LF198/LF298/LF398, LF198A/LF398A
Monolithic Sample-and-Hold Circuits
General Description
The LF198/LF298/LF398 are monolithic sample-and-hold
circuits which utilize BI-FET technology to obtain ultra-high
dc accuracy with fast acquisition of signal and low droop
rate. Operating as a unity gain follower, dc gain accuracy is
0.002% typical and acquisition time is as low as 6 µs to
0.01%. A bipolar input stage is used to achieve low offset
voltage and wide bandwidth. Input offset adjust is accom-
plished with a single pin, and does not degrade input offset
drift. The wide bandwidth allows the LF198 to be included in-
side the feedback loop of 1 MHz op amps without having sta-
bility problems. Input impedance of 10
10
Ωallows high
source impedances to be used without degrading accuracy.
P-channel junction FET’s are combined with bipolar devices
in the output amplifier to give droop rates as low as 5 mV/min
with a 1 µF hold capacitor. The JFET’s have much lower
noise than MOS devices used in previous designs and do
not exhibit high temperature instabilities. The overall design
guarantees no feed-through from input to output in the hold
mode, even for input signals equal to the supply voltages.
Features
nOperates from ±5V to ±18V supplies
nLess than 10 µs acquisition time
nTTL, PMOS, CMOS compatible logic input
n0.5 mV typical hold step at C
h
= 0.01 µF
nLow input offset
n0.002% gain accuracy
nLow output noise in hold mode
nInput characteristics do not change during hold mode
nHigh supply rejection ratio in sample or hold
nWide bandwidth
nSpace qualified, JM38510
Logic inputs on the LF198 are fully differential with low input
current, allowing direct connection to TTL, PMOS, and
CMOS. Differential threshold is 1.4V. The LF198 will operate
from ±5V to ±18V supplies.
An “A” version is available with tightened electrical
specifications.
Typical Connection and Performance Curve
Functional Diagram
DS005692-32
Acquisition Time
DS005692-16
DS005692-1
July 2000
LF198/LF298/LF398, LF198A/LF398A Monolithic Sample-and-Hold Circuits
© 2000 National Semiconductor Corporation DS005692 www.national.com
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage ±18V
Power Dissipation (Package
Limitation) (Note 2) 500 mW
Operating Ambient Temperature Range
LF198/LF198A −55˚C to +125˚C
LF298 −25˚C to +85˚C
LF398/LF398A 0˚C to +70˚C
Storage Temperature Range −65˚C to +150˚C
Input Voltage Equal to Supply Voltage
Logic To Logic Reference
Differential Voltage (Note 3) +7V, −30V
Output Short Circuit Duration Indefinite
Hold Capacitor Short
Circuit Duration 10 sec
Lead Temperature (Note 4)
H package (Soldering, 10 sec.) 260˚C
N package (Soldering, 10 sec.) 260˚C
M package:
Vapor Phase (60 sec.) 215˚C
Infrared (15 sec.) 220˚C
Thermal Resistance (θ
JA
) (typicals)
H package 215˚C/W (Board mount in still air)
85˚C/W (Board mount in
400LF/min air flow)
N package 115˚C/W
M package 106˚C/W
θ
JC
(H package, typical) 20˚C/W
Electrical Characteristics
The following specifcations apply for −V
S
+ 3.5V ≤V
IN
≤+V
S
− 3.5V, +V
S
= +15V, −V
S
= −15V, T
A
= T
j
= 25˚C, C
h
= 0.01 µF,
R
L
= 10 kΩ, LOGIC REFERENCE = 0V, LOGIC HIGH = 2.5V, LOGIC LOW = 0V unless otherwise specified.
Parameter Conditions LF198/LF298 LF398 Units
Min Typ Max Min Typ Max
Input Offset Voltage, (Note 5) T
j
= 25˚C 1 3 2 7 mV
Full Temperature Range 5 10 mV
Input Bias Current, (Note 5) T
j
= 25˚C 5 25 10 50 nA
Full Temperature Range 75 100 nA
Input Impedance T
j
= 25˚C 10
10
10
10
Ω
Gain Error T
j
= 25˚C, R
L
= 10k 0.002 0.005 0.004 0.01 %
Full Temperature Range 0.02 0.02 %
Feedthrough Attenuation Ratio T
j
= 25˚C, C
h
= 0.01 µF 86 96 80 90 dB
at 1 kHz
Output Impedance T
j
= 25˚C, “HOLD” mode 0.5 2 0.5 4 Ω
Full Temperature Range 4 6 Ω
“HOLD” Step, (Note 6) T
j
= 25˚C, C
h
= 0.01 µF, V
OUT
= 0 0.5 2.0 1.0 2.5 mV
Supply Current, (Note 5) T
j
≥25˚C 4.5 5.5 4.5 6.5 mA
Logic and Logic Reference Input T
j
= 25˚C 2 10 2 10 µA
Current
Leakage Current into Hold T
j
= 25˚C, (Note 7) 30 100 30 200 pA
Capacitor (Note 5) Hold Mode
Acquisition Time to 0.1% ∆V
OUT
= 10V, C
h
= 1000 pF 4 4 µs
C
h
= 0.01 µF 20 20 µs
Hold Capacitor Charging Current V
IN
−V
OUT
= 2V 5 5 mA
Supply Voltage Rejection Ratio V
OUT
= 0 80 110 80 110 dB
Differential Logic Threshold T
j
= 25˚C 0.8 1.4 2.4 0.8 1.4 2.4 V
Input Offset Voltage, (Note 5) T
j
= 25˚C 1 1 2 2 mV
Full Temperature Range 2 3 mV
Input Bias Current, (Note 5) T
j
= 25˚C 5 25 10 25 nA
Full Temperature Range 75 50 nA
LF198/LF298/LF398, LF198A/LF398A
www.national.com 2
Electrical Characteristics
The following specifcations apply for −V
S
+ 3.5V ≤V
IN
≤+V
S
− 3.5V, +V
S
= +15V, −V
S
= −15V, T
A
= T
j
= 25˚C, C
h
= 0.01 µF,
R
L
= 10 kΩ, LOGIC REFERENCE = 0V, LOGIC HIGH = 2.5V, LOGIC LOW = 0V unless otherwise specified.
Parameter Conditions LF198A LF398A Units
Min Typ Max Min Typ Max
Input Impedance T
j
= 25˚C 10
10
10
10
Ω
Gain Error T
j
= 25˚C, R
L
= 10k 0.002 0.005 0.004 0.005 %
Full Temperature Range 0.01 0.01 %
Feedthrough Attenuation Ratio T
j
= 25˚C, C
h
= 0.01 µF 86 96 86 90 dB
at 1 kHz
Output Impedance T
j
= 25˚C, “HOLD” mode 0.5 1 0.5 1 Ω
Full Temperature Range 4 6 Ω
“HOLD” Step, (Note 6) T
j
= 25˚C, C
h
= 0.01µF, V
OUT
= 0 0.5 1 1.0 1 mV
Supply Current, (Note 5) T
j
≥25˚C 4.5 5.5 4.5 6.5 mA
Logic and Logic Reference Input T
j
= 25˚C 2 10 2 10 µA
Current
Leakage Current into Hold T
j
= 25˚C, (Note 7) 30 100 30 100 pA
Capacitor (Note 5) Hold Mode
Acquisition Time to 0.1% ∆V
OUT
= 10V, C
h
= 1000 pF 4 6 4 6 µs
C
h
= 0.01 µF 20 25 20 25 µs
Hold Capacitor Charging Current V
IN
−V
OUT
= 2V 5 5 mA
Supply Voltage Rejection Ratio V
OUT
= 0 90 110 90 110 dB
Differential Logic Threshold T
j
= 25˚C 0.8 1.4 2.4 0.8 1.4 2.4 V
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX,θJA, and the ambient temperature, TA. The maximum
allowable power dissipation at any temperature is PD= (TJMAX − TA)/θJA, or the number given in the Absolute Maximum Ratings, whichever is lower. The maximum
junction temperature, TJMAX, for the LF198/LF198A is 150˚C; for the LF298, 115˚C; and for the LF398/LF398A, 100˚C.
Note 3: Although the differential voltage may not exceed the limits given, the common-mode voltage on the logic pins may be equal to the supply voltages without
causing damage to the circuit. For proper logic operation, however, one of the logic pins must always be at least 2V below the positive supply and 3V above the nega-
tive supply.
Note 4: See AN-450 “Surface Mounting Methods and their effects on Product Reliability” for other methods of soldering surface mount devices.
Note 5: These parameters guaranteed over a supply voltage range of ±5 to ±18V, and an input range of −VS+ 3.5V ≤VIN ≤+VS− 3.5V.
Note 6: Hold step is sensitive to stray capacitive coupling between input logic signals and the hold capacitor. 1 pF, for instance, will create an additional 0.5 mV step
with a 5V logic swing and a 0.01µF hold capacitor. Magnitude of the hold step is inversely proportional to hold capacitor value.
Note 7: Leakage current is measured at a junction temperature of 25˚C. The effects of junction temperature rise due to power dissipation or elevated ambient can
be calculated by doubling the 25˚C value for each 11˚C increase in chip temperature. Leakage is guaranteed over full input signal range.
Note 8: A military RETS electrical test specification is available on request. The LF198 may also be procured to Standard Military Drawing #5962-8760801GA or to
MIL-STD-38510 part ID JM38510/12501SGA.
Typical Performance Characteristics
Note 9: See Definition of Terms
Aperture Time
(Note 9)
DS005692-17
Dielectric Absorption
Error in Hold Capacitor
DS005692-18
Dynamic Sampling Error
DS005692-19
LF198/LF298/LF398, LF198A/LF398A
www.national.com3
Typical Performance Characteristics (Continued)
Note 10: See Definition
Output Droop Rate
DS005692-20
Hold Step
DS005692-21
“Hold” Settling Time
(Note 10)
DS005692-22
Leakage Current into Hold
Capacitor
DS005692-23
Phase and Gain (Input to
Output, Small Signal)
DS005692-24
Gain Error
DS005692-25
Power Supply Rejection
DS005692-26
Output Short Circuit Current
DS005692-27
Output Noise
DS005692-28
LF198/LF298/LF398, LF198A/LF398A
www.national.com 4
Typical Performance Characteristics (Continued)
Logic Input Configurations
Input Bias Current
DS005692-29
Feedthrough Rejection Ratio
(Hold Mode)
DS005692-30
Hold Step vs Input Voltage
DS005692-31
Output Transient at Start
of Sample Mode
DS005692-12
Output Transient at Start
of Hold Mode
DS005692-13
TTL & CMOS
3V ≤V
LOGIC
(Hi State) ≤7V
DS005692-33
Threshold = 1.4V
DS005692-34
Threshold = 1.4V
*
Select for 2.8V at pin 8
LF198/LF298/LF398, LF198A/LF398A
www.national.com5
Logic Input Configurations (Continued)
Application Hints
Hold Capacitor
Hold step, acquisition time, and droop rate are the major
trade-offs in the selection of a hold capacitor value. Size and
cost may also become important for larger values. Use of the
curves included with this data sheet should be helpful in se-
lecting a reasonable value of capacitance. Keep in mind that
for fast repetition rates or tracking fast signals, the capacitor
drive currents may cause a significant temperature rise in
the LF198.
A significant source of error in an accurate sample and hold
circuit is dielectric absorption in the hold capacitor. A mylar
cap, for instance, may “sag back” up to 0.2% after a quick
change in voltage. A long sample time is required before the
circuit can be put back into the hold mode with this type of
capacitor. Dielectrics with very low hysteresis are polysty-
rene, polypropylene, and Teflon. Other types such as mica
and polycarbonate are not nearly as good. The advantage of
polypropylene over polystyrene is that it extends the maxi-
mum ambient temperature from 85˚C to 100˚C. Most ce-
ramic capacitors are unusable with >1% hysteresis. Ce-
ramic “NPO” or “COG” capacitors are now available for
125˚C operation and also have low dielectric absorption. For
more exact data, see the curve
Dielectric Absorption Error.
The hysteresis numbers on the curve are final values, taken
after full relaxation. The hysteresis error can be significantly
reduced if the output of the LF198 is digitized quickly after
the hold mode is initiated. The hysteresis relaxation time
constant in polypropylene, for instance, is 10 — 50 ms. If
A-to-D conversion can be made within 1 ms, hysteresis error
will be reduced by a factor of ten.
DC and AC Zeroing
DC zeroing is accomplished by connecting the offset adjust
pin to the wiper of a 1 kΩpotentiometer which has one end
tied to V
+
and the other end tied through a resistor to ground.
The resistor should be selected to give ≈0.6 mA through the
1k potentiometer.
AC zeroing (hold step zeroing) can be obtained by adding an
inverter with the adjustment pot tied input to output. A 10 pF
capacitor from the wiper to the hold capacitor will give ±4 mV
hold step adjustment with a 0.01 µF hold capacitor and 5V
logic supply. For larger logic swings, a smaller capacitor
(<10 pF) may be used.
Logic Rise Time
For proper operation, logic signals into the LF198 must have
a minimum dV/dt of 1.0 V/µs. Slower signals will cause ex-
cessive hold step. If a R/C network is used in front of the
CMOS
7V ≤V
LOGIC
(Hi State) ≤15V
DS005692-35
Threshold = 0.6 (V+) + 1.4V
DS005692-36
Threshold = 0.6 (V+) − 1.4V
Op Amp Drive
DS005692-37
Threshold ≈+4V
DS005692-38
Threshold = −4V
LF198/LF298/LF398, LF198A/LF398A
www.national.com 6
Application Hints (Continued)
logic input for signal delay, calculate the slope of the wave-
form at the threshold point to ensure that it is at least
1.0 V/µs.
Sampling Dynamic Signals
Sample error to moving input signals probably causes more
confusion among sample-and-hold users than any other pa-
rameter. The primary reason for this is that many users make
the assumption that the sample and hold amplifier is truly
locked on to the input signal while in the sample mode. In ac-
tuality, there are finite phase delays through the circuit creat-
ing an input-output differential for fast moving signals. In ad-
dition, although the output may have settled, the hold
capacitor has an additional lag due to the 300Ωseries resis-
tor on the chip. This means that at the moment the “hold”
command arrives, the hold capacitor voltage may be some-
what different than the actual analog input. The effect of
these delays is opposite to the effect created by delays in the
logic which switches the circuit from sample to hold. For ex-
ample, consider an analog input of 20 Vp-p at 10 kHz. Maxi-
mum dV/dt is 0.6 V/µs. With no analog phase delay and 100
ns logic delay, one could expect up to (0.1 µs) (0.6V/µs)
= 60 mVerror if the “hold” signal arrived near maximum dV/dt
of the input. A positive-going input would give a +60 mV er-
ror. Now assume a 1 MHz (3 dB) bandwidth for the overall
analog loop. This generates a phase delay of 160 ns. If the
hold capacitor sees this exact delay, then error due to analog
delay will be (0.16 µs) (0.6 V/µs) = −96 mV. Total output error
is +60 mV (digital) −96 mV (analog) for a total of −36 mV. To
add to the confusion, analog delay is proportioned to hold
capacitor value while digital delay remains constant. A family
of curves (dynamic sampling error) is included to help esti-
mate errors.
A curve labeled
Aperture Time
has been included for sam-
pling conditions where the input is steady during the sam-
pling period, but may experience a sudden change nearly
coincident with the “hold” command. This curve is based on
a 1 mV error fed into the output.
A second curve,
Hold Settling Time
indicates the time re-
quired for the output to settle to 1 mV after the “hold” com-
mand.
Digital Feedthrough
Fast rise time logic signals can cause hold errors by feeding
externally into the analog input at the same time the amplifier
is put into the hold mode. To minimize this problem, board
layout should keep logic lines as far as possible from the
analog input and the C
h
pin. Grounded guarding traces may
also be used around the input line, especially if it is driven
from a high impedance source. Reducing high amplitude
logic signals to 2.5V will also help.
Guarding Technique
DS005692-5
Use 10-pin layout. Guard around C
h
is tied to output.
LF198/LF298/LF398, LF198A/LF398A
www.national.com7
Typical Applications
X1000 Sample & Hold
DS005692-39
*
For lower gains, the LM108 must be frequency compensated
Sample and Difference Circuit
(Output Follows Input in
Hold
Mode)
DS005692-40
VOUT = VB+∆VIN(HOLD MODE)
Ramp Generator with Variable Reset Level
DS005692-42
Integrator with Programmable Reset Level
DS005692-43
LF198/LF298/LF398, LF198A/LF398A
www.national.com 8
Typical Applications (Continued)
Output Holds at Average of Sampled Input
DS005692-46
Increased Slew Current
DS005692-47
Reset Stabilized Amplifier (Gain of 1000)
DS005692-49
Fast Acquisition, Low Droop Sample & Hold
DS005692-50
LF198/LF298/LF398, LF198A/LF398A
www.national.com9
Typical Applications (Continued)
Synchronous Correlator for Recovering
Signals Below Noise Level
DS005692-52
2–Channel Switch
DS005692-53
A B
Gain 1 ±0.02% 1 ±0.2%
Z
IN
10
10
Ω47 kΩ
BW .1 MHz .400 kHz
Crosstalk −90 dB −90 dB
@
1 kHz
Offset ≤6 mV ≤75 mV
DC & AC Zeroing
DS005692-59
Staircase Generator
DS005692-55
*
Select for step height
50k →≅1V Step
LF198/LF298/LF398, LF198A/LF398A
www.national.com 10
Typical Applications (Continued)
Definition of Terms
Hold Step: The voltage step at the output of the sample and
hold when switching from sample mode to hold mode with a
steady (dc) analog input voltage. Logic swing is 5V.
Acquisition Time: The time required to acquire a new ana-
log input voltage with an output step of 10V. Note that acqui-
sition time is not just the time required for the output to settle,
but also includes the time required for all internal nodes to
settle so that the output assumes the proper value when
switched to the hold mode.
Gain Error: The ratio of output voltage swing to input volt-
age swing in the sample mode expressed as a per cent dif-
ference.
Hold Settling Time: The time required for the output to
settle within 1 mV of final value after the “hold” logic com-
mand.
Dynamic Sampling Error: The error introduced into the
held output due to a changing analog input at the time the
hold command is given. Error is expressed in mV with a
given hold capacitor value and input slew rate. Note that this
error term occurs even for long sample times.
Aperture Time: The delay required between “Hold” com-
mand and an input analog transition, so that the transition
does not affect the held output.
Connection Diagrams
Differential Hold
DS005692-57
Capacitor Hysteresis Compensation
DS005692-56
**
Adjust for amplitude
Dual-In-Line Package
DS005692-11
Order Number LF398N
or LF398AN
See NS Package Number N08E
Small-Outline Package
DS005692-15
Order Number LF298M or LF398M
See NS Package Number M14A
Metal Can Package
DS005692-14
Order Number LF198H,
LF198H/883, LF298H,
LF398H, LF198AH or LF398AH
See NS Package Number H08C
(Note 8)
LF198/LF298/LF398, LF198A/LF398A
www.national.com11
Physical Dimensions inches (millimeters) unless otherwise noted
Metal Can Package (H)
Order Number LF198H, LF298H, LF398H, LF198AH or LF398AH
NS Package Number H08C
Molded Small-Outline Package (M)
Order Number LF298M or LF398M
NS Package Number M14A
LF198/LF298/LF398, LF198A/LF398A
www.national.com 12
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
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NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. 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
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 to the user.
2. A critical component is 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.
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Tel: 1-800-272-9959
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Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
www.national.com
Molded Dual-In-Line Package (N)
Order Number LF398N or LF398AN
NS Package Number N08E
LF198/LF298/LF398, LF198A/LF398A Monolithic Sample-and-Hold Circuits
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
LF298 - Monolithic Sample and Hold Circuit
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LF298 - Monolithic Sample and Hold Circuit
Datasheet Packaging Samples & Pricing Reliability Knowledge Base
Features
Logic inputs on the LF198 are fully differential with low input current, allowing direct
connection to TTL, PMOS, and CMOS. Differential threshold is 1.4V. The LF198 will
operate from ±5V to ±18V supplies. An "A" version is available with tightened electrical
specifications.
• Operates from ±5V to ±18V supplies
• Less than 10 µs acquisition time
• TTL, PMOS, CMOS compatible logic input
• 0.5 mV typical hold step at Ch = 0.01 µF
• Low input offset
• 0.002% gain accuracy
• Low output noise in hold mode
• Input characteristics do not change during hold mode
• High supply rejection ratio in sample or hold
General Description
The LF198/LF298/LF398 are monolithic sample-and-hold circuits which utilize BI-FET
technology to obtain ultra-high dc accuracy with fast acquisition of signal and low droop
rate. More...
Typical Application
See Datasheet for Application Information
Parametric Table expand
http://www.national.com/mpf/LF/LF298.html (1 of 3) [14-Jul-2009 3:59:02 PM]
LF298 - Monolithic Sample and Hold Circuit
• Wide bandwidth
• Space qualified, JM38510 Offset Voltage max, 25C 5 mV
Datasheet
RoHS Compliance Information Size in Kbytes Date
LF198/LF298/LF398, LF198A/LF398A Monolithic Sample-and-Hold Circuits 520 Kbytes 23-Aug-00 Download
LF198/LF298/LF398, LF198A/LF398A Monolithic Sample-and-Hold Circuits (Japanese)532 Kbytes
If you have trouble printing or viewing PDF file(s), see Printing Problems.
Package Availability, Models, Samples & Pricing
Part Number Package Factory Lead Time Models Samples &
Electronic
Orders
Budgetary Pricing Std
Pack
Size
Package
Marking
Format
Type Pins Spec. MSL
Rating Peak
Reflow RoHS
Report CAD
Symbols Weeks Qty Qty $US each
LF298M SOIC NARROW 14
STD
NOPB
1
1
235
260
RoHS N/A Full production N/A 1K+ $1.46 rail
of
55
NSUZXYTT
LF298M
6 weeks 1000
LF298MX SOIC NARROW 14
STD
NOPB
1
1
235
260
RoHS N/A Full production N/A
1K+ $1.46 reel
of
2500
NSUZXYTT
LF298M
6 weeks 3000
LF298H TO-99 8
STD
NOPB
1
1
NA
NA
RoHS N/A Full production N/A 1K+ $6.30 box
of
500 NSZXYTTE# LF298H
6 weeks 2500
General Description
The LF198/LF298/LF398 are monolithic sample-and-hold circuits which utilize BI-FET technology to obtain ultra-high dc accuracy with fast acquisition of signal and low droop rate.
Operating as a unity gain follower, dc gain accuracy is 0.002% typical and acquisition time is as low as 6 µs to 0.01%. A bipolar input stage is used to achieve low offset voltage and wide
bandwidth. Input offset adjust is accomplished with a single pin, and does not degrade input offset drift. The wide bandwidth allows the LF198 to be included inside the feedback loop of 1
MHz op amps without having stability problems. Input impedance of 1010Ohm allows high source impedances to be used without degrading accuracy.
P-channel junction FET's are combined with bipolar devices in the output amplifier to give droop rates as low as 5 mV/min with a 1 µF hold capacitor. The JFET's have much lower noise
than MOS devices used in previous designs and do not exhibit high temperature instabilities. The overall design guarantees no feed-through from input to output in the hold mode, even for
http://www.national.com/mpf/LF/LF298.html (2 of 3) [14-Jul-2009 3:59:02 PM]
LF298 - Monolithic Sample and Hold Circuit
input signals equal to the supply voltages.
Reliability Metrics
Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LF298H BIFET 0 12335 0 0 975000 4 276658912
LF298M BIFET 0 12335 0 0 975000 4 276658912
LF298MX BIFET 0 12335 0 0 975000 4 276658912
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence
using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.
For more information on Reliability Metrics, please click here.
[Information as of 13-Jul-2009]
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