LS404CDT

LS404 HIGH PERFORMANCE QUAD OPERATIONAL AMPLIFIER ■ ■ ■ ■ ■ ■ SINGLE OR SPLIT SUPPLY OPERATION LOW POWER CONSUMPTION SHORT CIRCUIT PROTECTION LOW DISTORTION, LOW NOISE HIGH GAIN-BANDWIDTH PRODUCT N DIP14 (Plastic Package) HIGH CHANNEL SEPARATION DESCRIPTION The LS404 is a high performance quad operational amplifier with frequency and phase compensation built into the chip. The internal phase compensation allows stable operation as voltage follower in spite of its high Gain-Bandwidth Product. D SO14 (Plastic Micropackage) The circuit presents very stable electrical characteristics over the entire supply voltage range, and is particularly intended for professional and telecom applications (active filter, etc). The patented input stage circuit allows small input signal swings below the negative supply voltage and prevents phase inversion when the inputs are over drivers. 14 Output 4 Output 1 1 ORDER CODE Package Part Number Temperature Range LS404C 0°C, +70°C LS404I -40°C, +105°C LS404M -55°C, +125°C Example : LS204CN PIN CONNECTIONS (top view) N D • • • • • • Inverting Input 1 2 - - 13 Inverting Input 4 + + 12 Non-inverting Input 4 Non-inverting Input 1 3 V CC + 4 Non-inverting Input 2 5 + + 10 Non-inverting Input 3 Inverting Input 2 6 - - 9 Inverting Input 3 Output 2 7 8 Output 3 11 VCC - N = Dual in Line Package (DIP) D = Small Outline Package (SO) - also available in Tape & Reel (DT) November 2001 1/11 LS404 SCHEMATIC DIAGRAM (1/4 LS404) Non-inverting input Inverting input Output ABSOLUTE MAXIMUM RATINGS Symbol VCC Parameter Supply voltage Vi Input Voltage Vid Differential Input Voltage Operating Temperature Range Toper 2/11 Ptot Power Dissipation at Tamb = 70°C Tstg Storage Temperature Range Positive Negative LS204C LS204I LS204I Value Unit ±18 V +VCC -VCC - 0.5 V ±(VCC -1) V 0 to +70 -40 to +105 -55 to +125 °C 400 mW -65 to +150 °C LS404 ELECTRICAL CHARACTERISTICS VCC = ±15V, T amb = 25°C (unless otherwise specified) LS404I - LS404M Symbol LS404C Parameter Unit Min. Typ. Max. Min. Typ. Max. Icc Supply Current 1.3 2 1.5 3 Iib Input Bias Current 50 200 100 300 Ri Input Resistance (f = 1kHz) 1 Vio Input Offset Voltage (Rs ≤ 10kΩ) DVio Iio Input Offset Voltage Drift (Rs ≤ 10kΩ) Tmin < Top < Tmax 5 Input Offset Current 10 DIio Input Offset Current Drift Tmin < Top < Tmax Ios Output Short-circuit Current Avd Large Signal Voltage Gain RL = 2kΩ, VCC = ±15V VCC = ±4V GBP en THD ±Vopp 0.7 Gain Bandwith Product f =100kHz, RL = 2k, CL = 100pF 2.5 0.5 20 mV µV/°C 80 nA 0.08 0.1 nA/°C 23 23 mA 100 95 86 100 95 dB 1.8 3 1.5 2.5 MHz Total Harmonic Distortion Unity Gain RL = 2kΩ, Vo = 2Vpp f = 1kHz f = 20kHz 8 10 18 15 10 12 20 0.01 0.03 0.4 0.01 0.03 nV -----------Hz % ±13 ±13 V ±3 ±3 22 20 22 20 Vpp 1 V/µs Vopp Large Signal Voltage Swing f = 10kHz, RL = 10kΩ RL = 1kΩ SR Slew Rate (RL = 2kΩ, unity gain) 0.8 1.5 SVR Supply Voltage Rejection Ratio Vic = 1V, f = 100Hz 90 94 86 90 CMR Common Mode Rejection Ratio Vic = 10V 90 94 86 90 100 120 Vo1/Vo2 Channel Separation (f= 1kHz) 5 5 40 nA MΩ 90 Equivalent Input Noise Voltage f = 1kHz, Rs = 50Ω Rs = 1kΩ Rs = 10kΩ Output Voltage Swing RL = 2kΩ, VCC = ±15V VCC = ±4V 1 mA 120 dB dB dB 3/11 LS404 4/11 LS404 5/11 LS404 APPLICATION INFORMATION: Active low-pass filter BUTTERWORTH The Butterworth is a "maximally flat" amplitude response filter (figure 10) Butterworth filters are used for filtering signals in data acquisition systems to prevent aliasing errors in samples-data applications and for general purpose low-pass filtering. The cut-off frequency Fc, is the frequency at which the amplitude response is down 3dB. The attenuation rate beyond the cutoff frequency is n6 dB per octave of frequency where n is the order (number of poles) of the filter. Other characteristics : ❑ Flattest possible amplitude response ❑ Excellent gain accuracy at low frequency end of passband BESSEL The Bessel is a type of “linear phase” filter. Because of their linear phase characteristics, these filters approximate a constant time delay over a limited frequency range. Bessel filters pass transient waveforms with a minimum of distortion. They are also used to provide time delays for low pass filtering of modulated waveforms and as a “running average” type filter. n π radians where The maximum phase shift is –---------2 n is the order (number of poles) of the filter. The cut-off frequency fc, is defined as the frequency at which the phase shift is one half of this value. For accurate delay, the cut-off frequency should be twice the maximum signal frequency. The following table can be used to obtain the -3dB frequency of the filter. -3dB Frequency 2 Pole 4 Pole 6 Pole 8 Pole 0.77fc 0.67fc 0.57fc 0.50fc Other characteristics : ❑ Selectivity not as great as Chebyschev or Butterworth ❑ Very little overshoot response to step inputs ❑ Fast rise time CHEBYSCHEV Chebyschev filters have greater selectivity than either Bessel ro Butterworth at the expense of ripple in the passband (figure 11). Chebyschev filters are normally designed with peak-to-peak ripple values from 0.2dB to 2dB. Increased ripple in the passband allows increased attenuation above the cut-off frequency. The cut-off frequency is defined as the frequency at which the amplitude response passes through the specificed maximum ripple band and enters the stop band. Other characteristics : ❑ Greater selectivity ❑ Very non-linear phase response ❑ High overshoot response to step inputs The table below shows the typical overshoot and setting time response of the low pass filters to a step input. Number of Poles Butterworth Bessel Chebyschev (ripple ±0.25dB) Chebyschev (ripple ±1dB) 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 Peak Overshoot Settling Time (% of final value) % Overshoot ±1% ±0.1% ±0.01% 4 11 14 14 0.4 0.8 0.6 0.1 11 18 21 23 21 28 32 34 1.1Fc sec. 1.7/fc 2.4/fc 3.1/fc 0.8/fc 1.0/fc 1.3/fc 1.6/fc 1.1/fc 3.0/fc 5.9/fc 8.4/fc 1.6/fc 4.8/fc 8.2/fc 11.6/fc 1.7Fc sec. 2.8/fc 3.9S/fc 5.1/fc 1.4/fc 1.8/fc 2.1/fc 2.3/fc 1.6/fc 5.4/fc 10.4/fc 16.4/fc 2.7/fc 8.4/fc 16.3/fc 24.8/fc 1.9Fc sec. 3.8/fc 5.0S/fc 7.1/fc 1.7/fc 2.4/fc 2.7/fc 3.2/fc - Design of 2nd order active low pass filter (Sallen and Key configuration unity gain op-amp) 6/11 - LS404 Fixed R = R1 = R2, we have (see figure 13) 1 ζ C 1 = ---- ------R ωc 1 1 C 2 = ---- ----------R ξ ωc Figure 13 : Filter Configuration C2 R1 R2 Vin Vout C1 Three parameters are needed to characterize the frequency and phase response of a 2nd order active filter: the gain (Gv), the damping factio (ξ) or the Q factor (Q = 2 ξ)1), and the cuttoff frequency (fc). The higher order response are obtained with a series of 2nd order sections. A simple RC section is introduced when an odd filter is required. The choice of ’ξ' (or Q factor) determines the filter response (see table 1). Table 1 ξ Q Bessel 3 ------2 1 ------3 Frequency at which Phase Shift is -90°C Butterworth 2 ------2 1 ------2 Frequency at which Gv = -3dB Chebyschev 2 ------2 1 ------2 Filter Response Cuttoff Frequency fc Frequency at which the amplitude response passes through specified max. ripple band and enters the stop bank. EXAMPLE Figure 14 : 5th Order Low-pass Filter (Butterworth) with Unity Gain configuration C2 Ri R1 C4 R2 R3 Ci R4 C1 C3 7/11 LS404 1 1 Ci = 1.354 ---- ------------ = 6.33nF R 2 π fc The same method, referring to table 2 and figure 15 is used to design high-pass filter. In this case the damping factor is found by taking the reciprocal of the numbers in table 2. For fc = 5kHz and Ci = C1 = C2 = C3 = 1nF we obtain: 1 1 C1 = 0.421 ---- ------------ = 1.97nF R 2 π fc 1 1 1 Ri = --------------- ---- ------------ = 25.5k Ω 0.354 C 2π fc 1 1 C2 = 1.753 ---- ------------ = 8.20nF R 2 π fc 1 1 1 R1 = --------------- ---- ------------ = 75.6kΩ 0.421 C 2π fc 1 1 C3 = 0.309 ---- ------------ = 1.45nF R 2 π fc 1 1 1 R2 = --------------- ---- ------------ = 18.2kΩ 1.753 C 2π fc 1 1 C4 = 3.325 ---- ------------ = 15.14nF R 2π fc 1 1 1 R3 = --------------- ---- ------------ = 103kΩ 0.309 C 2π fc The attenuation of the filter is 30dB at 6.8kHz and better than 60dB at 15kHz. 1 1 1 R4 = --------------- ---- ------------ = 9.6kΩ 3.325 C 2π fc In the circuit of figure 14, for fc = 3.4kHz and Ri = R1 = R2 = R3 = 10kΩ, we obtain: Table 2 : Damping Factor for Low-pass Butterworth Filters Order Ci 2 3 1.392 4 5 1.354 6 7 1.336 8 C1 C2 C3 C4 0.707 1.41 0.202 3.54 0.92 C5 C6 1.08 0.38 2.61 0.421 1.75 0.309 3.235 0.966 1.035 0.707 1.414 0.259 3.86 0.488 1.53 0.623 1.604 0.222 4.49 0.98 1.02 0.83 1.20 0.556 1.80 Figure 15 : 5th Order High-pass Filter (Butterworth) with Unity Gain configuration R2 Ci C1 R4 C2 C3 Ri 8/11 C4 R1 R3 C7 C8 0.195 5.125 LS404 Figure 16 : Multiple Feedback 8-pole Bandpass Filter C3 C6 R5 C1 R1 C2 IN 0.1m F R4 C9 3 ¼ LS404 1 R6 R11 C5 6 ¼ 4 R3 R9 7 5 LS404 11 R7 Vcc R2 C11 R8 2 C8 R10 R14 9 R12 8 ¼ 10 LS404 C10 R13 C4 0.1m F 22kW 13 14 C12 0.1m F Out C13 0.22m F C7 220m F 22kW 12 ¼ LS404 Figure 17 : Six pole 355Hz Low-pass Filter (chebychev type) 10kΩ 10kΩ 10kΩ 10kΩ 0.47µF 10kΩ 3.54nF 10kΩ 16.3nF 60nF 86.1nF 220nF 161nF 56kΩ This is a - pole Chebychev type with ±0.25dB ripple in the passband. A decoupling stage is used to avoid the influence of the input impedance on the filter’s characteristics. The attenuation is about 55dB at 710Hz and reaches 80dB at 1065Hz. the in band attenuation is limited in practise to the ±0.25dB ripple and does not exceed 0.5dB at 0.9fc. Figure 18 : Subsonic Filter (Gv = 0dB) 10kΩ C Fc (Hz) C (µF) 15 22 30 55 100 0.68 0.47 0.33 0.22 0.10 C Vout 22kΩ Figure 19 : High Cut filter (Gv = 0dB) C2 10kΩ 10kΩ 3 Vin 1 C1 2 Vout Fc (Hz) C1 (nF) C2 (nF) 3 5 10 15 3.9 2.2 1.2 0.68 6.8 4.7 2.2 1.5 9/11 LS404 PACKAGE MECHANICAL DATA 14 PINS - PLASTIC PACKAGE Millimeters Inches Dimensions Min. a1 B b b1 D E e e3 F i L Z 10/11 Typ. 0.51 1.39 Max. Min. 1.65 0.020 0.055 0.5 0.25 Typ. 0.065 0.020 0.010 20 0.787 8.5 2.54 15.24 0.335 0.100 0.600 7.1 5.1 0.280 0.201 3.3 1.27 Max. 0.130 2.54 0.050 0.100 LS404 PACKAGE MECHANICAL DATA 14 PINS - PLASTIC MICROPACKAGE (SO) G c1 b1 e a1 b A a2 C L s e3 E D M 8 1 7 F 14 Millimeters Inches Dimensions Min. A a1 a2 b b1 C c1 D (1) E e e3 F (1) G L M S Typ. Max. Min. 1.75 0.2 1.6 0.46 0.25 0.1 0.35 0.19 Typ. 0.069 0.008 0.063 0.018 0.010 0.004 0.014 0.007 0.5 Max. 0.020 45° (typ.) 8.55 5.8 8.75 6.2 0.336 0.228 1.27 7.62 3.8 4.6 0.5 0.344 0.244 0.050 0.300 4.0 5.3 1.27 0.68 0.150 0.181 0.020 0.157 0.208 0.050 0.027 8° (max.) Note : (1) D and F do not include mold flash or protrusions - Mold flash or protrusions shall not exceed 0.15mm (.066 inc) ONLY FOR DATA BOOK. Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. © The ST logo is a registered trademark of STMicroelectronics © 2001 STMicroelectronics - Printed in Italy - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States © http://www.st.com 11/11