LTC7652

LTC1052/LTC7652 Zero-Drift Operational Amplifier FEATURES ■ ■ ■ ■ ■ ■ DESCRIPTIO ■ ■ Guaranteed Max Offset: 5µV Guaranteed Max Offset Drift: 0.05µV/°C Typ Offset Drift: 0.01µV/°C Excellent Long Term Stability: 100nV/√Month Guaranteed Max Input Bias Current: 30pA Over Operating Temperature Range: Guaranteed Min Gain: 120dB Guaranteed Min CMRR: 120dB Guaranteed Min PSRR: 120dB Single Supply Operation: 4.75V to 16V (Input Voltage Range Extends to Ground) External Capacitors can be Returned to V – with No Noise Degradation The LTC®1052 and LTC7652 are low noise zero-drift op amps manufactured using Linear Technology’s enhanced LTCMOSTM silicon gate process. Chopper-stabilization constantly corrects offset voltage errors. Both initial offset and changes in the offset due to time, temperature and common mode voltage are corrected. This, coupled with picoampere input currents, gives these amplifiers unmatched performance. Low frequency (1/f) noise is also improved by the chopping technique. Instead of increasing continuously at a 3dB/octave rate, the internal chopping causes noise to decrease at low frequencies. The chopper circuitry is entirely internal and completely transparent to the user. Only two external capacitors are required to alternately sample-and-hold the offset correction voltage and the amplified input signal. Control circuitry is brought out on the 14-pin and 16-pin versions to allow the sampling of the LTC1052 to be synchronized with an external frequency source. , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS is a trademark of Linear Technology Corporation. Teflon is a trademark of DuPont. APPLICATIO S ■ ■ ■ ■ Thermocouple Amplifiers Strain Gauge Amplifiers Low Level Signal Processing Medical Instrumentation TYPICAL APPLICATIO 5V 3 Ultralow Noise, Low Drift Amplifier 160 VOLTAGE NOISE DENSITY (nV/√Hz) + – 1 7 6 8 4 0.1µF –5V 0.1µF 140 120 100 80 60 40 20 0 0 100 200 300 400 500 LTC1052 2 0.1µF 5V 100k INPUT 3K 3 + – 1 5V 7 ® 68k 8 6 1.5k 5V LT 1007 2 4 – 5V OUTPUT 100k VOS = 3µV VOS∆T = 50nV/°C NOISE = 0.06µVP-P 0.1Hz TO 10Hz 100Ω LTC1052/7652 • TA01 U Noise Spectrum FREQUENCY (Hz) LTC1052/7652 • TA02 U U 1052fa 1 LTC1052/LTC7652 ABSOLUTE AXI U RATI GS Total Supply Voltage (V + to V –) ............................... 18V Input Voltage ........................ (V + + 0.3V) to (V – – 0.3V) Output Short Circuit Duration .......................... Indefinite Storage Temperature Range .................. –55°C to 150°C PACKAGE/ORDER I FOR ATIO TOP VIEW CEXTB 8 CEXTA 1 + 7 V /CASE – IN 2 – + 5 4 V– 6 OUTPUT + IN 3 LTC1052 OUTPUT CLAMP LTC7652 CRETURN METAL CAN H PACKAGE OBSOLETE PACKAGE Consider the N8 Package for Alternate Source ORDER PART NUMBER LTC7652CH LTC1052CH LTC1052MH TOP VIEW CEXTA – IN REPLACES ICL7652CTV ICL7652ITV ICL7650CTV-1 ICL7650ITV-1 ICL7650CTV ICL7650ITV ICL7650MTV 8 CEXTB 1 2 +N 3 V– 4 – + 7 V+ 6 OUTPUT OUTPUT 5 CLAMP N8 PACKAGE 8-LEAD PDIP TJMAX = 110°C, θJA = 150°C/W J8 PACKAGE, 8-LEAD CERDIP OBSOLETE PACKAGE Consider the N8 Package for Alternate Source ORDER PART NUMBER LTC1052CN8 LTC1052CJ8 LTC1052MJ8 REPLACES ICL7650CPA ICL7650IJA Consult LTC Marketing for parts specified with wider operating temperature ranges. 2 U U W WW U W (Notes 1 and 2) Operating Temperature Range LTC1052C/LTC7652C ..........................–40°C to 85°C LTC1052M (OBSOLETE).....................–55°C to 125°C Lead Temperature (Soldering, 10 sec).................. 300°C TOP VIEW CEXTB 1 14 INT/EXT 13 CLK IN 12 CLK OUT CEXTA 2 NC (GUARD) 3 – IN 4 + IN 5 NC (GUARD) 6 V– 7 – + 11 V + 10 OUTPUT 9 OUTPUT CLAMP 8 CRETURN N PACKAGE, 14-LEAD CERDIP TJMAX = 110°C, θJA = 130°C/W J PACKAGE, 14-LEAD CERDIP OBSOLETE PACKAGE Consider the N14 Package for Alternate Source ORDER PART NUMBER LTC1052CN LTC1052CJ LTC1052MJ REPLACES ICL7652CPD ICL7650CPD ICL7652IJD ICL7650IJD ICL7650MJD TOP VIEW CEXTB CEXTA NC (GUARD) – IN + IN NC (GUARD) V– NC 1 2 3 4 5 6 7 8 16 INT/EXT 15 CLK IN 14 CLK OUT 13 V + 12 OUTPUT 11 OUTPUT CLAMP 10 CRETURN 9 NC SW PACKAGE 16-LEAD PLASTIC (WIDE) SO TJMAX = 110°C, θJA = 150°C/W ORDER PART NUMBER LTC1052CSW REPLACES LTC1052CS 1052fa LTC1052/LTC7652 ELECTRICAL CHARACTERISTICS SYMBOL VOS PARAMETER Input Offset Voltage (Note 3) (Note 3) The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, test circuit TC1, unless otherwise noted. CONDITIONS MIN LTC1052M TYP MAX ± 0.5 ● LTC1052C/LTC7652C MIN TYP MAX ± 0.5 ±0.01 100 ± 30 ±1 1.5 0.5 0.6 120 120 120 ± 4.7 140 150 150 ± 4.85 ± 4.95 4 1.2 ±5 ± 0.05 ± 90 ± 350 ± 30 ± 175 UNITS µV µV/°C nV/√Month pA pA pA pA µVP-P µVP-P fA/√Hz dB dB dB V V V/µs MHz ±5 ± 0.05 ± 90 ± 2000 ± 30 ± 1000 ∆VOS/∆Temp Average Input Offset Drift ∆VOS/∆Time Long-Term Offset Voltage Stability IOS IB enP-P In CMRR PSRR AVOL VOUT SR GBW IS fS Input Offset Current ± 0.01 100 ± 30 ● Input Bias Current ● ±1 RS = 100Ω, DC to 10HZ, TC3 RS = 100Ω, DC to 1HZ, TC3 f = 10Hz (Note 5) VCM = V – to 2.7V VSUPPLY = ± 2.375V to ± 8V RL = 10k, VOUT = ± 4V RL = 10k RL = 100k RL = 10k, CL = 50pF No Load ● ● ● ● ● Input Noise Voltage Input Noise Current Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Maximum Output Voltage Swing (Note 4) Slew Rate Gain Bandwidth Product Supply Current Internal Sampling Frequency Clamp On Current Clamp Off Current 1.5 0.5 0.6 120 120 120 ± 4.7 140 150 150 ± 4.85 ± 4.95 4 1.2 1.7 330 2.0 3.0 25 100 2 1.7 330 100 10 2.0 3.0 mA mA Hz µA RL = 100k –4V < VOUT < 4V ● ● 25 100 10 100 1 pA nA Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Connecting any terminal to voltages greater than V +, or less than V –, may cause destructive latch-up. It is recommended that no sources operating from external supplies be applied prior to power-up of the LTC1052/LTC7652. Note 3: These parameters are guaranteed by design. Thermocouple effects preclude measurement of the voltage levels in high speed automatic testing. VOS is measured to a limit determined by test equipment capability. Voltages on CEXTA and CEXTB, AVOL, CMRR and PSRR are measured to insure proper operation of the nulling loop to ensure meeting the VOS and VOS drift specifications. See Package-Induced VOS in the Applications Information section. Note 4: Output clamp not connected. Note 5: Current noise is calculated from the formula: in = (2q IB)1/2, where q = 1.6 • 10 –19 coulomb. TYPICAL PERFOR A CE CHARACTERISTICS Input Noise Voltage 5µV 0 VS = ± 5V, TEST CIRCUIT (TC3) DC TO 1Hz 5µV DC TO 10Hz 0 UW 10 SEC. 1052fa 3 LTC1052/LTC7652 TYPICAL PERFOR A CE CHARACTERISTICS Offset Voltage vs Sampling Frequency 12 VSUPPLY= ±5V 10 8 6 4 2 0 0 500 1000 1500 SAMPLING FREQUENCY, fS (Hz) 2000 10Hz PEAK-TO-PEAK NOISE (µV) INPUT BIAS CURRENT, IB (pA) VOS (µV) Aliasing Error 8 OUTPUT SPECTRUM (dB) (3Hz BANDWIDTH) COMMON MODE RANGE (V) VS = ± 5V AV = –1 TEST CIRCUIT TC2 2 0 –2 –4 –6 –8 0 1 2 4 5 3 6 SUPPLY VOLTAGE (±V) 7 8 VCM = V – IV/DIV fI–fS 50Hz/DIV fS Small-Signal Transient Response* OUTPUT VOLTAGE (20mV/DIV) OUTPUT VOLTAGE (2mV/DIV) VOLTAGE GAIN (dB) AV = 1 2µs/DIV RL = 10k CL = 100pF VS = ± 5V *RESPONSE IS NOT DEPENDENT ON PHASE OF CLOCK 4 UW fI 1OHzP-P Noise vs Sampling Frequency 5 VSUPPLY= ± 5V 1000 900 800 700 600 500 400 300 200 100 Input Bias Current vs Temperature GUARANTEED 4 3 2 1 GUARANTEED 0 100 1k SAMPLING FREQUENCY, fS (Hz) 10k 0 50 25 0 75 100 –50 –25 AMBIENT TEMPERATURE, TA(°C) 125 LTC1052/7652 • TPC01 LTC1052/7652 • TPC03 LTC1052/7652 • TPC02 Common Mode Input Range vs Supply Voltage 6 4 Overload Recovery (Output Clamp Not Used) VS = ± 5V OVERDRIVE REMOVED AV = – 100 50ms/DIV LTC1052/7652 • TPC04 Large-Signal Transient Response* 120 100 80 Gain Phase vs Frequency 60 VS = ± 5V CL= 100pF PHASE 60 GAIN 40 20 0 140 160 180 200 103 105 104 FREQUENCY (Hz) 106 220 107 120 80 PHASE SHIFT (DEGREES) 100 AV = 1 RL = 10k CL = 100pF VS = ± 5V 2µs/DIV –20 –40 100 LTC1052/LTC7652 • TPC06 1052fa LTC1052/LTC7652 TYPICAL PERFOR A CE CHARACTERISTICS Broadband Noise, CEXT = 0.1µF Broadband Noise, CEXT = 1.0µF Broadband Noise Test Circuit (TC2) R2 1M INPUT REFERRED NOISE (5µV/DIV) INPUT REFERRED NOISE (5µV/DIV) AV = – 1000 1ms/DIV Supply Current vs Supply Voltage 2.5 SUPPLY VOLTAGE = ± 5V SUPPLY CURRENT, IS(mA) SUPPLY CURRENT, IS(mA) SHORT-CIRCUIT OUTPUT CURRENT, IOUT (mA) 2.0 1.5 1.0 0.5 0 8 10 12 14 16 456 TOTAL SUPPLY VOLTAGE, V + TO V – (V) LTC1052/LTC7652 • TPC08 Sampling Frequency vs Voltage 600 TA = 25°C SAMPLING FREQUENCY, fS (Hz) SAMPLING FREQUENCY, fS (Hz) 500 400 300 200 100 0 500 600 14 16 8 10 12 456 TOTAL SUPPLY VOLTAGE, V + TO V – (V) LTC1052/LTC7652 • TPC11 UW R1 1k R3 1k 2 – + 1 5V 7 6 8 4 CEXTB 3 LTC1052 CEXTA AV = – 1000 1ms/DIV – 5V LTC1052/7652 • TPC07 Supply Current vs Temperature 3.0 8 6 4 2 0 – 10 – 20 – 30 Output Short-Circuit Current vs Supply Voltage ISOURCE VOUT = V – 2.0 1.0 ISINK VOUT = V + 12 16 456 10 14 8 TOTAL SUPPLY VOLTAGE, V + TO V – (V) LTC1052/LTC7652 • TPC10 0 50 100 –50 –25 25 75 0 AMBIENT TEMPERATURE, TA (°C) 125 LTC1052/LTC7652 • TPC09 Sampling Frequency vs Temperature SUPPLY VOLTAGE = ± 5V Comparator Operation VREF* 400 1k 2 – + 1 5 5V 7 6 8 4 0.1µF 1k 300 200 100 0 50 100 – 50 – 25 25 75 0 AMBIENT TEMPERATURE, TA (°C) LTC1052 3 VIN 0.1µF * – 5V ≤ VREF ≤ 2.7 V – 5V LTC1052/7652 • TPC13 125 LT1052/LTC7652 • TPC12 1052fa 5 LTC1052/LTC7652 TYPICAL PERFOR A CE CHARACTERISTICS Response Time vs Overdrive INPUT { TEST CIRCUITS Electrical Characteristics Test Circuit (TC1) R2 1M R1 1k V+ 2 R2 V+ R4 C4 2 3 – + 1 LTC1052 3 8 4 0.1µF V– THEORY OF OPERATIO DC OPERATION The shaded portion of the LTC1052 block diagram (Figure 1a) entirely determines the amplifier’s DC characteristics. During the auto zero portion of the cycle, the gm1 inputs are shorted together and a feedback path is closed around the input stage to null its offset. Switch S2 and capacitor CEXTA act as a sample-and-hold to store the nulling voltage during the next step—the sampling cycle. In the sampling cycle, the zeroed amplifier is used to amplify the differential input voltage. Switch S2 connects the amplified input voltage to CEXTB and the output gain 6 U UW 7 6 VREF + OVERDRIVE VREF – 1mV OUTPUT { 5V 50µV –5V 10µV 5µV 20ms/DIV DC to 10Hz and DC to 1HZ Noise Test Circuit (TC3) C2 C3 + LT1001 6 OUTPUT (NOISE x 20,000) OUTPUT RL R1 2 – + 1 7 6 8 4 0.1µF R3 – 34k LTC1052 3 0.1µF 0.1µF 34k LTC1052/7652 • TC01 V– BANDWIDTH 10Hz 1Hz R1 16.2Ω 16.2Ω R2 162k 162k R3 16.2k 162k R4 16.2k 162k C2 0.1µF 1.0µF C3 1.0µF 1.0µF C4 1.0µF 1.0µF LTC1052/7652 • TC02 stage. CEXTB and S2 act as a sample-and-hold to store the amplified input signal during the auto zero cycle. By switching between these two states at a frequency much higher than the signal frequency, a continuous output results. Notice that during the auto zero cycle the gm1 inputs are not only shorted together, but are also shorted to the inverting input. This forces nulling with the common mode voltage present and accounts for the extremely high CMRR of the LTC1052. In the same fashion, variations in 1052fa LTC1052/LTC7652 THEORY OF OPERATIO power supply are also nulled. For nulling to take place, the offset voltage, common mode voltage and power supply must not change at a frequency which is high compared to the frequency response of the nulling loop. AC OPERATION AND ALIASING ERRORS So far, the DC performance of the LTC1052 has been explained. As the input signal frequency increases, the problem of aliasing must be addressed. Aliasing is the spurious formation of low and high frequency signals caused by the mixing of the input signal with the sampling frequency, fS. The frequency of the error signals, fE, is: fE = fS ± fI where fI = input signal frequency. Normally it is the difference frequency (fS – fI ) which is of concern because the high frequency (fS + fI) can be easily filtered. As the input frequency approaches the sampling frequency, the difference frequency approaches zero and will cause DC errors—the exact problem that the zero-drift amplifier is meant to eliminate. The solution is simple; filter the input so the sampling loop never sees any frequency near the sampling frequency. At a frequency well below the sampling frequency, the LTC1052 forces I1 to equal I2 (see Figure 1b). This makes δ l zero, thus the gain of the sampling loop zero at this and higher frequencies (i.e., a low pass filter). The corner frequency of this low pass filter is set by the output stage pole (1/RL4 gm5 RL5 C2). S3 VREF + IN S1 + gm1 – + – RL1 gm2 RL2 VNULL gm3 – IN – – gm6 + U For frequencies above this pole, I2 is: I2 = VIN gm6 • 1 • SC1 SC2 and C1 I1 – I2 = VIN gm1 – VIN gm6 • C2 The LTC1052 is very carefully designed so that gm1 = gm6 and C1 = C2. Substituting these values in the above equation shows I1 – I2 = 0. The gm6 input stage, with Cl and C2, not only filters the input to the sampling loop, but also acts as a high frequency path to give the LTC1052 good high frequency response. The unity-gain cross frequencies for both the DC path and high frequency path are identical [f3dB = 1 (gm1/C1) = 1 (gm6/C2)] 2π 2π thereby making the frequency response smooth and continuous while eliminating sampling noise in the output as the loop transitions from the high gain DC loop to the high frequency loop. The typical curves show just how well the amplifier works. The output spectrum shows that the difference frequency (fI –fS = 100Hz) is down by 80dB and the frequency response curve shows no abnormalities or perturbations. Also note the well-behaved small and large-signal step responses and the absence of the sampling frequency in the output spectrum. If the dynamics of the amplifier (i.e., slew rate and overshoot), depend on the sampling clock, the sampling frequency will appear in the output spectrum. C1 C2 S2 gm4 CEXT B CEXT A + – + RL4 gm5 VOUT RL5 V– LTC1052/7652 • TPC13 Figure 1a. LTC1052 Block Diagram Auto Zero Cycle 1052fa 7 LTC1052/LTC7652 THEORY OF OPERATIO U C1 S3 VREF C2 + IN S1 l2 S2 gm2 RL1 RL2 CEXT B CEXT A gm3 gm4 + – + RL4 gm5 VOUT RL5 V– LTC1052/7652 • TO02 + gm1 – + – l1 δl – IN – – gm6 l3 + Figure 1b. LTC1052 Block Diagram Sampling Cycle APPLICATIO S I FOR ATIO EXTERNAL CAPACITORS CEXTA and CEXTB are the holding elements of a sampleand-hold circuit. The important capacitor characteristics are leakage current and dielectric absorption. A high quality film-type capacitor such as mylar or polypropylene provides excellent performance. However, low grade capacitors such as ceramic are suitable in many applications. Capacitors with very high dielectric absorption (ceramic) can take several seconds to settle after power is first turned on. This settling appears as clock ripple on the output and, as the capacitor settles, the ripple gradually disappears. If fast settling after power turn-on is important, mylar or polypropylene is recommended. Above 85°C, leakage, both from the holding capacitors and the printed circuit board, becomes important. To maintain the capabilities of the LTC1052 it may be necessary to use Teflon™ capacitors and Teflon standoffs when operating at 125°C (see Achieving Picoampere/ Microvolt Performance). CEXTA and CEXTB are normally in the range of 0.1µF to 1.0µF. All specifications are guaranteed with 0.1µF and the broadband noise (refer to Typical Performance Characteristics) is only very slightly degraded with 0.1µF. Output clock ripple is not present for capacitors of 0.1µF or greater at any temperature. 8 U On competitive devices, connecting CEXTA and CEXTB to V – causes an increase in amplifier noise. Design changes have eliminated this problem on the LTC1052. On the 14-pin LTC1052 and 8-pin LTC7652, the capacitors can be returned to V – or CRETURN with no change in noise performance. ACHIEVING PICOAMPERE/MICROVOLT PERFORMANCE Picoamperes In order to realize the picoampere level of accuracy of the LTC1052, proper care must be exercised. Leakage currents in circuitry external to the amplifier can significantly degrade performance. High quality insulation should be used (e.g., Teflon, Kel-F); cleaning of all insulating surfaces to remove fluxes and other residues will probably be necessary—particularly for high temperature performance. Surface coating may be necessary to provide a moisture barrier in high humidity environments. Board leakage can be minimized by encircling the input connections with a guard ring operated at a potential close to that of the inputs: in inverting configurations, the guard ring should be tied to ground; in noninverting Teflon is a trademark of Dupont. 1052fa W UU LTC1052/LTC7652 APPLICATIO S I FOR ATIO connections, to the inverting input. Guarding both sides of the printed circuit board is required. Bulk leakage reduction depends on the guard ring width. Microvolts Thermocouple effects must be considered if the LTC1052’s ultralow drift is to be fully utilized. Any connection of dissimilar metals forms a thermoelectric junction producing an electric potential which varies with temperature (Seebeck effect). As temperature sensors, thermocouples exploit this phenomenon to produce useful information. In low drift amplifier circuits the effect is a primary source of error. Connectors, switches, relay contacts, sockets, resistors, solder, and even copper wire are all candidates for thermal EMF generation. Junctions of copper wire from different manufacturers can generate thermal EMFs of 200nV/°C—4 times the maximum drift specification of the LTC1052. The copper/kovar junction, formed when wire or printed circuit traces contact a package lead, has a thermal EMF of approximately 35µV/°C– 700 times the maximum drift specification of the LTC1052. Minimizing thermal EMF-induced errors is possible if judicious attention is given to circuit board layout and component selection. It is good practice to minimize the number of junctions in the amplifier’s input signal path. Avoid connectors, sockets, switches and relays where possible. In instances where this is not possible, attempt to balance the number and type of junctions so that differential cancellation occurs. Doing this may involve deliberately introducing junctions to offset unavoidable junctions. LTC1052/7652 • AI03 U Figure 2 is an example of the introduction of an unnecessary resistor to promote differential thermal balance. Maintaining compensating junctions in close physical proximity will keep them at the same temperature and reduce thermal EMF errors. NOMINALLY UNNECESSARY RESISTOR USED TO THERMALLY BALANCE OTHER INPUT RESISTOR LEAD WIRE/SOLDER/COPPER TRACE JUNCTION W UU + LTC1052 RESISTOR LEAD, SOLDER, COPPER TRACE JUNCTION OUTPUT – Figure 2 When connectors, switches, relays and/or sockets are necessary they should be selected for low thermal EMF activity. The same techniques of thermally balancing and coupling the matching junctions are effective in reducing the thermal EMF errors of these components. Resistors are another source of thermal EMF errors. Table 1 shows the thermal EMF generated for different resistors. The temperature gradient across the resistor is important, not the ambient temperature. There are two junctions formed at each end of the resistor and if these junctions are at the same temperature, their thermal EMFs will cancel each other. The thermal EMF numbers are approximate and vary with resistor value. High values give higher thermal EMF. Table 1. Resistor Thermal EMF RESISTOR TYPE Tin Oxide Carbon Composition Metal Film Wire Wound Evenohm Manganin THERMAL EMF/°C GRADIENT ~mV/’C ~450µV/°C ~20µV/°C ~2µV/°C ~2µV/°C 1052fa 9 LTC1052/LTC7652 APPLICATIO S I FOR ATIO When all of these errors are considered, it may seem impossible to take advantage of the extremely low drift specifications of the LTC1052. To show that this is not the case, examine the temperature test circuit of Figure 3. The lead lengths of the resistors connected to the amplifier’s inputs are identical. The thermal capacity and thermal resistance each input sees is balanced because of the symmetrical connection of resistors and their identical size. Thermal EMF-induced shifts are equal in phase and amplitude, thus cancellation occurs. 50k 5V 7 6 8 VOS • 1000 0.1µF 2 100Ω 3 0.1µF 50k – + 1 LTC1052 4 0.1µF –5V LTC1052/7652 • AI04 Figure 3. Offset Drift Test Circuit 0 MIN 10 25°C TO 125°C PLASTIC OFFSET VOLTAGE, VOS (10µV/DIV) 0 10 25°C TO 125°C METAL CAN 0 OVEN SWITCHED ON (25°C) Figure 4. Transient Response of Offset Drift Test Circuit with 100°C Temperature Step 10 U Figure 4 shows the response of this circuit under temperature transient conditions. Metal film resistors and an 8-pin DIP socket were used. Care was taken in the construction to thermally balance the inputs to the amplifier. The units were placed in an oven and allowed to stabilize at 25°C. The recording was started and after 100 seconds the oven, preset to 125°C, was switched on. The test was first performed on an 8-pin plastic package and then was repeated for a TO-5 package plugged into the same test board. It is significant that the change in VOS, even under these severe thermal transient conditions, is quite good. As temperature stabilizes, note that the steady-state change of VOS is well within the maximum ± 0.05µV/°C drift specification. Very slight air currents can still affect even this arrangement. Figure 5 shows strip charts of output noise both with the circuit covered and with no cover in “still” air. This data illustrates why it is often prudent to enclose the LTC1052 and its attendant components inside some form of thermal baffle. 5 MIN 20 MIN 25 MIN ± 0.05µV/°C ± 0.05µV/°C OVEN STABILIZED AT 12 MIN 100 SECONDS/IN 1052fa W UU LTC1052/LTC7652 APPLICATIO S I FOR ATIO #1 COVERED 1µV #1 UNCOVERED #2 UNCOVERED Figure 5. DC to 1Hz (Test Circuit TC3) PACKAGE-INDUCED OFFSET VOLTAGE Since the LTC1052 is constantly fixing its own offset, it may be asked why there is any error at all, even under transient temperature conditions. The answer is simple. The LTC1052 can only fix offsets inside its own nulling loop. There are many thermal junctions outside this loop that cannot be distinguished from legitimate signals. Some have been discussed previously, but the package thermal EMF effects are an important source of errors. Notice the difference in the thermal response curves of Figure 4. This can only be attributed to the package since everything else is identical. In fact, the VOS specification is set by the package-induced warm-up drift, not by the LTC1052. TO-99 metal cans exhibit the worst warm-up drift and Linear Technology sample tests TO-99 lots to minimize this problem. Two things make 100% screening costly: (1) The extreme precision required on the LTC1052 and (2) the thermal time constant of the package is 0.5 to 3 minutes, depending on package type. The first precludes the use of automatic handling equipment and the second takes a long time. Bench test equipment is available to 100% test for warmed-up drift if offsets of less than ± 5µV are required. U 20 SEC W UU CLOCK The LTC1052 has an internal clock, setting the nominal sampling frequency at 330Hz. On 8-pin devices, there is no way to control the clock externally. In some applications it may be desirable to control the sampling clock and this is the function of the 14-pin device. CLK IN, CLK OUT and INT/EXT are provided to accomplish this. With no external connection, an internal pull-up holds INT/EXT at the V + supply and the 14-pin device selfoscillates at 330Hz. In this mode there is a signal on the CLK IN pin of 660Hz (2 times sampling frequency) with a 30% duty cycle. A divide-by-two drives the CLK OUT pin and sets the sampling frequency. To use an external clock, connect INT/EXT to V – and the external clock to CLK IN. The logic threshold of CLK IN is 2.5V below the positive supply; this allows CMOS logic to drive it directly with logic supplies of V+ and ground. CLK IN can be driven from V+ to V – if desired. The duty cycle of the external clock is not particularly critical but should be kept between 30% and 60%. Capacitance between CLK IN and CLK OUT (pins 13 and 12) can cause the divide-by-two circuit to malfunction. To avoid this, keep this capacitance below 5pF. 1052fa 11 LTC1052/LTC7652 APPLICATIO S I FOR ATIO OUTPUT CLAMP If the LTC1052 is driven into saturation, the nulling loop, attempting to force the differential input voltage to zero, will drive CEXTA and CEXTB to a supply rail. After the saturating drive is removed, the capacitors take a finite time to recover—this is the overload recovery time. The overload recovery is longest when the capacitors are driven to the negative rail (refer to Overload Recovery in the Typical Performance Characteristics section). The overload recovery time in this case is typically 225ms. In the opposite direction (i.e., CEXTA and CEXTB at positive rail), it is about ten times faster (25ms). The overload recovery time for the LTC1052 is much faster than competitive devices; however, if a faster overload recovery time is necessary, the output clamp function can be used. When the output clamp is connected to the negative input it prevents the amplifier from saturating, thus keeping CEXTA and CEXTB at their nominal voltages. The output clamp is a switch that turns on when the output gets to TYPICAL APPLICATIO S 5V Powered Ultraprecision Instrumentation Amplifier 5V 4 + IN 7 8 3 5V + – 4 7 6 8 1 0.1µF VOUT LTC1052 2 11 C1 1µF 12 R1 100 – IN 13 LTC1043 5V 43k 2 1N914 3 ≈ – 0.5V C3 1µF 6 5 14 0.22µF C2 1µF 0.1µF R2 100k + C4 1µF 18 0.0047µF 17 15 16 CIRCUITRY WITHIN DASHED LINES MAY BE DELETED IF OUTPUT DOES NOT HAVE TO SWING ALL THE WAY TO GROUND DRIFT = 50nV/°C VOS = 3µV GAIN = R2 + 1 R1 CMRR = >120dB DC – 20kHz BANDWIDTH = 10Hz 12 U within approximately 1V of either supply rail. This switch is in parallel with the amplifier’s feedback resistor. As the output moves closer to the rail, the switch on resistance decreases, reducing the closed loop gain. The output swing is reduced when the clamp function is used. How much current the output clamp leaks when off is important because, when used, it is connected to the amplifier’s negative input. Any current acts like input bias current and will degrade accuracy. At the other extreme, the maximum current the clamp conducts when on determines how much overdrive the clamp will take, and still keep the amplifier from saturating. Both of these numbers are guaranteed in the Electrical Characteristics section. LOW SUPPLY OPERATION The minimum supply voltage for proper operation of the LTC1052 is typically 4.0V (± 2.0V). In single supply applications, PSRR is guaranteed down to 4.7V (± 2.35V). This assures proper operation down to the minimum TTL specified voltage of 4.75V. Fast Precision Inverter 10k* INPUT 10k 8pF 1N4148 1000pF 5V 5V 7 6 8 4 1 10k W U UU 10k* 300pF 2 + – 7 LT318A 6 OUTPUT 2 10k 3 + – LTC1052 3 10k 4 –5V 0.1µF 0.1µF – 5V *1% METAL FILM FULL POWER BANDWIDTH = 2MHz SLEW RATE = 40V/µs SETTLING (10V STEP) = 12µs TO 0.01% BIAS CURRENT DC = 30pA OFFSET DRIFT = 50nV/°C OFFSET VOLTAGE = 5µV LTC1052/7652 • TA04 LTC1052/7652 • TA03 1052fa LTC1052/LTC7652 TYPICAL APPLICATIO S Offset Stabilized Comparator 5V 4 5V 13 330Ω 6 LT1011 11 3 7 5 4 1 10k COMPARATOR OUTPUT (± 5V) 150Ω 2k COMPARATOR INPUTS GROUND OR INPUT COMMONMODE VOLTAGE ZERO COMMAND 5V = ZERO – 5V = COMPARE 1HZ to 1.25MHz Voltage-to-Frequency Converter (5V Supply) 5V 470Ω 470Ω Q1 2N2907 0.01µF 3 + – 1 7 6 4 8 3.3k NC 2N3904 0.1µF 0.01µF 330pF 5V 10k 74C04 OUTPUT 1H to 1.25MHz LTC1052 2 0.1µF VIN OV TO 5V 10k FULL-SCALE TRIM (1.25MHz) 30.1k* *TRW MTR–5/ +1200ppm/°C **POLYSTYRENE–WESCO #32–P/ – 120ppm/°C ± 0.05% >120dB 0.01Hz/°C 20ppm/°C LINEARITY DYNAMIC RANGE ZERO POINT DRIFT GAIN DRIFT 14 U + 14 12 2 + – – 5V 8 – 8 7 1µF LTC1043 5 6 1M 2 + – 1 5V 7 6 8 4 0.1µF – 5V LTC1052 3 2 3 0.1µF 5V 15 18 STATUS OUTPUT OV = ZERO 5V = COMPARE 16 17 –5V LTC1052/7652 • TA05 10k 2k 5V 4 8 7 5V 10k 3.3pF 0.22µF 11 100pF** 12 LT1004-1.2V 0.1µF 13 1/2 LTC1043 17 16 LTC1052/7652 • TA06 1052fa 13 LTC1052/LTC7652 TYPICAL APPLICATIO S No VOS Adjust* CMOS DAC Buffer—Single Supply 15V CF * RFB 1k lOUT1 2 5 15V 7 8 4 1 15V 0.1µF 0.1µF 6 + LTC1052 12–BIT CMOS DAC lOUT2 3 – 43k 6 4 5 10k 11 1N914 + 0.1µF 12 1µF NON POLARIZED 1pF 15 16 1/2 LTC1043 15 ≈ – 0.5V LTC1052/7652 • TA07 17 STABILIZING AMP 3 + – 1 7 6 8 4 0.1µF 100pF – 5V 2k 30MHz TRIM 0.0.1µF 50Ω 5V 74S132 OUT 10k 0.22µF CHARGE PUMP 2N5486 5V 50Ω 2k 7 – 5V TRIGGER HP5082-2810 7.5k 2N3906 FET BUFFER 2N5486 NC RESET DIODE 2N3904 1Hz TO 30MHz OUTPUT LTC1052 2 0.1µF IN OV TO 3V 16.2k* 5V 8 100k 1000M 100pF † 100k – 5V 12 10 11 0.22µF LT1004–1.2V 10k 1Hz TRIM 14 U 14 Air Flow Detector 10k 100k ± 1% 2 LT1004-1.2 43.2Ω ± 1% 0.1µF AMBIENT – TEMPERATURE STILL AIR + 1k 3 5V VOUT FOR HIGHER SPEED, REFER TO “FAST PRECISION INVERTER” UNDER TYPICAL APPLICATIONS 5 + LTC1052 7 8 4 1 6 5V = NO AIR FLOW 0V = AIR FLOW – 0.1µF – TYPE K LTC1052/7652 • TA08 + 240Ω *OFFSET VOLTAGE CAUSES NONLINEARITY ERRORS. SEE: “APPLICATION GUIDE TO CMOS MULTIPLYING D/A CONVERTERS,” ANALOG DEVICES, INC. AIR FLOW 1Hz to 30MHz Voltage-to-Frequency Converter 5V 120Ω CURRENT SOURCE 12k 0.1µF 120Ω *TRW MTR-5/ + 120ppm/°C †WESCO #32-P/ – 120ppm/°C 13 1/2 LTC1043 16 11 5V 5 7490 10 1 12 1 14 5 5V 14 1/2 74S74 3 0.3Hz/°C ZERO-DRIFT ±0.08% LINEARITY 20ppm/°C GAIN DRIFT 150dB DYNAMIC RANGE 7 LTC1052/7652 • TA09 1052fa LTC1052/LTC7652 TYPICAL APPLICATIO S ±100mA Output Drive VIN 100k 5V 2 5V 100pF 6 8 4 1 0.1µF 0.1µF – 5V 100k – + 7 LTC1052 3 VOS = 5µV VOS/∆T = 50µV/°C GAIN = 10 FULL POWER BANDWIDTH = 1kHz Single 5V Thermocouple Amplifier with Cold Junction Compensation 5V 100k VT + LT1004-1.2 R1 5V 5k AT 25°C† 4 7 8 3 5V 1690Ω 187Ω 1820Ω 11 1µF 12 1µF 43k 5V 6 5 Rl IN914 0.0047µF U Increasing Output Current 5V 220pF 74C04 1M 10k 5V 2 LTC1010 VOUT ± 100mA INPUT – + 1 7 6 8 4 0.1µF OUTPUT LTC1052 3 – 5V RL 0.1µF LTC1052/7652 • TA10 10k LOAD 5k 2.5k 1k 220Ω OUTPUT SWING ± 4.92V ± 4.84V ± 4.65V ± 3.65V 100Ω 2000pF LTC1052/7652 • TA11 – 1k – + 1 7 6 8 4 0.1µF LTC1052 2 R VOUT = VT 1 + F Rl () 0.1µF RF CF* 13 14 2 + 3 1µF 1µF NONPOLARIZED 18 16 LTC1043 17 15 ≈ – 0.5V 10k LTC1052/7652 • TA12 † YELLOW SPRINGS INST. CO. PART #44007 *CHOOSE CF TO FILTER NOISE THERMOCOUPLE TYPE J K T S R1 232k 301k 301k 2.1M 1052fa 15 LTC1052/LTC7652 TYPICAL APPLICATIO S Increasing Output Current and Voltage (VSUPPLY = ±15V) DC Stabilized FET Probe INPUT CAPACITANCE BOOTSTRAP 5V FAST SOURCE FOLLOWER Q1 2N5486 5V 1N4148 LT1010 OUTPUT V+ 7 6 8 4 10M 7V 3k INPUT 0.1µF 2 2N3904 NC – + 1 7 6 8 4 0.1µF LTC1052 3 3 + – LT318A 2 4 0.1µF – 7V 2N3904 0.1µF NC STABLE FOR ALL GAINS, INVERTING AND NONINVERTING, OBSERVE LTC1052 COMMON MODE INPUT LIMITS Precision Multiplexed Differential Thermocouple Amplifier 5V COLD JUNCTION COMPENSATOR 100k LT1004–1.2V R1 7 5k AT 25°C† 1690Ω 187Ω 1820Ω 5V 16 6 5 1k 12 1 13 3 14 5 18 LTC1043 16 15 0.0047µF 2 – 5V 11 4 8 7 CD4052B – 5V 9 ADDRESS 10 17 15 16 U 7 INPUT 15V 30k 33pF 6 OUTPUT ± 12V AT 20mA | LIMIT 3k 10M – 5V –15V 1k DRAIN CURRENT SINK 10k Q2 2N2222 0.01µF 100Ω – 5V 2000pF DC STABILIZATION 1k + – 1 3 0.1µF 2 LTC1052 0.1µF 0.1µF LTC1052/7652 • TA13 0.1µF BANDWIDTH: 20MHz †RISE: 100ns DELAY: 5ns LTC1052/7652 • TA14 4 8 3 – + 1 7 6 8 4 0.1µF 1M 0.1µF VOUT = 1001 • VTHERMOCOUPLE LTC1052 2 11 1µF 12 – 5V 13 14 1µF 0.1µF 2 1µF 3 † YELLOW SPRINGS INST. CO. PART #44007 1µF THERMOCOUPLE TYPE J K T S R1 232k 301k 301k 2.1M LTC1052/7652 • TA15 1052fa LTC1052/LTC7652 TYPICAL APPLICATIO S Direct Thermocouple-to-Frequency Converter RT COLD JUNCTION TEMPERATURE TRACKING 1N4148 470Ω B C D E – + TYPE K THERMOCOUPLE 41.4µV/°C STABILIZING AMP 3 100k 1µF OPTIONAL INPUT FILTER-AND-OVERLOAD CLAMP 1N914 150k** 50k 60°C TRIM 33k** A† 5 1µF COLD JUNCTION BIAS 487Ω* 301k* 187Ω* 5V 1000pF 20Ω 3 1 20Ω 86 4 7 5V – 5V 470k* 3 3.3MΩ* BRIDGE DRIVE 1/2 LTC1043 + LM301A 1k 2N2905 2 – – 5V U + – 1 5V 7 6 8 4 1.8k* 33k A 74C04 0.68µF 0.1µF 10k LTC1052 2 0.1µF – 5V 3300pF 820pF 5V 74C04 F 5V 16 LTC1043 6 0.1µF 2 100pF 1k* LT1004–1.2V 4.75k* – 5V 3k 5V OUTPUT 0Hz TO 600Hz 0°C TO 60°C 74C903 *0.01% FILM-TRW MAR-6 **TRW/MTR/5/ + 120 RT = YELLOW SPRINGS INST. #44007 100pF = POLYSTYRENE † FOR GENERAL PURPOSE (1mV FULL-SCALE) 10-BIT A-TO-D, REMOVE THERMOCOUPLE— COLD JUNCTION NETWORK, GROUND POINT A, AND DRIVE LTC1052 POSITIVE INPUT LTC1052/7652 • TA16 Direct 10-Bit Strain Gauge Digitizer 5V 74C00 STRAIN GAUGE TRANSDUCER ZIN = 350Ω ZOUT = 350Ω 28k – 5V 14k CLOCK 0.003µF 5V 1000pF 2 INTEGRATOR 5V 7 – LTC1052 6 8 4 1 2 5V 14 1 43 5 10k 5V 1/2 74C903 FREQUENCY OUT B 1/2 74C74 7 – 5V 6 + FREQUENCY OUT A – 5V OUTPUT GATING OUT A = 1000 COUNTS FULL-SCALE OUT B *0.1% METAL FILM TRW MAR-5 SW1 = MAIN CURRENT SWITCH SW2 = CURRENT LOADING COMPENSATION SWITCH DATA OUTPUT = 0.01µF 8 – 5V 0.01µF 7 SW1 1N4148 1N4148 3.3M 12 SW2 13 11 16 14 CONNECT DIRECTLY ACROSS BRIDGE DRIVE POINTS 100k 10k CONNECT TO BRIDGE END OF 470k RESISTOR (OPTIONAL) TRANSDUCER ZERO NETWORK 22.3k* + 1k* 33µF LTC1052/7652 • TA17 1052fa 17 LTC1052/LTC7652 TYPICAL APPLICATIO S 16-Bit A/D Converter 74C00 EIN OV TO 5V 95k* 10k FULL-SCALE TRIM 2 3 0.1µF – 5V A DATA OUTPUT = OUT BOUT 100,000 COUNTS FULL-SCALE NO ZERO TRIM 20ppm/°C GAIN DRIFT *VISHAY S-102 RESISTOR 18 U – + 1 28k 14k CLOCK 820pF 5V 0.01µF BOUT 5V 14 1 42 10pF 10k 1/3 74C903 5V 7 LTC1052 4 62 1/2 74C74 A2 8 INTEGRATOR 7 5 6 0.1µF 5V AOUT – 5V 5V 5V 7 1k 16 13 4 14 2N4338 6 8 + – 1 3 LTC1052 2 12 0.1µF – 5V LT1009 1µF 0.01µF 11 39pF 4 0.1µF 75k* 20k LINEARITY TRIM CURRENT SINK – 5V 7 18 8 15 3 LTC1043 17 – 5V CURRENT SWITCH LTC1052/7652 • TA18 1052fa LTC1052/LTC7652 TYPICAL APPLICATIO S Precision Isolation Amplifier 1k* 10k 4 INPUT SIDE OUTPUT SIDE 10k 74C04 20k ZERO TRIM – LTC1052 14–PIN 7 10 2 1 14 13 11 5 11 74C90 ÷10 10 1 12 14 11 0.1µF INPUT 100k 5 + NC – 15V 25mA NC 15V 25mA 2N3904 2N3904 7 2.2µF 11k 1N4148 L1 DALE TC–10–11 8 4.3k 1 2N2222 POWER DRIVER 2 15V + 2.2µF FLOATING COMMON + FLOATING SUPPLY OUTPUTS 250V ISOLATION 0.03% ACCURACY *1% FILM RESISTOR U 4 100k* 2N5434 1 2N5434 – 15V 15V 30pF 22M 1 5 2 L2 STANCOR PCT-39 2N5434 100k 1000pF 3 + LTC1052 8 4 7 – 15V 15V 6 OUT 1k GAIN TRIM 13.3k* 2 2N5434 0.1µF 6 3 10k 5 74C90 ÷10 10 1 12 14 2k 2k 15V 1N4148 1N4148 1.8k 1k 68pF 330Ω 10k 100pF 74C04 – IN4148 10M (SELECT) 10k* 74C04 1000pF – 15V 20k 20k 2N2222 9 3 68pF 1.8k 15V 1k LTC1052/7652 • TA19 1052fa 19 LTC1052/LTC7652 PACKAGE DESCRIPTIO SEATING PLANE .010 – .045* (0.254 – 1.143) .016 – .021** (0.406 – 0.533) 45°TYP .028 – .034 (0.711 – 0.864) *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND THE SEATING PLANE .016 – .024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) H8(TO-5) 0.200 PCD 0801 20 U H Package 8-Lead TO-5 Metal Can (.200 Inch PCD) (Reference LTC DWG # 05-08-1320) .335 – .370 (8.509 – 9.398) DIA .305 – .335 (7.747 – 8.509) .040 (1.016) MAX .050 (1.270) MAX GAUGE PLANE .165 – .185 (4.191 – 4.699) REFERENCE PLANE .500 – .750 (12.700 – 19.050) .027 – .045 (0.686 – 1.143) PIN 1 .200 (5.080) TYP .110 – .160 (2.794 – 4.064) INSULATING STANDOFF OBSOLETE PACKAGE 1052fa LTC1052/LTC7652 PACKAGE DESCRIPTIO U J Package 14-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) .785 (19.939) MAX 14 13 12 11 10 9 8 .005 (0.127) MIN .025 (0.635) RAD TYP .220 – .310 (5.588 – 7.874) 1 .300 BSC (7.62 BSC) 2 3 4 5 6 7 .200 (5.080) MAX .015 – .060 (0.381 – 1.524) 0° – 15° .045 – .065 (1.143 – 1.651) NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS .014 – .026 (0.360 – 0.660) .100 (2.54) BSC .125 (3.175) MIN J14 0801 .008 – .018 (0.203 – 0.457) OBSOLETE PACKAGE 1052fa 21 LTC1052/LTC7652 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 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 .300 – .325 (7.620 – 8.255) 2 3 4 .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 .065 (1.651) TYP .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 ( 8.255 +0.889 –0.381 ) .100 (2.54) BSC 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 1052fa 22 LTC1052/LTC7652 PACKAGE DESCRIPTIO .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 .005 (0.125) .100 MIN (2.54) BSC ( +0.889 8.255 –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 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 N Package 14-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .770* (19.558) MAX 14 13 12 11 10 9 8 .255 ± .015* (6.477 ± 0.381) 1 .130 ± .005 (3.302 ± 0.127) .020 (0.508) MIN 2 3 4 5 6 7 .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .120 (3.048) MIN .018 ± .003 (0.457 ± 0.076) N14 1002 1052fa 23 LTC1052/LTC7652 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) 24 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● 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 1052fa LW/TP 1202 1K REV A • PRINTED IN USA www.linear.com  LINEAR TECHNOLOGY CORPORATION 1985