TL441CNSR

TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 D D D D D N PACKAGE (TOP VIEW) Excellent Dynamic Range Wide Bandwidth Built-In Temperature Compensation Log Linearity (30-dB Sections) . . . 1 dB Typ Wide Input Voltage Range CA2 VCC – CA2′ A1 Y Y A2 VCC + description 1 16 2 15 3 14 4 13 5 12 6 11 NC CB2 CB2′ GND B1 Z Z B2 This amplifier circuit contains four 30-dB 10 7 logarithmic stages. Gain in each stage is such that 9 8 the output of each stage is proportional to the logarithm of the input voltage over the 30-dB input NC — No internal connection voltage range. Each half of the circuit contains two of these 30-dB stages summed together in one differential output that is proportional to the sum of the logarithms of the input voltages of the two stages. The four stages may be interconnected to obtain a theoretical input voltage range of 120-dB. In practice, this permits the input voltage range typically to be greater than 80-dB with log linearity of ± 0.5-dB (see application data). Bandwidth is from dc to 40 MHz. This circuit is useful in data compression and analog compensation. This logarithmic amplifier is used in log IF circuitry as well as video and log amplifiers. The TL441 is characterized for operation over 0°C to 70°C. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright  2000, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 functional logic diagram (one half) A1 (B1) Log Σ –15 dB Log Y (Z) Log Y (Z) CA2 (CB2) A2 (B2) –15 dB Log CA2′ (CB2′) Y ∝ log A1 + log A2; Z ∝ log B1 + log B2 where: A1, A2, B1, and B2 are in dBV, 0 dBV = 1 V. CA2, CA2′, CB2, and CB2′ are detector compensation inputs. schematic VCC + Y Y A2 A1 8 6 10 5 11 7 9 4 12 13 CA2′ CA2 VCC – 2 3 14 1 15 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 Z Z B2 B1 GND CB2′ CB2 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltages (see Note 1): VCC+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 V VCC – . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 8 V Input voltage (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 V Output sink current (any one output) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 mA Package thermal impedance, θJA (see Notes 2 and 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67°C/W Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTES: 1. All voltages, except differential out voltages, are with respect to network ground terminal. 2. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) – TA)/θJA. Operating at the absolute maximum TJ of 150°C can affect reliability. 3. The package thermal impedance is calculated in accordance with JESD 51-7. recommended operating conditions MIN Peak-to-peak input voltage for each 30-dB stage MAX UNIT 0.01 1 V 0 70 °C Operating free-air temperature, TA electrical characteristics, VCC± = ±6 V, TA = 25°C TEST FIGURE PARAMETER MIN TYP MAX ±40 Differential output offset voltage 1 Quiescent output voltage 2 5.45 5.6 5.85 DC scale factor (differential output), each 3-dB stage, – 35 dBV to – 5 dBV 3 6 8 12 AC scale factor (differential output) DC error at – 20 dBV (midpoint of – 35 dBV to – 5 dBV range) 3 Input impedance Output impedance mV 4 Supply current from VCC+ 2 Supply current from VCC – Power dissipation POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 V mV/dB 8 mV/dB 1 dB 500 Ω Ω 200 Rise time, 10% to 90% points, CL = 24 pF UNIT 20 30 ns 14.5 18.5 23 mA 2 –6 – 8.5 – 10.5 mA 2 123 162 201 mW 3 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 PARAMETER MEASUREMENT INFORMATION VCC+ ICC + VCC– VCC+ VCC– ICC – CA2 CA2′ VCC+ VCC– Y A1 CA2 CA2′ VCC + VCC – Y A1 A2 B1 Y B2 Z DVM Z Y A2 B1 Z B2 Z CB2 CB2′ GND CB2 CB2′ GND VO PD = VCC+ Figure 1 4 • ICC+ + VCC– Figure 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 • ICC– TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 PARAMETER MEASUREMENT INFORMATION VCC+ VCC– CA2 CA2′ VCC+ VCC– Y A1 Y A2 B1 Z B2 18 mV 100 mV 560 mV Error ƪ ƪ + + V Z CB2 CB2′ GND DC Power Supply Scale Factor DVM ƫ –V mV out(560 mV) out(18mV) 30 dBV –0.5 V –0.5 V Vout(100 mV) out(560 mV) out(18 mV) Scale Factor ƫ Figure 3 VCC+ CI Atten 100 mV 0 mV Pulse Generator 50 Ω VCC– 1000 pF CA2 CA2′ VCC+ VCC– Y A1 Y A2 B1 Z B2 Tektronix Sampling Scope With Digital Readout or Equivalent Z CB2 CB2′ GND CL CL NOTES: A. The input pulse has the following characteristics: tw = 200 ns, tr ≤ 2 ns, tf ≤ 2 ns, PRR ≤ 10 MHz. B. Capacitor CI consists of three capacitors in parallel: 1 µF, 0.1 µF, and 0.01 µF. C. CL includes probe and jig capacitance. Figure 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 TYPICAL CHARACTERISTICS† QUIESCENT OUTPUT VOLTAGE vs FREE-AIR TEMPERATURE DIFFERENTIAL OUTPUT OFFSET VOLTAGE vs FREE-AIR TEMPERATURE 8 7 50 Quiescent Output Voltage – V Differential Output Offset Voltage – mV 60 40 30 20 10 VCC ± = ± 6 V See Figure 1 0 – 75 – 50 – 25 6 5 4 3 2 1 0 25 50 75 100 0 – 75 – 50 – 25 125 Figure 5 DC Error at Midpoint of 30-dBV Range – dBV DC Scale Factor (Differential Output) – mV/dBV 10 8 6 4 VCC ± = ± 6 V See Figure 3 25 50 75 100 125 DC ERROR vs FREE-AIR TEMPERATURE 12 0 25 Figure 6 DC SCALE FACTOR vs FREE-AIR TEMPERATURE 0 – 75 – 50 – 25 0 TA – Free-Air Temperature – °C TA – Free-Air Temperature – °C 2 VCC ± = ± 6 V See Figure 2 50 75 100 125 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 VCC ± = ± 6 V See Figure 3 0 – 75 – 50 – 25 TA – Free-Air Temperature – °C 0 25 50 75 100 125 TA – Free-Air Temperature – °C Figure 7 Figure 8 † Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices. 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 TYPICAL CHARACTERISTICS OUTPUT RISE TIME vs LOAD CAPACITANCE t r – Output Rise Time – ns 25 20 15 10 VCC ± = ± 6 V TA = 25°C See Figure 4, outputs loaded symmetrically 5 0 0 5 10 15 20 25 CL – Load Capacitance – pF 30 Figure 9 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 APPLICATION INFORMATION Although designed for high-performance applications such as infrared detection, this device has a wide range of applications in data compression and analog computation. basic logarithmic function functional block diagram The basic logarithmic response is derived from the exponential current-voltage relationship of collector current and base-emitter voltage. This relationship is given in the equation: INPUT A1 Log –15 dB m • VBE = In [(IC + ICES)/ICES] where: INPUT B1 Log –15 dB Log Log CB2 CA2 IC = ICES = m = VBE = INPUT A2 collector current collector current at VBE = 0 Log –15 dB q/kT (in V – 1) –15 dB Log base-emitter voltage Log Σ CA2’ The differential input amplifier allows dual-polarity inputs, is self-compensating for temperature variations, and is relatively insensitive to common-mode noise. INPUT B2 Log Y Σ Y Z CB2’ Z Outputs Figure 10 logarithmic sections As can be seen from the schematic, there are eight differential pairs. Each pair is a 15-dB log subsection, and each input feeds two pairs, for a range of 30-dB per stage. Four compensation points are available to allow slight variations in the gain (slope) of the two individual 15-dB stages of input A2 and B2. By slightly changing the voltage on any of the compensation pins from their quiescent values, the gain of that particular 15-dB stage can be adjusted to match the other 15-dB stage in the pair. The compensation pins also can be used to match the transfer characteristics of input A2 to A1 or B2 to B1. The log stages in each half of the circuit are summed by directly connecting their collectors together and summing through a common-base output stage. The two sets of output collectors are used to give two log outputs, Y and Y (or Z and Z), which are equal in amplitude, but opposite in polarity. This increases the versatility of the device. By proper choice of external connections, linear amplification, and linear attenuation, and many different applications requiring logarithmic signal processing are possible input levels The recommended input voltage range of any one stage is given as 0.01 V to 1 V. Input levels in excess of 1 V may result in a distorted output. When several log sections are summed together, the distorted area of one section overlaps with the next section and the resulting distortion is insignificant. However, there is a limit to the amount of overdrive that can be applied. As the input drive reaches ± 3.5 V, saturation occurs, clamping the collector-summing line and severely distorting the output. Therefore, the signal to any input must be limited to approximately ± 3 V to ensure a clean output. 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 APPLICATION INFORMATION output levels Differential-output-voltage levels are low, generally less than 0.6 V. As demonstrated in Figure 12, the output swing and the slope of the output response can be adjusted by varying the gain by means of the slope control. The coordinate origin also can be adjusted by positioning the offset of the output buffer. circuits Figures 12 through 19 show typical circuits using this logarithmic amplifier. Operational amplifiers not otherwise designated are TLC271. For operation at higher frequencies, the TL592 is recommended instead of the TLC271. TYPICAL TRANSFER CHARACTERISTICS 1.4 1.2 Output Voltage – V 1.0 Adjusted for Increased Slope and Offset 0.8 0.6 0.4 0.2 Adjusted For Minimum Slope With Zero Offset 0 – 0.2 10 – 4 10 –3 10 –2 10 –1 1 101 Input Voltage – V A1 – + Y Origin 1/2 TL441 + – Input A2 GND Y Output Slope Figure 12. Output Slope and Origin Adjustment POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 APPLICATION INFORMATION TRANSFER CHARACTERISTICS OF TWO TYPICAL INPUT STAGES 0.4 Output Voltage – V 0.3 0.2 0.1 0 0.001 1 0.1 0.01 10 Input Voltage – V 2 kΩ, 1% B1 2 kΩ, 1% Z 20 kΩ 1/2 TL441 + – Output 2 kΩ, 1% Input B2 GND Z 2 kΩ, 1% Figure 13. Utilization of Separate Stages 10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 APPLICATION INFORMATION TRANSFER CHARACTERISTICS WITH BOTH SIDES PARALLELED 0.4 Output Voltage – V 0.3 0.2 0.1 0 0.001 0.01 1 0.1 10 Input Voltage – V 2 kΩ, 1% A1 Y A2 20 kΩ TL441 Input 2 kΩ, 1% Y – Z B1 + Output 2 kΩ, 1% B2 GND Z 2 kΩ, 1% Figure 14. Utilization of Paralleled Inputs POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 APPLICATION INFORMATION TRANSFER CHARACTERISTICS 0.8 0.7 Output Voltage – V 0.6 0.5 0.4 0.3 0.2 0.1 0 10 – 4 10 –3 10 –2 10 –1 1 101 Input Voltage – V 2 kΩ A1 Y A2 Y VCC + = 4 V 1 kΩ 15 kΩ + – VCC – = – 4 V 5 kΩ 1 kΩ 20 kΩ 910 Ω B1 Z B2 Z + – VCC + = 4 V 2 kΩ + – 100 Ω Origin TL441 910 Ω Input 2 kΩ Slope 5 kΩ VCC – = – 4 V 5 kΩ 100 Ω NOTES: A. Inputs are limited by reducing the supply voltages for the input amplifiers to ± 4 V. B. The gains of the input amplifiers are adjusted to achieve smooth transitions. Figure 15. Logarithmic Amplifier With Input Voltage Range Greater Than 80 dB 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 Output TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 APPLICATION INFORMATION R A1 Y TL441 A2 + Input A – R R R R + Y see Note A + – R B1 + B2 – Y 1/2 TL441 A2 Y + – Z Input B OUTPUT W (see Note B) A1 – Z R R R R NOTES: A. Connections shown are for multiplication. For division, Z and Z connections are reversed. B. Output W may need to be amplified to give actual product or quotient of A and B. C. R designates resistors of equal value, typically 2 kΩ to 10 kΩ. Multiplication: W = A • B ⇒ log W = log A + log B, or W = a(logaA + logaB) Division: W = A/B ⇒ log W = log A – log B, or W = a(logaA + logaB) Figure 16. Multiplication or Division R A1 Input A 1/2 TL441 + – A2 nR R R Y – R + – B1 + Y + – B2 1/2 TL441 Z Output W Z R nR R NOTE: R designates resistors of equal value, typically 2 kΩ to 10 kΩ. The power to which the input variable is raised is fixed by setting nR. Output W may need to be amplified to give the correct value. Exponential: W = An ⇒ log W = n log A, or W = a(n loga A) Figure 17. Raising a Variable to a Fixed Power POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TL441 LOGARITHMIC AMPLIFIER SLVS328 – OCTOBER 2000 APPLICATION INFORMATION 2 kΩ Input A 2 kΩ Slope Origin – A1 + 20 kΩ + A2 1/2 TL441 Y Output W Y – 2 kΩ 2 kΩ NOTE: Adjust the slope to correspond to the base “a”. Exponential to any base: W = a. Figure 18. Raising a Fixed Number to a Variable Power 2.2 kΩ A1 Input 1 TL592 0.2 µF 50 Ω 0.2 µF 0.2 µF 50 Ω Output 1 1 kΩ 1 kΩ Gain Adj. 2.2 kΩ Z 20 kΩ B2 Open + – TL441 B1 + – 0.2 µF 2.2 kΩ 50 Ω TL592 TL592 Y Gain Adj. = 400 Ω For 30 dB Input 2 20 kΩ A2 + – Open 50 Ω Y TL592 0.2 µF + – 0.2 µF Output 2 Z CA2 CA2’ CB2 CB2’ 10 10 kΩ kΩ 2.2 kΩ 1 kΩ 1 kΩ Gain Adj. Gain Adj. = 400 Ω For 30 dB VCC – Figure 19. Dual-Channel RF Logarithmic Amplifier With 50-dB Input Range Per Channel at 10 MHz 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) TL441CN ACTIVE PDIP N 16 25 RoHS & Green NIPDAU N / A for Pkg Type 0 to 70 TL441CN TL441CNSR ACTIVE SO NS 16 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 TL441 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of