LF156J ,+/-22 V, monolithic JEET input operational amplifierFeatures
LF157A
LF155A LF156A Units
(Av = 5)
I Extremely 4 1.5 1.5 ps
fast settling
tim ..
LF156J ,+/-22 V, monolithic JEET input operational amplifierFeatures
LF157A
LF155A LF156A Units
(Av = 5)
I Extremely 4 1.5 1.5 ps
fast settling
tim ..
LF157H ,+/-22 V, monolithic JEET input operational amplifierGeneral Description
These are the first monolithic JFET input operational ampli-
fiers to incor ..
LF157H ,+/-22 V, monolithic JEET input operational amplifierFeatures
(LF155A, LF156A, LF157A)
I Low input bias current 30 pA
I Low Input Offset Current 3 ..
LF157H/883 ,MONOLITHIC JFET INPUT OPERATIONAL AMPLIFIERS [Life-time buy]Features- Low input bias current 30 pA - Low input offset current ..
LF157J ,+/-22 V, monolithic JEET input operational amplifierGeneral Description
These are the first monolithic JFET input operational ampli-
fiers to incor ..
LM146J/883 ,Programmable Quad Operational AmplifierElectrical Characteristic(V =±15V, I =10 µA)S SETParameter Conditions LM146 LM346 UnitsMin Typ Max ..
LM148D ,FOUR UA741 QUAD BIPOLAR OPERATIONAL AMPLIFIERSfeatures include input offsetcurrent and input bias current which are much lessthan those of a stan ..
LM148DT ,FOUR UA741 QUAD BIPOLAR OPERATIONAL AMPLIFIERSLM148LM248LM348FOUR UA741QUAD BIPOLAR OPERATIONAL AMPLIFIERS ■ LOW SUPPLY CURRENT: 0.53mA/AMPLI- ..
LM148J ,Series Quad 741 Op Ampmaximum ratings” may cause permanent damage to the device. These are stress ratings only, andfuncti ..
LM148J/883 ,Series Quad 741 Op Ampfeaturesn Low input offset current: 4 nAincludeinputoffsetcurrentsandinputbiascurrentwhicharen Low ..
LM148JB ,Quad General-Purpose Operational Amplifiermaximum ratings over operating free-air temperature range (unless otherwise noted)Supply voltage, V ..
LF156J-LF157H-LF157J-LF355BH-LF355J-LF356BJ-LF356J-LF357BH-LF357J
+/-22 V, monolithic JEET input operational amplifier
LF155/ 155A/ LF255/LF355/355A/3558/LF156/156A/LF256/LF356/LF356A/3SBB/LF157/ 157A/LF257/LF357/357A/357B
National
Semiconductor
LF155/ LF156/ LF 157 Series Monolithic
JFET Input Operational Amplifiers
LF155/LF155A/LF255/LF355/LF355A/
LF355B Low Supply Current
LF156/LF156A/LF256/LF356/ LF356A/
LF356B Wide Band
LF157/LF157A/LF257/LF357/LF357A/
LF357B Wide Band Decompensated (AVMIN = 5)
General Description
These are the first monolithic JFET input operational ampli-
fiers to incorporate well matched, high voltage JFETs on the
same chip with standard bipolar transistors (Bt-FETTM Tech-
nology). These amplifiers feature low input bias and offset
currents/low offset voltage and offset voltage drift, coupled
with offset adjust which does not degrade drift or common-
" Photocell amplifiers
II Sampie and Hold circuits
Common Features
(LF155A, LF156A, LF157A)
mode rejection. The devices are also designed for high slew a Low input bias current 30 PA
rate, wide bandwidth, extremely fast settling time, low volt- n Low Input Offset Current 3 PA
age and current noise and a low Iff noise corner. " High input impedance 10120
I: Low input offset voltage 1 mV
Advantages " Low input offset voltage temp. drift 3 psi/PC
u Replace expensive hybrid and module FET op amps a Low input noise current 0.01 pA/JFE
ll Rugged JFETs allow blow-out free handling compared n High common-mode rejection ratio 100 dB
with MOSFET input devices " Large dc voltage gain 106 dB
II Excellent for low noise applications using either high or
low source impedance-very low l/f corner Uncommon Features
a Offset adjust does not degrade drift or common-mode LF157A
rejection as in most monolithic amplifiers LF155A LF156A (AV: 5) Units
I: New output stage allows use of large capacitive loads " Extremely 4 1.5 1.5 #3
(10,000 pF) without stability problems fast settling
u Internal compensation and large differential input volt- time to
age capability 0.01%
. . a Fast slew
Agpllcatlons rate 5 12 50 vos
I: recision high speed integrators n . in
" Fast WA and A/D converters 3:35:11, 2.5 5 20 MHz
II High impedance buffers 11 Low input
a Wideband, low noise, low drift amplifiers noise voltage 20 12 12 WNW
n Logarithmic amplifiers
Simplified Schematic g,“
h nuns: 3 cc
13) it) J,', , [3)
"ti- " our
"3 pF in '..F157 series.
0 ' o "
. ' . (l)
. o 4E; TL/H/5646-1
Absolute Maximum Ratings
If Mllltary/Aerospace specified devlces are required, contact the National Semiconductor Sales offlttemltttrittutortt for
avallablllty and specifications.
(Note 8)
Supply Voltage
Differential Input Voltage
Input Voltage Range (Note 2)
Output Short Circuit Duration
H-Package
N-Package
J-Package
M-Package
LF155A/6AI7A
Continuous
Power Dissipation at TA --- 25°C (Notes1 and 9)
H-Package (Still Air)
H-Package (400 LF/Min Air Flow)
N-Package
J-Package
M-Package
Thermal Resistance (T ypical) Am
H-Package (Still Air)
H-Package (400 LF/Min Air Flow)
N-Package
J-Package
M-Package
(Typical) truc
H-Package
Storage Temperature Range
Soldering Information (Lead Temp.)
Metal Can Package
Soldering (10 sec.)
Dual-ln-Line Package
Soldering (10 sec.)
Small Outline Package
Vapor Phase (60 sec.)
Infrared (15 sec.)
560 mW
1200 mW
160''C/ W
65'C/ W
23°C/W
--65''C to + 150°C
-65''C to + 150'C
LF355Bf6B/rB
LF155/6/7 LF255/6/7
t22V A22V
140V , 40V
i 20V i 20V
Continuous Continuous
15ty'C 115''C
150°C 115''C
560 mW 400 mW
1200 mW 1000 mW
670 mW
1260 mW 900 mW
380 mW
160°C/W 160°C/W
65°C/W 65°C/W
130°C/W
100'C/W 100°Clw
195°C/W
23°C/W 23'C/W
260''C
21 5°C
-65''C to + 150°C
LF355/ tVT
LF355A/6A/7A
Continuous
400 mW
1000 mW
870 mW
900 mW
380 mW
16tPC/W
65'Cf W
1 3UC/ W
1 00°C/ W
1 95°C/ W
23'C/ W
--65% to + 150°C
21 5'C
See AN-450 "Surface Mounting Methods and Their Effect on Product Reliability" for other methods of soldering surface
mount devices.
ESD tolerance
(100 pF discharged through 1.5 kn) 1200V 12001/ 1200V 1200V
DC Electrical Characteristics (Note 3) TA = T, = 25%
Symbol Parameter Cttttdltlttrttt LF 1 SSAIGN 7A LF355A/6Al7A Unlta
Mln Typ Max Mln Typ Max
Vos Input Offset Voltage Rs = 500. TA =r. 25'C 1 2 1 2 mV
Over Temperature 2.5 2.3 mV
AVOS/AT Average TC of Input Rs = 50ft .
OffsetVoltage 3 5 3 5 PW/ c
ATC/Avos Change in Average TC Rs: 50tt, (Note 4) 0 5 0 5 wNPtl
with Vos Adjust . . per mV
Ios Input Offset Current Ti == 25''C, (Notes 3, 5) 3 10 3 10 pA
Ti STHlGH 1 0 1 nA
Its Input Bias Current Ti-- 25''C, (Notes 3, 5) 30 50 30 50 pA
Tj STHIGH 25 5 nA
Rm Input Resistance T1: 25°C 1012 1012 n
AVOL Large Signal Voltage Vs = , 15V, TA = 25'C 50 200 50 200 V/mV
Gain Vo--- i10V, FIL=2k
Over Temperature 25 25 V/mV
V0 OutputVoltage Swing Vs--- A15V, RL=1Ok " i113 Ali? 113 V
1ttr--k15V,Rc---2k :10 A12 110 112 V
HLSSIVLSSILSSIIILSZJ'IIVLS ”£9|-d1/8998/V992J'l/9985'l/953:l'|/V95”99 |-:l'lIESSSIVSSSISSSJ'IISSZd'l/VSSL[99H'l
LF155/ 155A/LF255/LF355/355A/3553/LF156/ 156A]LF256/LF356/LF356A/3568/LF157/ 157A/LF257/LF357/357A/357B
DC Electrical Characteristics (Note 3) TA = Ti = 25°C (Continued)
Symbol Parameter Condltlons LF155A/ BAHA LF355AftUU7A Units
Min Typ Max Min Typ Max
VCM Input Common-Mode == + 15.1 +15.1 V
VoltageRange vs *151/ All -12 All --12 V
CMRR gorpmon-Mode Rejection 85 100 85 100 dB
PSRR Supply Voltage Rejection (Note 6) 85 100 85 100 dB
AC Electrical Characteristics TA = Ti = 25°C, Vs = :15v
Symbol Parameter Conditions LF155A/355A LF156A/356A LF157AI357A U tilts
Min Typ Max Min Typ Max Min Typ Max
SR Slew Rate LF155A/6A; Av= 1, 5 10 12 Nlps
LF157A; AV = 5 40 50 V/ps
GBW Gain Bandwidth
Product 2.5 4 4.5 15 20 MHz
tg Settling Time to 0.01% (Note 7) 4 1.5 1.5 115
en Equivalent Input Noise Rs = 100ft
Voltage f-- 100 Hz 25 15 15 WNW
f-- 1000 Hz 25 12 12 WNW
in Equivalent Input f-- 100 Hz 0.01 0.01 0.01 pA/tTz
Noise Current f=1000 Hz 0.01 0.01 0.01 pAMTz
Cm Input Capacitance 3 3 3 pF
DC Electrical Characteristics (Note 3)
LF255/6/7
Symbol Parameter Conditions LFt55/6/7 LF3558/63/TB LF355/6f? Units
Min Typ Max Min Typ Max Mln Typ Max
Vos Input Offset Voltage Rs = 5011, TA = 25°C 3 5 3 5 3 10 mV
Over Temperature 7 6.5 1 3 mV
Avos/AT Average TC of Input Rs = 500 tt
Offset Voltage 5 5 5 11W C
ATC/AVos Change in Average TC Rs-- 50tt, (Note 4) o 5 0 5 0 5 pNI''ty
with vos Adjust . ' . per mV
los Input Offset Current T] = 25'C, (Notes 3, 5) 3 20 3 20 3 50 pA
T] STHIGH 20 1 2 nA
IB Input Bias Current T] = tWC, (Notes 3, 5) 30 100 30 100 30 200 pA
Ti STHIGH 50 5 8 M
Rm Input Resistance Tp= 25°C 1012 1012 1012 n
AVOL Large Signal Voltage Vs = * 15V, TA--- 25°C 50 200 50 200 25 200 V/mV
Gain Vo-- i10V.F1._=2k
Over Temperature 25 25 1 5 V/ mV
vo OutputVoltage Swing Vs---k15V,h--10k :12 :13 :12 +-13 :12 :13 v
Vs==uF15V,RLs--2k i10 t12 " dc12 1'10 k12 V
VCM Input Common-Mode = +15.1 t15.1 +15.1 V
VoltageRange Vs MSV tll -12 Ill -12 +10 --12 V
CMRR fpm.r.n-Mode Heiec' 85 100 85 100 80 100 dB
tion Ratio
PSRR 5upply Voltage Rejec- (Note 6) 85 100 85 100 80 100 dB
tion Ratio
DC Electrical Characteristics TA = Ti = 25''C, vs = A151/
LF155A/155,
LF156A/156 LF157AI157
LF255, LF355 , LF356A/356 LF357AI357
Parameter LF355 A 13553 LF256/356B LF25W357B Units
Typ Max Typ Max Typ Max Typ Max Typ Max Typ Max
Supply Current 2 4 2 4 5 7 5 1O 5 7 5 10 mA
AC Electrical Characteristics TA = Ti = 25~c, Vs = K15V
LF155I255/ LF156/256, LF156/256/ LF157/257, LF157/257/
Symbol Parameter Corttiltlttna 355/3558 LF3563 356/3563 LF3573 357/3578 Units
Typ Min Typ Mln Typ
SR Slew Rate LF155/6:Av=1, 5 7.5 12 V/ps
LF157: AV= 5 30 50 V/ps
GBW Gain Bandwidth 2.5 5 20 MHz
Product
ts Settling Time to 0.01% (Note 7) 4 1.5 1.5 ps
en Equivalent Input Noise Rs= 1000
Voltage f-- 100 Hz 25 15 15 WNW
1= 1000 Hz 20 12 12 nV/JFE
in Equivalent Input t= 100 Hz 0.01 0.01 0.01 PA/WE
Current Noise f= 1000 Hz 0.01 0.01 0.01 pA/JH_z
Cm Input Capacitance 3 3 3 pF
Notes for Electrical Characteristics
Note 1: The maximum power dissipation for these devices must be derated at elevated temperatures and is dictated by TNax, 9M. and the ambient temperature.
TA. The maximum available power dissipation at any temperature is Pir--fTNAx-TAJ/em or the 25'C PdMAX- whichever is less.
Note 2: Unless otherwise specified the absolute maximum negative input voltage is equal to the negative power supply voltage.
Note 3: Unless otherwise stated, these test conditions apply:
LF155A/6A/7A
LF 1 5 5 I / 6/7 LF255/ / tV 7 LF355A/6AI7A LF355B/6B/7B LF355/ / tV 7
SupplyVoltago,Vs i15VSV5Si20V i15VSVSSi20V i15VSVSSi18V t15VSVSi20V vs=¢15v
TA --55''ChcTAsc +125°C -25''CscTAsi; +85°C 0°CSTAS +70°C 0°CSTAS +70°C 0°CSTAS +70''C
THIGH + 125''C + 85'C + 70% + 70'C + 70°C
and Vos, I3 and tos are measured at Vm=0.
Note 4: The Temperetme Coefficient of the adjusted input offset voltage changes only a small amount (0.5;.N/‘C typically) tor each mV of adxustment from its
original unadlusted value. Comrnon-mtxm rejection and open loop voltage gain are also unaffected by offset adjustment.
Note s. The input bias currents are junction leakage currents which approximately double for every 10°C increase in the lunction temperature. Tr Due to limited
productlon test time, the input bias currents measured are correlated to junction temperature. in normal operation the Junction temperature rises above the ambient
temperature as a result of Internal power dissipation, Pd. TC-TA+ ha Pd where ' is the thermal resistance from junction to ambient. Use ot a heat sink is
recommended if input bias current is to be kept to a minimum.
Note 6: Supply Voltage Rejection Is measured tor both supply magnitudes increasing or decreasing simuitaneously, in accordance with common practice.
Note r.. Settling time is defined here, for a unity gain inverter connection using 2 kn resistors tor the LF155/6, It is the time required for the error voltage (the
voltage at the inverting input pin on the amplifier) to settle to within 0.01% of its final value from the time a 10V step input is applied to the inverter. For the LF157,
Ayn - 5, the feedback resistor from output to input is 2 kn and the output step Is 10V (See Settling Time Test Circuit).
Note 8: Refer to RETS155AX for LF155A. RETS155X for LF155, RETSF158AX tor LFISBA. RETSISGX tor LF15th FIETS157A for LF157A and RETS167X for
LF157 military smreitications,
Note th Max. Power Dissipation is defined by the package characteristics. Operating the part near the Max. Power Dissipation may cause the part to operate
outside guaranteed timits.
GLSSIVLS8/15851/19251/‘115|-ILSlJ1/8998/V9985'l/998d'lIQSZd'IIVQS l/99|-:l'l/8998/V958/598:l'lISSZd'IIVSSUSSH‘I
LF155/ 155A]LF255/LF355/355A/3558/LF156/ 156A/ LF256/LF356/LF356A/3568/LF157/ 1 57A] LF 2 57/ LF357/ 357A] 3578
Typical DC Performance Characteristics
Curves are for LF155, LF156 and LF157 unless otherwise specified.
Input Blas Current Input Blas Current Input Blas Current
88k 1% 'tt .
" rpm:
, 1* i "t , " III .
5 " m It E n k--. m Its ii, u
E ' "ss, g (1| V: "
a .. -lll'/t:] / 'i5,a, .---iiiii2; - ts " Td"'
il I 15 " tt , il I
ll 3 tt mu an
i i i a
- t - , -
1m: mun "
" I l1 l '
-Is 45 I a u a m -u At s s a u m -u " a 1 "
cu: rsmu‘mn: rc) CASE motnwnz Pet common: VOLT"! M
Voltage Swing Supply Current Supply Current
I -2k I
E 'il - w: Al 45"
'dl i ' , r
' , ' - / n m“:
ti tt" -m: t I I -
. 5 t m tl 1’1
i F C . - o r; . urn
E g I t //
g a Ti; ; 111': " a " Aw,
E lit“
1 t 1 l
' I " u " o I In 1: a " ' i " " " "
sumv vonAaE ttttl sumv mus: tttfl IUMV mun: (WI
Positive thtmrttttrt-Mttdtt
Negative Current Limit Posltlve Current Limit Input Voltage Limit
-t8 u "
f. " . ttW b'; " M" sra
E 5 5%
3 .-to g s'...' "
g 5 Iji'
I " I g; "
g g ii E
''lt' E s
' I 111 " n u a as u I " " " a n :5 u I " " "
output smx cnnam (Ml UUTPUI' " vac: tumult m) mm"! WP“ VOL“ M
TL/H/5646-2
Negatlve Common-Mode
Input Voltage lell Open Loop Voltage Gain Output Voltage Swing
"ll m "
- lr . g: s v, . 21w
tt s . - T " trt
'lf -1s 1 tPt 3 Th" -tt'tr 'il " A
- A . -
" E, n . are F, , "
i tl TA . Itr'e td t
3 E -11 E t" a "
g E E g
E '- It, te "
g i " 3 ''
" E i , I
5 til 15 " It " tll
NEGATIVE SUPPLY VOLTS (V) SUPFLV VOLTAGE 13V) OUTPUT Lott h tent
TL/H/ 5646-3
Typical AC Performance Characteristics
Gain Bandwidth
B Al N IAHBI‘IDTH (“H11
~55 -35-t5 5 " " M " ")5 115
IEWERATURE Ctr)
Output Impedance
1. - t5'T
vs" 215V
100 . ,
OUTPUT IMP! DANCE ($2)
t Av=tll
" III 18tlk 1M 1M
FREDIIENCV (Hz)
LF155 Small Signal Pulse
Response, Av-- + 1
001’?!” V0 LTAGE SWINE (50 mV/DIV)
IIIE (0.5 WOW)
TL/ H Mi648- 5
LF155 Large Signal Pulse
Response, Av= + 1
OUTPUT VDLABE SWING (EVIDIW
TIME n wow)
TL/H/5646-8
TI 1’ V
00 ll VOlTAGE SWINE (50m IDIV) OUYPHTIMPEDANCE (fl)
OUTPUT VDLYAGE SWING (EVIDIV)
UNITY GAIN lANIIVfl 0711 (MN!)
Gain Bandwidth
LF157 CURVES IDENUCAL
BUT MULTIPLIED " I
I.F156
~55 -35 -15 5 25 45 65 85 1115125
TEMPERATURE (°C1
Output Impedance
us25°c AV- um
Ilss MW
" th 1001 tM 10M
FREQUENCY (N11
LF156 Small Signal Pulse
Response, Av-- + 1
aa.). I
TIME (0.5 NOW)
TL/ H l MM6 -6
LF156 Large Slgnal Pulse
Response, Av--- +1
TIME " ul/UW)
TUH/5646-9
ourrur Vanna: mun tswnlvl
OUTPUT IMPEDANCE ((2)
OUTPUT VOUAGE SWING (50 mV/DIV)
Normalized Slew Rate
1.6 IIs " t1511
-55-35 -15 5 " " " 's1tl51N
TEMPE RATU RE ('NO
TL/H/5646-4
Output Impedance
TA = we
vs " t15V
Av . 1110
" 1111: um 1M 10M
FREDUENCV (Hz)
TL/H/5646-12
Small Signal Pulse
Response, Av = + 5
r: u a a tt I
TIME (0.1 NON)
TL/H/ 5646 -7
LF157 Large Signal Pulse
Response, Av= + 5
TIHE 1.5 MW)
TL/H/5646-10
ELSSIVZSSI 1985'" LSZJ'I/ VtSl/LS 151/ 8998/ V998:l'l/ 998:1'1/ 993:11/V99 l / 99 l:l'l/ ESSSIVSSSI 958:11/ SSZd'I/ V99 1 / SSH'I
LF155/ 155A/LF255/LF355/355A/3558/LF156/ 156A/LF256/LF356/LF356A/3563/LF157/ 157A]LF257/LF357/357A/357B
Typical AC Performance Characteristics (Continued)
Inverter Settling Time
E vg-mv 'V
o u u s "
smunc m: bal
Bode Plot
I " II:
rnzuutucv (mu)
Common-Mode Rejection
'd tot l, ,1,
2 " 'its,. h''" -
g A, N, TIIH'C
g " \ \
, " Cts "N I
L. " \ hqrisr
, N' N.
i " "N "N
E I Nc
10 m " III mt III Iu
muuzucv (HI)
Undlstortod Output Voltage
i.".e" vrmv
g It'll
E T.',
g
m mu m m
rnmutucv (an
POI!!! SURLV nuemou RATIO (a) 8A]. (ll) OUTPUT VOU’ABE MIG FRO. 0V (V)
mIVALEIn umn lam VOLTAGE (WW
Inverter Settling Tlme
" I I I I III
V3- ""
I. . m:
i I I1
u " I "IV
l l mu. AV . -I
' 1 ll um. hy . "
10 IN _ 1 HIV
smuuu TIME bat
Bode Plot
II 125
II m m
' . v.- :1" n
I Bl '
-II I a
-" -N ii
" -u g',
4: -1: tt
4: 4.:
"' 45:
I " In
rnmutuzv mm
Power Supply Belowon Ratlo
TA . tt't
a v. . mv
u sumv
IEBATIV!
" sumv
" m II tre mu m
rnmusucv mo
Equivalent Input Nolso
Voltage
Ta" m:
t " * " tilk
FIEOUZUEV (MI)
GAII “II OPEN l0” VIIIJAGE sun (ll)
mun WV nutmnu RATIO (III
:nmmm umn Inns: value: MAME)
Open Loop Frequency
Response
" la tt m mu: "I ma
razoumcv (Hz)
Bode Plot
(83311530) mm
PREMIER" Mitd
Powor Supply Rejection Ratio
POSITIVE Ill!“
IEBATWE [MU
1liit " m 1.3 III 1”
VHEOUEICY (I11)
Equivalent Input Nola:
Voltage (Expandod Scale)
" T. . te'tt
V. . 215V
"Willow (HI)
TUH/5tMtt-lt
Detailed Schematic
.7- 4) trot
{- "b--,
.1 u " u
Em m; -r-tot III‘
u ‘pu q In
m '/rii i,'ii N " 1 m
f f f Q 2'
'C = 3 pF in LFI 57 sedan. TL/H/5546-13
Connection Diagrams (Top Views)
Metal Can Package (H)
TL/HISG‘G-M
Order Number
LFISSAH. LF156AH, LF157AH,
LF155H, LF156H, LF157H,
LF255H, LF256H. LF257H,
LF355AH. LFSSGAH, LF357AH.
LFSSSBH, LF3563H, LF35rBH,
LF355H, LF356H or LF357H
See NS Package Number H086
DuaHn-Llno Package (d)
"-2 V inc
re-t Ls-nc
mms-i L2-.rm
INPUT 4 - 1L.e
INPUT ' o JiLouvut
v-U, LWHCE
ra-t, Lac
TL/Ht5646-30
Order Number
LF155J. LF158J. LF157J,
LF355J. Lassa, $357.1.
LF$558J, LFassBJ or LF357BJ
Soc NS Package Number gt4A
DuaI-ln-Uno Package (M and N)
IALAICE - - "
mm 2 Ce
mm ."i/2t L L oomn
v-U I.. nuns
TL/wsm-za
Order Number
LF355M, LF366M, LF357M,
LF3568H, LF3558N. LF356BN,
LF351BN. LF355N. LF358N or
LF357N
Soc NS Package Number
MOBA or NOGE
ELSSIVLSSILSSIIILSH‘IIVLSll £9H'I/ 8958/V99851/958d1/ 99351/V991/ QSH'II 899$] V998] 99851/ 993:!1/ VSSI-I 99 H1
LF155/ 155A/LF255/LF355/355A/3553/LF156/ 156A/LF256/LF356/LF356A/3563/LF157/157A]LF257/LF357/357A/357B
Application Hints
The LF155/6/7 series are op amps with JFET input de-
vices. These JFETs have large reverse breakdown voltages
from gate to source and drain eliminating the need for
clamps across the inputs. Therefore large differential input
voltages can easily be accomodated without a large in-
crease in input current. The maximum differential input volt-
age is independent of the supply voltages. However, neither
of the input voltages should be allowed to exceed the nega-
tive supply as this will cause large currents to flow which
can result in a destroyed unit.
Exceeding the negative common-mode limit on either input
will force the output to a high state, potentially causing a
reversal of phase to the output. Exceeding the negative
common-mode limit on both inputs will force the amplifier
output to a high state. In neither case does a latch occur
since raising the input back within the common-mode range
again puts the input stage and thus the amplifier in a normal
operating mode.
Exceeding the positive common-mode limit on a single input
will not change the phase of the output however, if both
inputs exceed the limit, the output of the amplifier will be
forced to a high state.
These amplifiers will operate with the common-mode input
voltage equal to the positive supply. In fact, the common-
mode voltage can exceed the positive supply by approxi-
mately 100 mV independent of supply voltage and over the
full operating temperature range. The positive supply can
therefore be used as a reference on an input as, for exam-
ple, in a supply current monitor andlor limiter.
Precautions should be taken to ensure that the power sup-
ply for the integrated circuit never becomes reversed in
Typical Circuit Connections
vos Adjustment
Driving Capacitive Loads
. vos is adiusted with a 25k potenti-
ometer 'LF15516 R- 5k
oThe potentiometer wiper is con- LF157 R=1.25k
nected to V+
o For potentiometer: with tempera-
ture coefficient of 100 ppm/T or
less the additional drift with adjust
is = 0.5 pV/‘C/mV of adjustment wr.
. Typical overall drift 5 yV/"C 1:0.5 Overshoot S 20%
pV/‘C/mV of adi.)
Settling time (ts) a 5 us
polarity or that the unit is not inadvertently installed back-
wards in a socket as an unlimited current surge through the
resulting forward diode within the IC could cause fusing of
the internal conductors and result in a destroyed unit.
Because these amplifiers are JFET rather than MOSFET
input op amps they do not require special handling.
All of the bias currents in these amplifiers are set by FET
current sources. The drain currents tor the amplifiers are
therefore essentially independent of supply voltage.
As with most amplifiers, care should be taken with lead
dress, component placement and supply decoupling in or-
der to ensure stability. For example, resistors from the out-
put to an input should be placed with the body close to the
input to minimize "pickup" and maximize the frequency of
the feedback pole by minimizing the capacitance from the
input to ground.
A feedback pole is created when the feedback around any
amplifier is resistive. The parallel resistance and capaci-
tance from the input of the device (usually the inverting in-
put) to ac ground set the frequency of the pole. In many
instances the frequency of this pole is much greater than
the expected 3 dB frequency of the closed loop gain and
consequently there is negligible efiect on stability margin.
However, if the teedback pole is less than approximately six
times the expected 3 dB frequency a lead capacitor should
be placed from the output to the input of the op amp. The
value of the added capacitor should be such that the RC
time constant of this capacitor and the resistance it parallels
is greater than or equal to the original feedback pole time
constant.
LF157. A Large Power BW Amplifier
= Vout
TL/H/5646-15
For distortion I 1% and a 20 Vp-p VouT swing,
power bandwidth is: 500 kHz.
Due to a unique output stage design, these am-
plifiers have the ability ta drive large capacitive
loads and stlti maintain stability. cuMAX) a 0.01
Typical Applications
Settling Time Test Circult
I Settling time is tested with the LF155/6 connected
'mJJx as unity gain invaner and LF157 connected for
Av = -5
. FET used to isolate the probe capacitance
. Output = 10V step
. AV = -5for LF157
OIIILLMEOK
TL/H/5646v16
Large Signal Inverter Output, Vou-r (from Settling Tlme Clrcult)
LF355 LF356
e P. a
it if. a
t wow , Mm m/mv
TL/H/5646-17 TL/H/5846-18 TLfH/5646-19
Low Drift Adjustable Voltage Reference
. A VouT/AT= 10.002961?
"m. . All resistors and ptotent'ormrters should be wire-wound
. P1: drift adjust
ll: :EJ . P2: Vour adjust
. Use LF155 for
I Low IB
-o Vuur'm I Low drift
tt'.tw
I Low supply current
TL/H/S648-20
SLSEIVLSSILSSII/ LSZd'I/VLSl[£9ld1/8998/V99851/9985'1/ 953:!1/V99 l [99 ld'l/GSSE/VSSS/ 958:!1/59331/‘1991/99 H'l
LF155/155A/LF255/LF355/355A/3553/LF156/156A/LF256/LF356/LF356A/3568/LF157/ 157A]LF257/LF357/357A/357B
Typical Applications (Continued)
Fast Logarlthmic Converter
Mw", I O vm-w
2yztl,, T i'.
m . [ . Dynamic range: 100 “A K li s 1 mA (5 dec-
= "i; k1 ades). |Vo|=1V/decade
P . Transient response: 3 psfor Al.= 1 decade
= . GI, ca R2, R3: added dynamic compensation
. vos adlust the LF15810 minlmlze quiescent errov
. Br: Tel Labstype081 + omerc
TL/H/5648-21
R " R 1
IVOUTI == [1 + 3] -rln)h [ r 1 -- log bh..-, R2 = 15.7k, Rr = lk, 0.3%I'C (fortempertsture compensation)
RT q VREF Ri Rili
Precision Current Monitor
I " . Vo--5 mmz (V/mA ot Is)
we T . m, R2, R3: 0.1 % resistors
' sum: . Use LFISS for
I Cttrttrttort-mode range to supply range
1 ILOWIB
- I Low Vos
I Low Supply Current
- TL/Hl5648-31
8-Blt DIA Converter with Symmetrlcal Offset Binary Operation
m Lu r
IV.‘I2')“||I.I7"
u , _ , I " u. t
"o.two-M7v.'L' In -
mn- ma ' hOlo
= I . '
e "-"u' u n -uv
-IIV TL/H/5646-32
. m, R2 should be matched wlthln $110596
. Full-scale response time: Spa
Eo BI B2 B3 B4 B5 B8 B7 B8 Common“
+ 9.920 1 1 1 1 1 1 1 1 Positive Full-Scale
+ 0.040 1 0 0 0 0 0 O 0 (+) Zero-Scale
- 0.040 0 1 1 1 1 1 1 1 (-) Zero-Scale
- 9.920 0 o o 0 0 O 0 0 Negative FuII-Scale
Typical Applications (Continued)
Wide BW Low Nolse, Low Drift Arttpllfler
RI '2ssaf
'sro-MN-e-
I 240 kHz
2rrVr,
. Parasitic input capacitance C1 IK (3 pF for LF155. LF156 and LF157 plus
any additional layout capacitance) interacts with ieedback elements and
creates undesirable high frequency pole. To compensate add C2 such
that: R262: RUM.
. Power BW: MAX =
Booatlng the LF156 wlth a Current Amplifier
. lourmm “150 mA (will drive RL 2 1000)
0 AVOUT 0.15 .
AT IO- 2 Ntps (with CL shown)
. No additional phase shift added by the current amplifier
3 Decades V00
Til, ot"
c,T,,r""
"A" TL/H/5848-26
- Vt; (RB + R7)
(8 Wu R8 R1) Cl
m, R4 matched. Uneamy 0.1% over 2 decades.
OSVcSSOV.1D HszSWKHz
Isolating Large Capacitive Loads
. Overshoot 6%
. is 10 ps
CWhen driving large cc, the Voor slew rate determined by Cr. and
'oumnmt
AVOUT 3 IO_m I 0.02
AT CL E- V/ws = 0.04 V/ws (with CL shown)
Low Drift Peak Detector
TL/H/5646-22
F-o Yrs"
TL/H/ 5646
. By adding D1 and Rt, VD1=0 during hold mode. Leakage of D2 provided
by feedback path through Rt.
. Leakage of circuit is essentially lb (LF155. LF156) plus capacitor leakage
of Cp.
. Diode 03 clamps Vou'r (A1) to vm-vm to improve speed and to limit
reverse bias of D2.
. Maximum input frequency should be < < 'htrRtCrxt where CD2 is the
shunt capacitance of Dt
Non-inverting Unity Galn Operation for LF157
RIC 2 (2w) is MHz)
_R2+Fl5
Awoc) = 1
f-s dB = 5 MHZ
Inverting Unity Gain for LF157
c-sl.', - mo 2 _‘_
"__ (br) (5 MHz)
II L be RI = T
. Awpc) -- -1
T." "a" f-s d8 = 5 MHZ
TL/H/5646-25
8198IVLSSILSBJ'I/LSZd'I/VLS ll £9151/9958/V9985'l/ 998:I'I/ QSZJ'I/VSSU QEH'I/ 8998/ V998] 998:!‘1/ SSZJ'II VSSL/SSH'I
LF155/ 155A/LF255/LF355/355A/3558/LF156/ 156A/LF256/LF356/LF356A/3568/LF157/ 157A/LF257/LF357/357A/357B
Typical Applications (Continued)
High Impedance, Low Drift Instrumentation Ampllfler
TL/HlM-ZG
R3 2R2
. VOUT =» Ti" [F +1]AV,V_ + 2V S VlNcommon-mode g V+
. System vos adjusted via A2 vos adjust
. Trim R3 to boost up CMRH to 120 dB. Instrumentation amplirar
resistor array recommended for best accuracy and lowest drift
Typical Applications (Continued)
Fast Sample and Hold
'h I I
I L. - m
( JFET "tTCh"
TIJH/5646-33
. Both amplifiers (AI, A2) have feedback loops individually closed with stable responses (overshoot negligible)
I Acqulsmon time TA, estimated by:
F-o-t VIN: Ch VI provided that:
TA 6: --._-......t
" < ans, RON Ch and TA > LG". RON is of SWI
iourissAm
' . . . . VIN Ch
It inequality not satisfied: TA = 20 m A
. LF156 develops full Sr output capability for vmz IV
. Addition of SW2 improves accuracy by putting the voltage drop across SW1 inside the feedback loop
I Overall accuracy of system determined by the accuracy of both amplifiers, A1 and A2
High Accuracy Sample and Hold
LFtt333
T. Vour
TL/H/5646-27
. By closing the low through M, the Your accuracy will be determined uniquely by A1.
No Vos adjust required for A2.
. " can be estimated by same considerations " previously but, because ot the added
propagation delay in the taedback loop (A2) the overshoot is not negligible.
. Overall system slower than test sample and hold
. m, ce additional compensation
. Use LF156tor
I Fast settling time
I LOW Vos
ELSSIVLSSI £9851/193d'l/ VtSl/ LSH'I/ 8958/V998d'l/ 998:!1/ 953:!1/ V99 |- / 9S L:l"|/ 8998/ VSSSI 99851/ 9935'” V99 l / 99 H1
LF155/155AILF255/LF355/355A/355B/LF156/156A/LF256/LF356/LF356A/3568/LF157/157A]LF257/LF357/357A/357B
Typical Applications (Continued)
[III "
High t2 Band Pass Filter
0 By adding positive feedback (R2)
a increases to 40
. tim-- 100 kHz
1iur =1N8
. Clean layout recommended
. Response to a 1 Vp-p tone burst:
300 ps
TL/H/5646- 28
High th Notch Filter
. 2R1 = R = 10 Mn
20 --- GI = 300 pF
q Capacitors should be matched to obtain high Q
ammo“ - 120 Hz, notch = --56 dB, ta >
I Use LF155 for
. LOW ls
I Low supply current
TL/H/5646-34
This datasheet has been :
www.ic-phoenix.com
Datasheets for electronic components.
National Semiconductor was acquired by Texas Instruments.
corp/docs/irwestor_relations/Pr_09_23_201 1_national_semiconductor.html
This file is the datasheet for the following electronic components:
LF155AH - product/If155ah?HQS=T|—nul|—nu|I-dscataIog-df-pf-null-wwe
LF155J - product/lf155j?HQS=T|-nu|I-nu|I-dscatalog-df—pf—nulI-wwe
LF156J - product/lf156j?HQS=T|-nu|I-nu|I-dscatalog-df—pf—nulI-wwe
LF357J - product/lf357j?HQS=T|-nu|I-null-dscatalog-df—pf—nulI—wwe
LF157AH - product/If157ah?HQS=T|—nul|—nu|I-dscataIog-df-pf-null-wwe
LF157H - product/If157h?HQS=T|-nu|I-nu||-dscatalog-df—pf—null-wwe
LF157J - product/lf157j?HQS=T|-nu|I-nu|I-dscatalog-df—pf—nulI-wwe
LF355BH - product/If355bh?HQS=TI-nulI-nu|I-dscatalog—df-pf-nuII-wwe
LF357BM - product/lf357bm?HQS=T|-null-nulI-dscatalog-df-pf—nuII-wwe
LF357BJ - product/If357bj?HQS=T|-nu|I-null-dscatalog-df-pf-null-wwe
LF357BH - product/If357bh?HQS=T|—null-nu|I-dscataIog-df—pf-null-wwe
LF356J - product/If356j?HQS=T|-nu|I-nu|I-dscataIog-df-pf-null-wwe
LF355BJ - product/If355bj?HQS=T|-nu|I-null-dscataIog-df-pf-null-wwe
LF355J - product/lf355j?HQS=T|-nu|I-nu|I-dscatalog-df—pf—nulI-wwe
LF356BJ - product/If356bj?HQS=T|-nu|I-nulI-dscatalog-df-pf-null-wwe
