 2.5V ECR= 2.5V, RCS= 0.5Ω IFG= -10uA IFG= 10uA Hn+, Hn- input D-range Min. 2.5 1.5 60 0.5 -100 20 -5 0.41 3.0 1.5 Typ. 0.3 4.5 1.2 1 -50 50 -1 0.51 - Max. 1 6 0.5 1.8 5 4.0 3.3 -20 100 0.61 VCC 0.5 4.0 Unit mA mA V V V uA V mVpp V mV mV uA A/V V V V TORQUE CONTROL Offset Voltage (+) Note: Guaranteed field ( No EDS / Final test ) 10 FAN8727 Electrical Characteristics (Continued) BTL Drive Part (Ta=25°C, VCC1=12V, VMBTL=12V, RL=24Ω) Parameter Quiescent Circuit Current Output Offset Voltage Maximum Output Amplitude Voltage Voltage Gain Ripple Rejection Ratio Slew Rate note note Symbol ICC VOO VOM GVC RR SR VMOFFCH VMONCH VOF IB1 VOH1 VOL1 ISINK ISOU1 note Condition VIN=0.1Vrms, 1kHz VIN=0.1Vrms, 120kHz 120Hz, 2Vpp pin37, 38, 39 = Variation pin37, 38, 39 = Variation f=1kHz, VIN= -75dB f=120Hz, VIN= -20dB f=120Hz, 2Vp-p f=1kHz, VIN= -20dB Min. -40 9.5 10.5 2.5 -20 11 10 5 - Typ. 18 10.5 12.0 60 1.0 25 8 75 65 1 80 Max. 25 40 13.5 1.0 +20 600 0.1 - Unit mA mV V dB dB V/us V V mV nA V V mA mA dB dB V/us dB CH Mute off Voltage CH Mute On Voltage NORMAL OP- AMP Input Offset Voltage Input Bias Current High Level Output Voltage Low Level Output Voltage Output Sink Current Output Source Current Open Loop Voltage Gain Ripple Rejection Ratio Slew Ratenote Common Mode Rejection Rationote note GVO1 RR1 SR1 CMRR1 Note: Guaranteed field ( No EDS / Final test ) 11 FAN8727 Calculation of Gain & Torque Limit Current VM IO VM RS Current / Voltage Convertor − Vin EC ECR + − Gm Absolute Values + R1 − + + + Vmax − VM Max. output current limiting Driver − VS Output Current sense + CS1 (Pin 9) Negative Feedback loop U IO V W Power Transistors Commutation Distributor H1 H2 H3 0.255 which is made from GM times R1 is fixed value within IC. 0.255 Gain = -------------RS Vmax (see above block diagram) is setted to 350mV. 350 [ mV ] --------------Itl [ mA ] = Vmax = ----------------------RS RS 12 FAN8727 Application Information 1. Mute Function 1) Mute Control Voltage Condition When using the mute function, the applied control voltage condition is as follows. MUTE ON Voltage MUTE OFF Voltage 2.5[V] Above OPEN or 0.5[V] Below Mute Function Operation Normal Operation 2) Separated Channel Mute Function These pins are used for individual channel mute operation. - When the mute pins (pin 37, 38 and 39) are OPEN or the voltage of the mute pins are below 0.5[V], the mute circuit is stopped and BTL output circuits operate normally. - When the mute pins (pin 37, 38 and 39) are above 2.5[V], the mute circuits are activated so that the BTL output circuits will be muted. - If the junction temperature rises above 175°C, then the thermal shutdown (TSD) circuit is activated and all the output circuits (4-CH BTL Drivers and 3-phase BLDC Driver) are muted. 2. 4-CH Balanced Transformerless (Btl) Driver VCC DRIVE AMP X2 Q1 27 29 33 Q3 36 M 26 28 32 35 GND Q2 DRIVE AMP X2 Q4 41 Vbias Vin Rextern 22 23 24 25 10k + AMP1 − LEVEL SHIFT - The voltage, Vbias, is the reference voltage given by the external bias voltage of pin 41. - The input signals, Vin, through the pins (pin 22, 23, 24 and 25) are amplified 10K/Rextern times and then fed to the level shift. - The level shift produces the current due to the difference between the input signal (Vin) and the arbitrary reference voltage (Vbias). The current produced as + ∆I and - ∆I are fed into the drive buffers. - The drive buffer operates the power TR of the output stage according to the state of the input signal(Vin). - The output stage is the BTL driver, and the motor (or actuator) is rotating in forward direction by operating TR Q1 and TR Q4. On the other hand, if TR Q2 and TR Q3 are operating, the motor (or actuator) is rotating in reverse direction. - When the input signal Vin, through the pin (pin 22, 23, 24 and 25) is below the Vbias, then the motor (actuator) is in forward direction. 13 FAN8727 - When the input signal Vin, through the pin (pin 22, 23, 24 and 25) is above the Vbias, then the motor (actuator) is in reverse direction. - If you want to change the gain, then modify the external resistor's value (Rextern) 3. Torque & Output Current Control Torque Control & Output Current Control VM VM RNF + Torque sense amp EC VAMP + − + − TSD ECR Current sense amp − VRNF IO Driver M Gain Controller - By amplifying the voltage difference between EC and ECR from the Servo IC, the torque sense AMP produces the input (VAMP) for the current sense AMP. - The current sense AMP produces the input for the Gain controller to allow the output current (IO) of the driver to be controlled by the input voltage (VAMP), where the output current (IO) is detected by the sense resistor (RNF) and is converted into VRNF. - In the end, the signals of the Servo IC control the velocity of the motor by controlling the output current (IO) of the driver. - When the junction temperature rises up to about 175°C, then the output drive circuit will be shut down. - The range of the torque control input voltage is as shown below. VRNF [V] Reverse Forward Rotation Ec < ECR Forward rotation Stop after detecting reverse rotation Ecoff− Ecoff+ Ec > ECR 3 mV 0 ECR-EC[V] The input range (EC) of the Torque Sense AMP is 0.5V ~ 3.3V 14 FAN8727 4. Power Save Function Bias block VCC 100k Start Stop 12KΩ 10 30KΩ Q1 - This function block operates the power saving function. - The power save circuit is activated by operating TR Q1. - When the SS (Start/Stop) pin 10 is high (VCC), the TR Q1 is turned on so that the bias circuit is enabled. On the other hand, when the SS (Start/Stop) pin 10 is Open or Low (GND), the TR Q1 is turned off so that the bias circuit is disabled. - The power save operation controlled by SS (pin 10) input conditions is as follows; Pin#10 HIGH OPEN/LOW FAN8727 START STOP 5. Short Brake Function VM Drive logic VCC OFF MOTOR 14 ON OFF 80KΩ 12 1KΩ Q1 ON 15 16 When the pick-up part moves from the inner to the outer spindle of the MD, the brake function of the reverse voltage is commonly employed to rate the rotational velocity of the spindle motor.However, if the spindle motor rotates rapidly, the brake function of the reverse voltage may produce too much heat at the drive IC. To remove these shortcomings and to enhance efficiency, the short brake function is added to FAN8727. When the short brake function is active, all upper Power transistors are turned off and the lower Power transistors turned on, so as to reduce the rotational velocity of the motor. The short brake operation controlled by SB (pin 12), and the inputs conditions are as follows. Pin#12 HIGH LOW SHORT BRAKE ON OFF 15 FAN8727 6. Thermal Shutdown (Tsd) Function When the junction temperature rises up to about 175°C, then the output drive circuit is shut down, when the junction temperature falls off to about 160°C, the output drive circuit will be normally operated. It has the temperature hysteresis of about 15°C. 7. Rotational Direction Detecting Function VCC H2+ H2− + − D R Q 11 DIR Rotation EC < ECR EC > ECR Forward Reverse DIR Low High CK H3+ H3− + − D-F/F - The forward and reverse rotations of the MD are detected by the circuit, as shown in the above Table. - The rotational direction of the MD can be learned by the output waveforms of the hall sensor and/or the driver. Let the three hall sensors be H1, H2 and H3 respectively. If the hall sensors turn on in the order, H1 → H2 → H3, of the reverse rotation, the output waveforms of the hall sensors will be as shown below. H1 H2 H3 ( a) Inversely, if the hall sensors turn on in the order, H3→ H2→ H1, of the forward rotation, the output waveforms of the hall sensors will be as shown mext page. 16 FAN8727 H1 H2 H3 ( b) In the cases above, the value of H2 at the falling edges of H3 is Low in figure , while High in figure . The rotational direction detector takes advantage of this phenomenon. 8. Reverse Rotation Preventing Function EC ECR + − Current Sense Amp H2+ H2− + − D CK D-F/F Q H3+ H3− + − Gain Controller Driver M - The forward and reverse rotation of the motor are detected, as shown in the table below, by the circuit shown above. Consequently at reverse rotation, the D-F/F output Q becomes Low and cuts off the output current sense Amp, resulting in the stoppage of the Gain controller function. - When the MD is rotating in forward direction, EC>ECR is sometimes controlled to retard and/or stop the MD. As the controlling time of EC>ECR gets longer, MD slows down, stops, and then rotates in the reverse direction. To prevent the MD from rotating in the reverse direction, a reverse rotation resistant function is required. Its operational principles are discussed below. Rotation Forward Reverse H2 H L H3 H→L H→L D-F/F H L Reverse Rotation Preventer ECECR Brake and Stop Stop 17 FAN8727 9. Fg Output Function The FG output, which detects the number of rotations of the MD, is generated by combination zero-crossing the output waveforms of the hall sensors. The FG output circuit is as shown below. + H1 − H2 + − FG OUTPUT + H3 − 10. Hall Sensor Connection External Hall sensors are used in series or parallel connection as shown below. VCC VCC HALL 1 HALL 1 HALL 2 HALL 3 HALL 2 HALL 3 1 VH 1 VH 18 FAN8727 11. Hall Input Output Timming Chart The 3-phase hall signal is amplified in the hall amplifiers and sent to the matrix section, where the signal is further amplified and combined. After the signal is converted to a current in the amplitude control circuit, the current is supplied to the output driver, which then provides a motor drive current. The phases of the hall input signal, output voltage, and output current are shown below. H1 + H2 + H3 + A1 output current A1 output voltage A2 output current A2 output voltage A3 output current A3 output voltage 19 FAN8727 Test Circuits 1 BTL Drive Part 10µF 12V VMUTE VMUTE 39 MUTE12 38 MUTE3 2.5V 48 H3+ 47 H3− 46 H2+ 45 H2− 44 H1+ 43 H1− 42 BTLSGND 41 BIAS 40 AVM4 VMUTE 37 MUTE4 V DO4+ 36 DO4− 35 RL4’ SW4 12V 10µF SW3 RL4 1 VH 2 FG 3 ECR 4 EC 5 VCC2 6 PC1 AVM3 34 DO3+ 33 DO3− 32 BTLPGND2 31 RL3’ RL3 V V FAN8727 7 SIGGND 8 VM 9 CS1 10 SS 11 DIR PWRGND OPOUT AVM12 OPIN+ OPIN− VCC1 12 SB BTLPGND1 30 DO2+ 29 DO2− 28 DO1+ 27 DO1− 26 DI1 25 D14 D13 D12 SW1 SW2 RL2 RL1 V A3 A2 15 13 14 A1 16 17 18 19 20 21 22 23 24 SERVO AMP 12V BTL SVCC A 10µF TRACKING 10µF 12V CONTROL TRAY FOCUS SLED OPIN (+) V 2 3 10µF OPIN (−) V 1 SW6 3 VIN3 2 VIN3 1MΩ OPOUT VCC SW5 1 V 1MΩ 1.2kΩ 1 SW7 2 3 VIN1 Vp1 + − Vs1 V 20 FAN8727 Test Circuits 2 Spindle Motor Drive Part H3+ H3− H2+ H2− H1+ H1− A V V 48 H3+ SW12 1 2.5V SW13 2 3 EC SW14 4 5 5V A 6 VH FG ECR EC VCC2 PC1 A A A A A 47 H3− 46 H2+ 45 H2− 44 H1+ 43 H1− 42 BTLSGND 41 BIAS 40 AVM4 39 MUTE12 38 MUTE3 37 MUTE4 24 DO4+ 36 DO4− 35 AVM3 34 DO3+ 33 DO3− 32 BTLPGND2 31 FAN8727 SW15 12V 7 8 V 9 10 V SW17 11 12 IFR SIGGND VM CS1 SS DIR PWRGND OPOUT AVM12 OPIN+ OPIN− VCC1 SB BTLPGND1 30 DO2+ 29 DO2− 28 DO1+ 27 DO1− 26 DI1 25 D14 D13 23 D12 SW16 A3 A2 SW18 A1 13 14 15 16 17 18 19 20 21 22 VSB SW19 SW20 21 FAN8727 Application Circuits FOCUS TRACKING MUTE HALL3 HALL2 HALL1 BTL BIAS VOLTAGE +5V 48 H3+ 47 H3− 46 H2+ 45 H2− 44 H1+ 43 H1− 42 BTLSGND 41 BIAS 40 AVM4 39 MUTE12 38 MUTE3 37 MUTE4 1 FG SIGNAL 100pF SERVO TORQUE CONTROL VCC 10K 2 3 4 5 6 0.1µF VH FG ECR EC VCC2 PC1 TRAY MUTE DO4+ 36 DO4− 35 AVM3 34 +5V DO3+ 33 DO3− 32 SLED MOTOR SLED MUTE TRAY MOTOR BTLPGND2 31 FAN8727 7 12V 8 9 SYSTEM CONTROL ROTATE DIRECTION SHORT BREAK SIGGND VM CS1 BTLPGND1 30 DO2+ 29 DO2− 28 DO1+ 27 DO1− 26 PWRGND OPOUT AVM12 OPIN+ OPIN− VCC1 DI1 25 D14 D13 D12 FOCUS ACTUATOR 10 SS 11 DIR 12 SB TRACKING ACTUATOR A3 A2 15 13 14 A1 16 17 18 19 20 21 22 23 24 SERVO AMP VCC +5V TRACKING FOCUS SLED CONTROL TRAY 22 FAN8727 23 FAN8727 DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPOTATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. www.fairchildsemi.com 2/4/04 0.0m 001 Stock#DSxxxxxxxx  2004 Fairchild Semiconductor Corporation 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.