Fairchild Semiconductors Linear 1.C.s - Operational Amplifiers Semiconductors LM108, LM108A, LM308A Super Beta Operational Amplifiers GENERAL DESCRIPTION The 108 series of Super Beta Operational Amplifiers is constructed using the Fairchild Planar epitaxial process. High input impedance, low noise, input offsets, and temperature drift are made possible through use of super beta processing, making the device suitable for applications requiring high accuracy and low drift performance. The 108A series is specially selected for extremely low offset voltage and drift, and high common mode rejection, making possible superior performance in applications where - offset nulling is undesirable. ABSOLUTE MAXIMUM RATINGS Supply Voltage 108A, 108 +20 V 308A +18 V Internal Power Dissipation 500 mW Differential Input Current +10 mA Input Voitage +15 V Storage Temperature Range -65C to +150C Operating Temperature Range Military (108A, 108) -55C to +125C Commercial (308A) Lead Temperature (Soldering, 60 seconds) Output Short Circuit Duration 0C to +70C 300C Indefinite CONNECTION DIAGRAM | See outline drawing No. 97 for dimensions. ZO INV nny (s) OUTPUT NON INV INPUT NC Pin 4 connected to case TOP VIEW FEATURES Guaranteed fow input offset characteristics. High input impedance, Low offset current. Low bias current. Operation over wide supply range. REFERENCE TABLE Code Stock No. LM108H 35797D LM108AH 35798B 35799X LM308AH _____.....-_. eeeeeeeeeeeeeeeeeee eee EEeEEE SSE eEeEEEEEeeeeeeeeSSSSSaaaaaSaEaeaeaeaeaEaEaaaaSNmaEEEEEeEeEeEEeEEEE ee PLEASE QUOTE STOCK NO. AND MANUFACTURER'S CODE WHEN ORDERING 755 National Semiconductor Semiconductors Linear |.C.s - Operational Amplifiers LM108A Series Operational Amplifiers REFERENCE TABLE Code Stock No. LM108AH 33136X LM208AH 33137R LM308A H 30603D GENERAL DESCRIPTION The LM108A, LM208A and LM308A are precision operational amplifiers having specifications about a factor of ten better than FET amplifiers over their operating temperature range. In addition to low input currents, these devices have extremely low offset voltage, making it possible to eliminate offset adjustments, in most cases, and obtain performarice approaching chopper stabilised amplifiers. The devices operate with supply voltages from 2V to .20V and have sufficient supply rejection to use unregulated supplies. Although the circuit is interchangeable with and uses the same compensation as the LM101A, an alternative compensation scheme can be used to make it particularly insensitive to power supply noise and to make supply bypass capacitors unnecessary. FEATURES Offset voltage guaranteed less than 0.56mV Maximum input bias current of 3.0nA over temperature Offset current less than 406pA over temperature Supply current of only 300nA, even in saturation Guaranteed 5pnV/C drift. COMPENSATION CIRCUITS The low current error of the LM108A series makes possible many designs that are not practical with conventional amplifiers. In fact, it operates from 10 MQ source resistances, introducing less error than devices like the 709 with 10kQ sources. Integrators with drifts less than 500nV/sec and analog time delays in excess of one hour can be made using capacitors no larger than 1pF. The LM208A is identical to the LM108A, except that the LM208A has its performance guaranteed over a 25 C to 85C temperature range, instead of 55C to 125C. The LM308A has slightly-relaxed specifications and has its performance guaranteed over a 0C to 70C temperature range. CONNECTION DIAGRAM* *Pin connections shown on schematic diagram are for TO-5 package Metal Can . Comp 2 **Unused pin(no (5) NC Internal conn- Note:Pin4 ectionfto allow connected to case for input antiteakage v- guard ring on printed circuit board layout See outline drawing No. 97 for dimensions. Standard Compensation Circuit RI R2 R1 Vin | RIC C2 RITR C+ 30pF Alternate"Frequency Compensation R2 pe Voit Cs Tt 100pF improves rejection of power supply noise by a factor of ten PLEASE QUOTE STOCK NO. AND MANUFACTURER'S CODE WHEN ORDERING 969 National Semiconductors Semiconductor Linear I.C.s Operational Amplifiers SSeS SESS ABSOLUTE MAXIMUM RATINGS Supply Voltage +20V (+ 18V Operating Temperature Range : LM308A) LM108A 55C to 125C Power Dissipation (Note 1) 500mW tMaOnA ree Differential input Current +10mA - (Note 2) Storage Temperature Range 65C to 150C Input Voltage (Note 3) +15 Lead Temperature (Soldering, 300C Output Short-Circuit Duration Indefinite 10 sec) ELECTRICAL CHARACTERISTICS (Note 4) LM108A/LM208A LM308A , Parameter Conditions Min. Typ. Max.| Min. Typ. Max. | Units Input Offset Voltage Ta = 25C 0.3 0.5 0.3 0.5 mV Input Offset Current T, = 25C 0.05 0.2 0.2 1 nA tnput Bias Current Ta = 25C 0.8 2.0 1.5 7 nA Input Resistance T, = 25C : 30 70 10 40 MQ Supply Current T, = 25C 0.3 0.6 0.3 0.8 mA Large Signal Voltage Gain | T, = 25C, Vs = +15V . . Vour = +10V, Rp > 10k2 | 80 300 80 300 Vimv Input Offset Voltage 1.0 0.73 mV Average Temperature Coefficient of Input Offset Voltage 1.0 5.0 1.0 5.0 wv? Input Offset Current 0.4 1.5 nA Average Temperature Coefficient of Input 0.5 2.5 2.0 10 pasc Offset Current Input Bias Current 3.0 10 nA Supply Current Ta = +125C 0.15 0.4 _ _ mA Large Signal Voltage Gain | Vs = +15V, Vour = +10V . R, > 10 kQ 40 60 Vimv Output Voltage Swing Vs = +15V, Ry == 10k2 +13~=E 14 +13 =414 V input Voltage Range Vs = 15V TS 13.5 +14 Vv Common Mode 96 110 96 110 dB Rejection Ratio Supply Voltage ~~ 96 110 9% =110 aB Rejection Ratio Note 1: The maximum junction temperature of the LM108A is 150C, whilst the LM208A is 100C and that of the LM308A is 85C. For operating at elevated temperatures, devices in the TO-5 package must be derated hased on athermal resistance of 150C/W, junction to ambient, or 45C/W, junction to case. Note 2: The inputs are shunted with back-to-back diodes for overvoltage protection. Therefore, excessive current will flow if a differential input voltage in excess of 1V is applied between the inputs unless some limiting resistance is used. Note 3: For supply voltages jess than +15V, the absglute maximum input voltage is equal to the supply voltage. Note 4: For LM108A +5V < Vs < +20V 55C < Ta < 125C For LM208A +5V < Vs < +20V 25C < Ta, < 85C For LM308A +5V < Vs < +15V O0C < T, < 70C MANUFACTURERS CURRENT LIST PRICES ARE ALWAYS CHARGED 970