ky SGS-THOMSON MICROELECTRONICS LS404 HIGH PERFORMANCE QUAD OPERATIONAL AMPLIFIERS a SINGLE OR SPLIT SUPPLY OPERATION aw VERY LOW POWER CONSUMPTION a SHORT CIRCUIT PROTECTION w LOW DISTORTION, LOW NOISE a HIGH GAIN-BANDWIDTH PRODUCT a HIGH CHANNEL SEPARATION DESCRIPTION DIP14 The LS404 is a high performance quad operational (Plastic 0.25) 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. The circuit pre- sents very stable electrical characteristics over the entire supply voltage range, and it is particularly in- tended for professional and telecom applications <t (active filters, etc.). The patented input stage circuit allows small input ; $0-14J signal swings below the negative supply voltage and prevents phase inversion when the input is over dri- ven. CONNECTION DIAGRAM AND ORDERING NUMBERS (top view) LT OUTPUT A I: 1% | OUTPUT D INV.INP. A le 3 | INV. INB O . N NON INY. INRA |: } NON INV.INP D Type DIP 14 $0-14 | +s (l- n ] WS LS404 - LS40401 LS404C LS404CB LS404CD1 NON INV. INP B j 5 10 } NON INV, INF LS 8404 - LS 8404M LS8404C _ LS 89404CM INV.INR, B l 6 9 ) INV. INP. C OUTPUT B f 7 8 I OUTPUT C $-3901 January 1989 1412 625LS404 SCHEMATIC DIAGRAM (one section) nae ry SOUt-S i ANN ONILESANI NON AndN! ON ILS SANI alia ky Ses THOMSON 626LS404 ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit Vs Supply Voltage +18 Vv Vv, Input Voltage (positive) +V, (negative) -V, -0.5 v V, Differential Input Voltage t (V, - 1) Top Operating Temperature S404 25 to + 85 C LS404C 0 to + 70 C Prot Power Dissipation (Tamp = 70C) 400 mw Tst9 Storage Temperature - 55 to + 150 C THERMAL DATA DIP 14 S$O-14 J Rthy-amp | Thermal Resistance Junction-ambient Max 200C/W 200C/W (*) Measured with the device mounted on a ceramic substrate (25 x 16 x 0.6 mm). ELECTRICAL CHARACTERISTICS (V, = +12 V, Tamp = 25 C, unless otherwise specified) Symbol p Test Conditi LS404 Ls404c Uni ymbo arameter est Conditions Min. | Typ. | Max. | Min. | Typ. |Max. nit ls Supply Current 1.3 2 1.5 3 mA to Input Bias Current 50 | 200 100 | 300 nA R, Input Resistance f= 1 KHz 07 | 25 0.5 5 MQ Vos Input Offset Voltage Rg = 10 K22 1 1 mV V5 | Input Offset Voltage | Rg = 10 KQ 5 5 UVEC aT Drift Tmin < Top < Tmax los Input Offset Current 10 40 20 80 nA Alos Input Offset Current Tmin < Top < Tmax 0.08 0.1 nA AT. Drift = Isc Output Short Circuit 23 23 mA Current G, Large Signal Open Ry = 2KQ Vs =t12V 90 | 100 86 | 100 dB Loop Voltage Gain Ve=t4Vv 95 95 B Gain-bandwidth f = 20 KHz 1.8 3 15 | 25 MHz Product en Total Input Noise f= 1 KHz Voltage Rg = 50 8 15 10 nv Rg = 1KQ 10 12 JHz Rg = 10 KQ 18 20 d Distortion Unity Gain RL = 2KQ f= 1KHz 0.01 | 0.04 0.01 %o Vo =2 Vpp f = 20 KHz 0.03 0.03 Vo DC Output Voltage AL = 2 KQ2 Vs=412V [| +10 +10 Vv Swing Ves=t4Vv +3 +3 kj SGS-THOMSON aie Y7 mickoe.zeTromice 627LS404 ELECTRICAL CHARACTERISTICS (continued) Symbol p Test Conditi LS404 Ls404c Uni ymbo arameter est Conditions Min. | Typ. |Max.| Min. | Typ. | Max. nit Vo Large Signal Voltage | f = 10 KHz Ri = 10 KQ 22 22 Vv Swing Ri = 1KQ 20 20 PP SR Stew Rate Unity Gain 08 | 15 1 Vius RL =2 KQ CMR Common Mode V,=10V 90 94 so | 90 dB Rejection . SVR Supply Voltage Vie1V f = 100 Hz 90 94 86 | 90 dB Rejection cs Channel Separation | f = 1 KHz 100 | 120 120 dB Figure 1: Supply Current vs. Supply Voltage. Figure 2 : Supply Current vs. Ambient Temperature. -43301 G-43321+1 Ig Is (mA} (mA) 1.6 2 16 16 1.2 1.2 1 0.8 0 +4 +8 +12 +16 Ve (V) -50 0 50 100) Tamb(C) Figure 3 : Output Short Circuit Current vs. Figure 4: Open Loop Frequency and Phase Ambient Temperature. Response. G-644/1 Is Gv I ma - ee ee Vg = 12V toh 200 1 \ i Rp=2ka 24 ~ yt aot . Lhe 20 60+ - 4120 40+ | 80 16 20} 4 40 2 - _ 0 ; -50 0 50 100 TampC) 10 107 10 fo = 108 10 (Hz) 412 {a7 SGS-THOMSON Jf icromscraomes 628LS404 Figure 5: Open Loop Gain vs. Ambient Figure 6 : Supply Voltage Rejection vs. Temperature. Frequency. G-3641 svR Gy Vg = 215V (4B) ) Ris 2kn 100 105 80 100 60 95 40 90 20 -50 0 50 100 Tamb(?C) 0 10? 10? tot 10 (Hz) Figure 7 : Large Signal Frequency Response. Figure 8 : Output Voltage Swing vs. Load Resistance. G-4429 Yo Vo ( 20 16 12 8 4 9 i 2 3 10 10 10 f (Hz) 10 Figure 9 : Total Inout Noise vs. Frequency. 10 R,(n) Wyre 15V io po HL WM Rgst0K aL: ky SGS-THOMSON Y/ MichosectaomesLS404 APPLICATION INFORMATION Active low-pass filter : BUTTERWORTH The Butterworth is a "maximally flat amplitude res- ponse filter. Butterworth filters are used for filtering signals in data acquisition systems to prevent alia- sing errors in sampled-data applications and for ge- neral purpose low-pass filtering. The cutoff frequency. fc, is the frequency at which the amplitude response in down 3 dB. The attenua- tion rate beyond the cutoff frequency is - n6 dB per octave of frequency where nis the order (number of poles) of the filter. Other characteristics : * Flattest possible amplitude response. Excellent gain accuracy at low frequency end of passband. Figure 10 : Amplitude Response. G-16e5 Ay (dB) -40 ~60 [--. 0. os} 3 fife BESSEL The Besselis a type of "linear phase filter. Because of their linear phase characteristics, these filters ap- proximate a constant time delay over a limited fre- quency range. Bessel filters pass transient waveforms with a minimum of distortion. They are also used to provide time delays for low pass filte- ring of modulated waveforms and as a running ave- rage type filter. The maximum phase shift is radians where nis 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 to this value. For accurate delay, the cutoff frequency should be twice the maxi- 612 i SGS-THOMSON mum signal frequency. The following table can be used to obtain the 3 dB frequency of the filter. 2 pole|4 Pole|6 Pole|8 Pole 0.77 f, | 0.67 f, | 0.57 f; | 0.50 fe. ~ 3dB Frequency Other characteristics : * Selectivity not as great as Chebyschev or Butter- worth. * Very small overshoot response to step inputs. * Fast rise time. Figure 11 : Amplitude Response. ad| | eid o -! | f tol ! -20 t pp po ..--t f fy eof - fet ty Pot dtl | -60} - -+ - + i 0.1 0s CHEBYSCHEV Chebyschev filters have greater selectivity than ei- ther Bessel or Butterworth at the expense of ripple in the passband. Figure 12 : Amplitude Response ( + 1 dB ripple). G- 3647 T Ay I \ (dB) | [ | ich | PLT ot bat canal = 4 | 2 | t -20 f 4-4-4 LL 4 -40 t - -ftpit ~60 O.4 0S MICRGELECTROMCE 630L$404 APPLICATION INFORMATION (continued) Chebyschev filters are normally designed with peak- to-peak ripple values from 0.2 dB to 2 dB. Increased ripple in the passband allows increased attenuation above the cutoff frequency. The cutoff frequency is defined as the frequency at which the amplitude response passes through the specified maximum ripple band and enters the stop band. Other characteristics : * Greater selectivity. Very nonlinear phase response. High overshoot response to step inputs. The table below shows the typical overshoot and setting time response of the low pass filter to a step input. | Peak . _ . en Number of | Overshoot Settling Time (% of final value) _ 7 Poles fe Overshoot| + 1% | + 0.1% | + 0.01% Butterworth 2 4 1.1f, sec 1.71. sec 19-f. sec. 4 i V7 2.8.4, 3.8.4. 6 14 24k. 39f, 5.0-f- 8 16 3 ath a FAG, Bessel 2 0.4 0.8-fe 1.4.fc 1.7 fe 4 0.8 1.0 fc 1.8.fc 24 fc ! 6 06 1.3 fe 2.1 fe 27 ' 8 03 161c 2.3.f . 3.2 fo Chebyschev (ripple + 0.25dB) 2 11 1.1-f 1.6.fc - 4 18 3.0-fc 5.4.fc - 6 21 5.9-Ic 10.4/fc - 8 23 8.4:fc 16.4;fc - Chebyschev (nipple + 1dB) 2 21 1.6 fe 2.7'fc - 4 28 4.8.fc 8.4-fc - 6 32 8.2:fc 16.3/fc - 8 34 11.6.f 24.8 /fc - Design of 2"" order active low pass filter (Salen and Key configuration unily gain op-amp; Figure 13 : Filter Configuration. mM Co S-3567/2 iw R R Vin | 2 O__ }+ * pvout : I Vo _ 1 Where : Vi 142% S 1 S2 oc = 2n fc with f. = cutoff frequency > 2 we (vc % = damping factor. SGS-THOMSON a iy MICE OELECY HORIS* 631LS404 APPLICATION INFORMATION (continued) Three parameters are needed to characterize the frequency and phase response of a 2" order active filter : the gain (Gv), the damping factor (} or the Q- factor (Q = (2 )"'), and the cutoff frequency (fc). The higher order responses are obtained with a se- Table 1. ries of 2" order sections. A simple RC section is in- troduced when an odd filter is required. The choice of '<' (or Q-factor) determines the filter response (see table). Filter Response Q Cutoff Frequency f, Bessel \3 1 Frequency at which Phase Shift is - 90C 2 v3 Butterworth wD 1 Frequency at which G, =~ 3dB 2 .2 Chebyschev yD 1 Frequency at which the amplitude response passes So > 3 wrough specified max. ripple band and enters the stop Figure 14 : Filter Response vs. Damping Factor. (dB) 5 (tg) EXAMPLE Fixed R = R: = Re, we have (see fig. 13) 1 8 Cre ge 1 ' Ce= R Ee The diagram of fig.14 shows the amplitude re- sponse for different values of damping factor in 2" order filters. Figure 15 : 5"" Order Low Pass Filter (Butterworth) with Unity Gain Configuration. 18 order Ke 8 -356641 24 order 632 kz SGS-THOMSON 7 RickosecTsomesAPPLICATION INFORMATION (continued) In the circuit of fig. 15, for fe = 3.4 KHz and Ri = Ri = Re = Rg = Ra =10 KQ, we obtain : LS404 The same method, referring to Tab. Il and fig. 16, is used to design high-pass filter. In this case the dam- 1 1 ping factor is found by taking the reciprocal of the Ci= 1.354 - Ro ba = 6.33nF numbers in Tab. Il. For fe = 5 KHz and C, = C1 = Ce c = C3 =C4=1 nF we obtain: 1 1 1 1 1 Ci =0.421. .- = 1.97 nF = ._.~ = ' R Ont, 7197" Fi= 7 354C Brig = 23.5 KO C2=1.753- 2. 1 =8.20nF Ai-t tt L785 6Ka Rs 2rfe , 0.421 C 2ntfe 1 1 1 1 1 C3= 0.309. : Ont = 1.45 nF Re= 753 Ont = 18.2 KQ 1 4 Rs=---1t.4 -103Ka Ca=3.325- = - = =15.14nF 3*0.309 C 2nfe ~ R ante The attenuation of the filter is 30 dB at 6.8 KHz and Reza. 1.1 ~o6Ka better than 60 dB at 15 KHz. 3.325 C ante Table Il : Damping Factor for Low-pass Butterworth Filters. Order ci C, C2 C3 Ca Cs Seg Cr; Ca 2 0.707 1.4 3 1.392 0.202 3.54 4 0.92 1.08 0.38 2.61 5 1.954 0.421 1.75 0.309 3.235 6 0.966 1.035 0.707 1.414 0.259 3.86 7 1.336 0.488 1.53 0.623 1.604 0.222 4.49 8 0.98 1.02 0.83 1.20 0.556 1.80 0.195 5.125 Figure 16: 5" Order High-pass Filter (Butterworth) with Unity Gain Configuration. | _ 18 order 24 order 274 order A577 S&S:THOMSON ote MICROELECTRONICS 633LS404 APPLICATION INFORMATION (continued) Figure 17 : Multiple Feedback 8-pole Bandpass Filter. q Wor fe = 1.180 Hz: A=1;C2=C3=Cs5 = Ce = Ca = Co = C10 = C11 = 3.300 pF : Ri = Re = Ro = Riz = 160 KO; Rs = Re = Rit = Rig = 330 KQ ; Rg = R7 = Rio = R13 = 5.38 KQ 1012 ky SGS-THOMSON Vf sicnos.ectaomes 634LS404 Figure 18 : Frequency Response of Band-pass Figure 19 : Bandwidth of Band-pass Filter. Filter. G-4220 G- 4218 (6B) (dB) fo: IMHz ONE + : -20 ? e . -40 -80 O1 03 | 3 T{KHz) Figure 20 : Six-pole 355 Hz Low-pass Filter (chebychev type). 1OKN OKA 1OKN 10K0 53-6224 This is a 6-pole Chebychev type with + 0.25 dB rip- 55 dB at 710 Hz and reaches 80 dB at 1065 Hz. The ple in the passband. A decoupling stage is used to in band attenuation is limited in practice to the avoid the influence of the input impedance on the - + 0.25 dB ripple and does not exceed 0.5 dB at filter's characteristics. The attenuation is about 0.9 fe. (G7 SGS-THOMSON Wie i MICROELECTRONICS 635LS404 Figure 21 : Subsonic Filter (Gy = 0 dB). OKA fe (Hz) C (uF) C 15 0.68 Yin O44 22 0.47 Ov 30 0.33 22kn out 55 0.22 100 0.1 S-6225 Figure 22 : High Cut Filter (Gy = 0 dB). --- 4f4--- fe (KHz) C1 (nF) C2 (nF) 1woKN 1oKr 3 3 3.9 6.8 Yin 5 2.2 47 ct 2 Vout 10 1.2 2.2 LI 15 0.68 15 5- 6226 tere ky SGS-THOMSON 7 cacnogecracmes 636