LTC1062

LTC1062 5th Order Lowpass Filter FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Lowpass Filter with No DC Error Low Passband Noise Operates DC to 20kHz Operates On a Single 5V Supply or Up to ± 8V 5th Order Filter Maximally Flat Response Internal or External Clock Cascadable for Faster Rolloff Buffer Available The LTC®1062 is a 5th order all pole maximally flat lowpass filter with no DC error. Its unusual architecture puts the filter outside the DC path so DC offset and low frequency noise problems are eliminated. This makes the LTC1062 very useful for lowpass filters where DC accuracy is important. The filter input and output are simultaneously taken across an external resistor. The LTC1062 is coupled to the signal through an external capacitor. This RC reacts with the internal switched capacitor network to form a 5th order rolloff at the output. The filter cutoff frequency is set by an internal clock that can be externally driven. The clock-to-cutoff frequency ratio is typically 100:1, allowing the clock ripple to be easily removed. Two LTC1062s can be cascaded to form a 10th order quasi max flat lowpass filter. The device can be operated with single or dual supplies ranging from ±2.5V to ±9V. The LTC1062 is manufactured using Linear Technology’s enhanced LTCMOSTM silicon gate process. , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS is a trademark of Linear Technology Corporation. APPLICATIO S ■ ■ ■ ■ ■ ■ ■ 60Hz Lowpass Filters Antialiasing Filter Low Level Filtering Rolling Off AC Signals from High DC Voltages Digital Voltmeters Scales Strain Gauges TYPICAL APPLICATIO 25.8k VIN 1µF 1 2 FB AGND V– BOUT OUT V+ 10Hz 5th Order Butterworth Lowpass Filter DC ACCURATE OUTPUT 8 7 BUFFERED OUTPUT Filter Amplitude Response and Noise 0 –10 COSC = 3900pF AMPLITUDE RESPONSE (dB) –20 –30 –40 –50 –60 –70 –80 –90 50 40 30 20 10 1 10 INPUT FREQUENCY (Hz) 0 100 1062 TA02 LTC1062 V – = – 5V 3 4 6 5 DIVIDER COSC RATIO COSC= 3900pF V + = 5V 1062 TA01 –100 NOTE: TO ADJUST OSCILLATOR FREQUENCY, USE A 6800pF CAPACITOR IN SERIES WITH A 50k POT FROM PIN 5 TO GROUND U FILTER OUTPUT NOISE (µV/√Hz) 1062fd U U 1 LTC1062 ABSOLUTE AXI U RATI GS Total Supply Voltage (V+ to V–) ............................... 18V Input Voltage at Any Pin ..... V– – 0.3V ≤ VIN ≤ V+ + 0.3V Operating Temperature Range LTC1062M (OBSOLETE) ............. –55°C ≤ TA ≤ 125°C LTC1062C ................................... – 40°C ≤ TA ≤ 85°C PACKAGE/ORDER I FOR ATIO TOP VIEW FB 1 AGND 2 V– 3 DIVIDER 4 RATIO N8 PACKAGE 8-LEAD PDIP 8 7 6 5 BOUT OUT V+ COSC ORDER PART NUMBER LTC1062CN8 TJ MAX = 100°C, θJA = 130°C/W J8 PACKAGE 8-LEAD CERDIP TJ MAX = 150°C, θJA = 100°C/W LTC1062MJ8 LTC1062CJ8 OBSOLETE PACKAGE Consider the N8 Package as an Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS + PARAMETER Power Supply Current Input Frequency Range Filter Gain at fIN = 0 fIN = 0.5fC (Note 2) fIN = fC fIN = 2fC fIN = 4fC Clock-to-Cutoff Frequency Ratio, fCLK/fC Filter Gain at fIN = 16kHz fCLK/fC Tempco Filter Output (Pin 7, Pin 13 in SW16) DC Swing Clock Feedthrough CONDITIONS COSC The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V = 5V, V– = – 5V, unless otherwise specified. AC output measured at Pin 7, Figure 1. MIN ● (Pin 5 to V –, Pin 11 in SW16) = 100pF fCLK C = 0.01µF, R = 25.78k = 100kHz, Pin 4 (Pin 6 in SW16) at V+, ● ● ● fCLK = 100kHz, Pin 4 (Pin 6 in SW16) at V+, C = 0.01µF, R = 25.78k fCLK = 400kHz, Pin 4 at V +, C = 0.01µF, R = 6.5k fCLK = 400kHz, Pin 4 at V+, C = 0.01µF, R = 6.5k Pin 7/Pin13 (SW16) Buffered with an External Op Amp ● ● 2 U U W WW U W (Note 1) Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C TOP VIEW NC 1 NC 2 FB 3 AGND 4 V– 5 DIVIDER 6 RATIO NC 7 NC 8 SW PACKAGE 16-LEAD PLASTIC SO 16 NC 15 NC 14 BOUT 13 OUT 12 V + 11 COSC 10 NC 9 NC ORDER PART NUMBER LTC1062CSW TJ MAX = 150°C, θJA = 90°C/W TYP 4.5 0 to 20 MAX 7 10 UNITS mA mA kHz dB dB dB dB dB % dB ppm/°C V mVP-P –2 –28 –52 0.00 – 0.02 –0.3 –3.00 –30.00 –60.00 100 ±1 –43 ±3.5 –52 10 ±3.8 1 1062fd LTC1062 ELECTRICAL CHARACTERISTICS+ PARAMETER Internal Buffer Bias Current CONDITIONS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V = 5V, V– = – 5V, unless otherwise specified, AC output measured at Pin 7, Figure 1. MIN TYP 2 170 2 RLOAD = 20k ● MAX 50 1000 20 UNITS pA pA mV V mA ● Offset Voltage Voltage Swing Short-Circuit Current Source/Sink Clock (Note 3) Internal Oscillator Frequency Max Clock Frequency Pin 5 (Pin 11 in SW16) Source or Sink Current Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: fC is the frequency where the gain is –3dB with respect to the input signal. ● ±3.5 ±3.8 40/3 COSC (Pin 5 to V–, Pin 11 in SW16) = 100pF ● 25 15 32 4 40 50 65 80 kHz kHz MHz µA Note 3: The external or driven clock frequency is divided by either 1, 2 or 4 depending upon the voltage at Pin 4. For the N8 package, when Pin 4 = V +, ratio = 1; when Pin 4 = GND, ratio = 2; when Pin 4 = V –, ratio = 4. TYPICAL PERFOR A CE CHARACTERISTICS Amplitude Response Normalized to the Cutoff Frequency 0 –10 –20 RESPONSE (dB) VS = ±2.5V TA = 25°C 1 = fC 2πRC 1.62 RESPONSE (dB) –30 –40 –50 –60 –70 –80 –90 fCLK = 10kHz, fC = 100Hz fCLK = 1kHz, fC = 10Hz 1 fIN/fC 10 1062 G01 –30 –40 –50 –60 –70 –80 –90 fCLK = 10kHz, fC = 100Hz fCLK = 1kHz, fC = 10Hz 1 fIN/fC 10 1062 G01 PASSBAND GAIN (dB) fCLK = 500kHz, fC = 5kHz fCLK = 250kHz, fC = 2.5kHz fCLK = 100kHz, fC = 1kHz –100 0.1 UW Amplitude Response Normalized to the Cutoff Frequency 0 –10 –20 VS = ±2.5V TA = 25°C 1 = fC 2πRC 1.62 Passband Gain vs Input Frequency 0.4 VS = ± 5V TA = 25°C 0.2 f CLK = 100kHz 0 –0.2 –0.4 –0.6 –0.8 –1.0 0.1 1 = fC 2πRC 1.62 1 = fC 2πRC 1.64 1 = fC 2πRC 1.6 fCLK = 500kHz, fC = 5kHz fCLK = 250kHz, fC = 2.5kHz fCLK = 100kHz, fC = 1kHz –100 0.1 0.2 fIN/fC 0.4 0.6 0.8 1 1062 G03 1062fd 3 LTC1062 TYPICAL PERFOR A CE CHARACTERISTICS Passband Gain vs Input Frequency and Temperature 0.4 0.2 PASSBAND GAIN (dB) 0 –0.2 –0.4 –0.6 –0.8 –1.0 0.1 VS = ± 5V fCLK = 100kHz 1 = fC 2πRC 1.62 0 –30 TA = 125°C TA = – 55°C PHASE SHIFT (DEG) FILTER OUTPUT NOISE (µV/√Hz) 0.2 fIN/fC 0.4 Normalized Oscillator Frequency, fOSC vs Supply Voltage 1.6 OSCILLATOR FREQUENCY NORMALIZED TO fOSC AT 5V SUPPLY 1.5 OSCILLATOR FREQUENCY (kHz) SUPPLY CURRENT (mA) 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 4 6 8 10 14 VSUPPLY (V) 12 16 18 20 4 UW 0.6 0.8 Passband Phase Shift vs Input Frequency VS = ± 5V fCLK = 100kHz 1 = fC 2πRC 1.62 TA = 25°C Filter Noise Spectral Density 80 70 60 50 fC = 10Hz 40 30 20 10 fC = 100Hz fC = 1kHz 1 1k 10 100 CUTOFF FREQUENCY (Hz) 10k 1062 G06 VS = ± 5V TA = 25°C –60 –90 –120 –150 –180 –210 0.1 1 0.2 fIN/fC 0.4 0.6 0.8 1 0 0.1 1062 G04 1062 G05 Oscillator Frequency, fOSC vs Ambient Temperature 260 240 220 200 180 160 140 120 100 80 V + = 5V – V = 0V V + = 10V – = 0V V 12 10 8 6 4 2 0 Power Supply Current vs Power Supply Voltage 16 14 TA = – 55°C TA = 25°C COSC = 0pF TA = 125°C 60 25 50 –50 –25 0 75 100 AMBIENT TEMPERATURE (°C) 125 4 6 8 10 12 14 16 18 POWER SUPPLY VOLTAGE (V) 20 1062 G07 1062 G08 1062 G09 1062fd LTC1062 BLOCK DIAGRA W SWITCHED CAPACITOR NETWORK ×1 fCLK V– 3 CLOCK GEN 6 V+ 8 BOUT 7 OUT ÷ 1, 2, 4 OSC 5 COSC 1062 BD For Adjusting Oscillator Frequency, Insert a 50k Pot in Series with COSC. Use Two Times Calculated COSC BY CONNECTING PIN 4 TO V +, AGND OR V –, THE OUTPUT FREQUENCY OF THE INTERNAL CLOCK GENERATOR IS THE OSCILLATOR FREQUENCY DIVIDED BY 1, 2, 4. THE (fCLK/fC) RATIO OF 100:1 IS WITH RESPECT TO THE INTERNAL CLOCK GENERATOR OUTPUT FREQUENCY. PIN 5 CAN BE DRIVEN WITH AN EXTERNAL CMOS LEVEL CLOCK. THE LTC1062 CAN ALSO BE SELF-CLOCKED BY CONNECTING AN EXTERNAL CAPACITOR (COSC) TO GROUND (OR TO V – IF COSC IS POLARIZED). UNDER THIS CONDITION AND WITH ± 5V SUPPLIES, THE INTERNAL OSCILLATOR FREQUENCY IS: fOSC ≅ 140kHz [33pF/(33pF + COSC)] FB 1 AGND 2 ÷ 4 AC TEST CIRCUIT 5V VIN R = 25.8k C = 0.01µF 50Ω 1 2 FB AGND V– BOUT OUT V+ 8 7 0.1µF R′ –5V 5V 5V –5V fCLK = 100kHz 2 3 + – 1 7 LTC1052 8 4 6 MEASURED OUTPUT FOR BEST MAX FLAT APPROXIMATION, THE INPUT RC SHOULD BE SUCH AS: 1 = fCLK 1 • 2πRC 100 1.63 0.1µF A 0.5k RESISTOR, R′, SHOULD BE USED IF THE BIPOLAR EXTERNAL CLOCK IS APPLIED BEFORE THE POWER SUPPLIES TURN ON LTC1062 V – = – 5V 3 4 6 5 DIVIDER COSC RATIO 1062 F01 Figure 1 1062fd 5 LTC1062 APPLICATIO S I FOR ATIO Filter Input Voltage Range Every node of the LTC1062 typically swings within 1V of either voltage supply, positive or negative. With the appropriate external (RC) values, the amplitude response of all the internal or external nodes does not exceed a gain of 0dB with the exception of Pin 1. The amplitude response of the feedback node (Pin 1) is shown in Figure 2. For an input frequency around 0.8 • fC, the gain is 1.7V/V and, with ± 5V supplies, the peak-to-peak input voltage should not exceed 4.7V. If the input voltage goes beyond this value, clipping and distortion of the output waveform occur, but the filter will not get damaged nor will it oscillate. Also, the absolute maximum input voltage should not exceed the power supplies. 6 4 2 0 VPIN1/VIN (dB) VS = ± 5V 1 = fC 2πRC 1.62 –2 –4 –6 –8 –10 –12 –14 0.1 1 fIN/fC 10 1062 F02 Figure 2. Amplitude Response of Pin 1 Internal Buffer The internal buffer out (Pin 8) and Pin 1 are part of the signal AC path. Excessive capacitive loading will cause gain errors in the passband, especially around the cutoff frequency. The internal buffer gain at DC is typically 0.006dB. The internal buffer output can be used as a filter output, however, it has a few millivolts of DC offset. The temperature coefficient of the internal buffer is typically 1µV/°C. Filter Attenuation The LTC1062 rolloff is typically 30dB/octave. When the clock and the cutoff frequencies increase, the filter’s maximum attenuation decreases. This is shown in the 6 U Typical Performance Characteristics. The decrease of the maximum attenuation is due to the rolloff at higher frequencies of the loop gains of the various internal feedback paths and not to the increase of the noise floor. For instance, for a 100kHz clock and 1kHz cutoff frequency, the maximum attenuation is about 64dB. A 4kHz, 1VRMS input signal will be predictably attenuated by 60dB at the output. A 6kHz, 1VRMS input signal will be attenuated by 64dB and not by 77dB as an ideal 5th order maximum flat filter would have dictated. The LTC1062 output at 6kHz will be about 630µVRMS. The measured RMS noise from DC to 17kHz was 100µVRMS which is 16dB below the filter output. COSC, Pin 5 The COSC, Pin 5, can be used with an external capacitor, COSC, connected from Pin 5 to ground. If COSC is polarized it should be connected from Pin 5 to the negative supply, Pin 3. COSC lowers the internal oscillator frequency. If Pin 5 is floating, an internal 33pF capacitor plus the external interpin capacitance set the oscillator frequency around 140kHz with ±5V supply. An external COSC will bring the oscillator frequency down by the ratio (33pF)/ (33pF + COSC). The Typical Performance Characteristics curves provide the necessary information to get the internal oscillator frequency for various power supply ranges. Pin 5 can also be driven with an external CMOS clock to override the internal oscillator. Although standard 7400 series CMOS gates do not guarantee CMOS levels with the current source and sink requirements of Pin 5, they will, in reality, drive the COSC pin. CMOS gates conforming to standard B series output drive have the appropriate voltage levels and more than enough output current to simultaneously drive several LTC1062 COSC pins. The typical trip levels of the internal Schmitt trigger which input is Pin 5, are given in Table 1. Table 1 VSUPPLY ± 2.5V ±5V ±6V ±7V VTH+ 0.9V 1.3V 1.7V 1.75V VTH– –1V –2.1V –2.5V –2.9V 1062fd W UU LTC1062 APPLICATIO S I FOR ATIO Divide By 1, 2, 4 (Pin 4) By connecting Pin 4 to V+, to mid supplies or to V–, the clock frequency driving the internal switched capacitor network is the oscillator frequency divided by 1, 2, 4 respectively. Note that the fCLK/fC ratio of 100:1 is with respect to the internal clock generator output frequency. The internal divider is useful for applications where octave tuning is required. The ÷2 threshold is typically ±1V from the mid supply voltage. Transient Response Figure 3 shows the LTC1062 response to a 1V input step. Figure 3. Step Response to a 1V Peak Input Step Table 2 NOISE BW DC – 0.1 • fC DC – 0.25 • fC DC – 0.5 • fC DC – 1 • fC DC – 2 • fC RMS NOISE (VS = ±5V) 2µV 8µV 20µV 62µV 100µV 1062fd U Filter Noise The filter wideband RMS noise is typically 100µVRMS for ±5V supply and it is nearly independent from the value of the cutoff frequency. For single 5V supply the RMS noise is 80µVRMS. Sixty-two percent of the wideband noise is in the passband, that is from DC to fC. The noise spectral density, unlike conventional active filters, is nearly zero for frequencies below 0.1 • fC. This is shown in the Typical Performance Characteristics section. Table 2 shows the LTC1062 RMS noise for different noise bandwidths. 200mV/VERT DIV 50ms/HORIZ DIV, fC = 10Hz 5ms/HORIZ DIV, fC = 100Hz 0.5ms/HORIZ DIV, fC = 1kHz f 1 =C 2πRC 1.62 W UU f 1 =C 2πRC 1.94 f 1 =C 2πRC 2.11 7 LTC1062 TYPICAL APPLICATIO S AC Coupling an External CMOS Clock Powered from a Single Positive Supply, V + VIN C 1 2 FB AGND V– BOUT OUT V+ 8 7 VOUT Adding an External (R1, C1) to Eliminate the Clock Feedthrough and to Improve the High Frequency Attenuation Floor VIN C 1 2 FB AGND V– BOUT OUT V+ 8 7 C1 0.01C Filtering AC Signals from High DC Voltages R 25.8k VIN 1 HIGH DC INPUT = 100V 2 C 0.01µF FB AGND V– BOUT OUT 8 7 C 0.01µF 12R 309.6k DC OUTPUT PASSBAND GAIN (dB) LTC1062 V – = – 5V 3 4 6 V+ 5 CLK IN = fC • 100 DIVIDER COSC RATIO V + = 5V EXAMPLE: fCLK = 100KHz, fC = 1kHz. THE FILTER ACCURATELY PASSES THE HIGH DC INPUT AND ACTS AS 5TH ORDER LP FILTER FOR THE AC SIGNALS RIDING ON THE DC 8 U R LTC1062 V– 3 4 6 5 100k 1062 TA03 V + 0.01µF V+ 0 DIVIDER COSC RATIO – R1 10R EXTERNAL BUFFER VOUT + LTC1062 V– 3 4 6 5 V+ fCLK 1062 TA04 DIVIDER COSC RATIO Passband Amplitude Response for the High DC Accurate 5th Order Filter 0.2 0 –0.2 –0.4 –0.6 –0.8 –1.0 –1.2 VS = ± 5V fCLK = 100kHz –1.4 0.01 1062 TA05 0.1 fIN /fC 1 1062 TA06 1062fd LTC1062 TYPICAL APPLICATIO S Cascading Two LTC1062s to Form a Very Selective Clock Sweepable Bandpass Filter R1 10k VIN R2 10k 1 2 R′1 10k R′2 12.5k 1 2 R1 VIN FB AGND V– BOUT OUT V+ 2 7 LTC1062 –5V 3 4 6 5 5V fCLK 1062 TA08 DIVIDER COSC RATIO Frequency Response of the Bandpass Filter 20 10 0 –10 –20 (dB) –30 –40 –50 –60 –70 –80 –90 0.5 1 1.5 2 2.5 (kHz) 3 3.5 4 4.5 VS = ± 5V R1 = 1 R2 R′1 = 0.8 R′2 VIN = 100mVRMS (dB) Frequency Response of the Notch Filter –10 0 10 20 30 40 50 60 70 100 300 500 (Hz) 700 900 1100 1062 TA10 1062 TA09 + – U FB AGND – BOUT OUT + 8 7 FB AGND – BOUT OUT V+ 8 7 VOUT LTC1062 –5V 3 4 V V 6 5 5V –5V 3 4 V LTC1062 6 5 5V DIVIDER COSC RATIO DIVIDER COSC RATIO fCLK 1062 TA07 Clock Tunable Notch Filter For Simplicity Use R3 = R4 = R5 = 10k; R5 = 1.234, fCLK = 79.3 fNOTCH R2 1 R4 R5 R2 1 8 R3 VOUT 1062fd 9 LTC1062 TYPICAL APPLICATIO S Simple Cascading Technique 5V 25.8k VIN 1µF 1 2 FB AGND V– BOUT OUT V+ 8 7 1 2 0.1µF FB AGND V– BOUT OUT V+ 8 7 0.1µF –5V 2 412k 3 LTC1062 –5V 3 4 6 5 –5V 3 4 DIVIDER COSC RATIO 10Hz, 10TH ORDER DC ACCURATE LOWPASS FILTER 60dB/OCTAVE ROLLOFF 0.5dB PASSBAND ERROR, 0dB DC GAIN MAXIMUM ATTENUATION 110dB (fCLK = 10kHz) 100dB (fCLK = 1kHz) 95dB (fCLK = 1MHz) CONTROL (HIGH, GROUND, LOW) 10 U + – 1 7 LTC1052 8 4 6 DC ACCURATE OUTPUT LTC1062 6 5 0.1µF DIVIDER COSC RATIO V + = 5V 1062 TA11 fCLK = 1kHz 100Hz, 50Hz, 25Hz 5th Order DC Accurate LP Filter 25.8k VIN 0.1µF 1 2 1 2 FB AGND V– 0.1µF 3 13 1/2 CD4016 4 BOUT OUT V+ 8 7 BOUT 5 VOUT 0.2µF LTC1062 –5V 3 4 6 5 5V 10kHz CLK IN DIVIDER COSC RATIO 100k 5V 100k TO PIN 5 OF CD4016 –5V 5V 100k BY CONNECTING PIN 4 OF THE LTC1062 HIGH/GROUND/LOW THE FILTER CUTOFF FREQUENCY IS 100Hz/50Hz/25Hz TO PIN 13 OF CD4016 100k –5V 1062 TA12 1062fd LTC1062 TYPICAL APPLICATIO S 7th Order 100Hz Lowpass Filter with Continuous Output Filtering, Output Buffering and Gain Adjustment R3 5V 2 R4 2.6k VIN 1µF 1 2 FB AGND V– –5V 5V THE LTC1052 IS CONNECTED AS A 2ND ORDER SALLEN AND KEY LOWPASS FILTER WITH A CUTOFF FREQUENCY EQUAL TO THE CUTOFF FREQUENCY OF THE LTC1062. THE ADDITIONAL FILTERING ELIMINATES ANY 10kHz CLOCK FEEDTHROUGH PLUS DECREASES THE WIDEBAND NOISE OF THE FILTER DC OUTPUT OFFSET (REFERRED TO A DC GAIN OF UNITY) = 5µV MAX WIDEBAND NOISE (REFERRED TO A DC GAIN OF UNITY) = 60µVRMS OUTPUT FILTER COMPONENT VALUES DC GAIN R3 R4 R1 R2 C1 C2 1 ∞ 0 14.3k 53.6k 0.1µF 0.033µF 10 3.57k 32.4k 46k 274k 0.01µF 0.02µF 10µF SOLID TANTALUM U 3 4 – + 1 7 LTC1052 6 8 4 0.1µF VOUT R1 R2 C1 C2 3 BOUT OUT V+ 8 7 0.1µF –5V LTC1062 6 5 5V 10kHz CLK IN 1062 TA13 DIVIDER COSC RATIO Single 5V Supply 5th Order LP Filter R 5V VIN C 25k 1 2 25k 5V FB AGND V– BOUT OUT V+ 8 7 BUFFERED OUTPUT C DC ACCURATE OUTPUT + LTC1062 3 4 6 5 5V CLK DIVIDER COSC RATIO 12R 1062 TA14 FOR A 10Hz FILTER: R = 29.4k, C = 1µF, fCLK = 1kHz 1 = fC THE FILTER IS MAXIMALLY FLAT FOR 2πRC 1.84 1062fd 11 LTC1062 TYPICAL APPLICATIO S A Lowpass Filter with a 60Hz Notch C7 0.1µF R6 19.35k R3 20k R 9.09k VIN C 1µF R2 20k R4 10k R7 20k FB AGND V– BOUT OUT LTC1062 V – 4 DIVIDER COSC RATIO 5 CLK IN 2.84kHz 1 = fCLK 2πRC 100 • 1.62 Frequency Response of the Above Lowpass Filter with the Notch fNOTCH = fCLK/47.3 –10 0 10 VOUT/VIN (Hz) 20 30 40 50 60 70 1 10 fIN (Hz) 1062 TA16 100 1k 12 + 3 6 V+ A2 1/2 LT1013 1062 TA15 V+ – 2 7 A1 1/2 LT1013 + – 1 U 8 R5 10k VOUT 1062fd LTC1062 PACKAGE DESCRIPTIO U J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) CORNER LEADS OPTION (4 PLCS) .405 (10.287) MAX 8 7 6 5 .005 (0.127) MIN .023 – .045 (0.584 – 1.143) HALF LEAD OPTION .045 – .068 (1.143 – 1.650) FULL LEAD OPTION .300 BSC (7.62 BSC) .025 (0.635) RAD TYP 1 2 3 .220 – .310 (5.588 – 7.874) 4 .200 (5.080) MAX .015 – .060 (0.381 – 1.524) 0° – 15° .045 – .065 (1.143 – 1.651) .014 – .026 (0.360 – 0.660) .100 (2.54) BSC .125 3.175 MIN J8 0801 .008 – .018 (0.203 – 0.457) NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS OBSOLETE PACKAGE 1062fd 13 LTC1062 PACKAGE DESCRIPTIO .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) NOTE: 1. DIMENSIONS ARE 14 U N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 .255 ± .015* (6.477 ± 0.381) 1 2 3 4 .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 .100 (2.54) BSC 1062fd LTC1062 PACKAGE DESCRIPTIO .030 ±.005 TYP N .420 MIN 1 2 3 RECOMMENDED SOLDER PAD LAYOUT 1 .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 0° – 8° TYP .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) NOTE 3 .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. U SW Package 16-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .398 – .413 (10.109 – 10.490) NOTE 4 16 15 14 13 12 11 10 9 N .325 ±.005 NOTE 3 .394 – .419 (10.007 – 10.643) N/2 N/2 2 3 4 5 6 7 8 .093 – .104 (2.362 – 2.642) .037 – .045 (0.940 – 1.143) .050 (1.270) BSC .004 – .012 (0.102 – 0.305) .014 – .019 (0.356 – 0.482) TYP S16 (WIDE) 0502 1062fd 15 LTC1062 TYPICAL APPLICATIO A Low Frequency, 5Hz Filter Using Back-to-Back Solid Tantalum Capacitors 5.23k VIN –5V RELATED PARTS PART NUMBER LTC1063 LTC1065 LTC1066-1 LTC1563-2/ LTC1563-3 LTC1564 LTC1569-6 LTC1569-7 DESCRIPTION 5th Order Butterworth Lowpass, DC Accurate 5th Order Bessel Lowpass, DC Accurate 8th Order Elliptic or Linear Phase, DC Accurate Active RC, 4th Order Lowpass 10kHz to 150kHz Digitally Controlled Lowpass and PGA Linear Phase, DC Accurate, 10th Order Linear Phase, DC Accurate, 10th Order COMMENTS Clock Tunable, No External Components Clock Tunable, No External Components Clock Tunable, fc ≤ 120kHz Very Low Noise, 256Hz ≤ fc ≤ 256kHz Continuous Time, Very High Dynamic Range, PGA Included No External Clock Required, fc ≤ 64kHz, S08 No External Clock Required, fc ≤ 300kHz, S08 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com + U + 10µF 10µF 8 7 VOUT 1 2 FB AGND V– BOUT OUT V+ BVOUT LTC1062 3 4 6 5 0.08µF 1062 TA17 5V DIVIDER COSC RATIO 1062fd LW/TP 1102 1K REV D • PRINTED IN USA  LINEAR TECHNOLOGY CORPORATION 1994