Dual Low Drop Voltage Regulator
TLE 7469
Features • Dual output 5 V (±2%), 215mA and 2.6 V1) (±4%), 200mA or 5 V (±2%), 215mA and 3.3 V (±3%), 200mA Ultra low quiescent current consumption < 55 µA Inhibit function Very low dropout voltage Reset with power-on delay Early Warning comparator Window watchdog Power sequencing for dual voltage µC Output protected against short circuit Wide operation range: up to 45 V Wide temperature range: -40 °C to 150 °C Overtemperature protection Overload protection Green Product (RoHS compliant) AEC Qualified
• • • • • • • • • • • • • •
Functional Description The TLE 7469 is a monolithic integrated voltage regulator with two voltage outputs specially designed to supply microcontrollers with dual supply voltage: 2.6 V1) or 3.3 V core and 5 V I/O voltage like the Infineon XC164 and XC161.
1) 2.5 V nominal specification range of most µCs is compatible with the 2.6 V output voltage range of the TLE 7469.
Type TLE 7469 GV52 TLE 7469 GV53
Data Sheet 1
Package PG-DSO-12 PG-DSO-12
Rev. 1.6, 2008-01-22
TLE 7469
The voltage regulator features an integrated reset circuitry which monitors the 2.6 V/ 3.3 V supply voltage. At power on the reset checks both supply voltages and performs the power-on reset with an adjustable delay time. The voltage difference is kept in the range -0.5 V < (VQ1 - VQ2) < 3.0 V even during power-on and power-down time enabling save µC operation without external clamping. Using the integrated early warning comparator an external voltage can be supervised. An integrated output sink current circuitry keeps the voltage at the Q1 pin below 5.5 V even when reverse currents are applied. Thus connected devices are protected from overvoltage damage. The regulator can be shut down via the Inhibit input causing the current consumption to drop below 9 µA. The TLE 7469 is designed for use under the severe conditions of automotive applications, and is therefore equipped with protection functions against overload, short circuit and overtemperature. It operates in the wide junction temperature range from -40 °C to 150 °C and offers the low quiescent current consumption required for body applications. For applications requiring extremely low noise levels the Infineon voltage regulator family TLE 42XY and TLE 44XY is more suited than the TLE 7469. A mV-range output noise on the TLE 7469 caused by the charge pump operation is unavoidable due to the ultra low quiescent current concept.
Data Sheet
2
Rev. 1.6, 2008-01-22
TLE 7469
I2
12
TLE 7469
10 Q1
Q2
Overtemperature Shutdown Bandgap Reference Reset Generator and Window Watchdog 9 5 RO WDI
1
Charge Pump 8 2 1 Inhibit Early Warning
7 4
DT SO
SI INH I1
3
Q1
Overtemperature Shutdown
1
Charge Pump GND 11
AEB03530_1.VSD
Figure 1
Block Diagram
Data Sheet
3
Rev. 1.6, 2008-01-22
TLE 7469
t
PG-DSO-12
I1 INH Q1 SO WDI GND
1 2 3 4 5 6
12 11 10 9 8 7
I2 GND Q2 RO SI DT
AEP03531.VSD
Figure 2 Table 1 1 2 3 4 5 6, 11 7 8 9 10 12 I1 INH Q1 SO WDI
Pin Configuration (top view) Pin Definitions and Functions Input voltage 1; block to ground directly at the IC with a 100 nF ceramic capacitor Inhibit Input; low level disables the IC. Integrated pull-down resistor Output voltage 1; 5.0 V, block to GND with a capacitor CQ1 ≥ 1 µF, ESR < 6 Ω at 10 kHz Sense output; Output of Early Warning Comparator, open collector output Watchdog Input; Trigger Input for Watchdog pulses Ground; Pin 6, 11 and heat slug must be connected to GND DT Delay timing; connect to GND, Q1 or Q2 to select Reset and Watchdog timing Sense input; Input for Early Warning comparator Reset output; open collector output with integrated 20 kΩ pull-up resistor Output voltage 2; 2.6 V (TLE 7469 GV52), 3.3 V (TLE 7469 GV53); block to GND with a capacitor CQ2 ≥ 1 µF, ESR < 6 Ω at 10 kHz Input voltage 2; block to ground directly at the IC with a 100 nF ceramic capacitor
Pin No. Symb. Function
GND DT SI RO Q2 I2
Data Sheet
4
Rev. 1.6, 2008-01-22
TLE 7469
Table 2
Absolute Maximum Ratings
-40 °C < Tj < 150 °C Parameter Input I1 Voltage Current Input I2 Voltage Current Output Q1 Voltage Voltage Current Output Q2 Voltage Voltage Current Inhibit Input INH Voltage Current Reset Output RO Voltage Voltage Current Delay Timing DT Voltage Voltage Current Symbol Limit Values Min. Max. 45 – 45 – 5.5 6.2 2 5.5 6.2 – 45 1 5.5 6.2 – 5.5 6.2 5 V mA V mA V V mA V V mA V mA V V mA V V mA – Internally limited – Internally limited Permanent Unit Remarks
VI1 II1 VI2 II2 VQ1 VQ1 IQ1 VQ2 VQ2 IQ2 VINH IINH VRO VRO IRO VDT VDT IDT
-0.3 – -0.3 – -0.3 -0.3 – -0.3 -0.3 – -0.3 -1 -0.3 -0.3 – -0.3 -0.3 -5
t < 10 s1)
Internally limited Permanent
t < 10 s1)
Internally limited Observe current limit
IINHmax2)
– Permanent
t < 10 s1)
internally limited Permanent
t < 10 s1)
–
Data Sheet
5
Rev. 1.6, 2008-01-22
TLE 7469
Table 2
Absolute Maximum Ratings (cont’d)
-40 °C < Tj < 150 °C Parameter Watchdog Input WDI Voltage Voltage Current Sense Input SI Voltage Current Sense Output SO Voltage Voltage Current Temperatures Junction temperature Storage temperature Symbol Limit Values Min. Max. 5.5 6.2 – 45 1 5.5 6.2 – 150 150 V V mA V mA V V mA °C °C Permanent Unit Remarks
VWDI VWDI IWDI VSI ISI VSO VSO ISO Tj Tstg
-0.3 -0.3 – -0.3 -1 -0.3 -0.3 – – -50
t < 10 s1)
internally limited Observe current limit
ISImax2)
– Permanent
t < 10 s1)
internally limited – –
1) Exposure to these absolute maximum ratings for extended periods (t > 10 s) may affect device reliability. 2) External resistor required to keep current below absolute maximum rating when voltages ≥ 5.5 V are applied.
Note: Maximum ratings are absolute ratings; exceeding any one of these values may cause irreversible damage to the integrated circuit. Integrated protection functions are designed to prevent IC destruction under fault conditions. Fault conditions are considered as outside normal operating range. Protections functions are not designed for continuous repetitive operation.
Data Sheet
6
Rev. 1.6, 2008-01-22
TLE 7469
Table 3 Parameter Input voltage Input voltage Input voltage
Operating Range Symbol Limit Values Min. Max. 45 45 45 150 4.4 107 58 48 V V V °C K/W K/W K/W K/W – 5.6 6.0 4.2 -40 – – – – Unit Remarks
Junction temperature Junction case Junction ambient Junction ambient Junction ambient
VI1 VI2 VI2 Tj Rthjc Rthj-a Rthj-a Rthj-a
VI1 > 8V VI1 < 8V
– – PCB, only Footprint1) PCB Heat Sink Area 300 mm2 1) PCB Heat Sink Area 600 mm2 1)
Thermal Resistances PG-DSO-12
1) Package mounted on PCB 80 × 80 × 1.5 mm3; 35µ Cu; 5µ Sn; zero airflow; 85 °C ambient temperature.
Note: In the operating range the functions given in the circuit description are fulfilled.
Data Sheet
7
Rev. 1.6, 2008-01-22
TLE 7469
Table 4
Electrical Characteristics
VI1 = 13.5 V; VI2 = 13.5 V; -40 °C < Tj < 150 °C; unless otherwise specified
Parameter Output Q1 Output voltage Output current limitation Symbol Limit Values Min. Typ. 5.0 – 300 25 20 60 – Max. 5.10 700 600 60 50 – 5.5 V mA mV mV mV dB V 1 mA < IQ1 < 215 mA, 6 V < VI1 < 16 V Unit Test Condition
VQ1 IQ1
4.90 320 – – – – –
VQ1 = 4.0 V IQ1 = 215 mA1)
1 mA < IQ1 < 215 mA
Output drop voltage; VDRQ1 VDRQ1 = VI1 - VQ1 Load regulation Line regulation ∆VQ1,Lo ∆VQ1,Li
Power Supply Ripple PSRR Rejection Reverse Output Current Protection Output Q2 Output voltage
VQ,REV
IQ1 = 1 mA, 10 V < VI < 28 V fr = 100 Hz, Vr = 1 Vpp IQ,REV = 1 mA, VINH = 0 V
1 mA < IQ2 < 200 mA, 6 V < VI2 < 16 V, TLE 7469 GV52 1 mA < IQ2 < 200 mA, 6 V < VI2 < 16 V, TLE 7469 GV53
VQ2
2.50
2.60
2.70
V
Output voltage
VQ2
3.20
3.30
3.40
V
Absolute differential voltage Output current limitation Load regulation Line regulation
VQ1 - VQ2 -0.5 IQ2
∆VQ2,Lo ∆VQ22,Li 300 – – –
– – 25 20 60
3.0 550 60 50 –
V mA mV mV dB
VQ1, VQ2 > 1 V VQ2 = 2.0 V
1 mA < IQ2 < 200 mA
Power Supply Ripple PSRR Rejection
IQ2 = 1 mA, 10 V < VI < 28 V fr = 100 Hz, Vr = 1 Vpp
Data Sheet
8
Rev. 1.6, 2008-01-22
TLE 7469
Table 4
Electrical Characteristics (cont’d)
VI1 = 13.5 V; VI2 = 13.5 V; -40 °C < Tj < 150 °C; unless otherwise specified
Parameter Symbol Limit Values Min. Current Consumption Quiescent current; Iq Iq = II1 + II2 - IQ1 - IQ2 Quiescent current; inhibited Inhibit Input INH Turn-on Voltage Turn-off Voltage H-input current L-input current Delay Timing DT Threshold Fast Timing Select Threshold Slow Timing Select Threshold Slow Timing Select – – – 5 55 9 µA µA Typ. Max. Unit Test Condition
Iq
IQ2 = IQ1 = 100 µA, Tj < 80 °C VINH = 0 V, Tj < 80 °C VQ1 & VQ2 on VQ1 & VQ2 off VINH = 5 V VINH = 0 V, Tj < 80 °C
– TLE 7469 GV52 TLE 7469 GV53 –
VINH ON VINH OFF IINH ON IINH OFF VDT,FAST
– 0.8 – – 4.5
– – 3 0.5 – – – –
3.1 – 4 1 – 3.3 3.6 0.8
V V µA µA V V V V
VDT,SLOW 2.3 VDT,SLOW 2.3
–
Threshold Watchdog VDT,OFF Turn Off2) Watchdog Input WDI H-input voltage threshold L-input voltage threshold Watchdog sampling time Ignore window time Open window time
VWDIH VWDIL tsam tOW tOW
– – 0.20 0.80 25.6 102 25.6 102
– – 0.25 1.00 32.0 128 32.0 128
3.0 0.8 0.30 1.20 38.4 154 38.4 154
V V ms ms ms ms ms ms
– – Fast Timing Slow Timing Fast Timing Slow Timing Fast Timing Slow Timing
Data Sheet
9
Rev. 1.6, 2008-01-22
TLE 7469
Table 4
Electrical Characteristics (cont’d)
VI1 = 13.5 V; VI2 = 13.5 V; -40 °C < Tj < 150 °C; unless otherwise specified
Parameter Closed window time Window watchdog trigger time Reset Output RO Reset switching threshold 2 Reset Headroom 2 Reset switching threshold 2 Reset Headroom 2 Reset hysteresis 2 Reset switching threshold 1 Reset hysteresis 1 Reset sink current Reset output low voltage Reset high voltage Symbol Limit Values Min. Typ. 32.0 128 44.8 179 2.38 190 3.07 240 45 60 4.65 90 – 0.15 – 20 8.0 32.0 10 – – 4.80 – 1 0.25 – 40 10.0 40 26 3.15 Max. 38.4 154 50.6 202 2.48 ms ms ms ms V mV V mV mV mV V mV mA V V kΩ ms ms µs Fast Timing Slow Timing Fast Timing Slow Timing TLE 7469 GV52, VQ2 decreasing TLE 7469 GV52 TLE 7469 GV53, VQ2 decreasing TLE 7469 GV53 TLE 7469 GV52 3) TLE 7469 GV53 4) 25.6 102 39.0 156 Unit Test Condition
tCW tWD
VRT2 VRH2 VRT2 VRH2 VRH2 VRT1 VRH1 IRO VROL
2.35 130 3.00 165 – – 4.50 – – – 4.5 10 6.0 24.0
VQ1 decreasing
–
VQ = 5 V, VRO = 0.5 V VQ2 ≥ 1 V
– Internally connected to Q1 Fast Timing (VDT ≥ 4.5 V) Slow Timing (VDT ≤ 3.3 V) –
VROH Integrated reset pull- RRO
up resistor Power-up Reset delay time TRD
Reset Reaction Time TRR
–
Data Sheet
10
Rev. 1.6, 2008-01-22
TLE 7469
Table 4
Electrical Characteristics (cont’d)
VI1 = 13.5 V; VI2 = 13.5 V; -40 °C < Tj < 150 °C; unless otherwise specified
Parameter Input Voltage Sense Sense threshold high VSIH Sense threshold low VSIL Sense output low voltage External SO pull-up resistor Sense input current Sense high reaction time Sense low reaction time 1.10 1.06 – 1.16 1.12 0.1 1.22 1.18 0.4 V V V Symbol Limit Values Min. Typ. Max. Unit Test Condition
VSI increasing (see
Figure 4)
VSI decreasing (see
Figure 4)
VSOL
RSO ext ISI tpd SO LH tpd SO HL
9.2
-1
– 0.1 4.0 4.0
– 1 – –
kΩ µA µs µs
VSI < 1.01 V; VI1 > 4.20 V; ISO = 0.5 mA VQ1 = 5V VSI = 5 V
– –
– –
1) Measured when the output voltage has dropped 100 mV from the nominal Value obtained at VI1 = 13.5 V, VI2 = 13.5 V. 2) Watchdog off, Reset in slow mode. 3) Specified by design, not subject of production test. 4) Specified by design, not subject of production test.
Data Sheet
11
Rev. 1.6, 2008-01-22
TLE 7469
Application Information
VBat
47 µF e. g. Ignition Key
R Vi * I2 100 nF 100 k Ω
TLE 7469 Q2 DT INH WDI RO SI SO 10 kΩ I1 Q1 GND 1 µF 47 µF XC 164 1 µF 47 µF
100 nF
= Optional
AEA03529_2.VSD
Figure 3
Application Diagram with Typical External Components
A typical application of the TLE 7469 is shown in Figure 3. To prevent the regulation loop from oscillating a ceramic capacitor of CQ1/2 ≥ 1 µF is required at each of the outputs Q1 and Q2. In contrast to most low drop voltage regulators the TLE 7469 only needs moderate capacitance at the outputs and tolerates ceramic capacitors to keep the stability. This offers more design flexibility to the circuit designer enabling the IC also to operate without tantalum capacitors. Additional a buffer capacitor CB of > 10µF should be used for each output Q1 and Q2 to suppress influences from load surges to the voltage levels. This one can either be an aluminum electrolytic capacitor or a tantalum capacitor following the application requirements. A general recommendation is to keep the drop over the equivalent serial resistor (ESR) together with the discharge of the blocking capacitor below the Reset Headroom (e.g. min. 130mV for the 2.6V Output).
Data Sheet
12
Rev. 1.6, 2008-01-22
TLE 7469
Since the regulator output current roughly rises linearly with time the discharge of the capacitor can be calculated as follows: dVCB = dIQ*dt/CB The drop across the ESR calculates as: dVESR = dI*ESR To prevent a reset the following relationship must be fullfilled: dVC + dVESR < VRH2 = 130mV Example: Assuming a load current step of dIQ = 50mA, a blocking capacitor of CQ = 22µF and a typical regulator reaction time under normal operating conditions of dt ~ 25µs and for special dynamic load conditions, such as load step from very low base load, a reaction time of dt ~ 75µs. dVC = dIQ*dt/CB = 50mA * 25µs/22µF = 54mV So for the ESR we can allow dVESR = VRH2 - dVC = 130mV - 54mV = 76mV The permissible ESR becomes: ESR = dVESR / dIQ = 76mV/50mA = 1.52Ohm During design-in of the TLE7469 product family, special care needs to be taken with regards to the regulators reaction time to sudden load current changes starting from very low pre-load as well as cyclic load changes. The application note “TLE7x Voltage Regulators - Application Note about Transient Response at ultra low quiescent current Voltage Regulators” (see 3_cip05405.pdf) gives important hints for successful design-in of the Voltage Regulators of the TLE7x family. As a dual regulator the TLE 7469 for correct operation should be always supplied at both input pins I1 and I2 out of one voltage supply. The dual voltage regulator with both inputs accessible, offers the possibility to reduce the power dissipation in the package. This can be achived by two different input voltages or a Drop Resistor* RVi (see Figure 3) at the input pin I2 for the 2.6V output. If one of this options is chosen,care should be taken, to apply the device as descibed under “Table 3: Operating Range”. The reset output RO features an integrated pull-up resistor. Thus it can be directly coupled to the microcontroller reset input.
Data Sheet
13
Rev. 1.6, 2008-01-22
TLE 7469
The sense comparator output SO is an open collector. An appropriate external pull-up resistor is typ. 5.6 kΩ … 47 kΩ, the minimum value of 5.6 kΩ being defined by the max. sink current capability of the SO output transistor. If the sense comparator is not used the pull-up resistor can be spared. In this case the SI pin should be directly connected to Q1 in order to keep the comparator inactive.
Sense Input Voltage
VSIH
VSIL
t
Sense Output High
t PD SO LH
t PD SO HL
Low
t
AED02559_7469
Figure 4
Sense Timing Diagram
Data Sheet
14
Rev. 1.6, 2008-01-22
TLE 7469
Circuit Description Power On Reset In order to avoid any system failure, a sequence of several conditions has to be passed. When the level of VQ2 reaches the reset threshold VRT, the signal at RO remains LOW for the Power-up reset delay time TRD. Then a second comparator checks whether VQ1 ≥ VRT1 and only if this test is passed the reset output is switched to HIGH. The Reset output is only released (set to High level) if both output voltages have passed their specific reset threshold VRT1/2. The reset function and timing is illustrated in Figure 5. The reset reaction time TRR avoids wrong triggering caused by short “glitches” on the VQ2-line. For power-fail, in case of VQ2 or VQ1 power down (VQ2 < VRT2 or VQ1 < VRT1 for t > TRR) a logic LOW signal is generated at the pin RO to reset an external microcontroller.
Data Sheet
15
Rev. 1.6, 2008-01-22
TLE 7469
VI
t
VQ1 VRT1
t
VQ2
VRT2
TRR
VRO VROH VROL
TRR TRD TRD
t
TRD
t
AET03532.VSD
Figure 5
Reset Function and Timing Diagram
Watchdog Operation The watchdog uses a fraction of the charge pump oscillator’s clock signal as timebase. Connecting the DT pin to Q1 or to Q2 the watchdog timebase can be adjusted. The watchdog can be turned off by a low level (VDT ≤ 0.8 V) applied to the DT pin. The timing values used in this text refer to typ. values with DT connected to Q1 (fast timing). Figure 6 shows the state diagram of the window watchdog (WWD). After power-on, the reset output signal at the RO pin (microcontroller reset) is kept LOW for the reset delay time TRD of typ. 8 ms. With the LOW to HIGH transition of the signal at RO the device starts the ignore window time tCW (32 ms). During this window the signal at the WDI pin is ignored. Next the WWD starts the open window. When a valid trigger signal is detected during the open window a closed window is initialized immediately. A trigger signal within
Data Sheet 16 Rev. 1.6, 2008-01-22
TLE 7469
the closed window is interpreted as a pretrigger failure and results in a reset. After the closed window the open window with the duration tOW is started again. The open window lasts at minimum until the trigger process has occurred, at maximum tOW is 32 ms (typ. value with fast timing). A HIGH to LOW transition of the watchdog trigger signal on pin WDI is taken as a trigger. To avoid wrong triggering due to parasitic glitches two HIGH samples followed by two LOW samples (sample period tsam typ. 0.25 ms) are decoded as a valid trigger (see Figure 8). A reset is generated (RO goes LOW) if there is no trigger pulse during the open window or if a pretrigger occurs during the closed window. The triggering is correct also, if the first three samples (two HIGH one LOW) of the trigger pulse at pin WDI are inside the closed window and only the fourth sample (the second LOW sample) is taken in the open window.
Reset
Always
Ignore Window
Trigger During Closed Window
No Trigger During Open Window
Always
Trigger Closed Window No Trigger
AEA03533.VSD
Open Window
Figure 6
Window Watchdog State Diagram
Data Sheet
17
Rev. 1.6, 2008-01-22
TLE 7469
Vi/V t VQ/V VRT t VRO/V TRD TRD
Normal operation
TRD
Power Fail
trr
t rr t
Wnd Ingnore Wnd
Don’t care WDI during IW
OW
CW
OW
CW
OW
OW
CW
(Wrong) Trigger in CW
OW t
1. Correct Trigger
WDI/V
tWD,p
No Trigger in OW
t
Figure 7
Window Watchdog Signal Flow
Closed window
Open window
Watchdog trigger signal
Open window
Closed window
WDI
Valid
WDI
Not valid
t ECW t EOW
AET02952
= Watchdog decoder sample point
Figure 8
Window Watchdog Definitions
Data Sheet
18
Rev. 1.6, 2008-01-22
TLE 7469
Package Outlines
0+0.1 STANDOFF
2.6 MAX.
2.35 ±0.1 (Body)
(1.55)
7.5 ±0.11)
0.8
0.1
7.8 ±0.1 (Heatslug) 7.6 +0.13 -0.1 6.4 ±0.11) B (Mold)
0.7 ±0.15 10.3 ±0.3 0.25 B
(1.8 Mold)
(4.4 Mold)
Bottom View
12
7
7
12
Index Marking
1
6
6
1
1 5x 1 = 5 5.1±0.1 (Metal)
12x 0.4 +0.13 0.25 M C A B
1) Does not include plastic or metal protrusion of 0.15 max. per side
GPS09628
Figure 9
PG-DSO-12 (Plastic Green Dual Small Outline)
Green Product (RoHS compliant) To meet the world-wide customer requirements for environmentally friendly products and to be compliant with government regulations the device is available as a green product. Green products are RoHS-Compliant (i.e Pb-free finish on leads and suitable for Pb-free soldering according to IPC/JEDEC J-STD-020).
For further packge information, please visit our website: http://www.infineon.com/packages. Data Sheet 19
1.6 ±0.1 (Metal) 4.2 ±0.1 (Metal)
Heatslug
Dimensions in mm Rev. 1.6, 2008-01-22
5˚ ±3˚
B
+0.0 0.25 -0.0 75
35
TLE 7469
Revision History
Version Rev. 1.6
Date
Changes
2008-01-22 Initial version of RoHS-compliant derivate of TLE 7469 Page 1: AEC certified statement added. Page 1 and Page 19: RoHS compliance statement and Green product feature added. Page 1 and Page 19: Package changed to RoHS compliant version. 2007-05-07 Modifications according to PCN No. 2007-070-A • Page 8: Parameter “Output current limitation IQ2” : Max. Value modified from 500mA to 550mA. • Page 3, Fig. 1 modified: RO pullup to Q1 instead to Q2. • Legal disclaimer updated. 2005-07-15 Final Datasheet
Rev. 1.5
Rev. 1.4
Data Sheet
20
Rev. 1.6, 2008-01-22
Edition 2008-01-22 Published by Infineon Technologies AG 81726 Munich, Germany
© 2008 Infineon Technologies AG
All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. Information For further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered.