LM146/LM246/LM346 Programmable Quad Operational Amplifiers General Description Features (ISET e 10 mA) The LM146 series of quad op amps consists of four independent, high gain, internally compensated, low power, programmable amplifiers. Two external resistors (RSET) allow the user to program the gain bandwidth product, slew rate, supply current, input bias current, input offset current and input noise. For example, the user can trade-off supply current for bandwidth or optimize noise figure for a given source resistance. In a similar way, other amplifier characteristics can be tailored to the application. Except for the two programming pins at the end of the package, the LM146 pin-out is the same as the LM124 and LM148. Y Y Y Y Y Y Y Y Y Y Programmable electrical characteristics Battery-powered operation Low supply current 350 mA/amplifier Guaranteed gain bandwidth product 0.8 MHz min Large DC voltage gain 120 dB Low noise voltage 28 nV/0Hz g 1.5V to g 22V Wide power supply range Class AB output stage - no crossover distortion Ideal pin out for Biquad active filters Input bias currents are temperature compensated Connection Diagram (Dual-In-Line Package, Top View) PROGRAMMING EQUATIONS Total Supply Current e 1.4 mA (ISET/10 mA) Gain Bandwidth Product e 1 MHz (ISET/10 mA) Slew Rate e 0.4V/ms (ISET/10 mA) Input Bias Current j 50 nA (ISET/10 mA) ISET e Current into pin 8, pin 9 (see schematicdiagram) ISET e V a b Vb b 0.6V RSET TL/H/5654 - 1 Order Number LM146J, LM146J/883, LM246J, LM346M or LM346N See NS Package Number J16A, M16A or N16A Schematic Diagram TL/H/5654 - 2 C1995 National Semiconductor Corporation TL/H/5654 RRD-B30M115/Printed in U. S. A. LM146/LM246/LM346 Programmable Quad Operational Amplifiers November 1994 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. (Note 5) LM146 LM246 LM346 g 22V g 18V g 18V Supply Voltage g 30V g 30V g 30V Differential Input Voltage (Note 1) g 15V g 15V g 15V CM Input Voltage (Note 1) Power Dissipation (Note 2) 900 mW 500 mW 500 mW Output Short-Circuit Duration (Note 3) Continuous Continuous Continuous b 55 C to a 125 C b 25 C to a 85 C Operating Temperature Range 0 C to a 70 C Maximum Junction Temperature 150 C 110 C 100 C b 65 C to a 150 C b 65 C to a 150 C b 65 C to a 150 C Storage Temperature Range Lead Temperature (Soldering, 10 seconds) 260 C 260 C 260 C Thermal Resistance (ijA), (Note 2) Cavity DIP (J) Pd 900 mW 900 mW 900 mW ijA 100 C/W 100 C/W 100 C/W Small Outline (M) ijA 115 C/W Molded DIP (N) Pd 500 mW ijA 90 C/W Soldering Information Dual-In-Line Package a 260 C a 260 C a 260 C Soldering (10 seconds) Small Outline Package a 215 C a 215 C a 215 C Vapor Phase (60 seconds) a 220 C a 220 C a 220 C Infrared (15 seconds) See AN-450 ``Surface Mounting Methods and Their Effect on Product Reliability'' for other methods of soldering surface mount devices. ESD rating is to be determined. DC Electrical Characteristics (VS e g 15V, ISET e 10 mA, Note 4) Parameter LM146 Conditions Min Typ LM246/LM346 Max Min Typ Units Max Input Offset Voltage VCM e 0V, RSs50X, TA e 25 C 0.5 5 0.5 6 mV Input Offset Current VCM e 0V, TA e 25 C 2 20 2 100 nA Input Bias Current VCM e 0V, TA e 25 C 50 100 50 250 nA Supply Current (4 Op Amps) TA e 25 C 1.4 2.0 1.4 2.5 mA Large Signal Voltage Gain RL e 10 kX, DVOUT e g 10V, TA e 25 C Input CM Range TA e 25 C CM Rejection Ratio RSs10 kX, TA e 25 C Power Supply Rejection Ratio 100 1000 50 1000 g 13.5 g 14 g 13.5 g 14 V 80 100 70 100 dB RSs10 kX, TA e 25 C, VS e g 5 to g 15V 80 100 74 100 dB Output Voltage Swing RLt10 kX, TA e 25 C g 12 g 14 g 12 g 14 Short-Circuit TA e 25 C 5 20 5 20 Gain Bandwidth Product TA e 25 C 0.8 1.2 0.5 1.2 Phase Margin TA e 25 C 60 60 Deg Slew Rate TA e 25 C 0.4 0.4 V/ms 35 V/mV V 35 mA MHz Input Noise Voltage f e 1 kHz, TA e 25 C 28 28 nV/0Hz Channel Separation RL e 10 kX, DVOUT e 0V to g 12V, TA e 25 C 120 120 dB Input Resistance TA e 25 C 1.0 1.0 MX Input Capacitance TA e 25 C 2.0 2.0 Input Offset Voltage VCM e 0V, RSs50X 0.5 Input Offset Current VCM e 0V 2 Input Bias Current VCM e 0V 50 1.7 2.2 Supply Current (4 Op Amps) 2 6 pF 0.5 7.5 mV 25 2 100 nA 100 50 250 nA 1.7 2.5 mA DC Electrical Characteristics Parameter (Continued) (VS e g 15V, ISET e 10 mA, Note 4) LM146 Conditions Large Signal Voltage Gain RL e 10 kX, DVOUT e g 10V Input CM Range Min Typ LM246/LM346 Max Min Typ Units Max 50 1000 25 1000 g 13.5 g 14 g 13.5 g 14 V/mV V CM Rejection Ratio RSs50X 70 100 70 100 dB Power Supply Rejection Ratio RSs50X, VS e g 5V to g 15V 76 100 74 100 dB Output Voltage Swing RLt10 kX g 12 g 14 g 12 g 14 V DC Electrical Characteristic (VS e g 15V, ISET e 1 mA) Parameter LM146 Conditions Min LM246/LM346 Typ Max 0.5 5 Min Units Typ Max 0.5 7 Input Offset Voltage VCM e 0V, RSs50X, TA e 25 C Input Bias Current VCM e 0V, TA e 25 C 7.5 20 7.5 100 nA Supply Current (4 Op Amps) TA e 25 C 140 250 140 300 mA Gain Bandwidth Product TA e 25 C 80 100 50 mV 100 kHz DC Electrical Characteristics (VS e g 1.5V, ISET e 10 mA) Parameter LM146 Conditions Min Input Offset Voltage VCM e 0V, RSs50X, TA e 25 C Input CM Range TA e 25 C CM Rejection Ratio RSs50X, TA e 25 C Output Voltage Swing RLt10 kX, TA e 25 C LM246/LM346 Typ Max 0.5 5 g 0.7 Min Units Typ Max 0.5 7 mV g 0.7 80 g 0.6 V 80 dB g 0.6 V Note 1: For supply voltages less than g 15V, the absolute maximum input voltage is equal to the supply voltage. Note 2: The maximum power dissipation for these devices must be derated at elevated temperatures and is dictated by TjMAX, ijA, and the ambient temperature, TA. The maximum available power dissipation at any temperature is Pd e (TjMAX - TA)/ijA or the 25 C PdMAX, whichever is less. Note 3: Any of the amplifier outputs can be shorted to ground indefinitely; however, more than one should not be simultaneously shorted as the maximum junction temperature will be exceeded. Note 4: These specifications apply over the absolute maximum operating temperature range unless otherwise noted. Note 5: Refer to RETS146X for LM146J military specifications. Typical Performance Characteristics Input Bias Current vs ISET Supply Current vs ISET Open Loop Voltage Gain vs ISET TL/H/5654 - 3 3 Typical Performance Characteristics Slew Rate vs ISET Gain Bandwidth Product vs ISET Phase Margin vs ISET Input Offset Voltage vs ISET Common-Mode Rejection Ratio vs ISET Power Supply Rejection Ratio vs ISET Output Voltage Swing vs Supply Voltage Input Voltage Range vs Supply Voltage Input Bias Current vs Input Common-Mode Voltage Input Bias Current vs Temperature Input Offset Current vs Temperature Supply Current vs Temperature TL/H/5654 - 4 4 Typical Performance Characteristics (Continued) Open Loop Voltage Gain vs Temperature Gain Bandwidth Product vs Temperature Slew Rate vs Temperature Input Noise Voltage vs Frequency Input Noise Current vs Frequency Power Supply Rejection Ratio vs Frequency Voltage Follower Pulse Response Voltage Follower Transient Response TL/H/5654 - 5 Transient Response Test Circuit TL/H/5654 - 6 5 Application Hints Isolation Between Amplifiers: The LM146 die is isothermally layed out such that crosstalk between all 4 amplifiers is in excess of b105 dB (DC). Optimum isolation (better than b110 dB) occurs between amplifiers A and D, B and C; that is, if amplifier A dissipates power on its output stage, amplifier D is the one which will be affected the least, and vice versa. Same argument holds for amplifiers B and C. LM146 Typical Performance Summary: The LM146 typical behaviour is shown in Figure 3 . The device is fully predictable. As the set current, ISET, increases, the speed, the bias current, and the supply current increase while the noise power decreases proportionally and the VOS remains constant. The usable GBW range of the op amp is 10 kHz to 3.5b4 MHz. Avoid reversing the power supply polarity; the device will fail. Common-Mode Input Voltage: The negative commonmode voltage limit is one diode drop above the negative supply voltage. Exceeding this limit on either input will result in an output phase reversal. The positive common-mode limit is typically 1V below the positive supply voltage. No output phase reversal will occur if this limit is exceeded by either input. Output Voltage Swing vs ISET: For a desired output voltage swing the value of the minimum load depends on the positive and negative output current capability of the op amp. The maximum available positive output current, (ICL a ), of the device increases with ISET whereas the negative output current (ICLb) is independent of ISET. Figure 1 illustrates the above. TL/H/5654-7 FIGURE 1. Output Current Limit vs ISET Input Capacitance: The input capacitance, CIN, of the LM146 is approximately 2 pF; any stray capacitance, CS, (due to external circuit circuit layout) will add to CIN. When resistive or active feedback is applied, an additional pole is added to the open loop frequency response of the device. For instance with resistive feedback (Figure 2 ), this pole occurs at (/2q (R1llR2) (CIN a CS). Make sure that this pole occurs at least 2 octaves beyond the expected b3 dB frequency corner of the closed loop gain of the amplifier; if not, place a lead capacitor in the feedback such that the time constant of this capacitor and the resistance it parallels is equal to the RI(CS a CIN), where RI is the input resistance of the circuit. TL/H/5654 - 8 FIGURE 3. LM146 Typical Characteristics Low Power Supply Operation: The quad op amp operates down to g 1.3V supply. Also, since the internal circuitry is biased through programmable current sources, no degradation of the device speed will occur. Speed vs Power Consumption: LM146 vs LM4250 (single programmable). Through Figure 4 , we observe that the LM146's power consumption has been optimized for GBW products above 200 kHz, whereas the LM4250 will reach a GBW of no more than 300 kHz. For GBW products below 200 kHz, the LM4250 will consume less power. TL/H/5654-9 FIGURE 2 Temperature Effect on the GBW: The GBW (gain bandwidth product), of the LM146 is directly proportional to ISET and inversely proportional to the absolute temperature. When using resistors to set the bias current, ISET, of the device, the GBW product will decrease with increasing temperature. Compensation can be provided by creating an ISET current directly proportional to temperature (see typical applications). TL/H/5654 - 10 FIGURE 4. LM146 vs LM4250 6 Typical Applications Dual Supply or Negative Supply Biasing ISET j Single (Positive) Supply Biasing lVb l b0.6V ISET j RSET Current Source Biasing with Temperature Compensation V a b0.6V RSET Biasing all 4 Amplifiers with Single Current Source TL/H/5654 - 11 ISET e 67.7 mV RSET 67.7 mV ISET1 R2 e , ISET1 a ISET2 e ISET2 R1 RSET # The LM334 provides an ISET directly proportional to absolute temperature. This cancels the slight GBW product Temperature coefficient of the LM346. # For ISET1 j ISET2 resistors R1 and R2 are not required if a slight error between the 2 set currents can be tolerated. If not, then use R1 e R2 to create a 100 mV drop across these resistors. 7 Active Filters Applications Basic (Non-Inverting ``State Variable'') Active Filter Building Block TL/H/5654 - 12 # The LM146 quad programmable op amp is especially suited for active filters because of their adequate GBW product and low power consumption. Circuit synthesis equations (for circuit analysis equations, consult with the LM148 data sheet). Need to know desired: fo e center frequency measured at the BP output Qo e quality factor measured at the BP output Ho e gain at the output of interest (BP or HP or LP or all of them) # Relation between different gains: Ho(BP) e 0.316 c Qo c Ho(LP); Ho(LP) e 10 c Ho(HP) 5.033 c 10b2 (sec) #RcCe fo # For BP output: RQ e # For HP ouput: RQ e # 3.478 Qo b Ho(BP) Ho(BP) b 105 105 c 3.748 c Qo J b1 ; RIN e # 3.478 Qo b1 Ho(BP) 1 a 10b5 RQ J 1.1 b1 1.1 c 105 Ho(HP) ; RIN e 3.478 Qo (1.1 b Ho(HP)) b Ho(HP) 1 a 10b5 RQ Note. All resistor values are given in ohms. 11 # For LP output: RQ e b1 11 c 105 Ho(LP) ; RIN e 3.478 Qo (11 b Ho(LP)) b Ho(LP) 1 a 10b5 RQ # For BR (notch) output: Use the 4th amplifier of the LM146 to sum the LP and HP outputs of the basic filter. 0R RH f e 0.316 notch L fo TL/H/5654-13 Determine RF according to the desired gains: Ho(BR) A fkkfnotch R e F Ho(LP), Ho(BR) RL A fllfnotch R e F Ho(HP) RH # Where to use amplifier C: Examine the above gain relations and determine the dynamics of the filter. Do not allow slew rate limiting in any output (VHP, VBP, VLP), that is: ISET 1 c VIN(peak) k 63.66 c 103 c (Volts) 10 mA fo c Ho If necessary, use amplifier C, biased at higher ISET, where you get the largest output swing. Deviation from Theoretical Predictions: Due to the finite GBW products of the op amps the fo, Qo will be slightly different from the theoretical predictions. freal j 1a fo Qo , Qreal j 2 fo 3.2 fo c Qo 1b GBW GBW 8 Active Filters Applications (Continued) A Simple-to-Design BP, LP Filter Building Block TL/H/5654 - 14 # If resistive biasing is used to set the LM346 performance, the Qo of this filter building block is nearly insensitive to the op amp's GBW product temperature drift; it has also better noise performance than the state variable filter. Circuit Synthesis Equations Ho(BP) e QoHo(LP); R c C e 0.159 RQ R e ; RQ e Qo c R; RIN e fo Ho(BP) Ho(LP) # For the eventual use of amplifier C, see comments on the previous page. A 3-Amplifier Notch Filter (or Elliptic Filter Building Block) TL/H/5654 - 15 Circuit Synthesis Equations 0.159 0.159 c fo ; Ro e Qo c R; RIN e RcCe fo CE c f2notch R CE e e Ho(BR)l Ho(BR)l f kk fnotch RIN f ll fnotch C # For nothing but a notch output: RIN e R, CE e C. 9 Active Filters Applications (Continued) Capacitorless Active Filters (Basic Circuit) TL/H/5654 - 16 # This is a BP, LP, BR filter. The filter characteristics are created by using the tunable frequency response of the LM346. # Limitations: Qo k 10, fo c Qo k 1.5 MHz, output voltage should not exceed Vpeak(out) s # Design equations: a e fo(BR) e fo(BP), 63.66 c 103 ISET(mA) c fo 10 mA R6 a R5 R2 R3 R7 R10 ,be ,ce ,de ,ee , fo(BP) e fu R6 R1 a R2 R3 a R4 R8 a R7 R( a R10 #1 bJ j f b c 0a, H b (V) o(BP) e a c c, Ho(LP) e c , Q o e 0a c b b R10 . o(BP) (C k k 1) provided that d e Ho(BP) c e, Ho(BR) e R9 # Advantage: foQo, Ho can be independently adjusted; that is, the filter is extremely easy to tune. # Tuning procedure (ex. BP tuning) 1. Pick up a convenient value for b; (b k 1) 2. Adjust Qo through R5 3. Adjust Ho(BP) through R4 4. Adjust fo through RSET. This adjusts the unity gain frequency (fu) of the op amp. A 4th Order Butterworth Low Pass Capacitorless Filter TL/H/5654 - 17 Ex: fc e 20 kHz, Ho (gain of the filter) e 1, Q01 e 0.541, Qo2 e 1.306. # Since for this filter the GBW product of all 4 amplifiers has been designed to be the same ( E 1 MHz) only one current source can be used to bias the circuit. Fine tuning can be further accomplished through Rb. 10 Miscellaneous Applications A Unity Gain Follower with Bias Current Reduction Circuit Shutdown # For better performance, use a matched NPN pair. # By pulling the SET pin(s) to Vb the op amp(s) shuts down and its output goes to a high impedance state. According to this property, the LM346 can be used as a very low speed analog switch. Voice Activated Switch and Amplifier TL/H/5654 - 18 11 Miscellaneous Applications (Continued) X10 Micropower Instrumentation Amplifier with Buffered Input Guarding # CMRR: 100 dB (typ) # Power dissipation: 0.4 mW TL/H/5654 - 19 12 Physical Dimensions inches (millimeters) Cavity Dual-In-Line Package (J) Order Number LM146J, LM146J/883 or LM246J NS Package Number J16A S.O. Package (M) Order Number LM346M NS Package Number M16A 13 LM146/LM246/LM346 Programmable Quad Operational Amplifiers Physical Dimensions inches (millimeters) (Continued) Molded Dual-In-Line Package (N) Order Number LM346N NS Package Number N16A LIFE SUPPORT POLICY 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 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. National Semiconductor Corporation 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 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. National Semiconductor Europe Fax: (a49) 0-180-530 85 86 Email: cnjwge @ tevm2.nsc.com Deutsch Tel: (a49) 0-180-530 85 85 English Tel: (a49) 0-180-532 78 32 Fran3ais Tel: (a49) 0-180-532 93 58 Italiano Tel: (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: (852) 2737-1600 Fax: (852) 2736-9960 National Semiconductor Japan Ltd. Tel: 81-043-299-2309 Fax: 81-043-299-2408 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.