LTC1062 5th Order Lowpass Filter U 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 U APPLICATIO S ■ ■ ■ ■ ■ ■ ■ 60Hz Lowpass Filters Antialiasing Filter Low Level Filtering Rolling Off AC Signals from High DC Voltages Digital Voltmeters Scales Strain Gauges 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. U TYPICAL APPLICATIO 10Hz 5th Order Butterworth Lowpass Filter 25.8k BOUT AGND OUT 8 BUFFERED OUTPUT 7 LTC1062 V – = –5V 3 4 V– V+ DIVIDER COSC RATIO 6 5 COSC= 3900pF V + = 5V 1062 TA01 AMPLITUDE RESPONSE (dB) FB COSC = 3900pF –10 –20 –30 –40 –50 50 –60 40 –70 30 –80 20 –90 10 –100 1 NOTE: TO ADJUST OSCILLATOR FREQUENCY, USE A 6800pF CAPACITOR IN SERIES WITH A 50k POT FROM PIN 5 TO GROUND 10 INPUT FREQUENCY (Hz) FILTER OUTPUT NOISE (µV/√Hz) 1µF 2 0 DC ACCURATE OUTPUT VIN 1 Filter Amplitude Response and Noise 0 100 1062 TA02 1062fd 1 LTC1062 W W W AXI U U ABSOLUTE RATI GS (Note 1) 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 Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C U U W PACKAGE/ORDER I FOR ATIO TOP VIEW FB 1 8 BOUT AGND 2 7 OUT V– 3 6 V+ DIVIDER 4 RATIO 5 COSC ORDER PART NUMBER LTC1062CN8 16 NC NC 2 15 NC FB 3 14 BOUT LTC1062MJ8 LTC1062CJ8 LTC1062CSW 13 OUT 12 V + V– 5 DIVIDER 6 RATIO NC 7 TJ MAX = 100°C, θJA = 130°C/W J8 PACKAGE 8-LEAD CERDIP TJ MAX = 150°C, θJA = 100°C/W NC 1 AGND 4 N8 PACKAGE 8-LEAD PDIP ORDER PART NUMBER TOP VIEW 11 COSC 10 NC NC 8 9 NC SW PACKAGE 16-LEAD PLASTIC SO TJ MAX = 150°C, θJA = 90°C/W OBSOLETE PACKAGE Consider the N8 Package as an Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS+ 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. PARAMETER Power Supply Current CONDITIONS COSC MIN (Pin 5 to V –, Pin 11 in SW16) = 100pF TYP MAX 4.5 7 10 ● Input Frequency Range 0 to 20 = 100kHz, Pin 4 (Pin 6 in SW16) at V+, Filter Gain at fIN = 0 fIN = 0.5fC (Note 2) fIN = fC fIN = 2fC fIN = 4fC fCLK C = 0.01µF, R = 25.78k Clock-to-Cutoff Frequency Ratio, fCLK/fC fCLK = 100kHz, Pin 4 (Pin 6 in SW16) at V+, C = 0.01µF, R = 25.78k Filter Gain at fIN = 16kHz fCLK = 400kHz, Pin 4 at V +, C = 0.01µF, R = 6.5k fCLK/fC Tempco fCLK = 400kHz, Pin 4 at V+, C = 0.01µF, R = 6.5k Filter Output (Pin 7, Pin 13 in SW16) DC Swing Pin 7/Pin13 (SW16) Buffered with an External Op Amp Clock Feedthrough ● ● ● ● ● –2 –28 –52 –43 ±3.5 UNITS mA mA kHz 0.00 – 0.02 –0.3 –3.00 –30.00 –60.00 dB dB dB dB dB 100 ±1 % –52 dB 10 ppm/°C ±3.8 1 V mVP-P 1062fd 2 LTC1062 ELECTRICAL CHARACTERISTICS+ 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. PARAMETER CONDITIONS MIN TYP MAX UNITS 2 170 50 1000 pA pA 2 20 mV Internal Buffer Bias Current ● Offset Voltage Voltage Swing RLOAD = 20k ● ±3.5 Short-Circuit Current Source/Sink ±3.8 V 40/3 mA Clock (Note 3) COSC (Pin 5 to V–, Pin 11 in SW16) = 100pF Internal Oscillator Frequency 25 15 ● 32 Max Clock Frequency 50 65 kHz kHz 4 Pin 5 (Pin 11 in SW16) Source or Sink Current 40 ● 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. MHz 80 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. U W TYPICAL PERFOR A CE CHARACTERISTICS 0 –10 0 VS = ±2.5V TA = 25°C 1 = fC 2πRC 1.62 –10 –20 –30 –40 –50 –60 RESPONSE (dB) RESPONSE (dB) –20 Amplitude Response Normalized to the Cutoff Frequency fCLK = 500kHz, fC = 5kHz fCLK = 250kHz, fC = 2.5kHz fCLK = 100kHz, fC = 1kHz –90 –100 0.1 0.4 VS = ±2.5V TA = 25°C 1 = fC 2πRC 1.62 VS = ±5V TA = 25°C 0.2 f CLK = 100kHz –30 –40 –50 –60 fCLK = 500kHz, fC = 5kHz fCLK = 250kHz, fC = 2.5kHz fCLK = 100kHz, fC = 1kHz –70 –70 –80 Passband Gain vs Input Frequency PASSBAND GAIN (dB) Amplitude Response Normalized to the Cutoff Frequency –80 fCLK = 10kHz, fC = 100Hz –90 fCLK = 1kHz, fC = 10Hz 1 fIN/fC 10 1062 G01 –100 0.1 1 = fC 2πRC 1.6 0 –0.2 1 = fC 2πRC 1.62 –0.4 1 = fC 2πRC 1.64 –0.6 fCLK = 10kHz, fC = 100Hz –0.8 fCLK = 1kHz, fC = 10Hz 1 fIN/fC 10 –1.0 0.1 0.2 0.4 0.6 0.8 1 fIN/fC 1062 G01 1062 G03 1062fd 3 LTC1062 U W TYPICAL PERFOR A CE CHARACTERISTICS 0 TA = –55°C –0.2 VS = ±5V fCLK = 100kHz 1 = fC 2πRC 1.62 TA = 25°C –30 TA = 125°C –0.4 –0.6 –60 –90 –120 –150 –0.8 –180 –1.0 0.1 –210 0.1 0.2 0.4 0.6 0.8 1 Filter Noise Spectral Density 0.2 0.4 0.6 1.5 240 OSCILLATOR FREQUENCY (kHz) OSCILLATOR FREQUENCY NORMALIZED TO fOSC AT 5V SUPPLY 260 1.4 1.3 1.2 1.1 1.0 0.9 0.8 12 14 VSUPPLY (V) 30 20 fC = 100Hz 0.8 fC = 1kHz 0 0.1 1 1 16 18 20 1062 G07 1k 10 100 CUTOFF FREQUENCY (Hz) Power Supply Current vs Power Supply Voltage 16 COSC = 0pF 14 200 180 160 V + = 10V – = 0V V 140 120 100 10k 1062 G06 220 80 10 fC = 10Hz 40 Oscillator Frequency, fOSC vs Ambient Temperature 1.6 8 50 1062 G05 Normalized Oscillator Frequency, fOSC vs Supply Voltage 6 60 fIN/fC 1062 G04 4 VS = ±5V TA = 25°C 70 10 fIN/fC 0.7 80 SUPPLY CURRENT (mA) VS = ±5V fCLK = 100kHz 1 = fC 2πRC 1.62 0.2 PASSBAND GAIN (dB) 0 PHASE SHIFT (DEG) 0.4 Passband Phase Shift vs Input Frequency FILTER OUTPUT NOISE (µV/√Hz) Passband Gain vs Input Frequency and Temperature V + = 5V – V = 0V TA = –55°C 12 TA = 25°C 10 8 6 TA = 125°C 4 2 60 25 50 –50 –25 0 75 100 AMBIENT TEMPERATURE (°C) 0 125 1062 G08 4 6 8 10 12 14 16 18 POWER SUPPLY VOLTAGE (V) 20 1062 G09 1062fd 4 LTC1062 W BLOCK DIAGRA For Adjusting Oscillator Frequency, Insert a 50k Pot in Series with COSC. Use Two Times Calculated COSC FB 1 AGND 2 SWITCHED CAPACITOR NETWORK 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: 8 BOUT ×1 7 OUT fCLK V– 3 CLOCK GEN ÷ 4 ÷ 1, 2, 4 6 V+ OSC 5 COSC fOSC ≅ 140kHz [33pF/(33pF + COSC)] 1062 BD AC TEST CIRCUIT 5V VIN R = 25.8k 3 50Ω 1 2 FB OUT 8 2 7 V 3 4 V– V+ DIVIDER COSC RATIO – MEASURED OUTPUT 0.1µF 5V R′ FOR BEST MAX FLAT APPROXIMATION, THE INPUT RC SHOULD BE SUCH AS: 1 = fCLK 1 • 2πRC 100 1.63 4 0.1µF 6 5 8 1 LTC1062 – = –5V 6 LTC1052 BOUT AGND 7 + C = 0.01µF A 0.5k RESISTOR, R′, SHOULD BE USED IF THE BIPOLAR EXTERNAL CLOCK IS APPLIED BEFORE THE POWER SUPPLIES TURN ON –5V –5V 1062 F01 fCLK = 100kHz 5V Figure 1 1062fd 5 LTC1062 U W U U 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 VS = ±5V 1 = fC 2πRC 1.62 4 2 VPIN1/VIN (dB) 0 –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 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 VTH+ VTH– ±2.5V 0.9V –1V ±5V 1.3V –2.1V ±6V 1.7V –2.5V ±7V 1.75V –2.9V 1062fd 6 LTC1062 U W U U APPLICATIO S I FOR ATIO Divide By 1, 2, 4 (Pin 4) Filter Noise 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. 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. Transient Response Figure 3 shows the LTC1062 response to a 1V input step. 200mV/VERT DIV 50ms/HORIZ DIV, fC = 10Hz 5ms/HORIZ DIV, fC = 100Hz 0.5ms/HORIZ DIV, fC = 1kHz f 1 = C 2πRC 1.94 f 1 = C 2πRC 1.62 f 1 = C 2πRC 2.11 Figure 3. Step Response to a 1V Peak Input Step Table 2 NOISE BW RMS NOISE (VS = ±5V) DC – 0.1 • fC 2µV DC – 0.25 • fC 8µV DC – 0.5 • fC 20µV DC – 1 • fC 62µV DC – 2 • fC 100µV 1062fd 7 LTC1062 U TYPICAL APPLICATIO S AC Coupling an External CMOS Clock Powered from a Single Positive Supply, V + VOUT VIN C 1 2 FB BOUT AGND OUT 8 7 LTC1062 V– 3 4 V– V+ DIVIDER COSC RATIO 6 V + 0.01µF V+ 5 0 100k 1062 TA03 Adding an External (R1, C1) to Eliminate the Clock Feedthrough and to Improve the High Frequency Attenuation Floor – EXTERNAL BUFFER R1 10R R VOUT + VIN C 1 2 FB BOUT AGND OUT C1 0.01C 8 7 LTC1062 V– 3 4 V– V+ DIVIDER COSC RATIO 6 5 V+ fCLK 1062 TA04 Filtering AC Signals from High DC Voltages Passband Amplitude Response for the High DC Accurate 5th Order Filter 0.2 R 25.8k C 0.01µF 1 HIGH DC INPUT = 100V 2 FB C 0.01µF BOUT AGND OUT 8 7 12R 309.6k LTC1062 V – = –5V 3 4 V– 6 V+ DIVIDER COSC RATIO 5 0 DC OUTPUT CLK IN = fC • 100 1062 TA05 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 PASSBAND GAIN (dB) VIN –0.2 –0.4 –0.6 –0.8 –1.0 –1.2 VS = ±5V fCLK = 100kHz –1.4 0.01 0.1 fIN /fC 1 1062 TA06 1062fd 8 LTC1062 U TYPICAL APPLICATIO S Cascading Two LTC1062s to Form a Very Selective Clock Sweepable Bandpass Filter R1 10k R′1 10k VIN R2 10k 1 2 FB BOUT OUT AGND 8 R′2 12.5k 1 7 2 FB AGND LTC1062 –5V 3 4 V – BOUT OUT 8 VOUT 7 LTC1062 V + DIVIDER COSC RATIO 6 5V 3 –5V 5 V 4 – V+ DIVIDER COSC RATIO 6 5V 5 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 R1 VIN R2 1 2 FB BOUT AGND OUT 8 R3 – 7 LTC1062 –5V 3 4 V– V+ DIVIDER COSC RATIO VOUT + 6 5 5V fCLK 1062 TA08 Frequency Response of the Bandpass Filter Frequency Response of the Notch Filter 20 –10 VS = ±5V R1 = 1 R2 R′1 = 0.8 R′2 VIN = 100mVRMS 10 0 –10 –30 10 20 (dB) (dB) –20 0 –40 30 –50 40 –60 50 –70 60 –80 –90 0.5 1 1.5 2 2.5 (kHz) 3 3.5 4 4.5 70 100 300 500 700 900 1100 (Hz) 1062 TA09 1062 TA10 1062fd 9 LTC1062 U TYPICAL APPLICATIO S Simple Cascading Technique 5V 25.8k 412k 3 VIN 1µF 1 2 FB BOUT AGND OUT 8 1 7 2 3 4 V– BOUT AGND OUT 8 2 7 DIVIDER COSC RATIO 6 –5V 5 3 4 V– V+ DIVIDER COSC RATIO 8 – DC ACCURATE OUTPUT 4 1 LTC1062 V+ 6 LTC1052 FB LTC1062 –5V 7 + 0.1µF 0.1µF 0.1µF 6 5 –5V V + = 5V 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) 1062 TA11 fCLK = 1kHz 100Hz, 50Hz, 25Hz 5th Order DC Accurate LP Filter 25.8k VOUT VIN 0.1µF 1 2 0.1µF 0.2µF 1 3 2 13 1/2 CD4016 4 FB BOUT AGND OUT 8 7 5 BOUT LTC1062 –5V 3 4 CONTROL (HIGH, GROUND, LOW) V– V+ DIVIDER COSC RATIO 100k 5V 100k 6 5 5V 10kHz CLK IN TO PIN 5 OF CD4016 BY CONNECTING PIN 4 OF THE LTC1062 HIGH/GROUND/LOW THE FILTER CUTOFF FREQUENCY IS 100Hz/50Hz/25Hz –5V 5V 100k TO PIN 13 OF CD4016 100k –5V 1062 TA12 1062fd 10 LTC1062 U TYPICAL APPLICATIO S 7th Order 100Hz Lowpass Filter with Continuous Output Filtering, Output Buffering and Gain Adjustment R4 R3 5V 2 2.6k R1 3 VIN 1 C1 2 FB BOUT AGND OUT 6 LTC1052 R2 1µF 7 – C2 VOUT 8 + 4 0.1µF 1 0.1µF 8 –5V 7 LTC1062 –5V 5V 3 4 V– V+ DIVIDER COSC RATIO 6 5 5V 10kHz CLK IN 1062 TA13 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 Single 5V Supply 5th Order LP Filter R 10µF SOLID TANTALUM 5V VIN C 1 25k + 2 C FB BOUT AGND OUT 8 7 DC ACCURATE OUTPUT BUFFERED OUTPUT LTC1062 25k 3 5V 4 V– V+ DIVIDER COSC RATIO 6 5 5V CLK 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 U TYPICAL APPLICATIO S A Lowpass Filter with a 60Hz Notch C7 0.1µF R6 19.35k R3 20k R7 20k R4 10k R 9.09k VIN C 1µF 1 2 FB 8 BOUT AGND R2 20k – 7 OUT + LTC1062 V – 3 4 6 V+ V– R5 10k A1 1/2 LT1013 5 DIVIDER COSC RATIO – A2 1/2 LT1013 + V+ VOUT 1062 TA15 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 VOUT/VIN (Hz) 10 20 30 40 50 60 70 1 10 100 1k fIN (Hz) 1062 TA16 1062fd 12 LTC1062 U PACKAGE DESCRIPTIO J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) CORNER LEADS OPTION (4 PLCS) .023 – .045 (0.584 – 1.143) HALF LEAD OPTION .045 – .068 (1.143 – 1.650) FULL LEAD OPTION .005 (0.127) MIN .405 (10.287) MAX 8 7 6 5 .025 (0.635) RAD TYP .220 – .310 (5.588 – 7.874) 1 2 .300 BSC (7.62 BSC) 3 4 .200 (5.080) MAX .015 – .060 (0.381 – 1.524) .008 – .018 (0.203 – 0.457) 0° – 15° NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS .045 – .065 (1.143 – 1.651) .014 – .026 (0.360 – 0.660) .100 (2.54) BSC .125 3.175 MIN J8 0801 OBSOLETE PACKAGE 1062fd 13 LTC1062 U PACKAGE DESCRIPTIO N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) .045 – .065 (1.143 – 1.651) .130 ± .005 (3.302 ± 0.127) .065 (1.651) TYP .100 (2.54) BSC .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) 1062fd 14 LTC1062 U PACKAGE DESCRIPTIO SW Package 16-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .398 – .413 (10.109 – 10.490) NOTE 4 16 N 15 14 13 12 11 10 9 N .325 ±.005 .420 MIN .394 – .419 (10.007 – 10.643) NOTE 3 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT 1 .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 3 4 5 6 7 .093 – .104 (2.362 – 2.642) 8 .037 – .045 (0.940 – 1.143) 0° – 8° TYP NOTE 3 .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 2 .050 (1.270) BSC .004 – .012 (0.102 – 0.305) .014 – .019 (0.356 – 0.482) TYP 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) S16 (WIDE) 0502 1062fd 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. 15 LTC1062 U TYPICAL APPLICATIO A Low Frequency, 5Hz Filter Using Back-to-Back Solid Tantalum Capacitors 5.23k VIN VOUT + 10µF 10µF + 1 2 FB BOUT AGND OUT 8 BVOUT 7 LTC1062 –5V 3 4 V– V+ DIVIDER COSC RATIO 6 5V 5 0.08µF 1062 TA17 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1063 5th Order Butterworth Lowpass, DC Accurate Clock Tunable, No External Components LTC1065 5th Order Bessel Lowpass, DC Accurate Clock Tunable, No External Components LTC1066-1 8th Order Elliptic or Linear Phase, DC Accurate Clock Tunable, fc ≤ 120kHz LTC1563-2/ LTC1563-3 Active RC, 4th Order Lowpass Very Low Noise, 256Hz ≤ fc ≤ 256kHz LTC1564 10kHz to 150kHz Digitally Controlled Lowpass and PGA Continuous Time, Very High Dynamic Range, PGA Included LTC1569-6 Linear Phase, DC Accurate, 10th Order No External Clock Required, fc ≤ 64kHz, S08 LTC1569-7 Linear Phase, DC Accurate, 10th Order No External Clock Required, fc ≤ 300kHz, S08 1062fd 16 Linear Technology Corporation LW/TP 1102 1K REV D • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 1994